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Zero compression in one cylinder head is off drum roll please

A

aquakenbush

Contributing Member
"So I posted last year for a m

"So I posted last year for a miss I was having at high RPM when the starboard engine was under stress, I troubleshooted my brains out until I pulled out the compression tester. I found a cylinder with 0 compression. The boat ran ok if I didnt beat it or have 5 large people on it so I ran it the rest of the season like that thinking it had a dirty exhaust valve or something. Now the mechanic has the head off and low and behold the piston has a hole in it! I am lucky I didnt grenade the motor as I ran it probably 40 hours like that. The mechanic is saying I need a long block... I havent seen it yet but I am going to have a look tomorrow. Do I need a long block? Is it not worth fixing?
My brother also suggested if I am replacing one motor I might as well do both... I figure 3kish for one 6kish for two. I also want to sell the boat and move up soon. Is it worth replacing both when one is fine (900hrs)I dont want to put more money into it if I am just going to sell it?? He says it will sell better??

I am running twin VP 432a's.

Your opinions please
"
 
2300$ for long block
1500-200

2300$ for long block
1500-2000$ for re&re
100$ for bits and pieces
+tax
Looking like around 5000$

I think I will stick with just replacing one...
 
"If the only thing wrong is ju

"If the only thing wrong is just that piston, and the engine is not worn out, then just replace that piston. You can ridge ream and hone just that cylinder and drop in the new piston. I did this on one of my engines, it took a weekend and the engine lasted 8 years until I decided to rebuild the whole thing. This will be much cheaper than a long block. And I definitely wouldn't replace a good engine unless you are made of money..."
 
"Do you want a motor that’s go

"Do you want a motor that’s going to work right or do you want to patch it together? What was the compression on the other cylinders? What was the leak down? And how much an hour are you paying your mechanic? Are you willing to rebuild it yourself? Do you have the tools and time to do it yourself? And how bad are the cylinder walls?

I you just want to patch it together, you should replace the piston yourself. Your mechanic will not want to do this, nor should he. Your goal at this point will be cheap cheap cheap. Because the cost constraint Pressure the owner puts on the mechanic at this point the mechanic will not have time to to check all of the internal motor specifications, as a rebuild shop will. To do a proper rebuild your mechanic will check specifications on everything. Cylinder out of round, bore diameter, bearing oil tolerances valve lapping, ect. And you don’t just check the bad cylinder, You check the whole motor. If you chose to have your mechanic replace the piston, and also check specifications on all internals, at the industry rate of $80/hour, your mechanic is quickly going to out price the remanufactured motor. A rebuilder can do it cheaper because that’s all he does. He’s allot faster at it and knows all of the specifications in his head.


It comes down to this if you want to do it right have a rebuilt motor put in with a warranty. If you’ve got time and patience go out buy the service manual and rebuild it yourself check everything, and you’ll find allot of stuff is out of specifications. And you’ll get to know your motor, there’s allot to be said about that.

good luck,
Kevin
Deep Blue Marine Repair LLC
San Diego, CA"
 
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