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I need advice about marine engines, have access to a 351w marine engine for $250-300 and am going to look at it tomorrow, going a compression check what else should i look/check for?
btw, it's out of a wrecked boat and has been sitting covered in the garage for about a year ran when parked.
It could be a reverse rotation motor, making the crank and cam useless for use in an automotive application. Beware of that aspect. Look at the heads to see if it's got the GT40 heads, these were used on marine engines starting in 88.
if it had salt water running thru it I would leave it right there........look for a heat exchanger, if it has one than it's had freash water running thru it, should be ok. Most cases a single engine boat will run the same as a regular engine, it's when you have two engines side by side that one will run backwards...I think.....might be wrong...don't hold me to it.
one way of checking the rotation is look at the prop.....
GT40's have vertical bars cast in the ends, along with "GT" somewhere on the topsides. I think Hemieater's right about the rotation on singles, twins did have one each way to counteract the torque steer.
heat exchanger? where and what do i look for? also he said something about having to change the flywheel (lower gear/torque) b/c of the prop sorry for sounding stupid but i don't know any thing about boats.
I'm going to have to ask someone explain what is different about the crank in a reverse rotation engine? I can see the cam but the crank part goes over this old guys brain. I can understand that it would need different pistons as the thrust side changes. Kotzy
If this is a single engine boat it's unlikely it is reverse rotation. Even if it was no big deal, you'll have to change the cam, distributor drive gear, and water pump. I have heard that the crank would be cut differently on a reverse rotation motor, but most production motors get only the minimum machine work, no knife edging or streamlining, so I don't see this as an issue.
The difference in a reverse rotation crank is the knurling at the rear, just forward of the seal surface, It's function is to pull excess oil away from the seal. If you run a reverse rotation crank in the opposite direction,(or a std crank vice-versa) it feeds more oil toward the seal, increasing the likelyhood that it'll leak.
heat exchanger? where and what do i look for? also he said something about having to change the flywheel (lower gear/torque) b/c of the prop sorry for sounding stupid but i don't know any thing about boats.
The heat exchanger is basicly a radiator......it is a long tube maybe 6" in diameter and maybe 3 feet long. sea water on one side and the engines coolant on the other. sea water is pumped into the tube to cool the freash water in the motor Keeping the engine free from the salt..........there should be an extra pump..belt driven... that pumps the sea water thru the exchanger....
think it was fresh water. No heat exchanger persay,y looks like water flowed from the pump through the exhaust manifolds and out, and like a dum *** i forgot to take pics for reference