[blades]

Got a buddy with a boat that needs a new 4.3 block, and he was wondering if it's the same block as the one used in the cars/trucks? Or is it specific for marine use?

Anyone know about this?

 

[MuddyS10]

i believe the block is the same, its the cam and something else that changes it into the marine engine.

 

[rat]

Here is the GM website for the Marine engine

http://www.gm.com/automotive/gmpowertrain/engines/vortec/apps/marine/4300_brochure.pdf

The 2 engines are produced in the same city it looks like.

 

[waxy_buildup]

the differences that i know of in marine and auto engines is like muddy says the cam, and i think its also the oil pan, i may be wrong on that, but i think boats have a bigger oilpan seeing as how they sloah around in the water like that so they can keep the pickup in the oil

 

[Trancer]

There was an article done in Truckin Magazine about this... The engines are not the same. Ok found it... Its in the July of 2003 issue. Here are several things that are different...
Heads, exhaust system, cooling system, engine operating ranges, internal engine components, camshafts, Compression ratios, cylinder heads, intake manifolds, fuel system, ignition, starer motor and alternator.

 

[MINTSICK]

There was an article done in Truckin Magazine about this... The engines are not the same. Ok found it... Its in the July of 2003 issue. Here are several things that are different...
Heads, exhaust system, cooling system, engine operating ranges, internal engine components, camshafts, Compression ratios, cylinder heads, intake manifolds, fuel system, ignition, starer motor and alternator.

However it does not say that the 4.3 block's are different but the cooling system is different, that would probably affect being able to interchange the two.

 

[obrien]

there are not as many differences as you think. It all depends on which engines you are comparing. with the newer 4.3s the bottom end and heads are the same. Mercruiser makes one version in MPI with make 220 hp. The ignition system has to be a sealed system to prevent explosions. They do have different exhaust manifolds.

 

[LaynLo]

the main difference other than one being marine and one being land is the flow of the coolant/ water flow. say a truck engine flows in a "clockwise direction, a marine flows in a "cou terclockwise" direction. so if you had to swap blocks you would have to accomodate for the change in the way the coolant/water flows.

 

[BigJimM]

Howdy GUYS
I am new here but I will answer anyway.

All of the marine engines I have messed with run counter clockwise. Yes the block and the crank, rods and pistons are the same. Because the engine runs backwards the cam is ground with the ramps on the WRONG side and the heads are the same. But everything outside the engine turns backwards... I think this is done to counteract the thrust of the propeller.. It sort of keeps the boat from leaning to one side or the other.
Big Jim M.

 

[pyros46290]

just flip the propeller around if your worried about the motor runnin CC

 

[blades]

Thanks for the info on this guys! My buddy is looking at an older RWD Monte Carlo with a V6, and thinking about dropping a V8 into the MC. Then we were wondering about the 4.3 block, if he would be able to use it for his boat or not.

I would certainly expect differences in the bolt-on components to the engine, but if the blocks/crank/rods/pistons truly ARE the same, he could have good justification for the purchase.

 

[obrien]

what kind of boat is it?

 

[MrCallaway]

ok the motors are totally different (gaskets, heads, intake, all that) so no you cant put it in your boat, it would last about 56 min MAX. And boat motors do not run counter clock wise!!!! If ya want really good power in your truck/car find a boat motor, they are built to run at high revs.........SO DO NOT WASTE YOUR TIME OR MONEY PUTTING IT IN!!!!!!