still getting gas in oil

[daveid]

hey guys,

As you guys probly already know,I have a High performance 454 chevy engine with 10:1 compression, a 292 dur cam with a 590 exh lift, open plane manifold and a 4150hp 750 holley carb, and a 280 gph electric fuel pump.
My problem is ever since i moved up to the 4000ft altitude i have been gassing out my oil pan in only driving about 10-15 miles. I had my carb professionally rebuild and put on a wet flow bench and jetted with 73 primaries and 84 secondaries. My vacuum at idle in drive is 5hg and i know i should have 2.5 powervalves, which i did have but they put 4.5's back in.
Anyways, im lost on what to look for next, i drove my truck around sea level for about 200 miles and never had the problem and then moved up here and have had the problem since.
My plugs also are black within about 10 miles too.

I also only have the electric fuel pump, there is no std pump on there and it has a block off plate on it.

Any suggestions?
thanx,
david

[MrPbody]

David,
Do you have a pressure guage and regulator? Many electric pumps can override the needle and seat instantly. 7 lbs. is enough for most Holley applications.
Did you talk to John about it?

Jim

[daveid]

hey jim,
I talked to one of the head guys there, (not john) and he said he thought it was the rings in the engine. ya i have the reg set up and then in between the reg and the carb is the gauge and i have it set at 5 psi.

thanx,
david

[MrPbody]

David,

Well, that vacuum at idle number is pretty low, even for such a cam. I suppose it's possible the power valve is staying open, dumping the excess fuel into the intake.

Can you do a leakage test on your cylinders? A compression test may or may not find any issues. The leakage test will "nail" it.

Jim

[daveid]

Ill try to get that tool for it. I dont know anything about them, but ill try to get one. Also, for the power valve, Ive been through like 5 different power valves and sizes and all still the same.

thanx
david

[daveid]

hmm... didnt know id need an air compressor. Lol, been hoping to get one for christmas. Anyways, I hoping it will be a doable task for me and be able to get equitment soon.

david

[daveid]

hey jim,
DO you think it could be a vacuum leak? Should i check for one before buying the leak down tester?

[MrPbody]

David,

A vacuum leak will typically create a lean condition, rather than a rich one. I doubt it.

Jim