Ford Muscle Cars Tech Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
52 Posts
Discussion Starter · #1 ·
Got a 351 with GT40 heads, mild cam, Edelbrock carb. I had FMS valve covers with dual breathers but had to install stock 5.0 covers. With only the PCV system it would blow oil out dipstick anytime oil cap was on. Had to install breather instead of oil cap to stop it.
Did a complete leak down test with air regulator at 90psi, pistons and TDC and the with guage attached to spark plug hole adapter i only got down to 85psi on 2 cylinders.
Im thinkink maybe using a exhaust venturi system to vent crankcase.
Can anyone think why its got so much or what im doing wrong with vent system. Im thinking it would be better to move the breather cap to opposite side as PCV but other than that Im lost
 

·
Banned
Joined
·
2,833 Posts
Either your rings are bad or valve guides letting to much pressure into the system. PCVshould handle it.
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #4 ·
"Either your rings are bad or valve guides letting to much pressure into the system. PCVshould handle it"
what did I do wrong on the leak down test then?
 

·
Registered
Joined
·
5,551 Posts
On 2006-06-05 21:46, alanmacdougall wrote:
I would put the breather on one side and the pvc on the other.
Would that not be like having a vacuum leak?
 

·
Registered
Joined
·
2,251 Posts
I tried that in the Hemieater and it still blows the dipstick out. Never tried to fix it I thought that i needed to put some miles on it to seat the rings.
 

·
Registered
Joined
·
3,658 Posts
mavman, most of the systems I've seen have a breather on one side and PVC on the other.

I guess it's a controlled vaccuum leak.
 
1 - 8 of 8 Posts
Top