Motor blown up!!!?? 1008 hrs

[wagskis2]

Some smoke and blowby out of the breather is normal on a higher hour engine-My 1999/330 hp with 900 hours has a little bit. If you have a distributer ignition, like the previous reply-start with the easy one-check that on TDC the rotor points to #1 to eliminate timing chain-though if it was off, all cylinders would be low or misfiring.
Broken rings would cause low compression, but since one is zero-hopefully it's a head gasket, especially since it's the adjacent cylinders that are low. The best way to check is a cylinder leakdown tester-that's where you are putting compressed air in the spark plug hole through a test gauge. You'll definitely hear air hissing from either the oil fill or intake/exhaust-or outside the motor, which will tell you which direction to head.
If it's a head gasket, which it sounds like, be sure to have the cylinder head crack checked and surfaced.

[wagskis2]

A little blowby out of the breather is normal on a higher hour engine. My Prostar/330 with 900 hours has a little bit. The easy check of distributer at TDC is a good place to start, but since #4 cylinder is at 0 and the two adjacent are at 30 psi, it's my bet you have a head gasket issue. The best way to check is with a cylinder leakdown tester-putting compressed air in the spark plug hole through a test gauge at TDC of compression stroke-you'll hear air hissing through the oil fill, intake or exhaust-or outside the motor, which will steer you in the direction you need to go.
If it is a gasket, be sure to have the head crack checked and surfaced. Good luck.
I grew up near Kankakee; just about got run over by a barge learning to water ski at age 13!

[thatsmrmastercraft]

If you don't have a leak-down tester, a quick check can be performed by bringing each cylinder to the top of the compression stroke and using an air nozzle in the spark plug hole and listen for air escaping. Won't find the small problems but will locate the big ones.

[TOO-TALL]

Can I rent a leak down tester?..also when I pulled the plugs for the compression test they were clean no metal debris on them.some were wet with fuel others were dry...???

[Rockman]

Troy,

Sorry to hear about the motor.

Need to get a fresh brew of the apple cider done asap to keep your mind off the boat for now.

[scott023]

Sorry to hear this Troy.

[thatsmrmastercraft]

Originally Posted by TOO-TALL

Can I rent a leak down tester?..also when I pulled the plugs for the compression test they were clean no metal debris on them.some were wet with fuel others were dry...???

Try your local AutoZone or O'Reillys.

[oldairboater]

It will not change ring and piston issues. It would be a quick easy check of the timing chain. Others have said do a leak down which is a good check. I would skip that if I find the timing near to correct. By pulling heads and intake I get a visual of the pistons, cylinder walls, and valves, and head gasket. Cracked heads and cylinder walls show up when exposed to air and moisture quickly once the oil is wiped off of them. No need to magnaflux. If engine has more issues then head gaskets it will show. If I had to pull the engine then I have lightened the block already. Any overhaul I would do would involve pulling the engine anyway. The choices I would be looking at is how much is salvageable. Just the way I have done things in the past a lot of times.

Originally Posted by CantRepeat

I don't understand how this would change if it was a piston/ring issue?

With smoke coming out of the breathers it sounds like a ring and piston issue.

[oldairboater]

Not sure how to word this. A 900 plus hour engine has seen good use and could see more good use. Once it develops a serious problem instead of looking at it as a disaster. I see it as an opportunity to build my own stronger, more dependable, almost bullet proof engine. I have a 351 in my boat. It is a great engine but there are inherent weaknesses in that engine that I would eliminate or diminish when I do a rebuild or install. 351's have potential for more and with the right builder and parts you don't have to sacrifice dependability if you build smart. Several members here have already demonstrated that before losing races.

[EricB]

A Cylinder Leakage Tester (CLT) will help you determine where the problems lie. Regulated air into each cylinder will show where the leakage is. If it is valves, you will hear air escaping in the intake or exhaust. If it is a head gasket or crack adjacent to cylinders, you will hear air escaping to the other cylinder.
The real point of the test (and doing it) is to identify where the problems are before you take it apart. Spend some time testing and diagnosing so you know what it is (and what it is not). Test-don't guess.