Upgrading from 11.1 to 12.7 Detroit

[MrMisfit]

How difficult would it be to swap out a 1998 11.1L Series 60 Detroit with a 1999 12.7L Series 60 Detroit. The receiving bus is a 1998 Prevost H3-41 and the donor bus is a 1999 MCI 102-DL3.

Has anyone done this? How hard would it be? Would the engine cradle handle the additional power (330HP to 430HP with additional torque)? What about the cooling system?

I've read through the archives and haven't found much on this. There was one member who did the swap. But I don't remember who it was.

TIA

[luvrbus]

It is easy upgrade you could get both in a Prevost so the cradle will be fine.? What transmission is behind the 11.1 if you have the 755 Allison it will require some wiring and a gear change for the B500, I know the 12.7 should have a B500 with the retarder from the DL3.The the H-41 used the same Superior radiator as the H- 45 with a 12.7, measure the charge air cooler I am not sure, but I think the 12.7 cooler has more CFM flow than 11.1 and the one from the DL3 maybe a challenge to fit,The 12.7 should be 430hp and 470hp on cruise control you will enjoy the difference. My H 41 had the 12.7 and a B500 I wish I would have kept that bus

[robertglines1]

my 98 xle prevost--12.7  had 4:57  gears fwiw  5 inch diameter on cac outlet.

[TomC]

11.1. 12.7, 14.0 all are the same exterior size. Good Luck, TomC

[freds]

So why the heck are thinking of doing this?

What is your end goal?

If it's more horse power to climb hills while towing, how about:

1. Bigger turbo
2. Better air flow path
    A. Intake
    B. Exhaust
3. Propane injection
4. Better fuel mileage
5. Already have it in hand so hey let's do it? Now I have seen 8V71 swaps to series 60's that were done where the donor was a burnt out Prevost that didn't affect the engine compartment.
6. Get ahold of a Detroit Diesel specialist and ask them to go to town on your current engine.

[luvrbus]

So why the heck are thinking of doing this?

What is your end goal?

If it's more horse power to climb hills while towing, how about:

1. Bigger turbo
2. Better air flow path
    A. Intake
    B. Exhaust
3. Propane injection
4. Better fuel mileage
5. Already have it in hand so hey let's do it? Now I have seen 8V71 swaps to series 60's that were done where the donor was a burnt out Prevost that didn't affect the engine compartment.
6. Get ahold of a Detroit Diesel specialist and ask them to go to town on your current engine.

The 11.1 had it's share of trouble about 400 hp is all one will take without scattering parts,he has got the right engine anything after 1998 and serial number 6R498505 are almost bullet proof for a million miles.Installing a 60 in a older Prevost with a 8v71 the engine compartment is good but modifications to tag axle is a bitch to make the 60 fit with a Allison