I have noticed my car running a little weird so i did a compression test and ...
cyl.#1- 185
cyl.#2- 185
cyl.#3- 225
cyl.#4- 220
heres the thing the spark plugs on cyl. 3+4 have a dark color ( the insulator and the iridium tip) my exaust smells like maybe unburned fuel or oil.what would you think this is? by the way it has a fresh valve job , y8 head gasket, fuel press. at 38 at idle, timing is adv. 2degrees, I personally thought it was pistons 3,4 blowing by, but hell who knows, could be the head gasket!!!!

 

maybe the head gasket around cylinder #1 & 2... or rings..?

 

the #'s are nice and high, but the variance is ehh. since you have low compression between 1 &2 cylindars and not 3 and 4 i would be lead to believe there might be something up with the headgasket between the 2 low cylindars

 

try putting a little bit of oil in cylinder #1 and 2 so see if compression goes up. If it does, well you know whats wrong.
If not do a leak down test, that will pinpoint the problem.

 

well if you think its 1+2 w/ the leak I would have thought that it was 3+4 because the plugs had a slight touch of oil or something on them every time i pull them out. plugs 1+2 are clean, man I think its fixin' to get forged pistons total seal rings , polished crank , that should fix it...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gloryhog &raquo;</TD></TR><TR><TD CLASS="quote">well if you think its 1+2 w/ the leak I would have thought that it was 3+4 because the plugs had a slight touch of oil or something on them every time i pull them out. plugs 1+2 are clean, man I think its fixin' to get forged pistons total seal rings , polished crank , that should fix it...</TD></TR></TABLE>

I don't see how a polished crank could effect compression (hint: sarcasm), but everything else .

 

the polished crank was something i was going to do while i was building the bottom end , so there would be no chance of it snagging a bearing , I have heard that many people do this on high reving motors. your right though it has nothing to do w/ the comp.

 

I DID ANOTHER COMP. TEST TONIGHT AND THE NUMBERS WERE MUCH BETTER
CYL# 1 - 200
CYL# 2 - 210
CYL# 3 - 220
CYL# 4 - 220
I DID NOTICE THAT THERE WAS A BLACK SCORCHED SPOT ON SPARK PLUG NUMBER 4 IT WAS VERY SMALL BUT i THINK IM RUNNIN KINDA LEAN.