Need some help-crate problems
Thread Starter
Racer
Joined: Nov 2006
Posts: 495
Likes: 1
From: Lubbock TX
Need some help-crate problems
I recently swapped a year one 350 into my 75. I went through the break in that they suggested and went even further just to make sure. The problem is that a little oil seeps out of the valve cover bolts under acceleration. Its not much but it will pool at the back.
It just barely seeps out like a mist. I have tightened them a couple times but i dont want to go any tighter. My pcv has pretty good vacuum 12-13". i hear it working, but when i hold my hand over he oil fill hole there is positive pressure, even at idle.
I sure hope somethin didnt go wrong with the rings at breakin. What is the best way to check this.
If something did go wrong, will this be covered under the warranty thatcomes with the engine?
Thanks,
Sean
It just barely seeps out like a mist. I have tightened them a couple times but i dont want to go any tighter. My pcv has pretty good vacuum 12-13". i hear it working, but when i hold my hand over he oil fill hole there is positive pressure, even at idle.
I sure hope somethin didnt go wrong with the rings at breakin. What is the best way to check this.
If something did go wrong, will this be covered under the warranty thatcomes with the engine?
Thanks,
Sean
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Something is wrong with your PVC. There should never be positive press in the crankcase, lifter valley, vlv train (vlv covers). The PCV is designed to regulate the crankcase vacuum (less than atmospheric press) the full range of engine load & rpm. PCV will open more for higher intake flow and act as a check vlv if intake is pressurized by back fire.
Could be your PCV dosen't match your big cam with lower vacuum. Or maybe the PCV is broken/stuck.
Do u have it connected to a good vacuum source on the intake? Maybe try a different PCV like one designed for one of the LTI hi-po engines ('69-'71), or even a hi-po big block PCV.
Also maybe some rubber gaskets under the bolts may help seal the bolts. I recall the GM bolt set for Vortec vlv covers comes with seals for this.
Hope this helps ya',
cardo0
Could be your PCV dosen't match your big cam with lower vacuum. Or maybe the PCV is broken/stuck.
Do u have it connected to a good vacuum source on the intake? Maybe try a different PCV like one designed for one of the LTI hi-po engines ('69-'71), or even a hi-po big block PCV.Also maybe some rubber gaskets under the bolts may help seal the bolts. I recall the GM bolt set for Vortec vlv covers comes with seals for this.
Hope this helps ya',
cardo0
Thread Starter
Racer
Joined: Nov 2006
Posts: 495
Likes: 1
From: Lubbock TX
I have the pcv hooked up to the largest port on the front of my q jet.
Wouldnt blow-by cause a lot of positve pressure inside the engine?
I'll go to autozone and pick up a different pcv and see if it helps. I am using the one that yearone suggested.
Sean
Wouldnt blow-by cause a lot of positve pressure inside the engine?
I'll go to autozone and pick up a different pcv and see if it helps. I am using the one that yearone suggested.
Sean
Racer
Joined: Feb 2008
Posts: 497
Likes: 0
From: Streator Illinois
You said you followed break-in procedures but you didn't say how many miles you have on the engine. Some rings like chrome need more time to seat - maybe a few thousand miles in some cases. Assuming the engine is really broken in and IF indeed your PCV is working properly, ie, allowing vacuum to be drawn through by the engine, AND there is still pressure coming out of the oil fill hole, then yes, there is a good possibility of an engine problem like blowby past the rings or some other reason that something is causing the crankcase to be pressurized. If it were mine, I'd do a compresssion test of all cylinders and then contact the manufacturer or distributor.
Terry
Terry
Last edited by tnovot; Aug 31, 2008 at 04:47 PM.
Thread Starter
Racer
Joined: Nov 2006
Posts: 495
Likes: 1
From: Lubbock TX
I have about 200 miles on the engine. I'll keep driving and see if it gets any better. I better get busy since the warranty is 1 year.
Tomorrow i will rent a compression tester and check it out. It sure would suck to have to swap again.
thanks,
Sean
Tomorrow i will rent a compression tester and check it out. It sure would suck to have to swap again.
thanks,
Sean
