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Desertprep · 01-29-2023, 11:49 AM

For a motor home. I have noticed that most of the MH I have seen have a large block 4xx cid in them. A 383 cid stoker has more horsepower and torque - even without maxing the 383 but weighs about half as much. Is there a reason for the big block? Dumping 400 pounds sounds really good.

Most of the MH I see for sale (1978-1985) are Fords. Does Ford have a durable 4 speed automatic transmission with overdrive that DOES NOT need a computer?

matcoman · 01-29-2023, 12:07 PM

It's all about torque, not cubic inches. The big block should be your choice.

EyezOpen · 01-29-2023, 02:22 PM

Don't let pop culture advertising sway you from a big block. GM big factory BB's are grossly underrated as to hp/tq. To use modern measurement standards think 330 up and about 450 ft lbs of torque.

What 383 has that much torque...in a usable power band. In a rv 4000 rpm pretty much the end...

Flyer15015 · 01-29-2023, 02:30 PM

Old saying that still rings true.

"There's no substitute for cubic inches".

Applies to gas OR diesel.

JMHO
Mike in Colorado

cadillac_al · 01-29-2023, 06:35 PM

not to mention the durability of a big block Chevy for hauling a heavy load it's entire life.

GypsyR · 01-30-2023, 08:48 AM

A Hotrod magazine type 383 stoker will be cammed up to put a fairly lightweight car through a quarter mile quickly. Useless in a big heavy RV. You want slow revving tractor type torque. First really steep hill you have to climb you'll get it. Consider an RV a very heavily loaded truck that never gets to unload, ever.

Years ago it was the "70's lesson". During the gas crunch back then people thought to order/build RV's with smaller engines, like small block Chevys. They found they weren't up to the task. To make similar power to a big block you have to rev one almost twice as high. Gas mileage was NOT better like that and engine durability was poor. Some folks went as far as to throw the small block setup out and swap in the biggest engine they could find. It's just how it works.

Desertprep · 01-31-2023, 01:10 PM

Thank you! Now...has anyone ever used a Chevy bb to replace a Ford bb? I like the selection of transmissions that Chevy has to offer for muscle.

matcoman · 02-01-2023, 06:05 AM

Quote:

Originally Posted by Desertprep

Thank you! Now...has anyone ever used a Chevy bb to replace a Ford bb? I like the selection of transmissions that Chevy has to offer for muscle.

Can it be done? Yes, of course!
Would a swap like that be practical? No. Motor mounts, transmission mounts, exhaust, and wiring harness(s) are all different and would require extensive time and labor to exchange. It would be a monumental task at best.

EyezOpen · 02-01-2023, 11:58 AM

As above...big wallet and or a skilled fabricator along with a very nice shop. 460 Ford's are a very good engines and there transmissions. Point in fact Ford literally dominated heavy trucks during that time frame. Fleet mgrs don't buy based on emotions, reliability and performance and the overall cost of ownership.

Rob_M · 02-01-2023, 01:10 PM

The Ford transmissions are plenty tough. They’re not used in drag racing because they have heavier internals than the GM counterparts and therefore more parasitic loss.

But I don’t think a Ford 4-speed w OD transmission (suitable for a big block) exists that doesn’t require a computer to run it.

The main benefit to running GM powertrain over Ford in racing applications is the aftermarket support.

Are you positive there’s 400# difference between a SBC and BBC? Maybe 200 which in a MH means nothing.

OHUQTU · 02-15-2023, 06:18 PM

Quote:

Originally Posted by Desertprep

For a motor home. I have noticed that most of the MH I have seen have a large block 4xx cid in them. A 383 cid stoker has more horsepower and torque - even without maxing the 383 but weighs about half as much. Is there a reason for the big block? Dumping 400 pounds sounds really good.

Should we assume the "383 stroker" you refer to is a Chevrolet engine, and not a Chrysler?

If so, please tell me what "big block" V8 weighs 400 pounds than a "383 stroker"?

Flyer15015 · 02-16-2023, 12:22 PM

I'm very happy with our 8.1 Chevy gasser and the Allison 1000 Tx with the UltraRV ECM /TCM mod's, and we work her pretty hard pulling an 8K# car hauler all over Colorado.
I have read that the limiting factor of the 8.1 are the small ports in the head, but there are aluminum heads available with much bigger ports, that supposedly set this engine free. This might be the easiest way to go if you want to hop this motor up and maintain reliability. Drop a better intake and throttle body in there to really make it breath better, and you might have a winner. Then of course long tube headers would also be required.

Just a thought.

Mike in Colorado