Page 1 of 1

Funky compression results

Posted: Sun Oct 27, 2019 6:07 am
by i_am_cool_fred
So, for a little background. 2316 build 80mm dpr crank webcam 86a grind, kB 96mm pistons in stock cut cylinders. So. Had motor in car, ran fairly decent. Then one day poof runs like crap got to hot. Got it home, had wifey crank on it and noticed smoke around base of intake on #1 compression results said something was wrong with number one. Took motor down, found compression leak at head, lapped cylinders, rechecked deck height, found the other issue (extra shim, stupidest of stupid mistakes) fixed back together ran compression.

Here’s where the question arises. Compression results are consistent but funky. #1-110 #2-125 #3-110 #4-125. Yes flywheel side is consistently 15lbs weaker than pulley side. Checked valve adjustment, checked cam lift all check good. What else should I check?????? Any insight would be appreciated cause I don’t want to have to pull this motor out of this beetle again. It was running great till the compression thing and I want to get it back to that point!!

Thanks in advance!!
-Brian

Re: Funky compression results

Posted: Mon Oct 28, 2019 10:59 am
by Clatter
A leakdown tester will tell you a lot.

Even a wet/dry with your regular tester might at least tell you where the issue is.

No matter what, if the thing was run with a crooked deck,
It should probably come back apart to have the decks trued up.

Maybe a temporary patch thing might be to run it for a bit and get it hot,
Then re-torque the heads and rockers and re-do the valve adjustment.

Maybe you'll get it to take a 'set' back into shape?
Kind of hack-ey, but it might help straighten things a tad before you take it apart and have the heads decked,
(and maybe the case too).

I'm guessing things are going to be pretty roached being run with an odd set of shims..

Re: Funky compression results

Posted: Mon Oct 28, 2019 2:18 pm
by wreck
Did you check the deck heights and CC the combustion chambers before you assembled the engine ?