Fresh Air feed to Valvecover?
Fresh Air feed to Valvecover? OK guys I’m trying to sort out my catch can situation on my 383 build
Here is my situation and my question..
I’m running an elite engineering catch can.. I am feeding the dirty side from the driver side valve cover.. around the back of the intake and along the passenger side valve cover to the catch can. My intention is to cap off the back port of the passenger valve cover and provide a fresh air feed to the front port of the passenger valve cover. And of course, naturally run the catch can outlet to the intake manifold port behind the throttle body.
My main question is this. I’m running a fast 102 that has an LS2 throttle body on it.. so there is no positive pressure fresh air port on that throttlebody. From everything I’ve been told and read I should be able to grab fresh air anywhere after the MAF.. and prior to the throttlebody. My my question is, wouldn’t that make it a negative pressure source under throttle and not "feed" the valve cover fresh air? And if so, does that matter for the purpose I’m trying to achieve.
Here is my situation and my question..
I’m running an elite engineering catch can.. I am feeding the dirty side from the driver side valve cover.. around the back of the intake and along the passenger side valve cover to the catch can. My intention is to cap off the back port of the passenger valve cover and provide a fresh air feed to the front port of the passenger valve cover. And of course, naturally run the catch can outlet to the intake manifold port behind the throttle body.
My main question is this. I’m running a fast 102 that has an LS2 throttle body on it.. so there is no positive pressure fresh air port on that throttlebody. From everything I’ve been told and read I should be able to grab fresh air anywhere after the MAF.. and prior to the throttlebody. My my question is, wouldn’t that make it a negative pressure source under throttle and not "feed" the valve cover fresh air? And if so, does that matter for the purpose I’m trying to achieve.
Last edited by LS1Silverado05; Apr 23, 2026 at 11:01 PM.
I am working to resolve an oiling issue with my set up. Started out with a Saikou Michi dual can, dirty coming from drivers rear valve cover (updated cover with orifice) and fresh air via a bulkhead fitting installed in my intake tube before throttle body.
With two different engines it has sucked oil and now even more so with my current set up. Thinking there was a problem with the Saikou cans I switched to an Elite single can/clean air system with no change, it actually might be catching even more than the Saikou. Then I started doing even more research.
I found that GM instructions for the LS3 crate direct you to use the LS3 valley cover and cap the driver valve cover. With a 454 LSX both the valley and valve cover are used. I installed an LS3 valley cover and capped the valve cover however my current combo is a 427. I will be testing this out over the weekend, hoping for a good result.
With two different engines it has sucked oil and now even more so with my current set up. Thinking there was a problem with the Saikou cans I switched to an Elite single can/clean air system with no change, it actually might be catching even more than the Saikou. Then I started doing even more research.
I found that GM instructions for the LS3 crate direct you to use the LS3 valley cover and cap the driver valve cover. With a 454 LSX both the valley and valve cover are used. I installed an LS3 valley cover and capped the valve cover however my current combo is a 427. I will be testing this out over the weekend, hoping for a good result.