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Testing Compression

MadRiver

Jedi Knight
Bronze
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Howdy gang!

Well, I've got the head off the MGC, and it did indeed have a blown engine gasket. No worries there. Easy to fix.

Now, here's my next question about compression. Since I've got the head off, I decided to test for leakdown issues. I poured some gasoline into each cylinder, and let it sit for about ten minutes or so. In that time, all were a bit lower, but couple of cylinders drained lower than the others, and in about twenty minutes, a couple of them had run dry.

This is the first time I've done that kind of test. Does the fact that two cylinders didn't hold the petrol for twenty minutes mean that new rings are in my future?

Thanks!

B.
 
Typically, a cylinder leak down test is completed with a leak down test kit, along with regulated compressed air thats introduced to the cylinders through a spark plug hole.

If you suspect that you mean have worn rings, you could check each cylinders bore with a telescoping gauge and a micrometer as well as feeling for a ridge on top of each cylinder.

You could always put a new head gasket on and do a proper leak down test or even a wet and dry compression test.

Hope this helps.
 
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