Breather and PCV location on Covers
04-07-2012, 09:56 AM
#1
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Breather and PCV location on Covers
I just got my engine back from the builder and he gave me a set of tall fabricated valve covers so they clear my valve train. The valve covers are solid and need holes cut in for the breather and PCV valve. I dont have any pics which show their location when I took the motor out..
I have a 74 with all the emissions stuff removed.
Where do you all have your breather and Valves located. On the front or rear of the valve cover? I was afraid that the breather in the rear may interfere with air cleaner.
Thoughts? Pictures?
- Thanks
I have a 74 with all the emissions stuff removed.
Where do you all have your breather and Valves located. On the front or rear of the valve cover? I was afraid that the breather in the rear may interfere with air cleaner.
Thoughts? Pictures?
- Thanks
04-07-2012, 10:08 AM
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On stock engines, PCV was in the left cover. Air cleaner connection was on the right side.
04-07-2012, 11:51 AM
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That's correct. And the reason for the PCV on the driver's side and the breather on the passenger side has to do with engine rotation and windage created in the crankcase: Having the PCV on the driver's side actually makes the system more effective. You can drill the holes off-center (forward or aft of centerline) to clear components, such as the air cleaner: Most Chevy valve covers have the holes at about the 75% location fore/aft, with the driver's side PCV being forward of centerline, and the passenger side breather being aft of center. Check location of the planned hole in relationship to the rocker arms: Don't put the hole directly over a rocker, but put it so it is aligned between a pair of rockers in that open space. This will prevent direct oil splash onto the penetration location. You'll still want to have a baffle/shield inside the cover to keep direct oil off the hole location. 
Last edited by lars; 04-07-2012 at 11:54 AM.
04-07-2012, 01:22 PM
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Great to hear from you Lars!!!
The covers do not have baffles. The builder said he has grommets the go into the cover an inch or so that tapers to a small slit and it acts much like the metal baffle... True?
So as far as the position on each valve cover, 75% of the way fromt/back sounds like the same position as the short ones I took off.
is there a preference as to closer to the front or rear of the valve cover? Does one look better than the other?
The covers do not have baffles. The builder said he has grommets the go into the cover an inch or so that tapers to a small slit and it acts much like the metal baffle... True?
So as far as the position on each valve cover, 75% of the way fromt/back sounds like the same position as the short ones I took off.
is there a preference as to closer to the front or rear of the valve cover? Does one look better than the other?
