Re-powering a 4104 question

[Electrician85]

What is the best power supply for a 4104?

We currently have 671 but would like to update.

Any suggestions?

[luvrbus]

A DDEC 6-71 330 hp will get you great fuel mileage with plenty of power I have 2 friends with the setup in 4104's and they hunt with the big dogs

good luck

[Tom Y]

cliff, 6-71 or 6-92?

[luvrbus]

Tom, a 6L71 inline 6 a real smooth little engine and not much work to install one in 4104 in marine use I have seen it set at 450 hp Don told me they can handle 500 hp with no problems

[JohnEd]

Usually you can take what Clifford say to the bank.  This isn't any exception, I am sure.  But various questions are begged:

Are you going to upgrade to and automatic in the future?  If so I think you will find that the trans has a "limit" on the horsepower of the engine.

If you are using a stick, as all 4104s were at their beginnings, you will have clutch issues with a bump to 330 HP.  Not a limiting factor and not close to the amt of money involved in a rebuild but still worth discussing here.

Converting over to another engine will be exceedingly expensive and time consuming.  Still, there are those that have converted to L10 and M11 Cummins with spectacular results in terms of power and MPG.  I think that move also involves a rotation reverser  be added in series between the engine and trans.  The differential is then geared to high for the lower rpm 4 stroke.

I have read that Knuts with  4104s have transplanted the third member and auto from a 4106 and I think some included the 8V71.

The costs here are crazy.  You need to do a lot of figuring before you decide.  I would suggest you consider a 4106 if you need power and like the GM.  God knows it is a terrific bus.  But so is yours in its own right.

I would check further with Clifford about what all is entailed with bumping a I6 71 to 330HP.  Don Fairchild would be a source for the parts unless Clifford has one laying in his back yard.  Don't laugh, Amigo!  Don could also give you comparative costs for "stages" of power increase.  

Good luck and my best wishes on you project.  Keep us all informed as we like to cheer Knuts on.

[uncle ned]

I have two 4104's  One with the 6-71 and four speed.and one with a 6v92 and v730.

Guess which one I drive.  Both have turbos and big injectors. But the auto makes the difference.

It is worth the fuel mileage loss.

I think the re-power is well worth the effort,but a series 50 and the zf might be the engine of choice in to days world.

I hear rumors of quite a few transit buses with that combination on the market today.

uncle ned