can i 4.3 liter block from a truck be used in a boat?

[lime4x4]

I can get a good deal on a 22 footer with omc stern drive but the block is missing.So can i use a 4.3 block from a truck and just change out the cam for a marine cam?

 

[paultech6]

Re: can i 4.3 liter block from a truck be used in a boat?

Change to marine camshaft as marine engines run in a differant RPM range then automotive engines .You will also have to use the correct heat range spark plugs available at marine supplier
Change the steel freeze plugs to brass. Steel will rust and rot out,
Plugs are behind the flywheel as well as on sides
You should also use a marine carb as it is jetted properly.
Hope this helps

 

[WillyBWright]

Re: can i 4.3 liter block from a truck be used in a boat?

More info please. What year and what was in it before? Do you have exhaust manifolds? Marine carb? Marine starter? Marine alternator? Marine fuel pump? Marine water pump? Marine ignition system? Is it a Real truck like a GMC or just a "truck" like a Chevy?

 

[Silvertip]

Re: can i 4.3 liter block from a truck be used in a boat?

The 4.3 whether used in a GMC or a Chevy (actually used in pickups and Astro/Safari vans and as a base engine in work/conversion/passenger vans) are identical motors. Those engines have lots of low end grunt so I wouldn't worry too much about changing the cam. Is it best to do so? Certainly -- but depending on the budget and performance you wish to achieve, not an absolute requirement. Those engines pull like a mule at low and midrange RPM. I've owned a bunch of them over the years.

 

[lime4x4]

Re: can i 4.3 liter block from a truck be used in a boat?

all engine parts are there except the block.It's a 1986 boat.Story i got was the crankshaft broke and the block was removed to have the crank replaced but it never was and the owner has no idea what happened to it.

 

[Four86Winns]

Re: can i 4.3 liter block from a truck be used in a boat?

Willy, what do you mean just a "truck" like a Chevy, GMC and Chevy are EXACTLY the same thing with different badging, even any GM dealer will tell you that. What constitues a "real" truck? Sorry I'm off topic, just wondering.

 

[Gary H NC]

Re: can i 4.3 liter block from a truck be used in a boat?

How cheap of deal is it? OMC drive and no block..Needs to be really cheap.

 

[WillyBWright]

Re: can i 4.3 liter block from a truck be used in a boat?

GMCs historically almost always have the heaviest duty versions of whatever motors are offered. Chevys can have just about anything from the lightest to heaviest versions. The older the truck, the more that's true. I would feel far more confident with a GMC motor than a Chevy motor in a boat. Given a choice of boneyard motors between GMC and Chevy, go for the GMC.

The cam issue is overlap timing. Automotive cams in marine applications leads to water ingestion.

 

[lime4x4]

Re: can i 4.3 liter block from a truck be used in a boat?

this is the boat in question

http://cgi.ebay.com/ebaymotors/ws/e...e=ADME:L:RTQ:US:1&viewitem=&item=130111890363

i was wondering would a 4cylinder 3.0 liter mercruiser and stern drive fit into that boat and actually be able to move the boat at a decent speed?

 

[jimmer4444]

Re: can i 4.3 liter block from a truck be used in a boat?

yes,,you can also use 6cyl,or a V8,they all have the same bellhousing bolt pattern

 

[John_S]

Re: can i 4.3 liter block from a truck be used in a boat?

With a 22 footer, I think you would want to be looking in the other direction, toward a 5.7L.

 

[lime4x4]

Re: can i 4.3 liter block from a truck be used in a boat?

Just thought i'd ask cause i have 3.0 with apha 1 gen II sterndrive but wasn't sure if the whole thru the transom are the same for a omc and mercruiser stern drive units.

 

[180shabah]

Re: can i 4.3 liter block from a truck be used in a boat?

is it an OMC "cobra" ?