PCV or via the exhaust pipes?

My son is running them on his pro-street 66 Malibu. It has a Chev 350 built for a blower, 671 blower and headers with 2” primaries into a 4” exhaust system. Finding flexible tubing that will last very long on the header collector probes has been a challenge. He had to use them because of the blower but after his experience I wouldn’t run them on a car that makes intake vacuum and can use a simple PCV valve.

Mike

Yes you need to evacuate your crankcase, otherwise it pressurizes and blows oil out the filters, and the crankcase fills with corrosive blow-by. A PCV system extends the life of a motor tremendously.

Those exhaust "aspirator" systems, like the one manufactured by Moroso, do not last very long. They're OK for a trailered race car, but not a street driven vehicle. If you used one you would be replacing it continuously.

They guys operating their race motors with the crankcases under a vacuum are utilizing a dry sump lubrication system. You do not want to create a high vacuum in the crankcase with a wet sump lubrication system, as the pump cannot draw oil from the oil pan if the crankcase is under vacuum. You must have one crankcase connection to a vacuum source to remove blow-by, and a second crankcase connection that allows filtered air to enter and replace the contaminated air removed by the vacuum source. The filtered air connection will prevent an excessive vacuum from building up.

Millions of people drive cars with engines equipped with a PCV system, without worry, without problems. If the oil is kept fresh, a simple, inexpensive PCV valve can easily last 100,000 miles without becoming sticky. Just make sure to connect the PCV system to a connection that feeds the air drawn from the crankcase to all 8 cylinders evenly, and not to a connection that favors only one or two cylinders (connections like that are intended for the power brake booster).

-G

I'm going to install the crankcase evac system as well. As I have an IR intake, I will be going with a Milidon system. That Mildon kit has a check valve in it, doesn't it? Do I need to install it with a check valve? If I install it angled on the exhaust, there should always be a vacuum, no?
The system in the link also uses hose connections. I want to use braided AN line, so I'd like to just make up my own system without the check valves, if that is OK.
Will

Will, a suggestion.

Install an 8 port tubing manifold BELOW your motor's IR intake manifold, plumb one 1/8" tube between each runner and the 8 port tubing manifold, and connect the 8 port tubing manifold to a PCV valve.

The picture is a hidden nitrous manifold, but it gives you an idea what I'm talking about.

-G

OK George. Now you've got me going. Forget the PCV valve...I want nitrous.
Really, whats the deal? Is it as nasty as they say? Can it be used and still allow an engine to last?
Will

quote:

Originally posted by 4NHOTROD:
... I want nitrous ...

sounds like a good topic for a new thread. lets not take Mikael's thread off topic.

-G

Nice hi-jack

20 years ago I had Denmark's perhaps first N2O installed in my 68 Camaro, did surprise a lot of people. Once blew a head gasket 400 miles from home, other than that no problems in the 4 years I raced it. Modern systems are even safer.

Hi-jacked my own thread. Because I'll go with Cowboy from Hell's first posting, I'll install PCV to a common vacuum source.