Hello all,
As some of you might remember I worked on a 1600 a couple years ago that
had the head shaved a couple of time to many. I ended up putting two head
gaskets in it. Worked pretty well for a couple of years. I had retorqued the
head bolts at 500 miles but when I pulled the head a couple days ago the bolts
seemed a bit loose. Most likely settled a bit more and should have been
torqued again at a thousand or so. Anyway I decided to go ahead and reshape
the
combustion chambers and get rid of the second head gasket. Here is what I did.
Removed the head and gaskets. Scraped the carbon from the head and pistons.
Using the gasket as a guide, mark the edge of the combustion chambers on the
head. Machinist layout dye on the face helps. Set 1 and 4 pistons a bit before
TDC. Rubbed oil on the tops of 1 and 4 pistons. Set the head in place and
loosely installed a couple head bolts to locate the head. Turned the engine
till
the pistons just touched the head. Pull the head off and where the oil
transferred to the head ground it down with a sandpaper flap wheel in the die
grinder. Make sure to not grind outside the line you drew with the gasket.
After
putting the head on and off the engine about a fifty times the combustion
chambers matched the piston profile. Then turned the crank 180 degrees and did
the same thing with 2 and 3 cylinders. What you end up doing is removing metal
from the squish band area, the shelf next to where the valve pocket area is.
Once it is profiled to match the pistons with no head gasket adding the
gasket will give it the proper clearance.
I've done this to a couple of heads and so far it seems to work fine. A
nice new uncut head is of course the best answer but those are getting harder
to find all the time.
keith"roadstersize muscle building workout"williams
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