86 Rinker OMC 4.3L swap with car block

[CatriderF7]

I bought an 86 Rinker last week with what i thought was a blown head gasket. Pulled the heads off and saw the block was cracked. So i did some looking around and found a few people who have swapped blocks or whole engines with auto engines swapping fairly minor parts. And after the third person who has done this with a 80s 4.3L i decided thats what i was going to do. I bought a carburated 4.3L complete engine out of an 85 Astro van (86 4.3s were fuel injected and i wanted to buy the same type incase something was different even tho i had my intake and carb still) I stripped the car motor down to just the block. Put the whole top end off the marine motor on it, and got it all ready to go. Then i took the bellhousing off the boat motor and saw that the flywheel/coupler was held on with studs coming off the crank, and the car one is held on with bolts. Then i held the marine flywheel up to the car block and saw it was completely different so i thought i could just swap the cranks, then i pulled the oil pans and saw they are completely different on the flywheel end. The marine engine is milled out on the end and the crank has about a 2 inch long collar that goes into the block some and has an extra seal on it for some reason

Does anyone know why this is? I didnt think they made a completely different block and everything for these. And i have talked to 3 people who have made this swap with a junkyard block from the 80s and have said all the 4.3 blocks are the same. Really sucks i spent all weekend working on this motor, plus the cost of buying it and now its completely useless

 

[86 century]

Re: 86 Rinker OMC 4.3L swap with car block

Are you sure on the years of the blocks the only differences I know of there where some changes when they went to the balance shaft blocks.
I'm not sure what year they made the change you might do some checking on that.

 

[86 century]

Re: 86 Rinker OMC 4.3L swap with car block

Are you sure on the years of the blocks the only differences I know of there where some changes when they went to the balance shaft blocks.
I'm not sure what year they made the change you might do some checking on that.

 

[Bondo]

Re: 86 Rinker OMC 4.3L swap with car block

Does anyone know why this is? I didnt think they made a completely different block and everything for these.

Ayuh,.... It's the difference 'tween the 2 pc rear main seal, 'n the 1 pc...

The switch by Chevy was in the '86/ '87 time period....

The 4.3l went through Alota changes over the last 30 odd years... ya gotta pay attention...

 

[kd7isf]

Re: 86 Rinker OMC 4.3L swap with car block

Make sure to use the camshaft from the old one. Auto Cam won't work good in a marine engine application...

 

[bruceb58]

Re: 86 Rinker OMC 4.3L swap with car block

Make sure to use the camshaft from the old one. Auto Cam won't work good in a marine engine application...

4.3L was never used in an auto...only trucks.

 

[CatriderF7]

Re: 86 Rinker OMC 4.3L swap with car block

Ah thatd be it then.. looks like im going to either look for the older style flywheel and coupler or find a newer block. Thanks

 

[CatriderF7]

Re: 86 Rinker OMC 4.3L swap with car block

Well that explains it then. looks like ill be looking for either the older style flywheel and coupler, or the newer block. Thanks

And Auto stands for automobile, which is what a truck is, is it not? lol..

 

[bruceb58]

Re: 86 Rinker OMC 4.3L swap with car block

My point is that a truck cam and a marine cam are the same. You can change the cam out if you want...your choice!

 

[CatriderF7]

Re: 86 Rinker OMC 4.3L swap with car block

huh that first one wouldnt show up til now on my computer.

Really? ive heard they put different cams in them to make more power low end.. Theyre all the same tho? if theyre the same i wont waste my time changing them

 

[CatriderF7]

Re: 86 Rinker OMC 4.3L swap with car block

Is there any reason why a vortec 4.3 block wouldnt work for this? with the non vortec marine heads, intake, carb and distributor off the non vortec motor the boat had originally?

 

[Bondo]

Re: 86 Rinker OMC 4.3L swap with car block

Is there any reason why a vortec 4.3 block wouldnt work for this? with the non vortec marine heads, intake, carb and distributor off the non vortec motor the boat had originally?

Ayuh,... What makes the Vortec motor, a Vortec is the heads, 'n intake....

use yer old parts, 'n it ain't a Vortec anymore...

 

[sam60]

Re: 86 Rinker OMC 4.3L swap with car block

4.3L was never used in an auto...only trucks.

We had an 80's Buick LeSabre 4.3L, so they are out there.

 

[Scott Danforth]

Re: 86 Rinker OMC 4.3L swap with car block

4.3L was never used in an auto...only trucks.

the 4.3 was in many cars, specifically G-bodies, large B-bodies

 

[Scott Danforth]

Re: 86 Rinker OMC 4.3L swap with car block

Is there any reason why a vortec 4.3 block wouldnt work for this? with the non vortec marine heads, intake, carb and distributor off the non vortec motor the boat had originally?

as bondo pointed out, the vortec heads and intake are the key to the vortec motor.

my recommendation would be get a new intake and use the vortec motor AND heads. you still have the 1-piece vs 2-piece flywheel to contend with.

 

[joewithaboat]

Re: 86 Rinker OMC 4.3L swap with car block

This might help.... lots of differences through the years. If you have found a engine with the vortec heads use that. Note that just because it says vortec on the valve cover doesn't mean it has the sought after better performing vortec heads.

http://www.hotsixes.com/index.php?option=com_content&view=article&id=14&Itemid=12

 

[CatriderF7]

Re: 86 Rinker OMC 4.3L swap with car block

Alright i got it now, i knew there was a difference in some years other than the heads and intake, but the one im looking at is only the heads so it should work out. Ill just put my marine heads on it so i dont have to re-drill the exhaust manifold holes.
thanks everyone

 

[Scott Danforth]

Re: 86 Rinker OMC 4.3L swap with car block

the exhaust manifolds are the same between vortec and non-vortec heads. its the intake manifold and ports that are different.

your heads are not "marine" heads. they are open chamber cast iron heads. the only thing that separates them from heads on a car is that yours were bolted to a block that was turned into an engine that was installed in a boat.

 

[CatriderF7]

Re: 86 Rinker OMC 4.3L swap with car block

I was talking about the exhaust manifold bolt holes for the boat manifolds, which are spaced out differently then the ones on the car engine i bought

 

[Scott Danforth]

Re: 86 Rinker OMC 4.3L swap with car block

they should not be different

time to post pictures of your old heads and the new heads.