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View Full Version : Crankcase evacuation system

STEVEB
04-20-2007, 05:37 PM
Will a crankcase evac system work on a car using mufflers? the car is an'85 Mustang with a 351C running a 3" exhaust that dumps at the rear axle.This is not a vacum pump style but the old one way valve at the header style.
JeffMcKC
04-20-2007, 05:55 PM
Yes it will, but behind the muffler so it does not oil up
Kelly Burns
04-20-2007, 06:57 PM
Yes it will, but behind the muffler so it does not oil up

Please explain...
JeffMcKC
04-20-2007, 07:56 PM
There is oil vapor in the air being pulled, it will settle in the muffler, there it pools if you get enough heat well you get the idea. I have not seen it but heard bad stories of trailer fires on the way home, no doubt it was burning when they shut it off.
GUMP
04-20-2007, 09:58 PM
AT WHAT POINT IS IT TIME FOR AN EVAC. SYS.=RING SIZE/TYPE, RPM?
JeffMcKC
04-20-2007, 11:24 PM
You should always have some sort on your car, you dont want pressure in the crankcase pushing gaskets out, how much power is to be gained is up to how well its sealed up and the ring package is part of that, thinner ring less tension more pressure by more need to evacuate to help keep the ring sealed to cylinder wall
Kelly Burns
04-21-2007, 12:29 AM
There is oil vapor in the air being pulled, it will settle in the muffler, there it pools if you get enough heat well you get the idea. I have not seen it but heard bad stories of trailer fires on the way home, no doubt it was burning when they shut it off.


No chit! I never thought about that! Do many people run the evacs behind the mufflers?
STEVEB
04-23-2007, 09:46 AM
I've been told by a few "experts" that using an evac with mufflers won't work because of the amount of back pressure in the exhaust would negate the benefits of the system,I'm just looking for something better than breathers in the v/covers that I've got now,I didn't think about the oil vapour collecting in the mufflers though,Do you think it would still be a problem with the mufflers located at the axle?
donho
05-15-2007, 04:51 PM
Header evacs are best used with open headers. Yes, oil will pool in the muffler. Especially turbo style with packing. Best used with open headers.

Consider buying a vac pump. It works. I picked up almost 2 tenths with one.
Scott McMullen
05-15-2007, 05:15 PM
Chris you know my Combo can I benefit from a E-vac Behind the Flowies I got from you?