Guys,

I just ran a compression test on my mild 440. Compression ratio unknown, can supply cam specs if needed.

Tests were done "dry" and "cold":

#1 - 175 to 180
#3 - 175 to 180
#5 - 180 to 185
#7 - 185 to 195; builds compression quickly compared to the others; white smoke from exhaust port
#2 - 160
#4 - 150
#6 - 150 to 155
#8 - 170

Car is down on power (99mph from 101-102mph) after an overheating event (I am paying the stupid tax now). I am hoping it is worn valve seals/guides (smokes pretty bad on startup and uses a ton of oil) and not the piston rings.

I am planning a leak down test.

Any insights from the above information?

Thanks.

Greg

To me the #'s dont look good (too much variation) plus the white smoke from #7. Did it smoke/use oil like that b 4 it overheated? I would suspect the rings and maybe gasket issue (the white sm). I'd pump it up to 15 lbs w the Stant rad pump & let it sit. Holler what it ends up being

The adv of the Stant pump is it'll tell you if coolant is leaking in (or out) as opposed to a leakdown which'll tell you what % of cyl psi is leaking out which maybe a combo of rings/valves/gasket. Not sure I'd buy a new one but I got one at a sale cheap & it does come in handy once in a while esp for checking cooling system integrity b 4 adding coolant & w you the white smoke worries me

Okay, thanks.

BTW, the smoke looked white, it was hard to tell. The car doesn't use any coolant.

My big thing is being to tell if the rings are okay or not. Dealing with bad heads = easy, dealing with bad rings = hard!

On a fresh battery recheck the low cylinders again. If low again, squirt some wd 40 in the hole and run the numbers again.
IMO 30 psi is significant. And the cylinders are adjoined.
well let me put it this way, If ity was my engine, I would be disappointed in those numbers, and would be looking for a root cause.
But I like things to be just so..