This has been an ongoing process for me and I have two fairly recent threads covering some of my issues (excessive smoking -
http://www.peachparts.com/shopforum/showthread.php?t=171662) and head replacement questions (
http://www.peachparts.com/shopforum/showthread.php?t=172367).
I think I finally did a compression and leakdown test correctly this morning - car at operating temp, WOT, etc.). Results for the compression test are as follows after removing all plugs and cranking the engine a few times to clear out the cylinders:
Cyl 1 - 150 psi
Cyl 2 - 140 psi
Cyl 3 - 150 psi
Cyl 4 - 120 psi (first test), 130 psi (second test)
Cyl 5 - 150 psi
Cyl 6 - 150 psi
I used a Milton Cylinder Leakage tester (picture below). Used 100 psi to pressurize each cylinder, each cylinder at TDC on compression and all cylinders showed 20% or less than 20% leakage (see picture), except for cylinder 4 which was right around 40% (start of the yellow, moderate range). No coolant bubbles, no leaky exhaust valves or intake valves (except maybe for cylinder 4 where I heard a little leaking in the rear carb - so I'm thinking maybe a valve needs adjusting). All hissing noise is heard from the oil dipstick tube and the oil filler in the valve cover for all cylinders, which according to the leakdown tester instructions is normal - it just depends on how much leakage is evident.
According to my manuals, normal compression is between 142 and 156 psi, with 120 psi being the minimum and 22 psi the maximum variation between cylinders.
My initial reaction is that these readings don't explain my smoking problem - and these numbers are not that bad. Cylinder 4 is a problem (a wet compression test raised compression from 130 to 150 psi, but it did not affect the cylinder leakdown test results). Am I correct in this assumption?
I really don't know what is going on now, but as I mentioned in an earlier thread I have a seriously leaking intake manifold and it seems that when I spray carb cleaner in the leak - with the car idling- it affects the smoke from the tailpipe. Is there any way that this leak could be contributing to my smoke?
Any help would be appreciated - I have been in the process of buying a new head, camshaft and towers and was thinking of pulling the head, but I'm not so sure I need to do that now???
Ryan