1984 OMC 3.8L............229 or 231 cu in????

[75GlastronMN]

I need to know if the 3.8L OMC used in 1984 was the GM 229 or 231 cu. in. engine????

 

[greentahoe]

Re: 1984 OMC 3.8L............229 or 231 cu in????

My 1984 OMC 3.8 is a Chevy 229. The other 3.8 is the Buick 231. The Chevy has the distributor in the rear, and I'm told that the Buick has it in the front.

 

[KaGee]

Re: 1984 OMC 3.8L............229 or 231 cu in????

Your '84 is a Chevy 229.
The 4.3 did not arrive until late'85.
The Buick was a 70's child.

 

[75GlastronMN]

Re: 1984 OMC 3.8L............229 or 231 cu in????

So basically if I want to use a car long block in my boat I should look for an 80's 229 and swap the frost plugs and camshaft. Will a front wheel drive or fuel injected long block 229 work?

 

[QC]

Re: 1984 OMC 3.8L............229 or 231 cu in????

Wasn't the Buick also an aluminum block? Just curious . . .

 

[Reel Poor]

Re: 1984 OMC 3.8L............229 or 231 cu in????

Will a front wheel drive work?

A front wheel drive block is different. I'm positive.

I would also think the EFI block may not have a place for the fuel pump to bolt on. Not sure here.

 

[Silvertip]

Re: 1984 OMC 3.8L............229 or 231 cu in????

The buick 3.8 V6 block was not aluminum. I don't believe the 229 Chevy was ever used in a front drive car. Those were either 3.8 Buicks or the 2.8/3.1 60 degree V6. The 229 and the 4.3 were used in rear drivers. You might want to do some checking as the 4.3 is likely a bolt-in for the 229 so you get a better engine. Since the 229 was derived from the 305 V8 (two cylinders chopped off) and the 4.3 was derived from the 350 V8, it stands to reason the 4.3 is a "bolt in" for the 229 since the 305 and 350 are externally identical engines. There should be a ton of 4.3's available in the bone yards as they are used in S10 Blazers, S10 Pickups and even the full size Chevy work trucks. Port injected balance shaft 4.3's were availble as a "W" option motor starting in 1991 all-wheel drive Astro and GMC Safari vans.

 

[75GlastronMN]

Re: 1984 OMC 3.8L............229 or 231 cu in????

So the 231 is a totally different engine.
I was looking at some older discussions and saw that you can failly easily swap a 3.8 (229) for 4.3 but I think I remember reading that the intake is different and the power difference is only 10hp more. I guess I will have to look into it a little more. I know there are other discussions on that one.

 

[Silvertip]

Re: 1984 OMC 3.8L............229 or 231 cu in????

10 HP is 10 HP. But -- there are a lot better parts available for the 4.3 than there ever were for the 229. The 229 in cars was a dog. I've owned lots of 4.3's and the S-10 crew cab I have now is rated 190 HP. If you find a 4.3 (complete or bare block), there should be no problem finding the marine parts to complete the package. I would not waste my time with a 229 as it has all the 305 small port/small valve heads where the 4.3 breaths like a 350.

 

[jmlloar]

Re: 1984 OMC 3.8L............229 or 231 cu in????

The aluminum buick engine was a 215ci V8

the 305 was designed after the 350 debored

One of the best heads to use is to take a HO 305 V8 head and port + add bigger valves and they will outflow a common 350 head

the 4.3 or 262ci chevy was actually a modified up 200ci V6 that was punched to 229ci then punched and beefed to 262.

All chevy V6's were patterned after the common V8 chevy small block not after any particular size V8 engine.

front wheel drive engines will not work

Use whatever engine you want and use a bolt on fuelie system designed to retro and older engine, most are a stand alone system and bolt to a standerd 4Bbl intake

 

[Bondo]

Re: 1984 OMC 3.8L............229 or 231 cu in????

Ayuh,........

The 4.3l Looks like a No Brainer,...........
But,.....
It could lead to some Fitment Issues,...... Switching Vintages will make this Worse.......

Most All are overcomeable,.......... On a Mercruiser anyways,.......
OMC,..... I Don't Know............

The 4.3l Vortec would be My 1st Choice..............

That's the Beauty of a Chevy,.............
If Any 1 of them Fit,.......... So can Any Other 1,........ 2.5l, to 454/502.........

 

[KaGee]

Re: 1984 OMC 3.8L............229 or 231 cu in????

So the 231 is a totally different engine.
I was looking at some older discussions and saw that you can failly easily swap a 3.8 (229) for 4.3 but I think I remember reading that the intake is different and the power difference is only 10hp more. I guess I will have to look into it a little more. I know there are other discussions on that one.

An 80-ish 4.3L will bolt up... if you can find one complete... however, nobody in this thread is considering the existing exhaust configuration and the valve cover height difference on the 4.3. You currently have the rear riser OMC manifolds. They bearly clear the valve cover of the 3.8 as it is.

The easiest fix is replace the 3.8. Look for any 80-84 Chevy 229.

Or call Raul at RapidoMarine dot com. He fixed me up with a re-manned 3.8L marine long block for $1300 shipped.

Edit: The manifold issue with the 4.3 is overcomeable... it's just a matter of $$. See my pics for the center manifold conversion of the 3.8. OSCO makes a shim kit to push the manifold out to clear the valve covers.

 

[whywhyzed]

Re: 1984 OMC 3.8L............229 or 231 cu in????

or check your pm's

 

[75GlastronMN]

Re: 1984 OMC 3.8L............229 or 231 cu in????

Thanks again for all the info guys. I am looking for simple and as little as hassle as possible so I am gonna stick with the 3.8 anyway. I actually got the boat to fix and sell to make a few bucks so the 4.3 has no value to me.

There are some local engines around here for $300 I will probly go with.

NEXT QUESTION: I am gonna get a manual but what is all involved with disconnecting the lower unit from the engine? I know on a car you just unbolt the torque converter bolts but not sure with a sterndrive. Any advice?????

 

[KaGee]

Re: 1984 OMC 3.8L............229 or 231 cu in????

The manual will best explain it. Too much detail to list here. Get the manual and if you have specific questions hollar back.