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-   -   Crankcase evacuation (https://www.racingjunk.com/forums/showthread.php?t=31376)

grego3474 12-11-2011 02:13 PM

Crankcase evacuation
 
I have read alot of posts concerning crankcase evacuation. I am in the process of setting up something now. I have a 502BBC making 625HP. I have a 225 nos kit on it.
I am running dynoflo mufflers on 3.5 in header collectors. I will be running 3.5 in bullet mufflers when I take it to the track. My problems are if I run an evacuation kit will these mufflers render the kit useless or even worse harmfull. As far as the moroso vacuum pumps do they make a bracket that will work on an engine with an alternator and a power steering pump. Any help you can give would be appreciated.

zipper06 12-11-2011 06:15 PM

Mufflers, usually are a big NO, when running nitrous and an evac system to the exhaust. we tried it with a 468" and a 250 shot and it blew oil out every where at high rpm on a 10.25 pump gas motor, so now we just move the exhaust sysyem over at the header flange at the track.

JMO

Zip.

markdunlap 12-11-2011 06:32 PM

crankcase
 
If you have the mufflers up front just behind the header collectors, you may be able to install the evac tube in the piping behind the muffler and still use a vacupan system.

If they don't make a bracket and you want to use a vac pump, then a fabricator can build you one out of metal plate and spacers.

JEFF69Z28 12-12-2011 02:44 AM


Originally Posted by zipper06
Mufflers, usually are a big NO, when running nitrous and an evac system to the exhaust. we tried it with a 468" and a 250 shot and it blew oil out every where at high rpm on a 10.25 pump gas motor, so now we just move the exhaust sysyem over at the header flange at the track.

JMO

Zip.

Any mufflers or ones with many baffles in them,i have a set of mufflers from schoenfeld that are 6 inches long with holes punched in the tube and a case welded around the tube they are a straight thru design with nothing more than holes pucnched thru the main tube to quite the car down I think 6-9 decbles and the 2 only weigh 6pounds.

RogueDog327 06-28-2012 06:03 PM

Re: crankcase
 

Originally Posted by markdunlap
If you have the mufflers up front just behind the header collectors, you may be able to install the evac tube in the piping behind the muffler and still use a vacupan system.


The venturi slot has to be placed right in front of the primary tubes to get a strong enough blast to create any vacuum so putting them behind the can is not a good idea. Usually the machining on the piece that gets welded in the header is pretty crude and you can enhance the efficiency of the slot with a file.

racear2865 07-01-2012 02:49 PM

Hey make you a stub nipple and place it in the pipe behind the muffler. Hook you a vacuum gauge to it and see if you are pulling vacuum. If you have a data logger, hook the nipple to it so you can see going down the track. Heck make this easy instead of hard and dont guess.
reed


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