318 - intake vacuum leaking
Has anyone had an intake vacuum leak (oil being sucked thru ports from poor sealing) due to shaved heads?
74’ basically stock 318
Heads shaved .100”
Edelbrock LD340
will that much throw the angle of the intake to head angles off and open up lower side to oil in lifter galley?
“why did I shave .100” off the heads?”
Replaced steel shim head gaskets 0.017”with the fel-pro blue 0.040” gaskets and tried to raise compression in the process up from the crappy factory 1974 specs 8.1
with all that said- what intake gaskets will fill the gaps to seal ports (intake to heads) because all signs point to that is my oil issue. Fel-pro makes a std gasket 0.060” or a special gasket 0.120”- I’m just not familiar with using thicker gaskets for this situation.
Syleng1
To my knowledge the factory steel shim is .019-.021. Call it .020..lol splitting hairs right...
So you milled .100 and added .026 by means of a .046 crushed pt8553 gasket.
So the head is sitting roughly .074 lower than it was...if trusting the .100 milled part.
One way you could have a vac or oil leak is if the The Machinist didn't set the head up right on The Jig when Milling it. A lot of guys don't do the old scratch test. You mount your head up on the jig... you get your levels out n you check it make sure it's level catty-corner across and long ways...then crank it down TIGHT and check it again...then you dial the cutter head up to clear the deck by a visual amount and move it over the end of the deck surface of the head...then you then spin the cutter by hand and slowly dial the cutter down till it just scratches the head...now with it hand spinning still... you move the cutter across the deck while watching the scratch width..it wants to be even...wrong will look like 'narrow to wide' as it goes across... and as the same end to end...it needs to be even ...this makes damn sure you are making a level cut and not deviating from the factory angle. I always do that, checking your level accuracy and beyond any margin of error.
Not all machines are the same, some do it digitally. I started with the machinist 1st because you stated you had him mill .100
With that said, it could only leak if A.. he deviated on the cut..so the angles are off. B... The intake is tapered or ootb incorrect angle-Common on those.
Or C... you used the metal gaskets on the aluminum ld340 and that's a leaker every time. Been there done that and bought the t shirt. It's almost a prerequisite. Lol
Like mentioned, look close with light under it or behind it to see if the angles are off.
Also keep in mind many use thick gaskets..and the gasket can eat .025 worth of gap on the bottom..so they never know.
Pics?
