I have have received several suggestions about what could be causing
the low compression in cyl. #2 and #3 in my 77 Midget. These
causes could be:
1. Worn rings.
2. Blown head gasket.
3. Burned/leaking valves.
4. All of the above.
The only way to really tell is to run a leak-down test. I gave
it a quick try tonight and I have some questions. The basic
idea is to charge the cylinder with air and see how fast it leaks
out. I am also supposed to listen at the tail pipe and carb. for
leaking valves, listen at the dipstick for worn rings, listen
in adjacent cylinders or look for bubble coming from the
radiator for a blown head gasket. I think that covers most things.
I tried the above but my connection at the spark plug hole was leaking
and it made too much noise to hear other leaks (I think). So now
I have the following questions.
1. How many PSI should I charge the cylinder to? (I used ~40 PSI)
2. How fast should the air leak out?
3. Will the volume of the cylinder affect this? If show how do
I figure in the location of the piston in the cylinder?
I am going to try a leak-down test to see if I can identify the
problems. I will then pull the head and look at the head gasket. If
it is blown I will just replace the head gasket and then run another
compression check. If the head gasket is blown how will I tell? Will
be obvious even to me :-)
That's about it for tonight. Thanks for the help.
-----
Bill Gilroy
77 Midget
wmgilroy@lucent.com
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