Thread: Crank Case Ventilation fully explained. (Naturally aspirated edition.)

Awesome write-up. I cast a second vote for sticky! That is unless it is already, (I didn't notice).

Quick question. Can a faulty PCV/system cause an excessive amount of fuel to enter the oil and how do you perform a check on the PCV? Thanks "a lot."

Yah it's already a sticky. =]

A faulty PCV system can increase blow-by which will increase the amount of fuel entering the oil. Whether or not it is "excessive" might be up for debate. It will contribute to that problem though, yes.

To perform a true check on the PCV valve you need to remove it from the valve cover and feed air through the valve cover side of the valve and make sure it passes air through it. Then you need to pressurize the other side and make sure it blocks flow from that direction after experiencing 0.5 - 3 psi.

I've added another good idea for crank case ventilation mods to the first page.
This method involves using a venturi effect in the exhaust to evacuate the crank case.

You will want to make sure you don't have any O2 sensors downstream of the venturi pipe and while catalytic converters might not mind the oil too much, I can't be 100% sure of that. This design likely won't pass modern emissions.

Read about it and see fancy pictures here:
Emissions and Crankcase Ventilation - Exhasut Scavenging

Love this idea, why not use what's already there. Goes along the lines of using a turbo

Yah it's a real elegant solution that's sort of been forgotten (and not used anymore by manufacturers due to emissions).

Ordered a kit, if anyone else is interested it is Crankcase Evacuation Kit, they have plenty of the kits for sale on the web and on eBay.

A faulty PCV system can increase blow-by which will increase the amount of fuel entering the oil. Whether or not it is "excessive" might be up for debate. It will contribute to that problem though, yes.

Well, it's not terribly excessive but when I broke the seal on the valve cover the gas smell was pretty strong and the oil was thinner than it should be. Thanks for the write-up and help!

Ben can you recommend a setup for my roller rocker sr20, ideally i wanna keep most if not all of the blow by gas from the intake, is there a vac pump you can recommend?

Mongo I can't recommend any right now. I haven't looked into them much. However it sounds like Autech is pretty familiar with them. Autech, can you recommend any air pumps for this use?

ive alwasy sourced locally from distributors here.

The ones we use are moroso and are about 1/2 ratio drive off the crank.

Its not the cheapest of setups, i thik with all earls fittings, a descent breathing tank and pulleys its close to 800 to setup properly.