Turbo and Supercharger discussion
User avatar
By york62
#6385 ok well i was talking to my tuner this weekend and i was telling him how i am blowing valve cover seals. so he told me i have to vent my cover, my question is has anyone done this here? or seen a write up anywhere about it? i woudl like to go for something like this. but on a SOHC.
(look at the valve cover, the AN fittings.)
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User avatar
By teal_dx
#6390 Check out the Catch Can thread I made in the Boost forum. On a SOHC, tapping 2 lines on the front of the valve cover is a little overkill for most applications. Are you running a catch can setup already? The hose that goes from the corner of your valve cover to your intake is the factory's solution for venting. Except you get oil blow-by sucked into your intake. A catch can will trap all that oil.

The catch Can can be 1: vented into the atmosphere, 2: connected to your intake, or 3: routed to the exhaust via slash cut method. The first option will not have any vaccum to suck the gas out of your valve cover. The second option removes the blow-by, but still sucks the used air back into your intake. The third is the most complicated, but when done right will work.

The valve cover and bottom end should both be vented in turbo applications. SOHC motors have the black box on the back of the block. There is originally a tube that goes from the black box back into the intake manifold, sucking some blow-by back into the system. This line is also ideal to have going to a catch can. Venting the bottom end of a turbo'd motor can help make life easier on your piston's rings.

What's your current setup?
User avatar
By york62
#6392 wow thanks man lots of usefull info. no i do not have a catch can right now .. right now i have a piece of hose leading to the ground from the valve cover...i was gonna make a catch can but didnt bother.

my current setup is:
D16z6 stock block, steel HG.
Aireasearch T3, Tial (knockoff) Wastegate with 10psi spring
XS FrontMount
P28 chipped for Crome and tuned by JDracing
HF manifold machined t3 adaptor and W/G flange.
homemade 2.5" downpipe
homemade dumptube
homemade charge pipe
XS Type H RFL
Autometer pro-comp boost gauge
DSM blue 450cc injectors & Teg resistor box

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User avatar
By teal_dx
#6396 Your turbo setup is almost exactly like mine - except yours is installed :thumb:

If the hose to the ground isn't enough of a vent on your setup, then I don't know if a vented catch can would do much better. You might be best off going with a catch can, but instead of a vented catch can, go with a hose to a vacuum source instead of a filter. If you do this, be sure to use a check valve in your vac line so air can only flow one way. This way under boost, you won't be pushing air back up into your valve cover.
I'm kind of surprised that the open tube to the ground didn't work well enough for you though. Since a vented catch can is more restrictive than an open tube, this means I'm gonna have to change my setup as well. Keep us updated on your setup and I'll do the same when I change mine.
I am going to do some more research on the exhaust slash cut method. There's a lot of variables that have to be correct for it to work right, but you get the best of both worlds. You get vaccum, and that dirty air gets sucked through the exhaust instead of in your intake.
User avatar
By york62
#6397 ya i will be sure to keep you updated, i dont have much for cash right now but i wanna do a bunch of research first, and thanks alot for the help man