View Full Version : Close Shave

11-29-2006, 10:54 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, 12:51 PM

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"

12-03-2006, 01:43 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."

12-04-2006, 06:11 AM
"Good advice, Jim, for one of those cylinders has a bunch higher compression ratio than the others.


12-04-2006, 09:28 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.

12-04-2006, 11:31 PM
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.

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

12-05-2006, 05:58 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.)"

12-05-2006, 06:37 PM
"You want the ones that are like Scotch Brite, not coarse sandpaper."