Are engines made just for RVs?

Fatbear5 · 10-14-2009, 09:00 AM

This is a Newbee question about RV engines... are they built specially for RVs or are they basic truck engines that have been adapted.

We have a 35' 1995 Coachman Santara with a Ford 454 engine. The exhaust manifold has a large crack in it and we are wondering if we should repair it or replace it. If we decide to replace it, are we going to have a hard time finding a replacement that is made specifically for an RV or is this something that is part of a basic truck engine that we can pick up easily at an auto repair shop?

Any thoughts?

Jeff

RustyJC · 10-14-2009, 09:13 AM

Ummm....if it's a Ford, it's a 460. If it's a Chevy, it's a 454.

Because of the thermal expansion/contraction fatigue problems with cast iron manifolds, some people go to tubular headers and eliminate the cracking problem.

Rusty

Jim Gibson · 10-14-2009, 09:39 AM

You cannot have a Ford 454,if it is a Ford it's a 460,my 460 has Banks headers on it,no more problems with cracked headers

Luv2go · 10-14-2009, 09:51 AM

On our old coach, we replaced the cracked 460 manifolds with Doug Thorley headers. We had some problems you may want to know about. The bolts were rusty and broke in both the heads. We ended up replacing both heads for $$$. By the time everything was done, we could have put in a crate motor for the same price! Note this was a class C where everything is tight and hard to work on.

BTW, once we got it done, the headers worked great, great sound, no leaks!

Stewart

sknight · 10-14-2009, 10:04 AM

To directly answer your question, yes the typical Ford truck manifold should be a direct fit. A visual comparison with any part is a good idea before installing the new part.

mfire1339 · 10-14-2009, 10:14 AM

Fatbear.
Get the Vin # of the chassis and go to a good auto parts store. They make aftermarket manifolds. That is much cheaper than installing headers. Soak the bolts for a couple days before trying to remove. If they break they can be drilled out with care and not ruin a cylinder head. I've done it on both engines.

Mike

Izzyblueye · 10-14-2009, 10:57 AM

Make very certain you know what engine you have before you go looking for parts. Ford did not make a 454.

EngineerMike · 10-14-2009, 11:09 AM

Manifolds, radiator hoses, thermostat housing & t-stat, etc. can be different on a MH chassis than for a truck w/the same block. Internally the cam may be different, etc. The displacement is probably the same (same pistons & crank), but these other elements can come into play to manage the differences of the chassis & GVWR.

E.g. I had a 6.5L GM turbo-diesel in a motorhome chassis. It had a cross-over pipe to combine exhaust from both banks prior to running it thru the turbo. Many pickups were sold w/the 6.5 turbo. The cross-over pipe was different because the manifold ends were different, & the turbo mount was changed... to account for mounting in the P30 chassis vs. the pickups. Because of that, there was a radiator hose that required a slightly different routing... Once you got past these physical constraint differences, the rest was in the ECM programming.

Short answer- likely there are subtle differences, but they will matter if you are R&R'ing that particular part. Need to look closely, not just a quick glance to be sure.

RustyJC · 10-14-2009, 11:34 AM

Quote:

Originally Posted by mfire1339

Fatbear.
Get the Vin # of the chassis and go to a good auto parts store. They make aftermarket manifolds. That is much cheaper than installing headers.

Yep, you can keep replacing parts that will ultimately fail, or you can pay more the first time and solve the problem. Your money - your choice.

Rusty

dajudge · 10-14-2009, 12:16 PM

My first mh was a southwind on chev chassis with 454. The manifold cracked and i was told by amuffler shop to put headers. I had the headers installed with dual 3inch exhaust pipes, mufflers and tail pipes and that solved my problems. The headers were way cheaper than manifolds. By the way, if you have a ford, it is a 460.

Fatbear5 · 10-14-2009, 10:27 PM

Ok, maybe it's a 460 and not a 454, but I DID say I was a newbee. We'll check it out and then explore the suggestions you guys gave us. Thanks for all the help.

Jeff