Motorhome engine replacement

[Rik]

I went back to Alabama to get my new-to-me 1983 Airstream motorhome, and found that is has a bad rod bearing. I would like to put in a Target or Mr. Goodwrench engine, but the upshot of dozens of phone calls is that GMC/Chevy apparently doesn't have the carbureted 454 motorhome engine available any longer - it's too OLD! Kind of like me.

The coach is presently in Huntsville, AL, in the northern part of the state. I love the rig, and, one way or another, WILL get a good motor in it and bring it home to Santa Cruz, CA.

Any and all suggestions would be greatly appreciated.

Best regards, and Merry Christmas,

Rik

[74Argosy24MH]

The early EFI engines just used a throttle body instead of the carb. Have you tried to find one of them? It might not be available as a dressed engine, but GM's website lists flat lifters for older engines, which to me means they must still make the long and short block.

How bad is the one in the MH? If it has just spun a bearing (knocking) and not actually thrown a rod it is rebuildable. There are dozens of outfits that do this and will give a decent warranty. Even if it is not rebuildable the only extra it will cost is the core deposit.

Try a Chevy or GMC truck dealer. These are truck chassis, they might have better part number lists than a car dealer.

John

[74Argosy24MH]

Try this. These engines were used for everything from trucks to irrigation pumps. I can't believe they are not available as a long block any more. Don't ask for the complete engine, just a short or long block.

John

[Rusty Bucket]

Brand new replacement big block Chevrolet engines are available fer sure, refered to as "crate motors" for most any application, from towing to race car. They come both long and short block or as pretty complete assemblies with some accessorys. They are reasonably priced for a new engine w/warranty. I don't have websites handy but look in any performance car magazine. Most have list of advertisers near the back. Look for Scoggins Dickey Performance Products or Berger Chevrolet, or ask the guy at the Chevy dealer that is the hot rod car guy. Chevy dealers sell 'em direect. I think the towing version is less than $2500, or a competent automotive machine shop can probably rebuild yours for a little less. Think I'd rather have the new one. Howard

[Curtis-79MH]

A Chevy mechanic told me that you can substitute a fuel injected motor for a carb. model but you'll have to install an electric fuel pump and the "brain" to make it work. But that might mean it wont pass a California emissions test.....

[Tripp]

Howard,

I agree with your crate motor option. There are several models to choose from in the Chevy line. I will pull out my latest car mags and look for an advertisement and repost to this thread tonight.

If I remember correctly, you can get the 502 towing motor which is basically the same motor as in new workhorse chassis motorhomes. You might have to change the manifold to work with your carb setup, but you might also consider going with something like the Holley Projection fuel injection kit. Its basically a bolt on replacement for carbureted engines in a TBI setup.

If you're going to throw money at it, might as well do it right!

If you're a huge horsepower nut (like me), throw in the Ram Jet 502! Just kidding! Powerbands are all wrong.

Tripp

[wb13798]

just passed on some info to bob for a engine and transmission . im going out of town for the holidays . i live in huntsville . so call bob and he will fill you in.
later al

[Tripp]

Sorry it took me so long to get back! I flipped through my magazines, and Scoggins Dickey is probably the best place to start with crate motors. You might check with your chevy dealer too though. They might just have a 454 or 502 crate motor thats been sitting there awhile and make a deal-not likely, but you never know.

Let us know how it turns out.


Tripp

[davidz71]

rik,
You might also pose your question on www.pickuptruck.com since a lot of those guys are replacing engines or have beefed them up for towing. They should have some good sources. By the way, since so many Chevy owners have complained about cold start knock due to short piston skirts on the 6.0 litre engines, it looks like Chevy is starting to replace the engine or give a 100,000 mile warranty on them according to the GM trucks portion of that forum.

[TRAPEZE]

How about Diesel?

Below is a post from member Joe. I wonder what would be involved in converting a 454 powered unit, to a Cummins 5.9 Diesel? I know if I ever have to spend the $ to replace my big block, I will look hard at this option!

Merry Christmas to all!

Scott

joepospisil
2 Rivet Member


1982 310 turbo diesel
Location:
Posts: 21
Karma:17
310 Repower
Another option for a 82 310 Turbo is a 5.9 Cummins with the 518 Chrysler automatic trans. It is a neat swap and makes a lot of power. We have done two of these in the last year and a half and they really work. Joe


__________________
joe

[74Argosy24MH]

Check your rear axle ratio; diesel run at a lower rpm than gas, you might be pushing top end pretty hard at expressway speeds. If it is turbocharged you need a source of vacuum for heater controls, brake booster, etc. You will need new motor and trans mounts, throttle cable, wiring, cooling, etc. I have seen many of these started and not finished because of the work, fabrication, and money.

Diesels are not cheap to start, expect to pay a decent amount for a used engine. Older diesels can be very expensive to maintain. For them to last they need an excellent maintenance program and you don't know the history of most donor engines. Gas to diesel conversion is not cheap, there are a ton of modifications and parts to be made. I would stick with a straight up gas replacement; by the time that dies it will be 2020 and have 200,000 miles.

John

[davidz71]

Feb. '03 issue of Off-Road shows a Ford 6.9 International diesel taken out of an F-250 and replaced with a Cummins diesel from a '92 Dodge. The article states that the '89-'98 Dodge trucks have the 12 valve non-electric Cummins motor which was easier for their install. They also stated that the '94-'98 have the best torque potential. The '92 engine was purchased for $2,000 and included the Chrysler 618 overdrive auto transmission. They also attached an Atlas II transfer case.

[TRAPEZE]

Rik,

Have you figured out what you are going to do? I am truly sorry you have to replace you engine, but I must say I am sure this group has a bunch of us out here thinking we are one big hill away from an engine replacement and are living vicariously through you!!!

[joepospisil]

Rik
The cummins swap is a real bell ringer but you are a long way from home to start on such a project. This project is best done when you have the luxury of time to procure parts do the job. It would be expensive to hire it all done and not be involved in the actual job. I swapped a cummins into our 82 310 and turned it into a unit that will operate above 90 mph and makes a real 14 mpg at 70 mph. The parts to do the conversion cost me about 4000 and it took about a month to do the swap in my spare time.
I dont know what to tell you about your unit but in my case the option was clear.
Good luck
Joe

[famalco]

Rik,

I was unable to get a replacement carberator last summer when I brought my "new to me" 1986 345 to California from Texas to be smogged. It tooks weeks, lottsa money, and many vendors before I was able to get a DMV pass. One advantage that you will have with your unit being out of state for more than 90 days is that you will avoid the "use" tax when registering.

I'm researching power & economy issues regarding improvements to my 454. Check out this vendor regarding straight up Chev BB replacement WITH carb:

http://www.rebuilt-auto-engines.com/...07103135265.6e

[Rik]

The link you posted is amazing! $1566 for a remanufactured 454 engine which INCLUDES the $500 core deposit??!! Hard to believe! I have found a shop I am happy with in Alabama to overhaul the engine, so will likely go with them -- about $2200 including the R&R. The big Chevy dealer in Huntsville wanted $8K! I'm praying that it's a good job! But just to add insult to injury, the tow truck that was towing it to the shop dropped it! Another problem to deal with!!

[menco]

Hi! I'm new here, but it certainly looks like the right place.

We recently bought a '77 20-foot Argosy motorhome in need of some TLC. Formerly owned by a traveling rock band (really), it's in deed of at least paint and interior resoration. It has an adequate Chevy 350 with headers and an ignition kit, but the idea of diesel won't go away.

No, here's my idiot idea of the week -- I have a source of Cummins-powered P30 stepvans (mostly late 80's, early 90's). The engines have about 40K, the chassis are probably all over 100K. These were all used for local potato-chip delivery and are coming out of service because the chip guys found out they can write off new vans real quick and decided to go to LPG and maybe cut their maintainance/operating costs.

Does it sound insane to consider lifting the body off the 1977 chassis and putting it onto one of these diesels (I have a forklift). Are the early/late P-30 chassis compatible, etc? What about noise through the antique plywood doghouse? Heat? What rear ratio is most desirable, given the weight of the coach, etc? We probably will tow something somewhere sometime but not always.

My connection at the source is the fleet mechanic. He thinks this is the best idea since sliced bread (He also built a supercharged 350cid Corvair Corsa, which kinda benchmarks his sense of practicality). He claims his average in/out P30 engine&tranny swap by itself is about 6 hours. Is this a better idea?

At least the iron will be cheap.


Thanks,

[joepospisil]

Hi Mike
I cant offer you much advice on your unit but i have a question. are the cummins engines 4 or 6 cylinders? i put a 6 cylinder 5.9 cummins in a p30 chassis that develops about 180 hp attached to a 518 chrysler automatic with a lockup converter. this unit weighs about 14000 and is 31 foot long. it is equipped with a 4.56 rear axle ratio. it is geared just a little tall for the area we are in. it operates the best at 70/75 on the interstate. if i were to change anything on this airstream i would drop the rear axle ratio to a 4.88 using 19.5 tires to make it a little more user friendly in the hills. i would suggest just changing the engine and transmisson and not try to do a frame job. heating is a non issue and the only time i notice the sound level of the cummins is when it is idling. at road speeds the sound level is just fine this is my second conversion in the last 2 years and have driven the 2 units about 40000 miles and they work great. mileage is about 14 at 65 mph and the hills just make you smile joe

[74Argosy24MH]

I pulled the body off mine, it is at least 10 times as much work as to r&r the engine. When the chassis leaves GM it is pretty bare, Airstream welded a platform for the body to sit on and built most of the cowl in the front. The floor is screwed to the platform everywhere (especially inside the walls), which means the mh must be gutted and the lower interior aluminum panels must be removed. The black, gray, propane tanks, and curved lower body panels are attached to the chassis and platform. Do the engine, it is a whole lot easier.

John

[stu]

Originally posted by Rik
I went back to Alabama to get my new-to-me 1983 Airstream motorhome, and found that is has a bad rod bearing. I would like to put in a Target or Mr. Goodwrench engine, but the upshot of dozens of phone calls is that GMC/Chevy apparently doesn't have the carbureted 454 motorhome engine available any longer - it's too OLD! Kind of like me.

The coach is presently in Huntsville, AL, in the northern part of the state. I love the rig, and, one way or another, WILL get a good motor in it and bring it home to Santa Cruz, CA.

Any and all suggestions would be greatly appreciated.

Best regards, and Merry Christmas,

Rik

if it's just a rod bearing you can pull the oil pan and slip in a new pair without motor dissasymbly, check in to it...stu