OMC 4.3 block

[surplusman]

Ok, after all the winter's work I finally got the boat on the water. Disaster has struck again. I overheated it in the fall, and have since rebuilt the entire top end. Took it out and after about five miles, began to lose oil pressure. The engine then began to knock. Now, When it was overheated, I had some water in the oilpan and neglected to goet it out right away. (I drained all other water, just never gave it a thought about being in the oilpan) Got a cold snap shortly after this happened. I was working on the engine, cranked it over and snapped the distributor shaft. Ok, frozen oil pump. Turbo heater, changed oil, found new distributor, all is ok. Back to last weeks trip on the water. My feeling is that I damaged the oil pump, lost pressure and spun a bearing or something along that line. I can kick myself now for not doing the bottom end when it was already tore down, but thats life. So, I will be pulling the block out in the next couple of weeks. Are the actual block internals interchangeable with automotive parts? ie. the rings, pistons, oil pump, bearings, etc.

 

[trog100]

Re: OMC 4.3 block

if u have run a bearing/bearings (likely) u will have damaged the crankshaft journals.. it might be easier/cheaper to look for another short block/engine.. bottom half.. i aint sure if the us terminology.. he he <br /><br />i think the internals are the same..<br /><br />trog100

 

[rabidfish]

Re: OMC 4.3 block

They will physically fit...<br /><br />You may have already answered your own question:<br /><br />"My feeling is that I damaged the oil pump, lost pressure and spun a bearing or something along that line. I can kick myself now for not doing the bottom end when it was already tore down"<br /><br />Honestly, not being smart here... How many times do you usually "kick" yourself, before you realize your mistakes?<br /><br />The "marine" versions of all these components are not identical to automotive in "every way". Heck, even the automotive ones vary from manufacturers. Stick with the marine parts to have an engine designed to work at the load and speed your boat was designed to run at. Saves wear and tear on the ole patootie...<br /><br />Good Luck !

 

[surplusman]

Re: OMC 4.3 block

Thanks rabidfish. I think I know what happened, I wasnt questioning that. Aside from the usual marine items on an engine, I did not know if the internal parts were different though. I know I can use aftermarket automotive parts to rebuild the bottom end strong enough for my boat, probably even better than original issue. What I was really wondering was if it was still a GM 4.3l at heart, or is it in fact different.

 

[KaGee]

Re: OMC 4.3 block

The internals of the SBC 4.3 should be the same except for the cam shaft.