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View Full Version : Too much crank case pressure?



Ovrated
07-26-2005, 12:24 PM
hiya fellas.. again.


i just fully built my redtop. and never had this problem with it being stock.. but now i do.
mods-
cp pistons
eagle rods
full race manifold
62-1 turbo
tial 38mm wastegate
hks 272 step 2 cams
comp springs
crower retainers
AEM EMS- map conversion
fmic
3" turbo back
820cc injectors
other things im sure im missing as well

anytime i boost alot, or run downt he track, i get oil comming from my breather filter on my valve cover. and it drips onto the manifold.

i have a brand new oem oil pump in the car, and it seems to have more pressure than the old one did.

someone told me that i should hook a "T" up to the valve cover, and make a hose that will go into my ehxuast to pretty much act like a "vent" for the crank case

anyone else have any other ideas?

i dont like the idea of having a hose go to my exhuast for this.

JimStinksAtDorifto
07-26-2005, 03:00 PM
catch can?

The T idea will just suck the crankcase air out so that it gets burnt in the exhaust.

rogoman
07-26-2005, 07:00 PM
someone told me that i should hook a "T" up to the valve cover, and make a hose that will go into my ehxuast to pretty much act like a "vent" for the crank case



Not a good idea! You'll get a lot of exhaust contamination in the valve cover chamber. Just set up everything up like the OEM PCV system.

jeremiah
07-26-2005, 07:07 PM
You can use the exhaust to pull vacuum on the crank case but you can't just "T" it in. You need to run a venturi nozzle in the exhaust and run a check valve in between. I have seen it done and it is pretty cool.

cwdmark
07-26-2005, 08:10 PM
just run a regular catch can. i get quite a bit of blowby, mainly do to the little plate you have to remove by the T to fit the rocker arm stoppers. got a cusco oil catch can and at least it catches it (have to dump it out every 1 or 1.5 months). with that plate installed i would get no blowby at all.. if you don't have r.a.s. and didn't remove the plate you may have another prob.

240Z_TwinTurbo
07-26-2005, 08:27 PM
You should try to retain the factory PCV for cruising around. Under boost you will want a line from the block to a catch can that is internally baffled. From the can you can run it to the inlet of the turbo. Under boost the turbo inlet creates vacuum on the can which helps to create neutral balance on the block eliminating your problem. You can either drain the catch can periodically or run the can back to the oil pan with a one-way valve in place to prevent sucking oil from the pan.
I have used this on several motors and recently on a twinturbo ZR1 Corvette I completed. On the dyno the can registered ~2-3in of vacuum. Here is the one I fabricated on the Twin Turbo ZR1
http://www.speedshopthagard.com/pics/projects/TTZR1/finished8.jpg
http://www.speedshopthagard.com/pics/projects/TTZR1/finished5.jpg
The single fitting on the top runs to a tee and to both turbo inlets. The fitting on the side runs to the y-block pictured and then to both valve covers.

Kookz
07-26-2005, 09:07 PM
http://www.honda-tech.com/zerothread?id=1197655

Ovrated
07-28-2005, 08:44 AM
240z, are you willing to sell those catch cans?

240Z_TwinTurbo
07-29-2005, 02:55 PM
240z, are you willing to sell those catch cans?


It is simply a modified Morosso catch can. I welded a male -12 an fitting to the top. I am not in a position to do fabrication outside my personal RB26 powered 240sx project. Sorry!