engine swap to diesel

[fleamarketer]

I own a 1981 Winnie Warrior.It has a 350 four barrel Chevy 195 hp engine.The rear end is a 4.11 gear ratio and it is a 400 Chevy tranny.The engine has mid 40,000 miles on it and I believe it accurate.

So I want to travel with it trouble/worry free.For my own peace of mind,I am thinking I want to freshen it up and maybe if I went the route,clean the bores with a .030 overbore.New cam and kit,bearings,rings,etc.

My question is given my motor home,how does the engine come out??.I have heard about some motor homes engines coming out the passenger door,some come out the front,and so on.I am looking for advise from some one who has done it on my yr and type of Winnie or a mechanic that has done that work for the same.I am a skilled mechanic,but have not worked on motor homes.

This brings me to the title of the thread.Over the last few weeks I have been following a thread on a Astro/Safari van site where a guy there swapped into a Astro van a 6.5 Chevy diesel.He has it in place and running and will add a down stream turbo this spring.He has 1,500 miles on it now and reported he really likes it.

So my question is has anyone swapped in a turbo diesel engine like the 6.5 Chevy in a motor home like mine??.My main reason would be the increase torque and hopefully increase fuel mileage.The Astro van I spoke about is getting from 20 to 22 miles per gallon and that van is about 4,200lbs.That is without the turbo too.My motor home is 8,000lbs and I would be thrilled with 12 to 14 mpg. I know the diesel have a very short torque band or power band,so I would think if I made the swap,I would have to do something about the rear end gear ratio of 4.11.All the rest I do know about to change to diesel.Lift pumps etc.The 400 tranny I think could handle the extra torque and I would go threw that with some mods to insure it could.I would think with the increased engine compartment over a Astro van's,I could have the stock location for the turbo in the M/H.


I look forward to your input and comments.

Please and Thank You,

Gary

[blackf3504dr]

The engine comes out the front in most vans after removing the sheet metal (or at least the grill), radiator and it's support and anything else that may be in the way... If it were me I would just rebuild the 350. The diesel sounds like an interesting swap but would take more money, time and debugging, but would make an interesting swap. I know someone here replaced their gas engine with a 5.9 Cummins and it looks really trick....

[94-Newmar]

Gary, take a look around and research transplanting with a Cummins 4BT Diesel. There have been *many* conversions into mini-vans, 1/2 and 3/4 ton pickup trucks and countless others. Just making some injection pump changes on the 4BT can result in numbers as hefty as 250hp/400 lb ft. of torque which makes it an extremely viable alternative. There is also a bountiful array of conversion parts, some that even let you use a good majority your existing drivetrain and existing cab wiring harnesses. If the room is available, transplanting a Cummins 6BT (5.9L), as mentioned above by blackf3504dr, would be an even more worthwhile project. Parts for either engine are plentiful and relatively inexpensive due to the sheer number of these powerplants humming along today. The 4BT and the 6BT share almost all the same internal and externals - the 4BT is merely a 6BT missing 2 cylinders.

The Chevy 6.5L would certainly be among my last choices, as they have probably the worst power/weight ratio, and were plagued with problems throughout their entire service life and parts are highly non-existent for decent prices now. We had several versions of this engine over different years in our Service Trucks back then and it is perhaps the worst mistake we ever made as each and every one of them were inundated with differing continual problems. A big black eye for Detroit Diesel in my opinion.

[JackHammr']

we had a 6.5 Turbo in a 96 Chevy , they were only rated around 190 HP , good strong motor for what we used it for , but we had the fuel pump problem , I think many had , they finally warrantied the fuel pump for 10 years from new model year or 120k miles ..

You stuff that 5.9L Cummins in there and the motor home will fall apart long before the motor

but I agree with the others , rebuild the 350 or , if it were me , I would locate a 400 small block

[fleamarketer]

I agree the 5.9 would be a answer.I know of a adapter company that makes them to the 400 tranny.Just got me thinking if as long as it is if it would fit my model motor home.Then if I get a rear end ratio to change out the 4.11's which I am thinking would not be a good match to the 5.9's.Sure would be cool if some company made adapter motor mounts.I could work out the details if those basic items I could buy.I really like the life span of the 5.9's and like everyone said their proven history.It is exactly what I want in that I do this once and then it's covered.

The 400's had some heat issues with the steam hole cooling system.I am a old engine tester from the engine plant in Tonn,NY.I worked on them and have seen problems with them over the yrs.The answer would be a after market block like from Dart little "M"'s,but it is hard to justify the costs for that.Best case for a gas engine would be to stroke the 350 to a 383,but I would have to watch closely the compression ratio on that(no more than 9.0) so I could still run todays gas of 87.

So I am still asking if anyone has done one of the 5.9 swaps on my model M/H and some details on that.I'll do a search on the net.I just not sure how to word that so it focuses on this swap.

Thanks Guys.Looking forward to more input.Yepper-as always IRV2 is just the best.

[SuperMike]

I know we all like to play, me more than most, but what will you actually gain by all this. The cost will far outway any payback and at 40K the original engine should only want a little bit of TLC to get up to the standard you wan't. Yes, changing may give you a little power, a little more MPG but such an operation needs serious thought before starting.

Of course if you do go ahead I wish you all the best. I must admit a nice new engine is wonderful. So far my 8.1 Chevy has only done 4K miles and is beginning to loosen up and purr when running. Excellent. One thing you Yanks can do, is build an engine. My little 1.2L Fiat toady has a sign on the side that says "My other vehicle has a 8.1L V8 Chevy engine. Honest". I love starting the Winnie just to listen to it run.

Anyway having rambled on and not actually added any thing to this thread, I wish you good luck in your endevours.

[Midniteoyl]

Closest I could find : Cummins into 73 Winnebago Brave - Dodge Chasis - TheDieselGarage.com

[Mikakuja]

The 6.5 would be the easier swap but not really worth it IMO, too many problems. And unless you are able to do the swap yourself it's going to cost a fair bit of $$$$. Definately not a direct bolt in swap but doable.. As for the cummins, definately my choice in diesel engines but is really not a great idea for your motorhome. This engine is very tall and probably weighs 3 times your 350's weight. Not only would you have to rework the frame and crossmembers to wedge the engine under the dog house, you would also have to figure out what to do with the suspension, the cummins would probably compress the front springs to the bump stops......... As for the transmission, even if you could get an adaptor that 400 would self destruct the first trip out unless you had it professionally built to handle the massive tourque and low rpm's the cummins puts out. Hell, the stock dodge transmission won't even last much more than 80k before self destructing unless it is modified.
My opiinion would be to rework the 350. Being an 81 there is quite a bit you can do to this engine to increase the HP torque and fuel mileage for a fraction of the cost of a diesel swap. For example, when you rebuild it get rid of the factory heads and buy a decent set that have a more efficiant combustion chamber, higher compression and better flow. match them up with a nice intake and carb, cam and high flow exhaust and you should be more than happy with the results. Just make sure you have an experienced engine builder match everything for your build to ensure everything works together for maximum power and mileage.

Good luck

[Midniteoyl]

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Agreed... I once saw a build that used the Edelbrock E-tec heads that managed a BSFC of .35-.45 that was better than a diesel.. Swap in a good overdrive tranny with lockup and enjoy life

[pwf16129]

I have been a mechanic for many years done some off the wall swaps( latest is a chevy 350/350 in a 95 dakota) i agree with a 383 built for torque and check into a gear vendors overdrive it will let you split all your gears an have a decent overdrive for the fuel mileage not cheap but bullet proof would pull like the diesel but cost like a gas engine when it needs repaired. I considering the gear vendors for mine if we start taking enough long trips to justify it.

best wishes frank,cricket and harley the dog

[fleamarketer]

I like the RHS heads with their clean cast iron heads.The intake runner size formula is .5 X the C.I.So for a 355 it would be about 180cc's and they build them that way.I think to upgrde to a EFI like a TBI could help.I would want to stay to about 9.0 compression ratio so I could still run 87 gas.The gearvendor's deal is about $3,500 and is hard to see a return on investment anytime soon.The only O/D G.M. tranny that isn't as expensive that"might" work is a 4L80E and that would have to have a stand alone controller and mods done.

But now I am getting away from the diesels.....................Please keep the inputs coming.

[Dennis Parker]

have you considered a wreck ?? low mileage suburban or trk
with the 6 Litre engine you would get the right tranny they were
set up to tow in a 2500 plus you would get the right rear end.
and that engine can be tuned to make lots of horse's
Dennis Parker

[Mikakuja]

Originally Posted by Dennis Parker

have you considered a wreck ?? low mileage suburban or trk
with the 6 Litre engine you would get the right tranny they were
set up to tow in a 2500 plus you would get the right rear end.
and that engine can be tuned to make lots of horse's
Dennis Parker

Agreed........If your going to do a swap this would be an excellent choice..

[Midniteoyl]

4L80E's are easy enough to find, and there are stand alone controllers to be had for $500 or so with wiring, sensors, etc..

Donor truck is the easiest though.. every thing there.