MC9 Blues

[Seville]

 Hi Folks,
I introduced myself a few weeks back and got a very warm reception. Thank You ! Now I really need your advice!

Let me start with a little back story. I bought the bus from a friend John, who was the head mechanic for a charter company who are no longer in business. It is an 84 mc9 with a 6v92 engine.

I started the conversion pretty much right away, as much as time and money would allow. I also started taking trips right away. Mostly around the New York area with an average of 2 to 3 hundred miles. South Jersey, PA, MD, Upstate NY etc...

By coincidence, I never went out on very hot days nor did I encounter any extreme hills or mountains. I didn't plan it, it just turned out that way. I was very lucky in that I had trouble free trips. Whenever I returned from a trip, I would take the bus to John's shop and we would tweek any issues before they became a problem. So basicly the bus was in tip top shape mechanicly. I had no reservations about taking the bus anywhere my wallet would allow.

Last July another good friend Will, who was doing the conversion for me and is also a good mechanic but not familiar with MCI buses decides he wants to relocate his family to Los Angeles. At this point the conversion is at the 50% mark. We strike a deal where I move his family and their belongings in the bus and make an adventure out of it!

We leave brooklyn early July 26th, Ive got a 15kw Kubota, two Coleman Mach 15s for the front of the bus and the back is filled with furniture and clothes etc.. Will follows in his Dodge Caravan with his wife and kids .
I also have the Bus AC which works great!

My first encounter with the mc9 blues happens in Southwest PA along I-70. For the first time ever I see the temp gauge hit 200! It stays there all day! It got so bad I had to stop at a Kmart to buy a Super Soaker type water gun and doused the radiators. Using this method, I was able to limp along as far as Ohio, where we made camp for the night.

The rest of the trip was ok as I babied this heat beast as best I could with my eyes on the temp gauge more than they were on the road!

One morning I was sleeping and Will was driving and I wake up to the sound of the overheating buzzer! We are in Limon, CO. People on the interstate must have thought we were a circus act! There I am with a huge neon geen and pink gun shooting water at the radiators. Thank goodness this was cooling down the engine!

We make it as far as Golden,CO but with the extreme heat and super steep hills the engine just would not go anymore!
I am loosing my mind! After all the money, time, blood, sweat and tears, the engine is boiling at 10pm in the evening!

We decided to re route our trip and head south on I-25 to Albuquerque then head west on I-40. The mountains out west absolutely kicked my a$$
We limped into West Covina, Ca on July 31st

The plan was for Will to finish the conversion in LA and I would come back in a few months to drive her home.
That week Will and I built a misting system with a powerful water pump and fans with a switch in the cockpit and that actually worked out great! I flew back to New York.

Fast forward 8 months and I fly back to LA with my girlfriend and after replacing the water pump on the Kubota, we depart downtown Los Angeles on Monday April 4th. We get as far as Riverside which is maybe 50 miles out and the temp gauge is at almost 200! I start hiting the misters and combined with driving like a turtle I am able to keep the temp under 200. We make it as far east as San Angelo, TX and on this particular day it is 98 degrees! In April ?!
We just gave up and checked into the KOA and drank beer by the pool!

After San Angelo I was able to get home without using the misters, however top speed was 60. Average speed was 55 and on hills I was down to30 mph! It took 8 days to get back!!

So here is my question. I am so far into this bus! I feel like I built a house on quicksand! I want to repower this gutless overheating specimen but with what? John the guy I bought the bus from recomends a series 50. He says it will fit perfectly into an MC9, but will it be able to get me up some west coast mountain in August at a decent speed without boiling over? 
Its terifying to be climbing up a hill at 35mph in the middle of the night while tractor trailers are flying by you at 60 to 70 mph and sometimes within inches of you!

Help me please. I really need advice!
Thanks

[RJ]

Seville -

What did the engine compartment temp gauge read compared to the dashboard unit?  Dash units are notorious for not reading accurately.

Do you have one of those inexpensive IR temp guns?  Well worth watching Harbor Freight for one when they're on sale - invaluable tool.

Dumb question for you:  Were you downshifting the automatic manually, or letting it do it on it's own?

Reading this might give you some clues, too:

http://www.busnut.com/bbs/messages/12262/16204.html?1167073154


As you've discovered, the Appalachians are nothing compared to what we have out West!  Simple speed bumps in comparison! 

When piloting a coach out here, you MUST pay attention to what you're doing, and what your coach is telling you.

Think about it - Greyhound ran a TON of MC-9s with this engine/transmission combination all over the USA, including all the mountains that kicked your a$$, 24/7/365.  Rarely did they have a road call for an overheated MC-9 - because their drivers are taught how to avoid such a situation!  (Or at least they were back then!)  Ponder that statement for a moment. . .

A 70/30 water/coolant mix cools better than 50/50, but freeze protection isn't as good.

Misting systems are a band-aid, you need to fix the problem.

Chances are very good that the seals around the radiators themselves, plus the seals on the radiator, blower box and rear doors are all shot.  ALL of the air being drawn in by the squirrel cages MUST go thru the radiators.  If the seals are bad, and it's sneaking around the rads rather than thru, you & John have some work to do.

Radiator cores could also be in dire need of repair.

If you're pulling a grade and you see black smoke, you're over fueling and over heating your engine.  Back out of the throttle until the smoke disappears.  If the coach maintains speed, you're good.  If it starts slowing, it's time to downshift.

That engine in your bus will pull all day long in 100^o weather on a partial throttle at 1800 - 1900 rpm without overheating if the cooling system is in top condition.  BTDT

MC-9s are NOT BMWs!  Don't expect to pull 6% grades at 45 -60 mph in a coach, it ain't gonna happen!  Even with a monster 500 hp 8V92 (IF you could keep it cool) or Series 60 in the tail, you'd still only see 45.  Why spend $20,000 to go an extra 10 mph??

So, just sit back and enjoy the scenery as you climb Rocky Top!

More info will be forthcoming from other busnuts.

FWIW & HTH. . .



PS:  Those 18-wheelers flying past you uphill in the middle of the night?  They're empty deadheaders! 

[artvonne]

 I have read plenty here and elsewhere, that these MCI's will run hot if everything, and these guys mean EVERYTHING, is not 110%. The bigger the Bus and the bigger the engine, the hotter. If you have an auto trans, hotter yet. If the seals around the radiators arent fully sealing, air will go around them instead of through them, and youll run hot. If the blower door isnt sealing, the blowers will suck air through the door gaps instead of through the radiators and youll run hot. IOW, the entire blower box area has to seal air so that all air flow is through the radiators into the blowers. Any air leaks = running hot. Clean blower fan blades and blower housings will flow more air than dirty ones. I read once that any visable dirt on the blades of a centrifugal fan could lower flow rate 30%. But if the radiators are clogged internally youll run hot, nothing short of pulling them and addressing them will fix it.  

 The first thing you should do is pull the radiators and check the cores. Then check/fix everything else while your putting it back together.

[chart1]

I pull the mountains at 30-35mph .. Enjoy scenery as you climb

[artvonne]

If you're pulling a grade and you see black smoke, you're over fueling and over heating your engine.  Back out of the throttle until the smoke disappears.  If the coach maintains speed, you're good.  If it starts slowing, it's time to downshift.

 Question. On the way home I watched the exhaust on grades. Now with these old tires I wasnt trying to run flat out but it would get away from me and I would catch myself over 70. Anyway, on a grade that wanted to slow me, id start to see a bit of black smoke. I tried backing off to not make any smoke and it slowed me way down. Rolling back on the throttle would speed me back up, but then I made smoke. But I was going to fast to downshift. So do we want to make zero smoke, or is some okay?

[Seville]

Hey RJ,
After a while I caught on that i needed to downshift manually and that really helped out alot.
Honestly, I can live with crawling up a hill. It' s the fear of overheating and frying the engine that takes the fun out
driving for me.
Looks like I won't be heading out west till I get this whole cooling system worked out, which is a shame cause I love it out there!
It's funny that you bring up the Greyhound drivers because I was thinking the same thing.
Can you imagine an MC9 leaving LA on a hot August day filled with 49 roudy people headed to las Vegas back in the 80's? Those drivers must have been really good and really patient !
I need to learn those skills.

[Chopper Scott]

I had similar problems with my 7. It has smaller radiators than your 9 so it is really marginal. I saw that others such as Jack Conrad installed a tranny cooler along with the resealing the radiator/ blower areas. Also have vented the side doors of the engine compartment. It helped tremendously but I still have to watch out.

[luvrbus]

The series 50 will help on the cooling and fuel but you are not going to gain but very little on the hill climbing speed very little torque and hp difference in the 6v92 and series 50 not enough to offset the cost to me

good luck

[bevans6]

Last year at SEBN Palmetto cove I met a number of people who had installed S50's into MC-9's.  To a person they were nothing but complimentary about the conversion, over the moon.  Better fuel mileage, better performance, electronic engine control, and cooling problems a thing of the past - cooling the S50 with one of the original radiators in one case, I seem to recall.  So if you decide to go that route there are people around to advise you.  $20K is about the budget to look at.  You will have to re=gear  or put in an overdrive trans as part of the deal.  From memory they all had put in around a 350 hp software package but had a lot more torque at the low range.  I didn't quite understand why they felt they had such better performance, but they said  night and day.

On the other hand, getting your 6V92 working right is also a good option.

Brian

[luvrbus]

I paid close attention when CA paid Greyhound for Stewart and Stevenson to install the 50 series in some of the MCI's they were not much here in the west I think they were 300 hp and around 1000# of torque about the same as 6v92 and the fuel mileage was about the same with the 740,over 40 grand each for the C.A.R.B with the tax payers money lol

good luck

[Melbo]

I had an 8 that overheated

It however was 8V71 and standard

I had the rads rebuilt the seals replaced the rad compartment completely redone

Still over heated ---was told to have the 71 rebuilt so I converted to a Cummins L10 and four speed auto

Problem solved  BUT  an auto with overdrive would have been better to keep the L10 rpms in the sweet spot at higher highway speeds

Mike put in his L10 with a B500 and likes his setup as well

HOWEVER all that said if your DD is in good shape you still need to get the cooling system up to speed for whatever you choose to do --- With the cooling system done and good driving habits you could save THOUSANDS and THOUSANDS

HTH
YMMV

Melbo

[Mike in GA]

Overheated my MCI with 8v92 on I-10 east of Kngman AZ on a long uphill grade. Wasn't watching my rpms and should have dropped the 740 AT into 2nd.
    Long story short, when I got back to ATL I checked the seals around the large upper real engine door. They were shot. Installed new rubber gaskets, Checked the seals around the rads and they were shot. Removed the old ones and shot Great Stuff foam all around their side edges. Checked the seals in the rear radiator access doors (the ones with turn screws), they were shot. Replaced them. Result - better cooling - but still not best.
   My radiators are old, and probably need replacing or recoring. Not cheap, but may still be in the cards.
  I would suggest you do all the resealing, above, before resorting to the heavy lifting of rad removal and replacement. It's cheap, gratifying, and easy - and may make an appreciable difference.  
  Just my way. H.T.H.
Mike in GA
PS:  In the Southeast Bus Nuts, as Brian says above, there are four prominent members who have installed Series 50s. All are VERY happy with all aspects, including power, and mileage that approaches 8 mpg!  Not cheap to do.

[Seville]

Thanks for all the input guys. Much appreciated !

I think I should do whatever I can to resolve the cooling issues before I take the plunge with a S50 transplant.
Looking back on it now, I think I have a pretty good engine. Other than the overheating, I haven't had any problems.

Last summer when I drove out west and used about a half a gallon of oil.
Last week driving back east, I used even less? I kept checking and and the level was fine.
Honestly, I think I used about a quart.

On the bright side, I have 2 months or so to fix my cooling problem before the real deal heat hits this area.
On a less happy note, I was very excited to attend my first bus rally in SC next week.  Now I don't think that's such a good idea.

[luvrbus]

50 series are not that great of a engine that was the first one to go from the 4 stroke family they haven't been made in a few years now.
But we all do it different I have 2 friends that have removed their series 50 engine they may work for the guys on the east coast but don't cut it here in the west and 8 miles mpg is not all that great most of the guys with series 60 do the same or better.
Just repair your cooling system and run the 6v92 till it gives up then do a change if you want a different engine,this has never made much sense to me a bus worth x dollars and spending big bucks for a engine and still have a bus worth x dollars

good luck

[Boomer]

All the above advise is sage, especially RJ's, he's been there and done that.  Some beginning cheap modifications you could try are replacing the air blower belt tensioner with a manual turnbuckle type.  The belt has to be tensioned properly with no slippage. This also eliminates leaky o-rings in the cylinder. You could also install a smaller blower drive pully to speed up the gearbox.  Do not run a horizontal mudflap under the rear bumper if you have one there, decreases air flow.  Keep the engine degreased and clean.  You could also add a second transmission filter to cool the trans oil a little more.  Pressure wash the radiators from the inside out real good and if there are any bent fins, comb them out. After all, they are 30 years old. These are all cheap little tricks, but the fact is most MC-9 radiators you will find are long since past their useful life limit.  The most gain will come from sealing up and/or replacing the rads with the bigger 8V92 rads.  You could do this one at a time to ease the $$ pain. The last ones I bought from MCI were around 900.00 each and I expect they might be around 1,500 now.  IMHO it is more cost effective to spend the money on the bigger rads than on rodding out your old ones to the tune of 400.00+ each.  Make sure you have an accurate, capilary type temp guage in the engine compartment to cross check with the front one, I can almost guarantee you that the front will be inacurate.  The 6V will give you good service and decent fuel milage if driven modestly, repowering would be a waste of money.  Hope this helps.