Oil catch can question
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Fresh 383 HSR, no blow by , rings are well bedded in.
Because I have the block decked and have not cut manifold , intake to block clearance is bigger than usual.Similar to OP , I am blowing out the rear intake seal ( very well done with RTV ) when I get on it.
Spoke to engine builder and he confirmed my thoughts that stock PCV system is not letting crankcase pressure out fast enough at revs
( there is little vac ) so getting some internal pressure , especially considering I now have 30ci extra displacement under the crank.
Resealed intake and installed a couple of push in breathers.Only been round the block so far but appears to be working.
Catch can setup soon.
Thread Starter
Instructor
Joined: Jul 2007
Posts: 181
Likes: 0
From: Boise ID
I just talked to the machine shop that did the work on my motor. He said because I used molly rings they may take as much as 1,000 miles before they are seated if I am beating on it ( which I am ). He also said that a catch can on this motor will not add much HP ( maybe 5 HP ) and won't do much more than the pcv system does now. With that info I think I will hold off on the catch can for awhile and be nice to this motor for about 1,000 miles if I can.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Moly rings are supposed to seat on a fresh engine before a flat tappet cam is run in. My builder warned me not to idle the engine at first startup as the moly rings need some good pressure on them to seat.
"said you need an evac system on this car"
That is different to a catch can; has fitting in header collectors to creat vac at revs to reduce crankcase pressure.
http://www.moroso.com/catalog/catego...?catcode=13023
http://www.camaros.net/forums/archiv...p/t-16899.html
Some say evac only works with open race exh system ; check this out.
Full exhaust street car with mufflers.
http://www.youtube.com/watch?v=wGrx2rvIxJ0
Catch can is passive ; just somewhere for the oil to collect instead of all over your engine.
Still got the air pump on your engine; use that to suck a vac through a catch can.
Last edited by rodj; May 30, 2008 at 03:28 AM.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
