[Shotimes] Oil blow-by?

[Leigh Smith]

I'd certainly check all the things everyone mentioned, but it is also
possible the rings are just getting tired by now. You didn't mention
mileage, but I'll assume it's 100k or more by now.
Old solid lifter "musclecar" engines had a serious problem with blow-by,
even when brand new and properly blue-printed, because the pistons were
forged and installed so "loose". They would literally puff smoke from the
valve cover fill cap if you opened it and disconnected the PCV. The SHO is
built MUCH tighter, but with those miles your rings are still well worn. To
check, pull the PCV hose, and vent hose, and open the oil fill cap, and see
how much smoke or puffing you get. None would be ideal. Put the PCV hose
back on. Make sure the hose itself pulls a vacuum. Then hold your hand over
the cap opening and check to see if the system can pull a vacuum thru the
crankcase while the engine is running.
Blue smoke that only appears at full throttle means the same thing.
A more sophisticated test would include a leak-down tester.
Race cars run vacuum hoses from the header collectors to get big vacuum
readings inside the crankcase, even at full throttle.
I remeber tests where that alone was worth 20HP.
Lee
----- Original Message ----- 
From: "Mark Mucher" <mmucher@bellsouth.net>
To: "'Shotimes@Autox. Team. Net'" <shotimes@autox.team.net>
Sent: Wednesday, June 16, 2004 8:58 AM
Subject: [Shotimes] Oil blow-by?


> I posted this on TechSHO but didn't get any bites...
>
>
> My "new" '90 has some damp oil spots on the top of the engine
>
> One area is to the left of the filler cap and another is towards the front
> of the throttle body on the intake joint.
>
> It kinda looks like the crankcase is not venting properly.
>
> Any ideas?
>
> (pix available)
>
> Thanks,
>
> Mark
>
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