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Valve covers without breathers???
Posted: Sun May 04, 2008 6:34 pm
by BigRedMachine
Getting ready to order a new set of valve covers for my street motor. Im looking at the fabbed aluminum valve covers. Question is will I need breathers on them , because they dont come with breather holes???
Re: Valve covers without breathers???
Posted: Sun May 04, 2008 7:46 pm
by WDCreech
You need some way for fresh air to get in the crankcase to replace the dirty air air that is drawn out by the pcv, or vacuum pump.
Re: Valve covers without breathers???
Posted: Sun May 04, 2008 7:51 pm
by BigRedMachine
right. I was just wondering if those valve covers were specifically made for engines with vaccuum pumps or can you put breathers in them??
Re: Valve covers without breathers???
Posted: Mon May 05, 2008 10:59 am
by Turbo chevelle
You should be able drill a hole in them the exact size you need for the breather grommet.
One on each side would be best.
cheers Marc
Re: Valve covers without breathers???
Posted: Sun May 11, 2008 9:00 am
by HonkIfPartsFallOff
BigRedMachine wrote:right. I was just wondering if those valve covers were specifically made for engines with vaccuum pumps or can you put breathers in them??
Just drill your own hole where you want/need it.
Re: Valve covers without breathers???
Posted: Sun May 11, 2008 1:21 pm
by BigRedMachine
thanks for the visual aid.
thats what Im gonna do
Re: Valve covers without breathers???
Posted: Mon May 12, 2008 6:50 am
by K-Star Automotive
I also use a hole saw, here are a few tips.
Use a few pieces of masking tape and lay-out the location of the holes. I usually put 2 or 3 on top of each other. It's a lot easyer to remove the tape if you don't like the hole location then trying to fix the hole after you drill it.
I put both holes in the front of the valve covers because there seams to be less oil splashing around in the front under acceleration. On the small block Chevys I locate them in line with the 2 bolt holes that attach the valve cover, that will place the breathers between the rocker arms.
As a rule the gromment for the PCV valve will need a 1" hole while the gromment for the breather needs a 1 1/8" hole. Measure both of them before you start drilling.
Have someone there to hold the valve cover while you drill it. Those hole saws have been known to grab some time, removing the drill from you hands and throwing the valve cover and the drill on the floor. I made a holding fixture outof wood and some long deck screws, and clamp the entire thing on to my work bench.
Be real careful taking the burr off the hole, one slip and you have a scratched valve cover. I let the tape on until i am totally done with the job.
Keith