Engine swap for GM

[JohnEd]

Chaz has a post along these lines that I didn't want to hijack.  My question is can a "T" drive be installed in the "V" drive coaches?  I know there isn't enuf room for the engine to fit if the bus is in stock form but can it be modified?  A name for these conversions has even occurred to me.  How does the 4106"Long" sound?  I know that "anything" can be done with enuf money and time but I am not talking about that sort of Project. Can it be done for a reasonable investment?

Many people simply love these GM coaches, and with good reason.  They are fast and maneuver almost like a car.  They look to be really fun to drive and with their weight and slight aerodynamic advantage I think they are the only bus out there that is boasting 12 MPG from a 2 stroke.  If I didn't have the need for room to full time I would be right on board with a 4106 that flew down the highway.

[kyle4501]

I have read where it has been done. Sorry, but I can't remember where I read it, but I think his profession was involved with aircraft mechanics. I do remember that it involved extensive bulkhead modifications. . . . Not to mention a very short drive line!

Maybe someone here can remember more details.  .  .

[Chaz]

Thanx for the concern, John. That is very nice of you.

And since I am definitely an "out of the box thinker", if a person were to do such a thing, instead of messing with the integrity of the bulkheads, etc, how about stretching the bus back a little?

Now, before all the "are you nuts?!?!" comments, I think something like that could be done and either look stock by stretching it back, or maybe just extend the lower half of the bus. It would be interesting and "MIGHT" even look ok if done correctly by someone who can work with metal.

Ehhhh, just a thought.
    Chaz

p.s. there was an extended bus for a motor swap at the rally last year in Cincy at the FMCA mail room. Looked great! Super job!

[kyle4501]

stretching will be fine IF you properly compensate for the changing load paths throughout the structure. That might not be as easy as it sounds.

Be very cautious of those that advise there is no problem doing this & it will be easy. . . .

Me thinks a drop box like used on Eagles & MCI5s will be needed.

[Sojourner]

FWIW

About "T" and "V" drive.....all "T" drive have shorter drive wheelbase than "V" setup. GM 4501 has shorter wheelbase than all other GM with "V" because as you know it take up more room. Either reduce last bay size via moving rear axle forward or add a "Bob Cat" design to accommodate "T" drive setup. It only love of labor and parts or hire someone to do it that will cost more than getting newer MCI or Prevost when finish and engineering problem of things that you didn't know you need to re-correct or redo about more 50 times until you be happy as it is.

Now what you have a heavier coach before all work done to a point it no longer the same GMC sport car handling because of the longer over hang to add the weight of momentum effect.

However, if you have 4501...than most of the works is done for newer state of art engine.

I admire the GMC buses for what it designs to do but that it.

FWIW

Sojourn for Christ, Jerry

[TomC]

I know of at least one 4104 that installed a 6V-92TA with Allison in a T drive.  They had about an 18" extension out the rear.
On my transit bus, the AMGeneral 10240B, it came with either V drive or T drive.  But the rear overhang on my bus is longer then the GMC's.
If you use a Cummins L10 with reverser gear, the V drive can be still be used.  Good Luck, TomC

[tekebird]

I have seen one T drive conversion....it was extended out the back..and IMHO looked like some cobbed together hack job.


Simple answer...it is a huge job to do right.  Every piece of skin and every rivet on a GM is a load bearing member.

[HB of CJ]

I do remember reading about a 4106 that had an 8V92N 400hp, but the manual tranny/driveline was left alone.  Apparently was quite the hot rod.  Bet it sounded cool also. 

[Dallas]

Flx made some New Look T-drives..

[pato-06]

The answer is yes. I have lengthed my 06 3 feet to accomidate a 8.3 cummins and allison 654. it turned out great, unless your familiar with a GM you cant tell The best part is I get 10 mpg. towing a5000lb. toad at 70MPH. This is with a 2.93 rear axle ratio. I will try round up some pictures.  Pat

[JohnEd]

OOOOOOOO, PAT!,

Nothing succeeds like success.  Pics?  I'm drooling.  70 MPH cruise AND 10 MPG towing a full size SUV with an automatic?  What do you get at 60?  What is the HP of the 8.3?

With all the stuff made out of fiberglass I should think there is a rear end for the 06 that would hide the metal work that is a modified "LOAD BEARING" element.

Hope we all hear from you soon Pat.

John

[tekebird]

GM made a number of T drive RTS's

Keep in mind adding length to your coach will severly adjust your departure angle

[pato-06]

John To anser your question.  First I can't type,so I will respond in small pieces. I have turned up the fuel and added a larger turbo,I would est. around the 350 hp. figure. These high dollar torque plates are not needed for the B&C engine to get more fuel into them. Just a 10mm deep well socket and a small screwdriver. ( P 7100 pump) Mine started out 215 hp. As for milage at 60 ,not alot different because I would be in 4 th gear. Since everyone is concerned about structure, the first thing I did was replace the whole bulkhead with 8 ga. steel, thats side to side,to include filling in the old transmisson hole. Been 2 years since project been done, still fine tuning. More to follow,still working 10-12 hours. (summer only) pat

[Chaz]

Wow Pat........................ I'm slobering too!! And I don't even know what an 8.3 Cummins is!!!    But I absolutely LOVE "custom" stuff and simple enginuity. I thrive on it!!!!! Hurry with those pix!

Teke,

Keep in mind adding length to your coach will severly adjust your departure angle

Good point. I guess one would just have to get use to it. 

[skipn]

Chaz,


   http://www.heavytruckparts.net/detailview.php?vehicle=6932&vendor=2677740&searchnum=745178

   Most start at 210 hp..........supposedly one can bump them up to 400hp w/ ~1200ft#.  Banks makes a
HP upgrade for the 8.3 isc's.

Enjoy

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