3.8 to 4.3 Engine swap

[DGN]

I have a 83 omc 800 stringer outdrive with a 3.8 GM v6 with a cracked block. The 3.8 is now hard to come by but there are lots of 4.3s around. Does anybody know if there is a bell housing that will mate the 800 sterndrive to the 4.3 Gm engine. the 4.3 bellhousing flange is larger then the 3.8. Other than that it looks like an easy swap.
Dave

 

[maxxman04]

Re: 3.8 to 4.3 Engine swap

4.3 shares same bell as 305/350 chevy. same bolt pattern anyways, i believe same exact bellhousing

 

[Howard Sterndrive]

Re: 3.8 to 4.3 Engine swap

The 3.8 is now hard to come by

no - google chevrolet 229. There's a dozen rebuilders in the lower 48 with 229's in inventory.

4.3 bellhousing flange is larger then the 3.8.

no, they are the same.

Other than that it looks like an easy swap.

Almost impossible. Of course nothing is impossible, but you would have to search a narrow range of 4.3's
You are going to hit two maybe 3 big roadblocks depending on vintage of 4.3.

1. different exhaust. Your 3.8 manifolds (if original log style) wont fit the 4.3

2. Ignition. The 3.8 has a different dist.

3. coupler. Only first year 4.3 have a crankshaft that will mate up to your stringer drive coupler.

there are lots of 4.3s around

but not ones to fit your boat.

 

[DGN]

Re: 3.8 to 4.3 Engine swap

Thank you for the information.
I'm pulling the engine this weekend and will find out just how much damage was done. It sounds like it would be easer to just find a good 3.8. All the 3.8 blocks or engines I have found have had a different water pump and timing chain cover. Not like the old traditional chevy small blocks of years past. I'll just keep looking.
Thanks again. Dave

 

[Howard Sterndrive]

Re: 3.8 to 4.3 Engine swap

The 229 3.8 Chevy uses the exact same timing cover as any small block chevy v8 from the late 1960's to late 1980's.
You must be looking at Buick engines or something?

 

[DGN]

Re: 3.8 to 4.3 Engine swap

The 3.8 motors I looked at had the distributor in the back of the block like the old chevy small block but had different style front cover that had the water pump and the timing chain cover all in one casting. They did not have the balance shaft.
I thought all the Buick motors had the distributor up front. I wounder if these 3.8s that I looked at are out of front wheel drive cars?
And I still don't know what to think of the different bell housing sizes I saw between the 3.8 and 4.3 engines. Both were supposed to be chevy engines out of early 80 S10. I saw the remains of the trucks. All four from different people. I'll have my bell housing out this weekend so I can take it with me and see what it fits, if any.
Dave

 

[maxxman04]

Re: 3.8 to 4.3 Engine swap

And I still don't know what to think of the different bell housing sizes I saw between the 3.8 and 4.3 engines. Both were supposed to be chevy engines out of early 80 S10.
Dave

the s10's never, ever used the 3.8. period. s10's started with the 2.5 4 cylinder in 82, followed in 83 with the addition of the 2.8 v6 as an option. the 4.3 did not make an appearance till the later half of the 1987 models. they shared the s10 with the 2.8 and the 2.5 4 cylinder. in 90-91 the 2.8 was killed totally for the 4.3. but again, NEITHER motor was used stock in s10's in early 80's.

 

[maxxman04]

Re: 3.8 to 4.3 Engine swap

i am a bit curious tho if you are certain it's a GM 3.8, not a ford motor? don't recall fords 3.8 being marinized, but i also don't know everything. tho it is possible that it is in fact buick. BOP generally shared same design, seperate from chev, however, if memory serves, chev and buick shared design on the 3.8l v6 from roughly 75-76 thru 82, i think.

 

[Howard Sterndrive]

Re: 3.8 to 4.3 Engine swap

the 229 /3.8 chevrolet was a popular marine engine used by OMC 1980-1985, but Mercruiser and VolvoPenta also used it in 1983/84

and you are right, the 229 was never in any GM truck except the El Camino

The last marine Buick was 1972 - different engine

 

[DGN]

Re: 3.8 to 4.3 Engine swap

Where the front wheel drive chevy engine bell housings different then the rear wheel drive engines?
Thanks for all the inbut Dave