Re-engining an MCI8 with a Detroit Series 50

[belfert]

[work together.  Even a old HT740 doesn't shift correctly for the low RPM 4 strokes.  Valve body can be modified for lower RPM shifts.   Yet, Jim Shepard installed an S60 into an Eagle and it's working fine.  I'll find out what he did with the trans this coming week.  He's at the FMCA rally in Charlotte.
I may be wrong, but seems as though Jim used a B500?

Jim used a 10 speed autoshift out of a truck.  One of his big problems was finding the right connecters to get the engine and tranny to hook up electronically.

Brian Elfert

[MC7S50]

The engine was installed level.  Did not see a reason for tilting it.

Here is a pic.

My friend Frank, who was the brains behind my conversion, has an 01 Eagle with a DDEC II S60 and an automatic that was taken as a unit from a fire truck.  Using a matching set of engine and tranny simplifies things a bunch.

My engine was already programmed for a manual because the Freightliner it came from had a manual.  Also, we used the entire electrical system from the Freightliner, including dash components. No voltage problems, as I had converted the bus to 12V years ago. 

John

[MC7S50]

Clarke

Do yu have a pic of one of the Stewart and Stephenson S50 conversions you mentioned?  It would be interesting to see how they did it.

John

[Burgermeister]

John,

I too was considering the S-50 after riding a "loaded to the gills" 45'  Greyhound to Reno from Sacramento last year.  Very impressive performance IMHO.

But Bob Sheaves, who was an engineer on the original S-60 design team, feels the M-11 is a much better engine for this purpose, even if you have to "stretch" the bus to accomodate the extra length.

DD has an installation manual that it appears you didn't reference.  Proper S-50 engine Installation requires tilting the "rear" (in the case of your bus - front o'wise) up 5 or 7 degrees. It  is part of the design strategy for keeping the engine cool.  It helps purge the air out of the head.

Trouble with doing "the tilt"  is the difficulty in matching the plane (i.e. making them parallel) of the yoke on the differential with the yoke out of the tranny.  You might have to put some wedges on the axle mount pads.   If you don't match the angles to make them parallel, you experience pretty short u-joint life.   If you have trouble working this out, send me drawing and measure the two yokes with a digital protractor or one of those accurate bubble levels from Sears and I'll make you a set of wedges.  You're set is on me!

Ugly part about the failure to do "the tilt"  is the cooling system may have more than enough capacity to keep the coolant with normal limits, but, like Clarke referenced below,  there's gonna be hot spots in the engine that could lead to real problems.  You'd never know, otherwise, just by looking at the guage.

[No, Gary, I'm not looking for "a life"  I'm hoping to increase John's engine life! FWIW]

Did you also get the correct motor mounts?  For the S-50, you have to provide for something like 7" lateral travel at the head.

There's lots more info in the installation manual that should be referenced.

Marc Bourget

[TomC]

While the Series 50 is an excellent engine, it has a couple of down falls.  If you don't use the super soft engine mounts, you'll get some vibration at idle (course how much idling do you do?), it is a very tall engine, is heavy for its' HP,  and how many of us need a million mile motor? Couple of alternative engines that are not discussed much are the "medium" sized engines.  The Cummins ISL puts out up to 400hp & 1200lb/ft torque and is a VERY quiet engine because of their common rail injection system-weighs 700lb less than the Series 50.  The Caterpillar C9 that also puts out up to 400hp but a bit less torque at 1150lb/ft- weighs 600lb less than the Series 50.  Both the Cummins and the Cat are much lower engines that wouldn't require floor alterations, are being made still (Series 50 is out of production), are the same length as the Series 50.  Both these engines put out more power than the Series 50's 350hp & 1150lb/ft torque.  The Cummins and Cat engines are considered to be 500,000 mile engines-more than enough for our uses.  Good Luck, TomC

[rv_safetyman]

JR, I look forward to seeing you this week.  We are in booth 171.

I chose to use an Eaton AutoShift.  It is a 10 speed "automated" manual transmission.  It was a challenge to get it to talk to the Series 60.  I had to change the ECM to a DDEC IV and then things went well.  The only issue is the hydraulic clutch.  I used Volvo truck parts and had an issue with both bleeding and not having a reservoir (had to remove the one that they use and made my own), but it developed a leak at the master cylinder. 

I am trying out a standard automotive master cylinder.  I need to make some adjustments to that design. 

Other than the clutch, the transmission is great.  A little slow on the acceleration as you loose turbo boost on each shift, but once it gets rolling, it is great.  You have a gear for every situation.  It is kind of fun to hear it go through the gears .

Some of the conversion details are on my project pages (link listed below).

[NJT5047]

Hi Jim,
I"ll be out there tomorrow afternoon.  Bringing Norm, who's MC7 is sitting in a parking lot with a clutch failure, to the speedway around 3.   I'll look you up.   
I've read your post on the engine conversion...very interesting project..way beyond my meager knowledge base! 
Having thought about the engine conversion thing, I believe that if my engine fails I'd probably go with the RV style Cat or Cummins that is popular with large diesel motohomes these days.  Get engine and trans.  They make 350 very dependable, smooth HP.  And they operate at a little higher RPM which more closely emulates the 2 stroke cruise RPMs.  Be able to keep my diff as is.   Still would get decent milage.  Still way too expensive to consider unless major engine failure.   I think that Lang did the RV style engine in his Starliner...I may be wrong.  But all the electronics and auto would work together.  And, as John did, use all the RV dash and electrical components for a ready to go package. 
If I found a burned or wrecked pusher with a low milage late 8 liter 350 HP diesel, I'd buy it strip out the powertrain and scrap the rest.  Just keep the
powertrain until I needed it.  However, my 6V92TA DDEC couldn't run any better.  Never been a problem with exception of a rear main seal....which probably indicates a good many miles on the engine.  I replace both the wear ring and seal.  Still runs great and solved the oil leak.  Total parts cost...$35.00.  Well, I did buy an engine dolly from Madbrit and had it shipped up here from Az...that was a little more!  The dolly makes it doable!   
Repowering is not something that I'd do for fuel milage...but I would would if the engine or trans suffered a major failure.
BTW, Norm is the "Air Tab" vendor at the FMCA Rally.  His MC7 has an apparent throwout bearing failure (the bus pulls, but the clutch won't release), and the fuel tank is leaking...sort of a "perfect storm?"  Luke has a fuel tank which he'll send down if the orig tank is beyond repair, and a guy from Lancaster, SC is going to R&R the fuel tank and pull the engine and repair the clutch, with the coach in the parking lot.   That's going to be a days work.  On a old coach, sometimes bolts don't agree, cannot find correct parts...guys gotta be good! 
See ya, JR

[Beatenbo]

Thought about buying an ex hound MC-12 with 50 series amd install a slide?? My old 6V92T with nooooo computer takes me down the road at 70-75mph and 7mpg with no problem.  I just aint much on transplants! How much fuel savings would make up the cost difference, unless you driving 100,000 a year... Just my 5 cents worth (don't get much for 2 cents these days.)

[belfert]

Thought about buying an ex hound MC-12 with 50 series amd install a slide?? My old 6V92T with nooooo computer takes me down the road at 70-75mph and 7mpg with no problem.  I just aint much on transplants! How much fuel savings would make up the cost difference, unless you driving 100,000 a year... Just my 5 cents worth (don't get much for 2 cents these days.)

I read somewhere that Greyhound had not yet released the MC-12s with the Series 50 engines.  This may have changed iin the last three or four months.

Brian Elfert

[Clarke Echols]

Clarke

Do yu have a pic of one of the Stewart and Stephenson S50 conversions you mentioned?  It would be interesting to see how they did it.

John

I don't have any pictures.  I do have a re-powered Neoplan AN-440 transit, but it was a different
animal.  It uses a combined radiator and charge-air cooler (intercooler) in a single unit.

As for the MCI conversions, they kept the left-side (driver side) radiator and replaced the right-side
with the intercooler.  Since the S-50 is longer than the 6V92s and a bit longer than the 8V92s
(or 8V71s ?), so the drive shaft has to be shortened.  They also built a somewhat heavier
cradle due to the higher torque, and used a different set of mounts (the same mounts used
by MCI when they went to S-50 power in the Greyhound MC-11 buses.  MC-11 is an MC-9
specially modified for Greyhound).  The HT-740 transmissions were usually retained.

The S-50 with a B500 Allison is a really sweet setup if you have a 4.69 rear-end ratio.  Top
speed of about 87 MPH in 6th gear (second overdrive) with beautiful shift points.  The engine
runs at "sweetheart" rpm at 65-70 mph (6th gear), 55-60 (5th), 45-50 (4th), 35-40 (3rd)
and 22-27 (2nd).

Clarke

[buswarrior]

The Greyhound MC12 I had a chance to drive Buffalo to Toronto sometime last year, or a little earlier, had a S50, and a build date of late 90's. Somewhere on someone's archive you might find the post I made at that time. Memory fades with age....

There is no MC11. The Greyhound model that looks like a MC9, only with a more aerodynamic roof line and factory square taillights, amongst other details, is an MC12.

The tranny only showed 5 gears on the display. The S50 adequately mates to the B400 Allison in transit use, I wouldn't know why it would be mated to a B500 for Greyhound. Remember, the dogbus is very good at not spending money when they shouldn't...

For whatever stupid reason, I never thought to dive in and get the good details on that coach....

Next time I see one sitting still here in Toronto, I will make amends and dive in and get the details.

Bad, bad, buswarrior!

happy coaching!
buswarrior

[MC7S50]

Burgermeister, do you know where one can get hold of the S-50 install manual you reference?  I have had no problems with cooling so far.  Of course, I don't drive when the ambient is very high, for many reasons.  Do you know if the "tilt" you reference is recommended for S60 engines as well as the S50?  I could not find a post where Clarke mentioned possible cooling issues caused by installing the engine level.  Can you be more specific?  Thanks for the info and the offer of making wedges for me.  But I need to be sure I don't cause worse problems like eating U-joints.

I chose the S50 mainly because I did not want to do any chassis mods, it was available for a reasonable price, and because I was advised that it was the only 4-stroke that would fit into the 7/8/9 engine bay without chassis mods.  I did not use super soft engine mounts.  There is some vibration when the engine is shut down; almost none at 800 rpm idle. At no time has the vibration been a problem.

[Burgermeister]

You're from Sacto!

I'm in Stockton.

I'll have to check for some of your questions. I'd expect the intallation manual is available from DD.  Clarke duplicated the S&S engineered installation, probably taking it for granted.  Your "amateur" status is what prompted my earlier question about tilt. 

The installation tilt came from an eningeer for DD on the original S-60 design team.  The same "approach" was kept with the 50 so the tilt is preferred.   Again, the insidious nature of this is like going out in the sun with a new bathing suit,  the "newly exposed" areas burn, while the rest of you is just fine.

You'll need the wedges IF you tilt the engine (assuming the original 2 stroke was level and the pinion matched that.  Regardless, output axis of rotation should closely match pinion axis of rotation or you experience U-joint problems, shortened life, etc.

Marc Bourget

[MC7S50]

I found a copy of the S50 installation manual.  Am now reviewing it to see if there is anything I need to change in my installation.  Haven't found anything yet. 

Clarke advises he has a Neoplan.  Did he also duplicate the S&S installation in an MCI?

Not sure what you mean by "amateur status".  I guess that means I am not an engineer by training.  If so, that is correct.  Very few of the folks I know who do extensive work on their busses are engineers, although I agree that one can get into trouble by not knowing more about the engineering implications of what one is doing. An example of this appears to me to be installing a slideout in a monocoque constructed bus like a GM or MCI.  I would not attempt this without the advice of a structural engineer on how to reinforce the structure after cutting out a large hole in the side of the bus.  However, I have seen several MCIs with slides.  I wonder if they were reinforced correctly.

I am not too concerned about air being purged from the cooling system within 30 seconds of initial fill, as required in the installation manual.  I think the vent line from the top of the thermostat housing to the air space in the expansion tank should take care of that.  Since I retained the standard MCI overhead radiator configuration, the air should seek the highest point in the system, which is the expansion tank. I don't think there is much chance of the water pump becoming air locked in this configuration.   I retained both radiators.  The CAC is in the left engine side access door, which is about level with the engine.

Yes, we did know of the need to be sure the axle and the engine are in the same plane to keep from going thru u-joints rapidly.  It is the same thing as when doing an engine swap in a car.

Thanks for your help.

John

[Clarke Echols]

There is no MC11. The Greyhound model that looks like a MC9, only with a more aerodynamic roof line and factory square taillights, amongst other details, is an MC12.

The guys at the Greyhound shops told me in the early 1990s that they were MC-11s.

The tranny only showed 5 gears on the display. The S50 adequately mates to the B400 Allison in transit use, I wouldn't know why it would be mated to a B500 for Greyhound. Remember, the dogbus is very good at not spending money when they shouldn't...

The B-500 has two overdrives, 35% and 55% which makes for a fast-rolling bus at 1500 RPM.  That's
why they use the B-500 in 'hounds.  Shifts as smooth as silk too.  The shop manager at Greyhound in
Denver took me for a ride in one of their buses one night to demonstrate it.

CE