6.5 td in motorhome

[TurboBob]

My parents have a 34' 1995 Rockwood motorhome. It's a pusher on a Spartan chassis with a 6.5 td. It's good on the very flat, but it bogs down in the shadow of a hill, let alone trying to climb one. Does anyone know if this motor is built with the same specs as in the p/u, or is there anything GM did different to put this in a class A chassis. Is there anything I could do to get it more power short of a rebuild? It does have a washable air filter, anything that might be done with the exhaust would have to be totally custom($), or is the only real option to put a lot of money in it, as in a Peninsular stlye rebuild? They like it otherwise, so they're not too keen on looking for another rig with a Cummins. Thanks in advance for any help.:confused:

[Bnave95]

You can put a power chip in the ECM that would help alot.
I have used Banks,JK and am runing the Bill Healths 2.0 chip. Eazy to change out once you know where the ECM is located. It will add some fuel and boost.

[TurboBob]

Thanks, I'll do a little bit of searching through the advertisers here. although most of them seem to require a phone call for anything involving an RV.

[Bnave95]

JK and Heathdiesel would be the one's to go with. They are more than willing to help and can answer to what would be best.

[moondoggie]

Good Day!

The 1st thing you have to do is determine if it has a DS4 (electronically-controlled) or DB2 (mechanical) IP. I don't think replacing the EPROM won't do you any good if you have the mechanical IP. (I've read in numerous other posts in various topics that GM continued supplying 6.5TD's in motorhome chassis WELL past 93, when they switched our trucks to the electronically-controlled DS4 IP. It's certainly possible your, & other, motorhomes came with the DS4, but it's awful easy to be sure, so you know where to begin.:))

Even if this motorhome has a DS4 IP, I respectfully disagree with starting by replacing the EPROM for more power. IMHO the only safe things that can be done on any 6.5TD is to open up the exhaust & intake. Changing anything else B4 getting gauges is risking dangerously high EGT's without knowing it's happening. It's unfortunate your motorhome would require custom exhaust, but shop around - there's bound to be someone who will do this work for a reasonable price. Maybe JK or Heath might have some suggestions here also.

So, get a free-flowing intake & exhaust & gauges (EGT & boost, MINIMUM) & here's the 6.5TD mods I can think of in no particular order:
Baro pressure fooler
Boost fooler
(DB2 only) turn up the IP
DS4 only) performance EPROM
(mechanical Wastegate Actuator only) Fiddle for more boost
High-flow cooling mods
Hopefully others here will chime in with the rest. I'd be a little careful - the 95 engine isn't the strongest one they ever built, & a motorhome will make it work at a higher average % of output, more of the time, than the same engine in a truck like mine (unless pulling a trailer all the time). If you exercise reasonable caution, you should be able to mod this rig so you're quite a bit happier with it. You might not pass everyone on the grades, but certainly this rig can be made to produce significantly more grunt.

I'd hunt down RJ's three articles about his engines & their story. It's a great read, he's done most of the things we'd all like to do, & I think it's likely he built one of the strongest 6.5's ever - good info to have on-hand if you ever need to replace your engine.

Blessings!

[tommac95]

Voting with Moon~... Before attempt to increase output of an old engine, restore cooling. In this case the '97 cooling upgrades would be nice on heels of exhaust. Also, check boost (gages will), as a loss of boost renders sluggsh.

[Mark Rinker]

One additional thought: Add an intercooler, or better yet water/methanol injection with an intercooler, only for running hills. You could draw water directly from your storage tanks or add another tank and pre-mix it with windshield washer fluid (methanol).

You may have plenty of space up front of your radiator that our pickups don't have. Cooling the boost air charge will make more power and lower EGTs - without changing anything else.

[TurboBob]

Thanks for all the input, I thought about the gauges right away, especially EGT and boost, it just came with the basics.
I'm going to have to do a bit of digging next time they're here with the rig to see which IP it 's running.
It does run fine until it sees a hill, but think about what we're trying to do with it, the thing grosses at 18,000lbs, add a Cherokee to the rear bumper and it's working real hard. As for an intercooler, I'll need to figure out where the best place is to put one, it is a pusher(engines in the back, so's the radiator), so finding a place with good airflow that's not too far from the engine might be a challenge.
Thanks again, the new info ought to keep me out of trouble for a while.:)

[Mark Rinker]

...probably a tank of propane along for the ride on that big beast, too. There is another potential source of extra power for the hills - 'on demand'.

[Bnave95]

Looks like I jump the gun on this one. Knowing what Ron wrote about years when made and sold,I learned also. Seeing how this being a rear mount Eng. one would think the Elect. would be the way to go. For a DB2,they make cables that long for the Pump?

[arveetek]

For a DB2,they make cables that long for the Pump?

Yes, they do. All of the older diesel pusher motorhomes, whether 6.2L, 6.5L, Cummins, Cat, etc., all had tremendously long cables from the foot feed in the front to the engine in the rear. The electronic engines really simplified that particular aspect of coach building.

Casey

[More Power]

The folks at www.peninsularengine.com have developed a program to improve power and cooling of the 6.5 in a motorhome application. Might be worth a call to learn more. Peninsular will be attending the Safari Trek rally, located in Missouri this June, and will provide a seminar on the 6.5's used in motorhomes.

Jim