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I am picking up on an LS swap that PO abandoned. I think it’s an LM4, but not positive. It currently has an edelbrock carb and manifold on it, and an MSD spark box. I just finished getting the basics hooked up and got it running. Now I’m working on some details.
PO has both valve cover vents connected to breathers. On a SBC, id put a PVC plumbed to the carb base in one and a breather in the other. Is that correct here?
PVC plumbed to the carb base in one and a breather in the other
More or less... although it's ALOT less un-sanitary to use a breather element that goes inside the air cleaner, rather than one of those stuuuuupid things that plugs into a valve cover.
Stock LS motors mostly (butt CERTAINLY not "all") had the PCV valve or orifice in the driver's side VC and the makeup air inlet in the pass side one.
Ok so in theory (i get the ‘not all’ part) I could run a hose from the LH valve cover to the carb base, and run a breather on the RH one. I agree an air cleaner mounted one would be a cleaner look, but I’m in ‘get it working’ mode currently, so ugly but correct is fine for now.
No, not exactly. Run a line from the big port at the carb base to a PCV valve, and from there to a VC; and a clean air line from a filter or something in the air cleaner base, to the other VC. No need for prominently visible "breathers" spewing oil and whatnot all over the top of your engine just so the 8-yr-old kids can ooooh and aaaaah over how "cool" they "look".
Edelbrock used to have a little filter thing you could buy that went in their air cleaner bases that would provide the clean air function. For that matter you could use a dragout and just install yerbasic old carb-style filter in there easily enough. No idea about this "cleaner look" thing you speak of; personally, I think "cleanliness" and "look" requires, FIRST OF ALL, an absence of dirt; butt, it seems some people have a different idea of "clean". Not that I want "ugly" as such, butt, true CLEAN (absence of dirt) must come first. Then, once "clean" (absence of dirt) is achieved, "looks" can be worked on next.
I did some more poking and as you described, the LH valve cover has a PCV valve in it. So that is good news, I can just plumb that to the carb base (and get rid of the breather PO put there.). I’ll figure out something to connect the RH to the air cleaner…
Only reason a breather can spews crap everywhere is because it wasn't drained of the condensation that builds up in them during the winter time if you're driving the car during the winter months. I have both valve covers with 10AN lines running to a single breather can and I never have to drain because oil doesn't build up in there.
You know what else is nice about it? Not having all of that crap building up in my intake or on the valves and mixing with my air fuel mixture.
Last edited by 01CamaroSSTx; Aug 1, 2025 at 04:52 AM.
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Breather questions 
