View Single Post
  #8 (permalink)  
Old 12-27-2016, 04:23 PM
Texasdoc's Avatar
Texasdoc Texasdoc is offline
CC Member
Visit my Photo Gallery

Join Date: Feb 2012
Location: Keller, TX
Cobra Make, Engine: Lonestar Classics LS427. Self-built 408W, AFR 195 heads, Performer RPM Intake, Quick Fuel 750, 407rwhp, 479rwtq
Posts: 528
Not Ranked     

I did a compression test two months ago and all were around 180 +/-. A leak down test showed one cylinder <5% (cylinder #7 that had the broken spring) and the rest <3% leak down.

So, either the intake gasket is pulling up oil into the runners from the lifter valley, the rocker studs are draining down from the top of the heads, or the valve guides/seals aren't working. I checked and replaced the intake gaskets a few months ago. I sealed the intake rocker studs when I installed them. So, unless I'm missing something, it must be the seals or guides.

I'll take the heads to the machine shop for inspection next week.

Any other thoughts? Am I missing something else?

Last edited by Texasdoc; 12-28-2016 at 09:49 PM..
Reply With Quote