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1993_yamaha_stern_130
11-29-2006, 11:54 PM
"After discovering water in the oil of my 3.0 litre GM engine, I brought the cylinder head to a machine shop. They found that it was warped 0.012 inches. They shaved 0.015 inchs off to create a perfectly flat surface.

Do you think that taking this much metal off will have any impact on the running of my engine ? If yes, what should I do about it ?

Thank you for providing your own experience, opinion, and suggestions!"

Capt William Myers
12-03-2006, 01:51 PM
"Jim

To get more speed out of engine we used to shave the heads to bump up the compression. I see no negative attached to this situation. It should run just fine, and perhaps better then a stock engine. ANd you should be free from head gasket problems. Don't worry about it enjoy the boat"

jimn
12-03-2006, 02:43 PM
".015" is quite a bit but not necessarily going to be a problem, just make sure the spark isn't advanced too much and listen for detonation."

fastjeff
12-04-2006, 07:11 AM
"Good advice, Jim, for one of those cylinders has a bunch higher compression ratio than the others.

Jeff"

1993_yamaha_stern_130
12-04-2006, 10:28 PM
With all due respect to Jeff and Jim - I like Capt's the best !

Now if I can just clean the top of the block without scraping it ... perhaps a brass brush.

linesix
12-05-2006, 12:31 AM
3M Roloc discs are by far the best tool for this job. They will remove any foreign material without removing any metal from the block.

jimn
12-05-2006, 01:01 AM
"The brown discs, not the green ones with the abrasive."

1993_yamaha_stern_130
12-05-2006, 06:58 PM
"Brown 3M Roloc Disks - got it!

I was concerned that disks might drop some grit that would drop into the pistons. (Even with towels and tape, stuff can drop into the cylinder.)"

jimn
12-05-2006, 07:37 PM
"You want the ones that are like Scotch Brite, not coarse sandpaper."