I have the 4-71 DD out of my Courier 96 and I am doing a complere overhaul. I wanted to fix some messy oil leaks and pulled it out, so now it is sitting in my shop nice and handy, so I might as well have some fun with it. The head is going to a rebuilder for a reconditioning. I am installing cross head pistons with new rods and replacing the crank bearings and chequing everyting.
I've had a turbo on it for a couple of years now. It puts out about 12 psi of boost max.
The blower was rebuilt at that time with the better, harder oil seals.
I am going to change the timing from advanced to standard.
It is with a 5 speed manual Spicer and is driven "on the governor" all the time. (2500 rpm no load). (60 mph).
The rad is being recorred with dimpled tubes and serpentine fins.
I am appealing to the mechanics on the board for advise on a few things:
It has had N65 injectors so far. Should I stay with them or would you go bigger: 70, 80?
What would be a good setting for injector timing, valve clearances, Jakes?
How about a turbo boost bypass to the air box, so as to not "overload" the blower. It was discussed not too long ago on this board.
I have the DD service manual, but this won't be "stock" anymore.
I know some of you guys have experience and a lot more expertise than me on the subject, so tell me what you would do.
JC
As you know I had this done. If you don't add an aftercooler, then the max I'd suggest is 75 injectors for 174hp and about 500lb/ft torque (1/2 of the 8V-71T). If you air to air intercool it, install the bypass blower valve (not quite sure if it was made for the 4-71 blower), and use 90 injectors, you could go as high as 225hp @ 2100rpm (more like 265hp @ 2400rpm) and 675lb/ft torque. Also, maybe install Jake brakes? Any further questions, I'd call Don Fairchild @ 661-391-4520. Good luck, TomC
Thanks TomC, I don't think I want to go with an aftercooler or intercooler. I read somewhere it would rob more power than it would make for a small engine like mine. The shop I'm getting the overhaul kit from, is also sugesting 70 or 75 injectors. My new and improved rad should be able to handle the heat from them I think. I have Jakes that I'll re-install in the head. I'll call Don F. and he'll have sugestions.
JC
JC -
I had a nice chat with Don down in Quartzsite three weeks ago - well worth the time for you to chat with him on the phone.
He's got 71-series engines that meet the US EPA's Tier II emission regs and putting out more HP in the process - tough to do!
Oh, and I found a steering wheel - but it was cracked worse than yours! Still searching other sources than the one we talked about last summer in Rickreal, will come up with something for you yet!
FWIW & HTH. . .
;)
JC, I really don't understand your comment on the charge air cooler. There is nothing in the system that takes any mechanical energy other than the fan (if you have to have an auxiliary unit). If you can find a way to put it in front of the radiator, then there would be no mechanical losses to "rob" the power. Even an auxiliary fan would not have a huge power demand.
It just makes good sense to cool the air going into an engine as much as possible. It increases power and keeps the operating temperature of the combustion chamber parts (pistons, valves, etc) cooler, so that they last longer.
I would keep my mind open to this option.
Jim
JC- virtually every on road Diesel, from small cars to big rigs, have air to air intercooling and turbocharging. The air to air intercooler will not take extra power (don't quite frankly know where you got that idea), it will only increase the power since it is cooling the heated turbocharged air and making it more dense-hence more air in the combustion chamber. If you have at least 4" in front of your radiator, you can just install it there. That's what I did since my bus was made with the same power train for both the 96" and 102" wide-and since my is a 102" wide, had an extra 6" in front of the radiator to play with. Even installing it on the right side with an electric fan will increase efficiency. Good Luck, TomC
Thanks RJ.
Jim and Tom, I had heard I don't remember where, that the net gain between pushing the air through the plumbing to the intercooler and back vs the advantage of the cooler, more dense air would be marginal. It sounds like you are right and it would be worth doing. My rad is above the engine. The air comes from the roof and down. The fan draws the air through it, then out the bottom of the engine compartment. Upstream of the rad and right against it are shutters. Lots of space in front of the shutters. Would I remove the shutters, or keep them and mount the intercooler in front of them? When the shutters are closed, I wouln't get any air circulating through the intercooler either. Maybe I should ditch the shutters?
JC
Unless you are in sub freezing weather, I would ditch the shutters. That small 4-71 is working hard most of the time, so cooling will be more of an issue. Also, if you get rid of the shutters, you probably will have room for the air to air intercooler. I would make sure you have the largest radiator core possible, and replace the thermostats in the engine with new 180 degree. Even back in 1980 when I bought my first truck with the 8V-92TA, it was considered to be shutterless cooling, because of better thermostats. Good Luck, TomC
Hey RJ. If you happen to come across 2 steering wheels like JC has, i would be interested in the second one to replace the newer style MCI wheel that is now in my 5A. ;D
Quote from: Ed Hackenbruch on February 05, 2009, 07:42:04 PM
Hey RJ. If you happen to come across 2 steering wheels like JC has, i would be interested in the second one to replace the newer style MCI wheel that is now in my 5A. ;D
Whaddaya gonna do, Ed? Make me buy two complete, worn-out old Crown skoolies??? ;D :D ;D
;)
Well sure RJ, why not? ;D I thought maybe you were just getting the steering wheels by themselves.....didn't realize the rest of the bus was attached to them!!!! :o
Bigger the better. Positive reinforcement. More boost, cooler air, more power, more boost, cooler air, blah, blah, blah. Will work better in winter than summer, but you will need it more in hot weather. Go for it. You can make a 6 out of your 4. HB of CJ
subjective opinion post
Hey JC, i think that a year or two ago i saw a clip on a company that rebuilds steering wheels for old cars. I think it might have been on an episode of My Classic Car on the Speed channel. Might be an option for you.
Lost,
Long ago in galax...... I was reading about turbos and intercoolers. The gist of this was that the intercooler "will not" boost your max HP. That number is the same for both configurations. Here is the rub: you floor it and the temp in the intake is cool. But, uit starts rising cause you are compressing air. It continues to rise to a high temp. Hot air at the intake robs your engine of power. What the intercooler does is "keep the temp down" close to the point where you first floored it. The on intercooled engine will loose power on a hill and you may need to down shift even though the fade is constant. Intercooled you can carry the hill in whatever grear will pull the hill at the bottom as the power remains constant. Maybe someone can correct me but I read where a turbo diesel makes more power AND gets better MPG than an N....or could. Seems the use of the thermal energy in the ex translates to efficiency and that means MPG. Strange world! Work real hard to get an intercooler in your design.
I think I would go with a six. People keep saying that the L10 will slip right into a DD inline six slot. I would guess that your engine compartment would accommodate a DD inline six.
I think what you have is a smoke turbo. I am easily wrong on that though. Can you go to a full turbo boost and have the engine tolerate full throttle for extended periods? Is there a four valve head available?
Good luck with this,
John
John and everybody, I am convinced now and I am looking into installing an intercooler. I have seen them at truck wrecking yards. There is room in front of the rad. The tricky part is the plumbing. I will piece it together out of used parts and silicone connectors.
I don't want to swap my engine: I am overhauling the 4-71 that is in the bus and making the most power out of it. (Within reason). I used to drive this bus in revenue service for Brewster's in Banff, Lake Louise, Jasper, Calgary in the early 70's, and the 4-71 in it, is a big part of the nostalgic factor for me and I am not changing it. I have modern 4 stroke engines in my other bus, ( S60) and other vehicles that I enjoy for what they are. The Courier 96 is staying as stock as possible and practicle.
I remember one summer as a rookie being in Calgary in July doing 2 city tours a day in the heat of the city, ( manual steering, sky view windows, all the side windows open, taking a shower at lunch break and another one at supper time it was so hot, then doing Stampede transfers in the evening in the relative cool of the night. We also drove them up and down the Sunshine Village ski hill road before they built the gondola in '78. Lots of memories... Later with more seniority, I drove MC 5s, 7s, 8s, 9s, but none had the character of the Courier 96s. Brewster's sold them in '77 and I knew then they would make a nice motorhome. 30 years later...
JC
good for you JC I have a 1940 Ford coupe with the origanal 60 hp v8 and people are always telling me to install a small block Chevy and do away the 60 hp that is not going to happen with me , keep your history not enough left nowdays
David
Kinda ruins a Ford for me when they stick a chevy engine in it.....makes me want to buy a 57 Corvette and put a 351 Windsor in it and see what kind of reaction i get. ;D
Right on ED!
As to horsepower difference between natural and turbocharged, take an 8V-71N with N65 injectors, and you'll have 304hp with 800lb/ft torque (net not sae horsepower). Exchange that for a 8V-71TA with the same 65 injectors and you'll have 325hp and 975lb/ft torque. Always more fuel efficient with turbocharging and intercooling. Good Luck, TomC
Tom,
Not fair! The HP is a function of the rate at which duel is consumed and by keeping the injectors in your example at N65 the HP remains sorta constant.....304 to 325. That wouldn't inspire many to make the investment in a turbo. Doesn't that 8V71 march right up to 400HP with the proper injectors...or was it more? Or are you talking about the "smoke" turbo alone?
John
I don't know about the numbers, but the difference in power after I installed the turbo 2 years ago is VERY noticeable. I gained 1 gear going uphill (5 speed manual). I also feel a definite increase in torque lower down into mid rpm range. And no more smoke, except at start up, untill the turbo spools up. I am now looking forward to the results of my overhaul: x head pistons, rebuilt head with N 75 injectors, new radiator with dimpled tubes and serpentine fins, new rod and crank bearings, standard timing. Oh boy! I might have to paint it before I slide it back in! I am still looking at putting in an intercooler. It will be a chalenge finding a spot for it and plumbing it... I just have to do some more head scratching. I was thinking an intercooler is also good protection for the engine in case of the turbo disintegrating: the debris would be caught in the intercooler before it enters the blower and engine.
JC
JC,
Part of the significant gain in HP from a turbo with the same cubic inches came from the reduced compression ratio. You have a limit on the compression you can handle and the turbo increase the "effective" compression ratio. The result is that with a simple turbo inst you can't use much boost and with boost comes power. I think if you build a "turbo" motor correctly, you use pistons that yield lower static CR. I think turboed diesels are harder to start for that reason but the CR is still so high it gets them lit without problem until they get worn out.
You mentioned the "X" pistons. Are those 71 turbo items? I envy you the adventure. Have fun.
John
I don't really understand why lower compression is better for a turbo. Can somebody explain.
My engine, like most older 2 stroke DD, have the one piece "trunk" pistons. I am installing the 2 piece "cross-head" , lower compression pistons. The crown is more resilient to heat, and the skirt is seperate and cools better. "The piston skirt, being seperate, is free from vertical load distortions; thermal distortion is also reduced as the piston crown expands." (From Da Book). Xhead pistons are the standard now for turgo charged engines.
JC
I have the two piece higher compression non turbo pistons (18.7:1). This is why we decided to keep the boost to only 15psi and use 9G75 injectors for 375hp & 1125lb/ft torque. To slam more air into the combustion chamber, the compression ratio is lowered on a turbo engine to 17:1. Still high enough for starting in cold, but enough to allow over 20psi of boost. On some military engines, Detroit lowered it to 15:1, which Don Fairchild had an engine like that. It smoked starting on a 70 degree day for quite awhile.
To get 400hp and 1200lb/ft torque, 80 injectors are needed (this is the highest stock power output that Detroit had for the on highway 8V-71TA). 90's can be used to boost up to 450hp and 1350lb/ft torque, but then you have an engine that will probably only last about 200,000 miles. Good Luck, TomC
I haven't got the new parts yet, so I'm still open to suggestions. The most I have seen from my turbo is 12 psi of boost. Should I get 18.7 to 1, or the 17 to 1 cross-heads? The head is being rebuilt and it will have N75 injectors.
You guys have to realize that this is my first time rebuilding any engine. I have been a shade tree half mechanic all my life, but I am really stretching my abilities this time... Although I like to learn and I'm loving every minute of this. I am going by the DD service manual, which is very good. So the wrenching is not really difficult. It takes some care and patience to do it right. It is taking more time than I thought, and I only average 2 or 3 hours a day, but I am aiming to be back together and running by spring. (April, early May). I am getting advise from my supplier Alberta Engine in Calgary. And I need to pick your brains here on the board, to figure out what is best as far as what parts would be the right parts. I really appreciate any and all sugestions.
Today, I am hoping to have the clutch and flywheel housing off, to get at the timing gears to move to standard timing, and to replace the crank shaft oil seal. I will take a picture or two then, because that is as far as I will go dismantling. It will be a big moment, because I will start the rebuilding process after that.
JC
JC,
I admire your enthusiasm. I think you need more help and hand holding than you "seem" to be getting. Go with the "turbo" piston which has the lower compression ratio. It will give you much more HP even if you don't install the correct turbo. You should have more than 25 pounds of pressure out of the turbo....don't quote me....verify. The 15 psi turbo you have is a smoke turbo or might have the waste gate set for 15 psi and be the right item after all....verify.
S. Oregon diesel, Dave, showed me a 8V71 that had lost the cam timing gear. Was overhauled a few months prior by another shop in another state. As Dave told me "it has a few bent valves. Shouldn't be too hard to FIX, right?" and we laughed. The owner was not present. So many things to verify. Got mics? Dial indicators? And I wish not to discourage you.
About that compression ratio: If you have two engines and one has more displacement than the other, the bigger wins...right? The reason is because you can get more fuel and air into the larger. Now, if you psi in the intake is 25 and the displacement is 100 ci the volume of gas inhaled will be some quantity over 100 ci due to pressure. Now, if you reduce the CR you are effectively increasing the volume of the cylinder at Bottom Dead Center , BDC, cause to reduce the CR you had to move the crown down so when it went to TDC there was a larger volume and less compression...right? That larger volume associated with lower CR is filled up with more air than the higher CR. In short, it acts like a larger CI engine. 5 psi is better than N and 20 is better than 5 and 25 is better than 20. You are stuffing more air.....you can also stuff more air into a bigger hole.
From what Tom says he seems to have normal compression 2 piece pistons and 15 psi boost. Lower compression pistons with that same 15 psi would seem to be able to get him more power and certainly lower CR with 25 psi would be bigger still. Now the question is "why did so savvy a guy opt for this lower power configuration....especially when he sunk $10+ into the overhaul". Enquiring minds and all that....I pondered this long ago when I first heard the story.
Don't think I have the official answers on this....I don't. My only objective is to inspire you to asking the board all the right questions as far as I can. I think I will get something out of this as well so it ain't charity. Risky behavior, though, on my part.
John
John- I overhauled my engine in the first year after the conversion was done-in 2001. Basically at that time the block was bored .010 over so that I had to replace the liners to fit the .010 block overbore (to correct a shabby liner fitting by the PO). The pistons were retained and the engine was built to what it was before- a brown tag N65 non turbo engine.
Fast forward now to 2006 when I had Don Fairchild turbo charge and air to air intercool the engine. Since it was still fresh, I didn't want to spend the extra money on a new set of pistons, and was more interested in high altitude power without the smoke. The turbo was added, along with air to air intercooler, bypass blower valve, fuel modulator, bigger injectors (9G75), along with bigger radiator, air cleaner, muffler, and auxiliary transmission cooler.
As to turbocharging an engine without injector increase, remember that turbocharging will keep the power the same on an engine up to 10,000ft elevation, whereas a non turbocharged engine will loose about 5% power per 1,000ft of elevation. So at sea level, both a turbocharged and non turbocharged engine with the same injectors will have about the same power. Good Luck, TomC
John, do I understand that a low comp. piston is shorter from wrist pin to top of crown? So there is more volume of air both at BDC and TDC. I didn't know that. This is great, thank you. Maybe I missed it in Da Book. I'll have to look again.
JC
Lostagain diesel engine compression come from the depth of the bowl on a piston unless the 2 strokes are totally different the deeper the bowl the higher the compression works this way on Cat,Cummins and the 60 series.They make gauges to check for the depth
David
Lostagain, I don't think you can get your top fuel economy with the lower compression ratio. And there are plenty of people around who do not like taking an ether can to their recent rebuild where they have lowered the compression ratio.
I know of cases that the owners said that they couldn't start their turboed two strokes below 40 degrees without ether. And the higher the elevation, the sooner you have to use ether.
For me, I would want the economy and easy starting as much as the additional horsepower. So, I would look for the best solution that I could get with the higher compression ratio.
Good luck with your rebuild.
Tom Caffrey
PVCCES doesn't mention that he lives in Alaska. The lower compression pistons are "stock" on the 8V71 TA and T 92 series. You are not building a hot rod or breaking new ground in any way. Tom is right about the starting being harder but on a fresh rebuild you shouldn't see a problem. He is also right about the turbo using more fuel in spite of every test that has ever been done proving that it "could" get better MPG. It is your foot sunk deep into HP you didn't used to have that ruins the MPG and if it wasn't fun and natural we all wouldn't do it. On the open road using cruise control you should get close or better.
PVCCES drives a 4106 with a fresh 8V71N and it went through the streets of Eugene cornering like a Porsche and accelerating like a Corvette. You follow my drift. With his performance and MPG i would't be hot to turbo my rig either. You are in a different boat with a 4L71N installed in a NON Aluminum framed GMC.
Yes the crown is closer to the top of the wrist pin,,,,as one way to do it. Another is to dish the top of the piston or to increase the volume of cylinder head and another is to use a thicker head gasket like BMW does for bikes they sell in Africa and other third world countries. You could also restroke the crank like the pros do. When I blueprinted I gouged out some of the head and then "sunk" the valves by grinding the seats for a final adjust. Dished pistons yield the worst results in a gas engine and I suspect a D also.
John
I have no idea what John is trying to tell you but the combustion take places on top of the piston in a DD diesel engine that is the purpose of the dish they do not have a combustion chamber in the head.Reading the book on a 2 stroke DD engine there is only .040 difference between the 19:! and the 17:1 the 19:1 being .040 deeper in the bowl
David
The shop I get my parts from is telling me they usually put the high comp. pistons in turbo rebuilds. Which is probably what I should do, unless someone gives a compelling reason for low comp.
I got the clutch out yesterday and it looks fine: 7/16th. The fly-wheel has surface cracks where it contacts the clutch, so I'll take it in to a shop for a look and possibly resurfacing. The fly-wheel housing won't come off unless the rear motor mounts are removed: big 1 1/2" bolts that did not want to budge last night. I'll probably use the angle grinder to cut the nuts off today. I am inching closer to the timing gears... It takes more time than one would think. Oh and the shop that has the head called yesterday saying they found antifreeze where there shouln't be. It is under pressure overnight and they will call me back today. Now I'm thinking I should maybe strip the block of all remaining parts and have it checked out too? Oh well, what's another couple of days...
Anyway, thanks for all the advise and moral support. I can really use it now.
JC
JC,
That shop you are dealing with either miss understood you or the other way around. They have given you the exact opposite advice of what is called for. I have exhausted whatever little credibility I might have on this subject and I expect you want/need more expert advice than I can give. I "strongly urge" you to PM the professional/more knowledgeable Knuts on this board and run this conversation past them. You are about to spend a LOT of money and do many hours of demanding labor and I know you know that. Contact Don Fairchild or Dallas or Gumpy or TomC or PVCCES or BK or any of a host of others that easily distinguish themselves as knowledgeable on this board excluding VanTare/David. I will speak with him off line by PM to sort out his erroneous advice.
Sincerely,
John
John, don't worry, I will get advice from as many of the good mechanics as I can. I will have this engine as good as possible. I have already invested a lot of hours dismantling it, and the parts aren't cheap, so I'll make sure the most suitable parts go into it.
I finally got the fly-wheel housing off and the timing turns out to be "standard" after all. Good, at least I know for sure now.
The coolant leak in my head (engine), turns out to be from an inj. tube. They are getting replaced as well as the valve guides, so all is well on that front now.
JC
On second thought, only part:
David,
You can easily "learn" what a combustion chamber is by Googling the term and selecting the reference for Wikipedia (http://en.wikipedia.org/wiki/Combustion_chamber)
In that reference it refers to the "direct injection diesel" as using the dish in the top of the piston as the combustion chamber. It infers that only that particular version of internal combustion engine, and all of them in fact, is designed that way and that all others use the pocket machined/cast into the head plus the gasket thickness and piston dish and/or piston "sink". as the combustion chamber. In spite of that being Wiki's official explanation, I doubted the validity of that info. I contacted the west coast DD rep that is considered their resident expert on two cycle diesels, Dave Mueller. Dave informed me that the "all" two stroke diesels have a flat head and use the dish in the piston as the "combustion chamber". I asked about the Series 60 and he said that it has a pocket in the head and that pocket is the combustion chamber in that "direct injection" engine. Seems WIKI is wrong on their point that "all direct injection engines use the pocket in the piston as the combustion chamber".
Now that is a small point in the grand scheme of things but don't ya just luv it when that happens? Me too.
John
JC,
Thank you for that update and the coolant leak loc is good news. Good for you!
Your right about that....I was concerned for you and that I might have let you down in some way.
With a smaller displacement engine is it probable that you would slip the clutch moreso than with a biggie? Is that scorching normal? I know some of the 8V71 guys have opted for a heavy duty clutch and others have mentioned a dual disc unit.
Along the lines of the clutch, have you ever heard of letting the "high speed idle gov" start you out on a hill? That yields minimal clutch slippage and sometimes makes a start possible. People here get apoplectic at the mention of that but it just makes so much good sense to me.
Write often and long Amigo and good luck,
John
All I can say about the flywheel being scorched and cracked is it must be from the POs abuse. I always start from a stop at iddle with my foot off the accel. pedal. The flywheel is probably 52 years old like the bus. I am taking it next week to a specialty shop in Calgary. We'll see what they say. I have 2 others off 4-71s, but they are different for different applications.
JC
I have seen many engines apart. The statement that all direct injection diesel engines have flat heads and the combustion chamber in the head is completely true. I have yet to see and direct injection head, including Series 60, with any kind of pocket or dish in it. Now on my Mercedes-Benz with prechamber, yes it does have a pocket for the fuel charge to come out of the prechamber. Just my 2¢. Good Luck, Tomc
Howdy,these are the top of my 692TA's pistons,the heads are flat.On another note,you guy's surely remember Luvrbus,Cifford's engine(8V92TA) boasts 500+HP with 19:1 pistons and 17lbs of boost and can pull away from most 60 series engines.fwiw. Van
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi457.photobucket.com%2Falbums%2Fqq292%2Fcwvanhagen%2FDSC01471.jpg&hash=308d956cf2eaea4da5423996e442781c051d5df5)
Quote from: lostagain on February 04, 2009, 11:21:23 AM
I have the 4-71 DD out of my Courier 96 and I am doing a complere overhaul. I wanted to fix some messy oil leaks and pulled it out,
2-stroke Diesels don't leak oil.
They MARK THEIR TERRITORY.
TomC,
They did say that Dave Mueller is the "2 Stroke" expert. Maybe he is all wet about the S60 series heads. Can't argue with what you have seen, of course. He did tell me that the 60 had pocket Chambers in the heads.....no kidding. I haven't seen either engine torn down so I am going on what the most expert info is I can find. Your on that list so I guess I now have two experts disagreeing with each other. And, I don't imagine either of you are loosing sleep. Me, on the other hand, I'm really anal on this stuff. ::) :o ;D
I'll call DD on this later today. For what its worth, I talk to these guys and when I have my answer they say something like "Is that all?" and "call back if you have more questions. Happy to help." You know, real disagreeable like up here in the Great Northwest.
Van,
I am surprised that the 92T has 19::1 and only 17 lbs of boost. No wonder they say that you can boost it to over 600HP easily. Is 19::1 standard? I have read more than once that the 6V92 runs more than 25 PSI of boost....is that wrong? From what I have read the 92 series uses identical parts in the 6 or 8 config so they should have the same specs for PSI boost and such....seem reasonable? Also may not be true.
John
John ,I myself am no expert,but 17:1 is the standard and so far as the 6v vs the 8v I believe they are mostly the same parts but are not identical in every respect .Fwiw you know me and I too have to rely on the experts here on the boards as well as the manual.I do know the marine engines are set up for 600hp + ,all I know is I want one LOL,have a great week end.
novice expert
at large
Here is a picture
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Quote from: lostagain on February 14, 2009, 09:34:18 AM
Here is a picture
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"Whaddya mean, you came in for a turn signal bulb????"
Hey, it worked! Thanks Dreamscape for turning me on to Photobucket.
Here is a couple more. This a momentous occasion for me because this is as deep as I go into my engine. Head is off, pistons, rods, liners, crank bearings, transmission, clutch, flywheel and housing all off. I feel like I am over the hump, and from now on, the rebuilding process can start with new parts. And there is more, like going from oil bath oil filter to dry, intercooler, cleaning up engine compartment, etc, etc...
JC
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One more.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi582.photobucket.com%2Falbums%2Fss267%2Flostagainphoto%2F011.jpg&hash=f60a6b5ec568d946436dbadb1dd987a808c11ef6)
And one more.
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The rad is off too. I got it back last week all recored with dimpled tubes and serpentine fins.
JC
Man, I wish I had a bus shop and the time/ambition to pull my engine out. Even though it is a Series 60 I still have some minor oil leaks and other minor issues it would be nice to correct.
Nice job!
JC- highly recommend you clean up, prime and paint your engine compartment. One of the problems that the bus manufacturers had in the 80's when Detroit changed to silicone gaskets, was they found the engine compartments were rusting since they didn't have the oil be slung from the engine anymore to coat everything. Besides-it just looks good. Good Luck, TomC
Quote from: belfert on February 14, 2009, 04:32:41 PM
Man, I wish I had a bus shop and the time/ambition to pull my engine out. Even though it is a Series 60 I still have some minor oil leaks and other minor issues it would be nice to correct.
I'm sure that there are a bunch of us who would be more than happy to pull that 60 out for you. In fact, I volunteer. Just go get some lemonade, take a nap, come back some time tomorrow. I'm sure you will be surprised to discover that the Series 60 looks remarkably like an 8V71, when you see it sitting there in the driveway . . !
JC, I applaud you for taking on this task and keeping it as stock as possible! There aren't many of us nuts who would do that!
This is a very interesting thread, Thanks for sharing! Topics like this is how we novice DD guys can learn!
Glad you like the Photobucket thing, it sure makes a big difference on what we see on this board. Good Job!
What is your Photobucket Link, so I can keep up with what you are doing?
Paul
Nice pics and nice bus garage, sure looks nicer than an open field. BTW the more pics of the teardown and rebuild the merrier, it will help me (and perhaps some others here) understand these engines a little more.
BG6- not quite sure how a V8 two stroke engine with a blower on the top of it can look anything like a 4 stroke inline six! Good Luck, TomC
BG6,you must plan on drinking alot of lemonade? :D :D.Tom you know,6-8-12,if "Ya seen one you've seen em' all" :D ;).have a great BN day.Van
Lostagain, the worst thing you could do is put high compression pistons in your engine. If you want longivity and service with a turbo you must use low compression pistons, retard the timing and increase the fuel. The reference reading for this is at pittsburgdiesel.net and they have alot of experience with big horsepower that goes back many years. Gasoline engines can make more power with more compression, diesel engines cannot, they just grenade.
NJT,
I hear you! I have been trying to make sense out of that also and I was coming up empty. I happened on a thought though: The "static" compression of a forced induction, read turbo or blown, engine is much power than that called for in a "normal" aspirated engine. There is a term called "effective" compression ratio. That is computed using the PIS of boost and the static CR as terms. Don't know how that is done but the max CR on gasoline is something like 14::1 and that is the max ECR and the limit of the boost at low rpm. SOOOOO, looking at it that way a "turbo" piston must be able to tolerate more compression so it could be called a high compression piston. Now, I am wrapping myself around the axle on this and I do well agree with your post and your caution and your reference to Pgh Diesel.
Thank you for your effort and concern on behalf of a fellow Knut. Yours is the spirit that keeps this place "solid gold" instead of merely "really usefull". I think he is on his way to a successful outcome.
John
I have replaced the front oil seal, rear seal, trans. oil seal, diff. oil seal and a couple of gaskets, got the flywheel resurfaced, replaced the throwout bearing grease line, etc. Every part to be reinstalled needs cleaning up because it all was quite greasy from all the leaks, so it all takes time. I got all the parts and overhaul kit, (high compression cross-head pistons and matching rods, bearings, cranks bearings, rebuilt head, etc.), and will be getting to that soon.
Meanwhile, I am putting the flywheel back on this morning and the service manual calls for applying "International Compound no. 2" on the bolt threads. I have Permatex thread locker blue or red. Which should I use? I am hoping some experienced mechanic or two on the board could tell me. Being Saturday, my local contacts aren't in. I'm going back to the shop to clean up and reinstall the starter. I'll check back here at lunch time. Thank you.
JC
JC, international 2 compound is a lubricant I don't believe it is a thread locker, watch out for brass washers on the bell housing and the end plate if not in the right place it will leak.My manual shows grease in the thread hole with the #2 compound then wiping the excess, international #2 is just a assembly grease fwiw good luck
Jc
Looks like you're doing a great job. Gail and I are enjoying the sun in Apache Jct Az. See you in May.
Gary
JC,
I have read tech discussions on "torque specs" and the gist was that lube on the threads will change your torque force a bunch. The lube on the threads makes it easier to turn the bolt/nut. Torque "without" grease seems to assume a perfect world of "clean and dry" bolt and hole threads". Prelim lube will give you the most accurate and repeatable setting but there was a GIANT flaw/warning. You grease a blind hole and part of your torque setting will be compressed air. I think that would be especially true for Permatex or locker. See if the instruction has a caution to "lightly" grease the bolt. Even if the hole is open, the use of thread locker will cause you to UNDER torque the bolt as the locker presents resistance long before high torque is reached so that resistance must be subtracted from the set torque to achieve the required torque within the parts.
Please share the compression ratio spec for the "high compression pistons" you are using. What was the "stock" CR? Are you still planning to use a turbo and if so what is your boost pressure.
I envy you your shop and project. Looks and sounds like fun.
John
Da Book states: "Apply International Compound No. 2, or equivalent, to the threads and to the bolt head contact area (underside) of the bolts. The bolt threads must be completely filled with I. C. no 2 and any excess wiped off." It then goes into the torque specs. (50 lb-ft, then turn the bolts an additional 90 to 120 deg.). The bolts and holes are very clean after removing, so the last re builder apparently did not use any goop. Should I use anti-seeze compound? Or nothing at all? I don't want the flywheel to "fly" off...
The new pistons are 18.7 to 1 comp. I used advice from several competent and very experienced DD mechanics, most of which recommended high compression for my application.
The turbo is going back on. It will be improved by a dry air filter. (From oil bath filter that I have been running). I also got an air to air intercooler at a wrecker's in Calgary, that I have to install as well.
Lots to do yet!
JC
JC,
I may have missed it, but you ARE using new flywheel attaching bolts aren't you?
Just a thought.
Dallas
Hey Gary i tried calling you a few days ago and left a message, are you and Gail coming to Yuma? the space is available if you are. :) Ed
Dallas, no I wasn't going to. Should I?
JC
JC,
Yup,
Every time you remove the flywheel you need to reinstall it with new bolts.
The old bolts have been torqued and the threads stretched and are only good for one use. DD recommends replacing them every time.
This is the same reason you replace the head bolts on a Ford escort... first the bolts are torqued to a certain value and then the bolt is turned 90° to stretch the treads and lock them into place. Once they are removed, they will never retorque correctly and stay that way.
Good Luck, I'd hate to see you have the flywheel come bouncing out from under the bus at 60 mph, especially after all the work you've put into it.
Dallas
JC, when you buy the 6 or 8 bolts it will blow your mine to see the thread locker on the new bolts figure that one after reading the book. good luck
You'll also probably becrap yourself when you see what they want for those 6 or 8 bolts!
They aren't even plated in gold or platinum!
DF
Quote from: lostagain on March 07, 2009, 01:21:10 PM
Dallas, no I wasn't going to. Should I?
Not if you really enjoyed all the work you're doing and you want to do it again soon.
There is way too much energy depending on your flywheel bolts to risk reusing them.
Thanks for the heads up guys. I'll be making a call Monday morning to order new bolts. Da Book does not mention new bolts, so I wasn't concerned untill Dallas brought it up. Now how about head bolts? Crank bearing cap bolts? Connecting rod bearing bolts?
JC
When DD went to the twist and torque they did call for new head bolts but if you have a manual with the torque in lbs I would reuse the head bolts those babies are 11 buck each and rebuilders use the same head bolt.FWIW in section 1.4 page 1 in my book it says use new flywheel bolts.If you need the torque on the head bolts Dallas can help he is my go to guy when I need the torque on head bolts for the DD good luck
Thanks Luvrbus,
I had to go to the shop and look at my book. It is the Inline 71 Service Manual, 1978 edition. It does not mention using new bolts, but I beleive you and Dallas, and will get some new ones for the peace of mind. As I posted 10 replies above, it specifies 50ft/lbs, then turn an extra 90 to 120 degrees.
Boy, I am greatfull to have you guys!
JC, my manual is 1988 good luck
I grew up in Jasper Alberta and road those busses alot. Before the road was built into Marmot Basin Brewster had those in service to bring the skiers to the old upper chalet. Another note is some of those Brewster Couriers were purchased from the Jasper Park Lodge, at that time they had a brown and yellow paint scheme. Do you Jerry at Gainford 50 miles west of Edmonton with his Flxible and Courier collection?
84bluebird, no I hadn't heard of Jerry with the Courier and Flx collection. Tell us more. Maybe I could drop in if I'm in the area one day. There is a guy, Russ Young, in Lumby, BC, near Vernon, that has about 6 Courier 95s and 96s, plus one on tracks that was a snowcoach at the Columbia Icefield in the seventies. I have gotten parts from him for mine. I drove out of Jasper in winter of 75-76.
Take care,
JC
JC I was also in Jasper those years. Jerry at Gainford is also a busnut he has dial-up internet so doesn't come to the forums often. He runs a business called Jerry's Car Care, its located right on highway 16, he does autobody and hotrod work. I believe he has 2 Couriers one is an ex Brewster skyline and the other is a converted MH, he has about 5-6 Flx's all with diff drive trains. If you want his number let me know and I can get it for you.