BCM Community

Hi All,
1) What would be the problem with changing the cooling system on a 1966 GMC TDH4519(Fishbowl) with a 6V71 and an automatic trans,  so there were no heater cores for parlor heat? Just the components needed for the engine, and small lines up to the dash and a small automotive heater core for defrost and driver heat? Except for the drivers heat and windshield defrost components, all cooling system components would be in the engine compartment. Parlor heat will come from an rv furnace.
I know that it will dramatically reduce the cooling system capacity, but modern day vehicles of the same weight, load, and horsepower get by just fine on 20qts.

2) What would be the problem with running a 12psi cap on a modified coolant tank, and allowing the engine to run at 195-205 operating temp? Much like a modern engine?

3) Can I loose the factory fan and run an electric fan instead? Or does that fan do more than draw air?

4) Why is the (I'm assuming it's a) fan clutch mechanism so long and heavy? It seems I could save a few hundred pounds by removing that and using the electric fan I mentioned in 2.

Thanks for any and all answers/ideas.

Keith

I think you will find that stretching your bus will be a huge project, while doable, it won't be by most.  Keep in mind that everything on your bus is structural......start removing rivets at the rear and the engine will drop onto the ground.

as for your cooling system.  There is alot of arguement on both sides on the elctric fans......biggest is you loose that sensor and you overheat quickly.......

Removing your coach heat is no big deal other than loosing good free heat......while only saving a bit of coolant and gaining some small space.

your bus ins supposed to run at 180 degrees......205 is very hot.

You fan clutch is big....but what do you think saving 100 lbs will save you?


just my thoughts....but you ought to consider buying a bus that lends itself to a stretch or is already

PLEASE- leave well enough alone with the cooling system.  The 2 stroke engines are sensitive to overheat, 210 is the absolute highest they should go without cracking heads. 
Electric fans will NOT pull enough air through. Remember you are sucking all the air from the side rather than the nice frontal ram action trucks and cars have.  On my bus, the fan is a straight gear drive that is direct connected all the time.
On my transit, I ditched the under floor heater system (was a Portland Or bus, no A/C) and kept the big heater core.  Had it tested and mounted it going the length of the bus in the hallway beneath my closet/washer-dryer.  Then have 2-14" elec radiator fans with four vents just dumping into the hallway-no ducts.  It is so powerful, that when you turn it on, count to 10 and you can feel heat at the front of the bus.  Also kept the front defroster-that alone can heat nearly the whole bus.  You will be woefully disappointed trying to use RV heat while driving.  If it is propane, it will be blowing out constantly as you drive.  If you have hydronic heat (that takes alot of space) you could use that.
I hope you have at least a 3 speed V730 Allison transmission.  If you have only a 2 speed with the 6V-71, it will be actually unsafe to drive.  In my opinion the 6V-71 is not enough power. Luckily, you could change to the 6V-92TA without too much problems with the V730.  It will require a larger radiator, air cleaner and muffler (I know I just turboed my 8V-71), but since you're keeping it for the long run, it will be worth it.  What would really be the absolute best would be to have a Detroit series 50 (4 cylinder that can put out 350hp with 1100lb/ft of torque) used with a reverser gear (V drives run in reverse rotation) to
accommodate the V730.
Highly recommend that you look at systems that others are using and what is commonly used in the RV industry and keep with that.  Then your theory of simplicity with the fishbowl will be maintained throughout your conversion.  Good Luck, TomC

with all these mod's you want to make to your bus ...I think you bought the wrong bus ... JMHO
Ron

Paid $100 and drove it home...I way bought the right bus!
As for the powertrain, it is a 6V71 and a 2 speed.
I am perfectly happy tooling around at 55-60mph and 45 on the grades. I have no desire to go past 60 in anything I am in control of that weighs over 10k lbs! I'm kinda conservative that way. (My kids call it "chicken", but what do they know?!)
Seriously, I'm good with underpowered by todays standards.

For the cooling system, 210f is the dangerzone? Cracked heads? I figured that as heavy as the DD engines are, and as big, anything short of a gallon of nitro poured into the intake would result in noisy protests at worst!

My desire isn't to modify for the sake of change, but to improve on what I have. Engineeres thought differantly and didn't know what we know today. The boost in temp is an attempted boost in efficiency. The boost in system pressure facilitates that.

The weight savings from dumping the clutch fan assembly is for handeling. Any weight removed from the engine compartment, or anywhere behind the rear wheels, will help with ride and handleing, if the shocks are adjusted to matck the new load.

As I said, I'm looking for improvements, bases on modern practices. I won't make a change that I think will increase complexity or reduce reliability. But I will brainstarm, and then throw it out here to see what comes back!

Thanks
Keith

Hi Keith
Is your bus a suburban Fishbowl??
Where did it originate from??

Have you crawled under the unit and read the differential Tag??

Have you had it on the highway???

I ask this as many of the "transit " Fishbowls have the 5:39 rear end which basically gives you 48-50 Mph with the VH 9 2 speed tranny.  That lets you see a lot of scenery on a trip.

Paso Said "I ask this as many of the "transit " Fishbowls have the 5:39 rear end which basically gives you 48-50 Mph with the VH 9 2 speed tranny.  That lets you see a lot of scenery on a trip."
LOL!!! Yes it would!

Actually, the current rear gear doesn't matter because it will get a 2 speed diff, so I'll switch to the highway gear when I need it.

Keith, Not knowing your qualifications and background I am going to have to say you have a huge project in front of you and alot of learning to do and alot of mistakes to make.

shaving a few hundred pounds is not going to affect your handling at all....keep in mind that your bus was designed to tote around 40 people at 160# each or so 6400# and that does not include standees.....this is not a japanese tuner car.......that you can goe by adjustable shocks etc for on the internet.


Screwing with the cooling will result in cracked heads......and at an op temp of 205 you are alomost to that point.

Also with that two spped tranny...with any grade your likely going to be closer to 20 mph

Just curious:  What do you intend your budget to be for the completed project?  And what ammount of time/labor do you think it is going to take?

For qualifications, mechanical and electronic engineer, master auto mechanic, and more pig-headed that my wife can appreciate at times.

For the weight savings, no, a few hundred pounds wont matter unless they are in an area where it act like a lever, as does all the weight aft of the rear tires. 125lbs removed from the cl of the engine removes 400lbs of weight from the rear tires. I must remove 400 lbs just in front of the rear tires to have the same effect. I know it sounds wrong, but it's in the leverage and position of the weight. The vehicle weight will only change by 125lbs if I remove 125lbs, but the balance of the vehicle will change by 400lbs.


For things to learn and mistakes to make...yup! Thats why I'm here.


I will be using a 2 spd diff, so in theory I'll be ok on the grades.

As for the budget- 15k and 1 year to be able to use it for weekends. Thats shell completed, interior in, basic services in and outer shell done and sealed, and tires.
another 60k  and 3 to finish the interior, paint the shell, good windows, fixtures and appliences, another set of tires.

We shopped for the coach we wanted, and when we found it, the price tag was 270k. And it was so modern that I would need another 12k in tools to service it, and still need help from the dealer. I don't trust many mechanics, and theres no way I'm letting some jo-bob wrench on a 270k vehicle of mine! If I cant fix it, it's not worth fixin. I have made a lot of money off the modern technology in todays vehicles. Most of it is un-needed at best. I'm anti-complicated. My DD6v17 runs as well or better than one with a DDEC system on it, and burning veggie oil, as I do, it's cleaner...and after it's started you can remove the battery and take it for a drive. Try that with a modern coach...lol

Sorry ..... I'll put away the soapbox now...

Keith

Hi Keith,
If you find a 2-speed diff. that will work in our older GM buses please post here where you found it because there will be a lot of us that will want one. Have you been under your bus to see how the pinion shaft enters the diff. at an angle? I think this is unique to a v-drive bus and unless you build your own 2-speed, I don't think you will find one. I hope you do because then I can put one in our 4106 and make it a lot more driveable with the 4-speed manual transmission.
My experience has been that no matter what you think it will cost to convert a bus, you will be way under estimating. One way we saved a lot on our conversion was buying a late model wrecked travel trailer and using its components. I was amazed at the amount of small things we used from the trailer that had never gotten onto the list of items needed to convert a bus.
You have come to a very good site to learn about your hobby. Please continue with your questions and you will learn a lot here. Not only that, but, you will be helping the rest of us to learn along with you.
Good luck with your project. Sam 4106

Obviously the reality of what you want to do has not set in yet.

Messing with the cooling system, Stretching an already limited chassis another 10 feet.
changing structural systems and DOT approved systems.

Running with an orphan powertrain with few parts available. That 210 hp 6V71 will dust your cookies as will the 2-speed
tranny.

If you want to be more realistic, Buy an RTS with a 6V92TA and V-730, gear it up for highway.

Buy another RTS shell and cut a section and add it for your 45 foot size.

It will be much cheaper and nicer looking and parts will not be an issue for the next 20 years.

8) 8) 8)

"The weight savings from dumping the clutch fan assembly is for handeling. Any weight removed from the engine compartment, or anywhere behind the rear wheels, will help with ride and handleing, if the shocks are adjusted to matck the new load"
                       
                                                If a skinny friend wants to go for a ride,Dont let it sit in the back of the bus.......OR you will be back to square  one.

Keith, I hope that was a misprint on your grade speed. The real speed on a real hill is going to be around 4.5 mph, not 45 mph. If you try to pull a trailer with that 2 speed you should consider a push vehicle as that tranny and engine combo will not pull the hills in low lockup with your trailer and its going to build a lot of heat in low converter. Perhaps an air cooled Deutz in the trailer would help. (Less coolant)! and a true pusher. The day of the 6V71 and 2 speed Allison are gone. In my opinion if you cross the California border you could risk being towed out of the state as well as jail time. CARB is gonna freak! The 2 speed Allison was designed for stop and go city driving. If you run it down the highway you need to stop and start often to cycle fluid thru the tranny to avoid melting the seals in the converter. It was not designed to be driven more than a few miles in hi lock. Any attempt to increase coolant pressure will need to be followed up with engineering improvements in hose and clamping areas. The main reason we don't run a lot of pressure in bus cooling systems (pre DDEC) is when you loose the coolant, the coolant temperature reads cold, not hot and you usually loose the engine as well. If you run over normal pressure on the cooling system it has to be tight and strong enough to hold up at highway speeds. Also realize when you tear into a 7 mile pull up the mountain, so you can see the other side, that I wasn't joking about your road speed not being anywhere near your projections. Seven miles up at 7 MPH is realistic with your equiptment. Last time I sat on a 7 mile pull at 7 MPH it took me almost an hour to get over the top! That is why the old time engineer put a 125lb fan on your bus. Paso One said it best "your gonna get to see a lot of scenery".

It is obvious, but I will say I have never driven this coach, or any coach with a 2 speed, past 42mph. The tires on it right now are really rough, so I have not pushed my luck. As it is a project right now, tires are not a priority.
With that said, my thinking is this, regarding highway capabilities. The 4519's all had 6v71's and either 4speeds or the 2 speed auto. They did highway service, even if it was not their intended purpose. That led me to presume that the limitations are purely gearing, and with the right gears, it will do whatever I need it to. The engine is not a limiting factor up to maybe 65mph.
Am I on track in this thinking? Even if it means a differant trans?

NJT 5573 said "If you run it down the highway you need to stop and start often to cycle fluid thru the tranny to avoid melting the seals in the converter. It was not designed to be driven more than a few miles in hi lock."
The fluid doesn't circulate enough in high lock to prevent damage? Is this trans really that bad for highway use? I know a 2 speed is not ideal for highway, but is it as bad as it sounds?

"The day of the 6V71 and 2 speed Allison are gone" While it may be true of the Allison (I have no idea and won't claim to know these tranmissions), IMHO, the day of the 6V71 is here now more that enev, compared some of the over-complicated hulks that are available today. The beauty of a diesel engine is in it's simplicity and reliability. Numbers don't tell it all. Yeah, sub 300hp engines can be tough to live with at times...but not near as tough as a 375hp engine that wont run because some $400 sensor that takes 5 hours to replace has failed! Yes, parts for a 6V71, and the rest of my coach, are sparse. So is money sometimes, and parts are easier for me to make that money is. Those government types are persnickity about printing money!

Sam 4106, I have a few ideas for the 2 speed diff that I have to develop more, but I am confident that it will work. The pinion angle looks to be the only major hurdle. I'll post more as I develop it.

DrDave-Reloaded said to get a RTS...better looking finished project...
Nothing looks as good as a Fishbowl silly!

Maybe this thread needs to fork? We have drifted away from cooling systems a bit?

So it sounds like the objections to the cooling system mods I asked about are centered around leaks introduced from the increased pressure, and not knowing it by the gauge? So what if I could be equally sure that I won't spring any leaks at 12psi and 195-205f as I am of the factory system? Is that the only concern? Does reliability drop at that temp range? Do I run a risk of engine damage? Cracking heads? I can build a systen that won't leak. I can't build one that won't crack the heads if 220f with no steam pockets is all it takes.

you will not gain any appreciable efficeincy running at 195-205 even if you don't crack your heads.

Don't you think the big room full of engineers might have an edge on you as well as the rest of us in the engineering department.

I just  sold my 4104 with a 6-71 ( inline) that I have driven all over the country and had  been in the family for 30 years.......and the new Corporate owners plan on doing a three year all over the coutry promotional tour with it........so power is not the issue.

Your trans may not be that bad.......early Buffalos came with VS2-8's and ran fine...in fact the newest addition will be headed east from CA on Wen  with a VS2-8.  On it's test drive it got to 75mph.


your larger headach will be the gearing.......and I think your two speed rear will be a problem as well

I would thin that if your willing to spend 80k over whatever period you might like to have something worth more than junk value at the end.  Unfortunatley that is what most fishbowl Conversion are worth.....and thats why most of them are not done to a high standard as far as the conversion.....hole with 6 wheels

tekebird wrote "you will not gain any appreciable efficeincy running at 195-205 even if you don't crack your heads."

Thats what I'm going for, increased efficiency.

"Don't you think the big room full of engineers might have an edge on you as well as the rest of us in the engineering department."
I thing a group of engineers had an advantage over the general population 60 years ago, but no, I don't think that the group of engineers that designed the 6V71 engines 60+ years ago have any advantage over us today. We have so much more information, information that simply didn't exist then, to draw from now. They did awesome with what they had to work with. We have much more to work with now, and we can do better.
It's not cocky to think that way, or derogatory to them. It is just the nature of how knowledge increases.

I saidf you WILL NOT gain any noticable effiiciency.

as for the room full of engineeres 60 years aaago.......that would be about the same time that the SR-71, and the XB70 as well as a whole bunch of very advanced aircraft were designed.........true they did not care about efficiency then.........

but you can't ahve both worlds......simplicity and efficiency do not go hand in hand normally.........that is why they have  computer controlled things with $400.00 sensors and you need a $2000.00 code reader to find out what is wrong.

How do you intend on making your 4519 to test prior to youu adding on to it?  Are you also going to fabricate all the appropriate test jigs and telemeetry sensors so you do it right?

With what you intend, there are two options that make more sense

1/ Buty a straigh truck with a box....easily insulated and you can stretch a truck frame easily...and it will still tow any trailer you want.

2. Build from the ground up using components from the 4519

you have yet to enlighten us to your engineering background, fabrication abilities etc.

I am sure a bunch are curious.......as you are not the only person who has ever popped in with grand ideas........most have disappeared...likely after they had a mental breakdown after spending all their money and a bunch of their life building something that either could not be built....or was well beyond the scope of their abilities.

I will be curious to see your results.

WorkingOnWise, do you have any idea how many horsepower the fan takes? What do you think you will use for electrical power to run that 25 hp fan?

That's why it's so heavy. It also has a big effect on fuel economy. The two stroke will need 1 1/2 gallons per hour of fuel at full power governed speed just to run the fan in the factory setup.

This is one reason why the fuel mileage doesn't fall more than it does when running the coach in near freezing weather; while it takes more effort to push the coach in cooler weather, it takes less effort running the fan.

Our coach got 10 mpg on two of the fillings on our last trip. We were running 65 mph, so we were burning 6.5 gph. At 140,000 btu per gallon, we were producing some 910,000 btu per hour, with around 300,000 btu going into the cooling system.

With no ram effect over the radiator, it takes a lot of energy to pull enough air over the radiator to get rid of the heat. What do you suppose will happen if we hit a mountain grade and start burning 14 gph while climbing?

That's what the big fan and radiator are there for.

Good luck with your project.

Tom Caffrey

tekebird...the SR71? It leaked worse than a DD 2 stroke when it was on the ground! Engineers today would be able to build it so it didn't leak fuel as a normal operating mode! Thanks for making My point.

"you have yet to enlighten us to your engineering background, fabrication abilities etc.

I am sure a bunch are curious.......as you are not the only person who has ever popped in with grand ideas........most have disappeared...likely after they had a mental breakdown after spending all their money and a bunch of their life building something that either could not be built....or was well beyond the scope of their abilities."

I came here with grand ideas, yes. And grand questions. Looking for Grand and honest, and Informed answers. And a willingness to listen and consider each one.
So what is your coach like? Cookie-cutter copy a a thousand others with a personalized engraved plate on the dash?

Do not try to belittle my skills or ideas unless you have the drive to get out of you own little comfy box first.


pvcces - I would like to learn more about the fuel consumption you discussed. Is there a link you can give me? Or is this personal experience? It almost sounds like I should lose the fan and replace it with a pair of electrics, because the fans can be off when running down the highway if I duct the radiator properly, and let the electrics do the work at low\no speeds. This soulds like a way to save fuel, is I understand you correctly, that the fan consumes about 1.5 gph at highway speed.  Did I miss something?

First nobody is trying to belittle your skills.  Just trying to get you to think resonably.

The SR 71 was designed to leak...and if designed today it would leak by design too.....the DD was not and a properly maintained one does not.  What about the Xb70...it didn't leak.

Drive to get out of my box........I think thow should not talk bullshit untill you produce product my freind.

pretty much everyone who has replied has told you the problems with your ideas...and offered good solutions......if you are such the engineer you should not need any links for the Fuel use  PVCCES discusses....and you ought to read......as the electrical draw for the fans you intend to use are huge....and thus also cost fuel, and are less reliable than a mechanical fan system......

No Need to reply to any of this as I have lost interest and desire to give you any logical guidance

On the transmission and rear end.  I am a new truck salesman for Freightliner and have many factory reps to lean on for my bus project.  I too wanted to have a two speed rear end, but the bottom line is that Rockwell, now Meritor, just did not make one.  And there is not enough room between your trans and axle for one.  I highly recommend that you chuck the 2spd trans in favor of the Allison V730- that is still in use today with parts still being made.  Remember-when travelling, there is nothing worse than breaking down but to find that the broken part is obsolete.  Whereas the V730 is simple and can be worked on by any Allison dealer.  When you get tired of going 10-20mph up the hills and overheating your engine, I'm quite sure you'll change you engine to the 6V-92TA with the V730.  You can take just so much humiliation and embarrassment with a slow bus being honked at going up the hill.  Plan on adding 2-3000lb to the bus for the conversion.  Good Luck, TomC

WOW - the reason you are getting a number of Nay votes on some of your ideas is because many of these people have already attempted some of the things you are trying to do and failed (not due to their knowledge and ability) and many Newbies have said dam the torpedoes I'm gonna do it anyway, never to be heard from again - these people, more than any you will find anywhere else, are here to help you fulfill your dreams (if possible) - they are merely trying to enlighten you on large hills (figuratively) you will have to climb to attain your goal - no one will tell you it can't be done (because many of them have and a whole lot more) - Here are some of the issues they are trying to enlighten you on;

1) you have a bus that may be underpowered for your intended use

2) your tranny may not be suitable for your intended use

3) the configuration of your drive train (not a V) may be a hinderance to the ability to find/install a 2 speed differential

4) the structure of your bus does not lend itself to slide installations

5) the structure and drive train of your bus does not lend itself to the towing of large trailers

6) the structure of your bus does not lend itself easily to any "stretching"

7) the initial cost of the vehicle pales in the amount of time and money needed to alter it from its initial intended use and capabilities

Please don't let this post be another Nay vote but just a little food for thought, and when you do decide to attempt these projects the people who are enlightening you now will be the same ones trying to help yout out of whatever jam you are in at the moment - some have posted an interest in your project and may be willing to lend a hand in your "experiment" - take them up on amy such offers as there is a wealth of knowledge and hands on experience to be gained from this group - HTH

Don't know much about all the streching and cooling system changes but I will say this. I have a 4106 w/ 8v71 w/ 75 injectors, 730 allison ( with more than 2 speeds) a trans cooler that i can turn on when pulling a grade. The air cleaners have been changed to paper element that I stay carefully on top of cleaning or changing. A pristene radaitor and rebuilt fan clutch. This engine has about 40,000 miles since its last major overhaul and runs sweet.
That said, when I leave Tucson headed for the beach with full fule tank and water tank (100 gals.) I have to fight her to keep her under 70 on flat ground. Making that pull coming up from the desert at octilla to Cajone ( the sign says 6% I figure it, based on milage and elevation to be more like 7 1/2 ) I'm in low at the top running about 25 mph watching my trans temp start to move into the yellow range (250) and my engine temp up to about 200. But if a fish bowl with a 671 and a 2 speed allison ever blows past me on that road i'll figure it was yours.
My thoughts. you have a fine coach there and your into it for almost nothing. fix every thing important, brakes, suspention, rebuild what you have. I could buy a bigger engine and trans, I could buy a bigger coach if i wanted to, then I could spend more time at work paying for it all.

 When I first got my bus I had alot of thoughts of doing alot of racey stuff to her, Now were use to each other and  I spend all my spare time driving her. We have put on about 15000 miles since last fall and are getting ready to do about 5000 more this summer. You could do like we do, plan you route on roads that don't have tough grades( we will be talking the 10 into California and staying off the 8 when we add the toad this summer) and the only  I,m thinking about addingbigger is the ice chest..........

           For what its worth.........................Tucson

TomC, 2 to 3k lbs to convert from a 6v71/VS2 to a 6V92/V730? Wow that seems like a big penalty in weight. Where is the bulk of the extra weight from, the engine or the trans? I have had it in the back of my mind to look into another trans because the one I have has seen much better days. Slips bad in 1st...vert bad. Right now, it would not even move if I put it against a 4" curb. I'd have to get a little run at it, so the trans it a reasonable upgrade in my eyes because I am sure this one needs major attention. The engine however, has only 25k miles on it since its last overhaul.

niles500, I welcome the nays, as long as they are followed with some thought and reason, like yours are. Saying that it wont work because  really smart guys 60 years ago didn't get it to work isn't helpful. Thanks for your thoughts. They are helpful.

About the trans. I looked up the v730 after I read TomC's post about it being still produced and readily serviceable, and good parts availability. Seems like Allison got that trans right. I see it was used at least as far back as 1982. Thats a lifespan of 25 years. Impressive! I also see that the v730 was used in the Fishbowls with a 6v71, so it seems that I can put it into my coach, and if I still am not happy with it, I can slip in a 6V92T at a later date. Does that sound right?
If so, where do I look for good info on the v730 and purchasing one for my coach.

WorkingOnWise......you quoted "......you have the drive to get out of you own little comfy box first" (unquote).....I am with you......I've been there & still am. I don't believe in not trying to do to make it better than it was in the past. Am not afraid to challenge anything in working with fabricates & machining metal, plastic, wood, electrical, plumbing and cad drawing. It is fun to see the outcome.

Experience is the name everyone gives to their mistakes.
Oscar Wilde (1854 - 1900), Lady Windermere's Fan, 1892, Act III
.

About radiator:
Tom is correct about "With no ram effect over the radiator,"
There is air wave on side of bus like ocean wave.....the faster travel the larger. Another word high pressure wave & low pressure wave areas along full length. Depending on traveling speed, it varies in pressure wave in radiator area. It is not like normal truck frontal area which is given more freely flow of air.

I agree to improve better air flow but electric motor has to be big enough to equal the OEM spec or greater air flow. Alternator will be robbing more energy than mechanical design system. DD 2-cycle is about ¼+ more BTU than 4-cycle.

FWIW

Sojourn for Christ, Jerry

I apologize, my post was a bit unclear.  Converting your engine/transmission from the 6V-71N/VS2 to the 6V-92TA/V730 will be at the most a few hundred pounds difference-mainly to upgrade the radiator, muffler, and air cleaner.
The 2-3000lb weight reference was to the total conversion of the bus.  My bus weighed 28,000lb without seats before starting.  After insulating, and all (including the generator), now weighs 31,000lb-so I added 3,000lb to the bus.  Considering my bus has a 36,000lb gvw (gross vehicle weight) rating, I'm still 5,000lb from capacity! (compare that to the nearly overloaded sticks and staples when you buy them, before adding a ton of personal stuff).  Hence, with my 11R-24.5 tires, I only run 90psi in them, and still that is a bit high.
Once again on my soap box- If you want the best ride, tire life, etc, weigh you bus in traveling form per axle.  Then look up on the tire inflation guide for your specific tire size and manufacturer for the correct tire pressure.  Those of you that are running using the maximum tire pressure printed on the side of the tire are just getting a fork lift ride-or better put-your ride would be much better at the proper inflation.  Good Luck, TomC

Whew! Thanks for clearing that up TomC! I had visions of my coach doing wheels with all that extra weight hanging out past the rear wheels! LOL.

We have figured that we will be adding 5500lbs to the coach, which based on how many people I have seen theses things carry day in and day out when I rode them as a kid going to school, that's not a bad number. I don't have numbers on gvw so I am basing my numbers on bus weight with full fuel-all the seats and rails+all the stuff we want to add+full fuel and potable water=coach weight. As long as that number is less that bus weight with full fuel+(60 people*150lbs), we are fine. I choose the number 60 because for years I rode these busses in Detroit and they ran for several hours each day with that many people. And their performance was great, even with that load.

Quote from Niles
[WOW - the reason you are getting a number of Nay votes on some of your ideas is because many of these people have already attempted some of the things you are trying to do and failed (not due to their knowledge and ability) and many Newbies have said dam the torpedoes I'm gonna do it anyway, never to be heard from again]

me thinks this is another one....

You bought a $100 bus and you are going to put $80K into and it will still be a $100 bus.

You have no idea (you probably think you do) on the hours, effort and money required, to complete a project this large. I have over 6000 hrs and $80K into mine and it's not done yet, and I didn't put any slideouts in or do any structual changes to it, other that to raise the roof, but none of the changes that you are suggesting .... I did my convertion in 2 yrs, working on it 8 hrs a day, 7 days a week, and worked my 8 hr day job as well. I haven't done anything to the bus in 2 yrs. I'm too burnt out to work on it, but it is 90% done for us to enjoy and will complete it in the nexst 2 yrs.

So many don't realize how large of a project converting a bus is .... I certainly didn't after the 1st month, all I had done was strip out the seats, washrm and floor ... I had to have a talk with myself and came to the conclusion that I had to work at this way harder to get it to a state where we could use it. (read ... so my wife wouldn't kill me for dumping 80K into something that we couldn't use or sell for more than 20K, because it wasn't completed).

If I were doing it now, from what I've learnt, I would buy that Prevost Marathon on eBay ... at the time I did my convertion that bus would have been double the price it's selling for now, so it was out of my price range. I believe prices of bus convertions have fallen considerably in the last few years.

You can find alot of these examples (uncompleted buses) on eBay for time to time and it's sad to see how much money the seller will lose because he bit off more than he could chew and couldn't complete the project.

Good luck with your project, but watch how much you bit off you may drown in it.

Ron

glad I am not the only one that is thinking sensibly

prevost82- Thanks for the thoughtful words. I do know that the reality of the project will not match the idea of the project. That's y we have spent 18 months doing research and study on these matters....to minimize the bumps and blocks we will run into.

I'm not trying to be confrontational, but I have an observation.
I have heard many people here and other places say how undoable what we want to do is, but no one has ever stated something like " I tried that and this is what happened." Every person who has said the structural changes I have proposed are not reasonable, even foolhardy, has based it on their own theory and learning, but none on real experience. Yes it is risky to totally redesign a proven machine, to try to make it into something it was not intended to be.
We here all understand enough about diesel engines to know that running it on veggie oil is at least possible. We don't need to do it to know it can be done. Many have tried and failed, but many have tried and succeeded. Even with all that, do you have any idea how many people told me I was gonna make a storage shed out of my coach after I blew the heads off or some other death event before I actually ran my coach on the stuff? Lots! None had ever tried it. They just figured that a diesel engine burns diesel fuel, and anything else was instant death. Of course, they didn't know that the first "diesel fuel" was actually peanut oil.
I have done things all my life that others have said are foolish, dangerous, and destructive. Sometimes they were right, sometimes not. My experience has been this. The ones that were right had some experience in the matter, and the ones that were wrong didn't, usually. There have been times that the ones with no direct experience were right, and vicea versa, but it is the exception, not the rule.

I want to hear from the wacko's that tried it and ended up with a $30k storage shed!

As for the 2spd diff, yeah, that will be interesting. ou all are right in that there is no room for one under my bus using existing geometry and off-the-shelf parts. I'm not sure I want a 2spd diff bad enough to design one, and then build it. It is definitely a phase 2 project priority!

With all that said, I am still 6 months from starting up the sawsall, so if there are still corrections to my plans needs, I have time. And I am listening. Even to you tekebird, even if you do think my meds need to be adjusted!  =)

Ok so now my curiosity is peaked.
1. When you lengthen the bus are you going to maintain the monico design or are you going with a modified monico with a beam structure?
         In the 70's we were used to adding a H frame to unibodies some times they didn't work out. No biggy for we weren't out a ton of money.
          we usually had more money in the engine than the cars we were putting them in.
2. Cooling efficiencies are gained by increased air flow, increased surface area, increased pressure, and/or increased volume. If you change the air flow
     what else are you willing to change? Increased pressure doesn't always increase efficiency.
3. It would take a very secure person to admit they have a 30k storage shed. Mine is only a 20k shed and I am trying to keep things as stock as I can.
     Another week or so and I might be road worthy again but until then realistically it is only my workshop and shed. ok so I lied about the 20k but I won't admit 30.

   I wish you luck.
  Skip

One of the wackos (kindred spirits?) is now present...

Don't do the electric fan.  Not worth it...  The hydraulic fan I attempted to replace with electric ended up going back in after only three months.  I spec'd out everything from the 15HP electric motor to the custom PWM controller (which I designed and built myself).  After about $4K in parts, it still didn't work as well as the original fan.  I found that some of the other modifications that I made in the course of swapping in the electric improved the over-all system performance - but had nothing to do with the electric motor...

The first thing I did to improve the cooling was to separate the transmission cooler from the radiator, giving it a separate intake, and a 24VDC fan that kicks on above 150 degrees (which is ducted out the back away from the engine radiator intake).

Then I added a high-temp "blow-off" above the engine access door in the rear, which has several louvers and three 24VDC pancake fans to blow out that high-heat pocket that builds in the engine space around my exhaust (this pops open and turns on at 200 deg F - as a good portion of the heat the block rejects is done directly out of the side of the block and the headers).  This is coupled with a deflector below the radiator which ensures the exhaust air from the radiator fan (which blows into the engine space) does not wrap hot air back around to the radiator intake (which would increase the ambient radiator temp and reduce it's effectiveness).  I also added a set of electrically actuated louvers to replace the stretch mesh grille on the radiator intake door, which open at 150 degrees and act like small wings (with incremental depth) thus re-directing passing air into the radiator opening (not a single giant scoop - I'm too afraid to cut down pedestrians with one of those ;D) they also keep the radiator warm in the winter if it's running cold by staying closed.

Finally, I have a few pieces of 1" L-channel welded to the side of the bus to break up the laminar air flow (air that aligns to the side of the bus as a high pressure-straigtened "surface") so that the radiator intake louvers had a better chance of pealing off some of the passing air.

What I ended up doing with the fan, was changing the way the valve worked.  The factory valve was a "dumb" thermostatic proportioning valve that couldn't be adjusted very finely.  I ended up putting a tach on the fan shaft, intake and outlet temperature sensors, and building a servo control for the proportioning valve so that I could re-program it (on the "fly" even if needed).  This coupled with my exhaust pyros, fuel flow/consumption sensors, and the instrument display software I wrote (for data fusion) - give me a better picture of how efficient my engine is running (or if I'm over-doing it...).  This is all on an '84 6V92TA MUI engine (no DDEC).


Try to remember that these older engines were planned as more of a system.  Newer Engineering methodology is to have discreet components doing individual jobs (so they can be individually tuned and accountable for specific design variables).  The task of adding any efficiency will be best served by looking at where some of the wastes are.  For example - do you need hot water?  Put in a heat exchanger so that you don't have to burn more fuel to heat a tank.  If you're not using all of the power the prime-mover is producing, flip on a secondary alternator to charge your house batteries.  By converting much of this "waste" into useful work - you are in fact (by definition) improving the over-all efficiency, and you may not need to modify the actual engine to do so.

With all due respect to current engineering practices (as I am an EE) - I believe a return to some of the "neat and tidy" Engineering of the 50's and 60's wouldn't hurt ;) - too much.

Cheers!

-Tim

Edit #1: I though I should add - I've owned my bus for 3+ years already - and I've still done limited sawsalling.  It's basically a transit with a few minor adjustments so far.  I haven't had the balls to cut the window rails yet as I've looked deeper and deeper into the construction and have found basic structural things I wanted to change first (I found in the Gillig Phantoms, that the wall-base to frame connection is the biggest weakpoint...).  Oh and I'm 27 years old now, so I've given myself some time to finish this project  ::) -Tim

Edit #2: I forgot to mention, I kept the old Carrier heater core as a secondary radiator.  The concern was driving it through hot/arid locations (I'm in CA and I wan't to go to Las Vegas - right by the Mohave desert...).  My feeling is that If I can't cool the rig down with almost 1/3 more heat-exchanger surface area and twice the air flow - I should park it until sunset...  -Tim

Ok, now we're talkin prozac!
skipn-
1) I intend on doing a modified monoque -  box rail lower, monoqueish roof section, slides in between. The box rail section will basically go from just aft of the front tires to just fore of the rear wheels, and will not be so rigid as to be able to support the ends on it's own. The help will come from the roof rails and skin (the monoque-ish part) The model and simulations will decide the details.
2)Actually, the efficiency I am after is engine efficiency. The reason for the added pressure is to allow higher temp without the steam pockets, to help avoid the cascading meltdown that happens with a low pressure system that overheats. That way, I can run at 200f normal temp, and if the temp rides to 220, while not good, is not a death sentence either. The operating temp increase is the goal, without  adding any problems.
The desire to loose the fan/clutch assembly is for weight distribution reasons. Weight is more harmful to vehicle dynamics in some places more that others.
3)20k shed huh? Cool. If it isn't on the frame rails, it don't count, sorry! lol  =)

Tim Strommen- You did this high tech work on a transit? I'd love to see some pics, maybe schematics too, of your work. Sounds like something I want to look into.
Your cooling system mods sound like a perfect example of what I said earlier- these engineered did great with what they had...we have better now.

I have entertained the idea of fitting an engine management system from a 1996 or newer v6 gas car to the engine, as a way of monitoring the engine/trans and related systems. Then I could plug in my modis into it ans see exactly whats going on. It would have no control capabilities, so if there were a sensor failure, I'd get a code, but not effect on the vehicle. I'd just have to learn what codes to ignore (O2, Torque converter, etc) and which to heed.
The old-timer engineers had the right methods and practices, we just have better information to draw from now.

I'll have to dig the bus out of winter storage...

I think I still have board layouts and schematics...  I'll see about posting those to this thread.  As for the 1996 ECU - it's easier/cheaper to build an application specific one from scratch these days.  I'm about ready to do the final revision on the controller for my rig which has the anti-theft stuff built in and the new engine supervisory and maintenance monitor logic (got rid of about 200lbs of control/instrumentation wires going between the front an rear - replaced them with one Cat-5 UTP cable with serial RS-485 signalling).  This system will also tie into the interior energy management system and climate control I'm building, along with the DC power plant (which has a couple refridgeration compressors and an aux-air compressor to maximize the system efficiency).

Many will say it's too complex, but I think that's why I'm doing it (it's a mental excersise AND a hobby :)).

Cheers!

-Tim


P.S. My bus is a mass-transit, El-Cheapo, cookie-cutter... (your moniker here...) - rig.  I think they did what fit the design price-point for the majority of their intended customer base on that model (super customization is really expensive and not something that most transit districts will pay to do - that's more "limo" like what we do :)). Something to keep in mind is that I've taken my bus out of its original design envelope - so some modifications are required to retain its original reliability.  This doesn't however suggest that the changes I've made are any different that what was available in the "old days" or that previous Engineers hadn't implemented them somewhere else, just that for my model, make, and year - my bus didn't have them as part of the design. -Tim

That would be great if you could post that stuff Tim. Thanks
As for the ECU, I can get a donor car for dirt and have all the electronics and connectors, and most of the wiring. I don't have to design the communications bus, data conversions, sensor interfaces, nothing. And I already own the data interface tools, so the cost and effort are quite low. But, if you don't already own the scanner and tools to service the specialized electronics, yes, it would be tons easier to design a stand-alone system. I may still, but if I don't want to think that hard, I can fall back to the '96 ecu plan. The thing that has me going back to that is the ability to detect misfires. it took GM 4 years to be able to do it fairly accurately, and Chrysler 3 years, but it is very useful now. To re-invent that ability, and eliminate the false positives from vibration....not so easy, I imagine.

Hmm...

     Most of the older (OBDI/II based) misfire detection was based on a gear tooth magnetic pickup signal being compared to time.  If there was an expected firing, the gear tooths would accelerate as they pass the sensor under the combustion stage and frequency would increase - if the cylinder mis-fired, it would result in a minor deceleration (frequency would decrease) for that stage.  A few occurences of the deceleration at one cylinder's expected time would trigger the misfire flag.  Several, on different cylinders would set the misfire flag with a distributor or coil service notice.  This is just as simple to do now as a stand-alone processor task with a cheap sensor that'll probably be there already for the tach.
     The new-fangled way to detect the combustion quality and sucess is to have a slightly capacitive spark plug, and after the initial spark shot is fired into the plug - a lower (but still high) voltage is placed on the wire and a field impeadance measurement is taken (this allows the O2 content for the specific cylinder to be read before it opens the exhaust valve {or valves}).  With a certain impeadance, it can tell a mis-fire occured (before the engine would have slowed down).  An added side bonus is that a fast microprocessor can adjust its PID algorithm and LUT to account for the O2 content (and thus the burn efficiency, by adjusting the PWM duty cycle for the injector {fuel-shot volume} and the timing advance for the next spark plug {duration of power stroke}) in near real time - providing better RPM/Power transient response (in other words the gas pedal feels more responsive).

     Of course, with an o'l 2-stroke there's no need to get any more complicated than an OBD-I git'up.  There is no timing adjustment to be had, and without electronic injectors and variable valve timing there's no timing to control.  With a pyrometer, you can read the load on the engine, and with a high precision tooth sensor as a tach with a simple firing order table/counter, you can figure out which cylinder/injector is not tuned properly - or if you have an injector failure (no-fuel or stuck wide open).  And we're not watching O2, as our rigs are (for now) emmissions unrestricted.


There are some other interesting things to watch while your engine is running that OBD-I doesn't pay attention to though:

• Tach
• Fuel Control Position
• Air Intake Temperature (this can indicate possible need to reduce power demand)
• Air Intake Vacuum (before turbo if equiped - can indicate air filter restriction requiring service)
• Turbo Boost (if turbo equiped - interesting to watch in high altitudes)
• Air Temperature after the Turbo ("charge air" if turbo equiped- this can indicate possible need to reduce power demand)
• Exhaust Temp (one for each side if a V-Engine, combined with tach and fuel control sensor - one can derrive "lugging" condition and can indicate possible need to reduce power demand)
• Head Temperature
• Engine Compartment Temperature
• Radiator Air Intake Temperature
• Radiator Inlet Temperature
• Radiator Output Temperature (difference between this and other above readings can be used to determine BTUs rejected, and cooling efficiency)
• Fuel Pump Inlet GPH
• Fuel-Rail Outlet GPH (difference between this and above can be used to derrive your consumption GPH and with speed your actual MPG - and with Exh. Temp, can determine operation efficiency)
• Oil Presure

These variables, combined with the appropriate math (and presentation) can speak volumes about the health of an engine or the way it's being used ;).

Cheers!

-Tim

Keith -

Back to the original thread topic. . . but first, an introduction to my background:

I spent 25+ years in the bus industry, the first 10 pounding the pavement to the tune of 80K/mi/year, the latter in Operations Management and Training.  I don't have an engineering background, other than turning a wrench on Corvairs as a hobby. I was a business major in college, back when the computer science guys were still writing programs using punch cards (and I drove a skoolie to pay for skool, too!).  I've been sharing my real-world industry experience with others in the busnut community for the last 10 years or so, as well as gaining a lot of good insight from others who also have been willing to share (many of whom are sorely missed since they are no longer posting).

In all my years behind the wheel, I never had a coach overheat on me, and that included running in the Mojave Desert in the summertime with MCIs, which are notorious for overheating.  I'm in CA, and from where I live, whether I go N, S, E or W, I have to climb 6% grades to get out of the Central Valley.  So, based on my real-world experience, here are some of my thoughts for you to ponder, as well as a very important trick to keeping it cool:

I've read your comments about engineering "then and now", and do not disagree with you.  However, I'd like you to consider some of the design criteria that the factory was dealing with, which was (and is) considerably different than that of the guys building cars.  Building a commercial vehicle, one who's purpose is to generate income for it's owner (yes, even if it's a government-subsidized transit agency) means designing the entire vehicle to minimize down-time.  Transit buses especially are ridden hard and put away wet, and still survive.  Everything from the door operation, the floor-mounted turn signal switches, the brakes, suspension, steering, and powertrain are all engineered with reliability and ease of servicing in mind.  Nowdays, compared to your Fish, this includes meeting all the government mandates that didn't exist previously.  But the overall concept is still valid.  Nobody likes to get a call that "there's a bus broken down on 41st Ave blocking the intersection", especially during morning/afternoon rush.  So keep the reliability and ease-of-service in mind as you progress with your project.

GM offered the cooling system on the Fishbowls two ways - direct drive, and the torus drive (looks like a big torque converter between the block and the fan).  Direct drive is obvious - the fan runs all the time.  The torus drive acts conceptually like the viscous clutch on a 327 Chevy's fan - the fan freewheels until the engine reaches a certain temperature, then locks up to increase the cooling capacity.  Whoever bought the coach initially had the option of choosing which one they wanted, both worked, and worked well.

Radiator sizing varied depending on what powertrain was installed in the coach.  Fish with 6V71s used a slightly smaller capacity radiator than those who's buyer checked the box for the 8V71 engine.  The radiator on my 8V71-powered 1964 PD4106 is huge compared to my friend's 1960 PD4104 with a stock 6-71 in it.  His coach has a direct drive fan, mine's got a torus drive.  My fan is also considerably larger than his, and is more tightly shrouded.  As Tom pointed out, that big fan on a 4106 draws upwards of 25 hp when locked up - and if you stand close to the radiator with the engine running at 2100 rpm and the fan engaged, it's really hard to not get sucked up against the side of the coach - those fans draw a HUGE amount of air at speed.  As others have found out, matching OEM with aftermarket electric is a fruitless pursuit.  (Side note:  Some of the late-model Prevosts with the 500 hp 8V92TAs stuffed in their tails have hydraulically-driven fans that draw in the neighborhood of 40+ hp!).

System maintenance is a critical element that is often overlooked.  Not only the condition of the components, but also the chemistry of the coolant itself.  Are you aware of the phenomena known as "coolant cavitation" in a diesel?  Detroit's got very specific guidelines for the coolant chemistry for the two-stroke, just like they have very specific requirements for the type of engine oil to be used (that's a whole different thread!!), in order to help control this phenomena.  This cavitation, if not controlled, can actually lead to cylinder wall failure in the most extreme cases.  This isn't just a matter of mixing anti-freeze and water in the right proportion, it also includes the type of anti-freeze used and a couple of other things that escape my memory at the moment.  Test strips to check the chemistry are available at your local Detroit dealer.

Most automatic transmission-equipped coaches come with a transmission oil cooler.  For 99% of the time, the OEM design is adequate for the application.  It's that odd 1% that can bite you, and it's usually in conditions where the coach is being used for something other than it's original design.  (That means us, you know. . .)  Jack Conrad came up with a good idea that works well for his coach, and is applicable to others:  He uses an additional cooler mounted on the curbside access door, that's tied into the transmission coolant lines.  Not uncommon.  But what he did differently was to tie it back in in such a way that if it cools the oil too much, it's routed back thru the OEM cooler, in order to maintain the transmission oil in the same range as the engine's coolant temp.  Perhaps Jack can jump into this thread and explain it in a little more detail.

(Slight detour here:  The VS-2 in your coach has three modes: hydraulic, 1st gear, 2nd gear.  Starts in hydraulic, then locks into 1st at around 25 mph, then into 2nd at about 35/40 mph, so it feels like a three-speed even tho it isn't.  But that also explains why it will hardly climb a 4" curb from a dead stop - and you'll rapidly heat the transmission oil as you try - because there is no actual mechanical connection between engine/transmission until it locks up into 1st.)

But IMHE, it's been the weight of the driver's right foot that creates the biggest cooling problems.  That, coupled with inattention and a "gotta get there" mentality, has probably fried more engines than all of the above combined.

The real trick to keeping a Detroit two-stroke cool in most conditions is to keep it in the "sweet spot" of the power band, i.e. 1800 - 1900rpm on a partial throttle.  You should be able to step further on the throttle and still accelerate w/o a lot of black smoke.  As long as the coach will maintain speed or slightly accelerate while climbing in this rpm range, most coaches with cooling systems in good condition will not overheat.  BTDT.

As soon as the coach will not maintain speed, or starts to smoke heavily when trying to accelerate from the sweet spot, it's time to grab the next lower gear and get back into the above rpm range.  This is very easy to do with a stick-shift, or a late-model Allison, but virtually impossible with your VS-2.  BTDT, again.

Be aware that heavy black smoke is going to be a problem with any non-turbocharged Detroit when you get up into the higher altitudes (above 5000 ft), and therefore requires even more concentration on what you're doing.

Droopy eyelids preclude me from continuing at this point, but hopefully this post has been informative.

Start another thread on weight distribution, and I'll share some more real-world experience related to that with you.

FWIW & HTH. . .

;)


PS:  What's the VIN on your Fishbowl?

Tim & Keith....you guys bring back memories while I was working in GM Engineer Staff in APE division in Warren, Mi. That was my dream to work in the "wonderland of experimenting" place. Am now retired since 96, would love (if you will) to learn your data report whenever it available. I am too going to increase cooling system pressure as long the DD 2-cycle water pump allowed as far as wear & tear on seal. Later the Lord willing...going to switch to 60 series DD with World Trans. It already lengthens to accommodate longer engine.
It a MCI-8 (102x43.5) with a large radiator opening on the left lower side. In a few weeks I will be installing a radiator with A/A cooler. So if you don't mind, keep me or the MAK board informs what works better or doesn't. I am at least a year to go in project before I can get any reasonable data can be taken such as air flow of side, rear end turbulent and heat study.

PS...done under hood heat study to reduce heat damage on battery, plastic and improve a/c's condenser air exhaust flow. Rework radiator concept design from the normal. All kind of hose & clamp testing. To name a few during my life time.

FWIW

I'm 69 slow but ready to be with the Lord with new eternal body. Praise the Lord!

Sojourn for Christ, Jerry

Jack Conrad came up with a good idea that works well for his coach, and is applicable to others:  He uses an additional cooler mounted on the curbside access door, that's tied into the transmission coolant lines.  Not uncommon.  But what he did differently was to tie it back in in such a way that if it cools the oil too much, it's routed back thru the OEM cooler, in order to maintain the transmission oil in the same range as the engine's coolant temp.  Perhaps Jack can jump into this thread and explain it in a little more detail.

    When I installed the Hayden cooler and 3000 CFM fan on the passenger side engine compartment door, we ran all new transmission hoses (OEMs were getting questionable). The transmission cooler output goes to the top of the added cooler, exits the bottom of this cooler, goes to the OEM (engine mounted) cooler and then back to the transmission. This allows engine heat to help warm the transmission fluid when bus is first started. I do not know how much heat is actually removed by the aux. cooler, but IF the fluid leaving the aux cooler is cooler than the engine mounted cooler, it will extract heat from the engine to bring the trans temp to engine temp. Any heat removed by the aux. cooler is that much heat that does not have to be removed by the radiators. Since doing this all temperatures (water, oil, & transmission) run about 10-15 degrees cooler.  This is without even turning on the 3000 CFM fan. So far we have found that we get an adequate air flow created by the squirrel cage blowers and natural air flow.
    Another thing we added that we really like is a pyrometer. I was amazed at how fast this gives an indication of engine heat. When climbing a hill, I watch the pyrometer.  as the pyrometer starts to climb, I downshift, and watch the pyrometer drop back. All this happens almost as fast as I am writing this. All right, I type slow with 2 fingers, but it still happens pretty quick.  Jack

WorkingOnWise, you dodged the question concerning your background, experience, & abilities. Before you diss someone's background, share your own. This info will help us to answer your questions more completely.

Some of your comments & questions have me a bit confused as to your basic understanding of engineering. It seems to me that your planning & research is not as far along as you thought.

Where is Clarke? He can definately share some info on the custom engineering issues.

I still think you will be time & money ahead by getting a better starting point, but this is comming from someone with four PD4501's. (If anyone cares, I have a BSME & design OEM machinery in a machining & fabricating shop.)

Oh, another 2 cents worth:
Being a newbie to the board & dissing someone or their bus is not the best way to get information here.

Jack- Thanks for the detail. The trans cooling mods are great! With auto trans service being my absolute least favorite thing to do, it's important to make it live long, and only need fluid, filters, and an occasional external adjustment!

I would not have considered a pyrometer to be useful on a non-turbo engine. I have one, so I'll have to give it a try.

Sojourner- You worked in Warren huh? Cool. I lived in Macomb County most of my life.
The data you are talking about, do you mean the crash simulation data? I'll share everything we find on the board.
I never considered the water pump being a potential limitation to raising the system pressure. Anyone know about that? Is the same waterpump used in a high pressure system?

Kyle4501
Yes, I did dodge the question. I felt the question was more of a dis than an inquiry intended to help anyone to answer my questions more completely, and I responded to him, and only him, in the way I saw fit.

There are things I know, and I know them well. There are things I don't know, and I will gladly state them. I will ask, even if it is a question that I probably should know the answer to.
Thanks
Keith

Keith -

Since it was rather late when I wrote my missive, I forgot to mention an important part of the GM cooling system.

Look under your coach.  Do you have a full-width mudflap across the coach behind the rear axle?  If not, then you need to install one.  OEM was in three pieces, I have the specifications for each piece if you need it.

If you have one hanging off the back bumper, you need to take it off.

Why?

Because that full-width mudflap creates a low pressure area under the engine compartment, helping to draw hot air out while running down the road.  Simple and very effective.  OTOH, hang one off the rear bumper, and you trap the hot air right where you don't want it.

Crown and Gillig used this same trick with their midship-mounted powerplants, except they hung the full-width flap right behind the front axle.

FWIW & HTH. . .

;)

I've got the answer (s)

A remote front mounted radiator.......nope that would put weight forward of the front axle effecting handling

a roof mounted radiator.....nope that would raise the CG also screwing with the handling

AHHH..........a midship mounted radiator.....with a ducted roof scoop and a bank of squirel cage fans.........set it up similar to the MCI system which shuts off the airflow of the cage fans ( a squirel cage fan that is not moving air draws practically no power)

Doug -

Your sense of humor's showing again!   ;D ;D ;D ;D

;)

some people just bring it out......LOL

Keith, you still won't share what your background is. Why? Are you afraid someone will ask for your help?

So far you don't come across as a realistic person, or at least not one that has done any planning at all.

Lets see;

I got a great deal on this bus so I'm gonna use it no matter what!

But first I'm gonna add slide outs &/ or stretch it 10 feet.

Now this engine that is so great is under powered, so I'll increase the power.

Now this great engine is so inefficient, so I'm gonna redesign the cooling system to fix that.

The transmission is shot so I'll be replacing that too.

This bus is so great, but the 60's technology is crap, so I'll redesign it to the modern technology level.

Let's not forget the trailer to be pulled by a vehicle that was not designed to do that either.


Am I missing something? Or do you just have this thing to reinvent the wheel?

Sorry if this is harsh, but I'm beginning to smell something here.

Keith says he is a Mechanical Engineer/Electrical engineer, Master Auto Mechanic too. 

I agree with all your  points.......either BS, Crazy, someone with more brains than sense (alot of engineers are like thisin my experience)

every once in a blue moon there is a guy on this board or that board that likes to get rises out of people by proposing the absurd........

maybe they are lonely, ful of themselves, trying to boost there  'rating" on the board......

I have seen this too many times.......  I agree with your suspicions

Quote from: tekebird on April 17, 2007, 06:54:20 AM
I've got the answer (s)

A remote front mounted radiator.......nope that would put weight forward of the front axle effecting handling

a roof mounted radiator.....nope that would raise the CG also screwing with the handling

AHHH..........a midship mounted radiator.....with a ducted roof scoop and a bank of squirel cage fans.........set it up similar to the MCI system which shuts off the airflow of the cage fans ( a squirel cage fan that is not moving air draws practically no power)

Ha...cute. Actually, all those may have merit, or a combination of them. I like the roof mounted idea. The hot air being lighter, would create lift, thus improving mileage. And, when it overheated, the lift would increase, reducing the load on the engine, thus reducing the fuel consumption, thus reducing the heat generated by the engine, causing the engine to cool down to a normal temp again. Good thinkin man!

Unfortunately, my issue is not to address an overheating condition caused by an poorly designed cooling system. It is to increase engine efficiency via increased operation temperature, while not inducing an overheat condition in the process, as I hace stated more that once it this thread, which you have clearly missed.



Wow kyle4501, I sure hope others don't read the thread you read!
I spent lots and lots of time training degree holding idiots how to do their job when I worked as a network admin and sheetmetal protorype machinist. I spent a lot of time explaining to engineers that just because you can draw it on your computer does not mean you can make here in the real world in a production environment. In both cases, these educated people did not understand the real world. Only their books. If the book says, it is. The ones who were open to listening, and understanding the problems between their ideas and the reality are the ones who had experience before and after their degree training.
With that said, I know for sure the the paper one holds is not worth the roll in their bathroom until they get into the real world, learn that there are other ways besides theirs, and that they do not know everything by nature or their paper.
When people insist on paper id, it usually means that the paper is what they base their opinion on, not the person holding it.

Lets see;

I got a great deal on this bus so I'm gonna use it no matter what!
Yes. So? It is very rare that I have more than a few $k to spend on any given item, and I don't carry debt except the house and a credit card. It is what it is.

But first I'm gonna add slide outs &/ or stretch it 10 feet.
If you will read, you will see that while I intent on structural mods, I am still in the planning stage, and in fact have decided to not stretch it, although the reason was for maneuverability and not engineering difficulties.

Now this engine that is so great is under powered, so I'll increase the power.
Yeah. So? Are all these guys fools that repowered their engines, or added turbos?
Hey, you! With the 400hp 8V71! Where do you think you're gong with all the extra power Mister?!

Now this great engine is so inefficient, so I'm gonna redesign the cooling system to fix that.
To want to increase efficiency is not the same as stating that the engine is inefficient. They are not reciprocal. The engine is efficient. I believe it can be more efficient.
Naw, that black smoke ain't cuza incumplete cumbuston. It'sa cuz weiz burnin coal tar. Don't make nears mucha mess iff'n it leaks. It just kinda ooooozes out slowlike.

The transmission is shot so I'll be replacing that too.
Um, yeah. So? The 2 spd is not real great, even in top form, right? The 3 spd is better, right? I can get a good V730 for $500, which means I can have it in my coach for under a grand. I fail to see the problem.

This bus is so great, but the 60's technology is crap, so I'll redesign it to the modern technology level.
Who said the 60's technology is crap, besides you? If it were crap, I would not even have a 41yo coach to work on!
So the 60's tech is good enough for us today, right? How big would the trailer need to be to carry the DDEC4 box and sensors if it were built with 1966 technology!? How big does the garage need to be that you put your 60's technology based Pentium 4 PC?
We just know more today than they knew then, and with that we can do better. I already said this, but clearly you missed it.
Whatcha all need thems slide ruelz fer? I gots this abacus, a tablet o'stone and a chisel. I'll git thems new numbers in a jiffy. .......... Be right back, gotta get some mortar to erase a number.

Let's not forget the trailer to be pulled by a vehicle that was not designed to do that either.
Um, ok. So no trailers either? Wow your rving life must be a blast!
Ok, everyone, unlock the hitch, drop the trailer jack, and pull slowly away from the trailer and no one will get hurt.

Am I missing something? Or do you just have this thing to reinvent the wheel?
You are missing a lot. As for reinventing the wheel, it sounds like if it were up to you the wheel was an silly thing to make. Dragging things around was good enough for them and it should be good enough for us by golly!

Sorry if this is harsh, but I'm beginning to smell something here.
Is there something to help you with that in your bathroom?

To the rest of you, I apologize. I should have done a better job of keeping my thread on-topic, especially in regards to the structural stuff, as that is in a different active thread, that some here decided to mix with this one. I'll do better at on-topic in the future.

Sorry and Thanks
Keith

Keith's Updated Resume'

37 year old
mechanical Engineer
Electronic Engineer (whats the difference between electronic and electrical engineer?  Seriously)
Network Administrator
sheetmetal protorype machinist

On top of that he has trained plenty of other engineers that what they can design can't always be built.

He is  conservative and is OK driving 60 Max in anything over 10,000#

Thankyou tekebird. Now that that is out in the open, we can all relax, and read the threads a bit closer.

Personally, I think fishbowls are pure de ugly, but if you like them there is a very interesting one on ebay (180106459544)  8V-71 with a stick and factory bays.  Might make a good start for someone though way overpriced.

hot air casues lift?

thats a new one.......I know hout air rises but "lift"

Len Silva- I saw that one on ebay. It got a look, but I agree, it is too expensive. That 8v71 in a 40' is pretty though.
As to the look, the fishbowl are very balck/white. Fortunately, my wife and I are the same color!
We love'em!

tekebird....now you know. I'm no engineer at all....i'm an illiterate high school drop out living in central park...you got a quarter mister?

sounds that way because I have yet to see any good engineering verbage come off your posts.

A smart High Scool Student can spout what you are.

"(whats the difference between electronic and electrical engineer?  Seriously)"

  Smaller electrons  ;D

  Skip
  BSCS class of 85 (spent 5 years writing programs for engineers)

Yea ...I'm in your camp tekebird... there's one of these that pop up ever now and then.

And what the heck is a sheetmetal machinist. I have a machinist ticket ... never heard of that one ... maybe he means tool and die.

Ron

Quote from: prevost82 on April 17, 2007, 08:54:24 AM
And what the heck is a sheetmetal machinist. I have a machinist ticket ... never heard of that one ... maybe he means tool and die.

Ron

Ron, you have to read All the letters in a sentence....
I said "sheetmetal prototype machinist"
It involves thinking about how to do what has not been done, or in a way it hasn't been done yet, with sheetmetal, small castings, and sub assemblies. Simular to tool and die, but much more emphasis on tool and die design.

Mr workingUNwise.

"You can't make a silk purse from a sow's ear"

I invented an electronic devise to clean the bird sh1t out of cukoo clocks..... I am real proud of meself !!!
No takers yet. I am worried the Chinese are going to steal my idea.

I just looked at my clock, it's time for me go to work The little hand is on 9 the small hand is on seven..

WorkingOnWise

ROTFLMAO
RE:When people insist on paper id, it usually means that the paper is what they base their opinion on, not the person holding it.

I wasn't looking for paper ID. I was interested in your point of reference to explain the inconsistancies & contradictions in your posts. Normally I don't care, but when things don't line up & the dots don't connect .  .  . well, lets just say the person holding it wasn't making a clear impression.
Your lack of formal training in statics, dynamics, kinematics, materials, thermodynamics, & etc shows in your posts.

I design machines every day & improvements can be a good thing - IF - you KNOW what you are improving. Before you can sucessfully improve something, you must understand why it was designed the way it was. BTW, I trained under a 65 year old master machinist.

Kieth, you need to loose the attitude that "engineers are idiots". I have respect for ALL trades. I have noticed that there are fools & idiots everywhere & no profession is immune from them.

I'm sure a sheetmetal prototype machinist can be of benefit to this board.

I've re-read some of the posts & one of the main reasons you gave for sticking with your current bus was the soundness of the engine. It just seems odd that this cornerstone of your conversion needs proping up.
A V-drive is quite limited in your choices.
A T-drive has lots more to choose from.
The cheaper you try to be with a bus, the more $$$ it'll cost you.


Whatever

You can lead a horse to water, but you can't make him think.

What is not to evident with the Ebay 40ft fishbowl with under storage is that it has a raised floor like what was used in the 4501 Scenicruiser.  If you flaten it out, you only have about 6ft or bit more of headroom, compared to a flat floor that has 6'10".  And what about that steel plate that is rusting behind the front door-usually put in when a structural problem was detected.  Like on the 4501's that had steel plates installed between the windows because of cracking aluminum.  Good Luck, TomC