I just did a cylinder head and cam change on my 77 with a 302. I niticed that the chrome valve covers I bought on ebay, while having adequate clearance for my roller tip rockers, do not have a baffle over the pcv and breather port. I have also noticed that mu oil consumption has increased substantially, so I am assuming I am sucking oil vapors in thru the pcv at too high a rate. The immediate solution, I guess, would be to get some valve covers with the baffle to prevent too much oil through the pcv. Although, when looking at the valve covers, there is not much room under the brake booster for taller ones. Any comments or suggestions?
Check carefully. IF you are burning oil, evidenced by smoke, that could be the case. Check for leaks and look at the PCV valve line. It should have a filter for that line in the air filter assembly. If you are sucking in oil that way, the filter would be soaked with oil leaving oil in and around your air filter. I doubt this is happening. You may need to look at other ways that you are losing oil. Seth
Well, I just ordered some Edelbrock Signature Series valve covers which are a little taller and have the baffles in them. I hope they clear the brake booster. I should probably elaborate on the plumbing..... From the factory, on the passenger rear valve cover was a simple elbow that fed into the breather element mounted in the air cleaner housing. The oil fill cap of the driver's side front had the PCV with a vacuum hose that went to the base of the carb, if I remember correctly. When I converted to a Holley 4 barrel, I did not change the plumbing. But when I did the heads and cam, however, I got rid of the factory valve covers and replaced them with chrome ones off ebay. I relocated the pcv to the rear passenger side, as I didn't have to run as much hose this way(the Holley fitting is on the back passenger side too), and used a chrome breather on the front. That is the set up I have now. To experiment, I removed the pcv and replaced it with a simple beather in both vavle covers, you could definitely see the vapors coming out of both breathers. That seems a little odd to me. The car doesn't seem to smoke at all out the tailpipes.
I doubt... ...that you are sucking a great deal of oil into the carb. You would be fogging the roads if you were. I agree with Barry, do a leakdown test.
Thing is, I wasn't burning any oil before the new heads. I put some new baffled covers on, and I will see how much that helps...
Then a bad head gasket maybe? Some how you're getting combustion gasses into the crankcase. Once upon a time I had a similar problem with a pair of heads that I had milled. Seems the machine shop left a hairline gouge in the head surface and it connected a combustion chamber, an oil drainback hole and a water jacket hole all together. What a mess!
Put on baffled covers, and no more consumption problems. Anyone need a set of chrome covers with no baffles. They should work well on a car without a PCV system.
