65 vette & pcv hookup

[brumbach]

My 65 vette has a 1968 327-ci block. The heads and intake are correct. It also has a holley 4160 (list 3367) four barrel. The breather and oil fill tube are correct for 65. The valve covers are chrome aftermarket with a pcv valve on the passenger side and an air breather on the driver’s side to complete the pcv setup.



I intend to install the 7 fin aluminum covers to give the engine a more authentic look. Because the block is 68, the orifice next to the firewall that is supposed to be used for filtered fresh air intake to the block is nonexistent. During an earlier forum discussion, many remedies were suggested to support my intentions but the one that seemed to be the simplest was to cut a hole in the correct valve cover in an inconspicuous place (backside near firewall) and connect a hose from it to the air breather. Discussions did not cover the pcv connection or valve.



I’m ready to order parts to perform the task but have additional questions.



Most generic diagrams I’ve seen for pcv show the setup to run from “front to rear” of block (oil tube to right of distributor) or from “side to side” (valve cover to valve cover). To gain the near correct appearance of my engine, my setup will go from the oil tube (output) to the valve cover rear (input). Will this make any difference?



I plan to replace the 65-oil fill tube with a 67 tube w/ pcv valve installed. Even though the tube will be wrong, it is very similar in appearance. I’d use the existing tube but don’t know of a way to introduce the pcv valve other than possibly an in-line aftermarket valve. My holley doesn’t appear to have a threaded port to accommodate the 65-check valve. Do you agree with my approach?



I welcome your advice. Thanks in advance.



Bill

 

[paul67]

Can you not run the PCV from the 1967 oil fill tube to the Holley as shown in the pic. And the relief hose from the rear of the driver's valve cover to the base of the air cleaner (very close to the stock configuration with a crankcase vent tube as shown)?

 

[brumbach]

Absolutely. That's my plan. Should it work?

 

[paul67]

It works for me. You may need a small oil/splash baffle of some type at the inside/back of the valve cover where you drill the hole. That will prevent liquid oil from being sucked up into the air cleaner. You only want fumes getting through.

 

[brumbach]

Thanks. And by the way, your engine looks great. Hope mine will look almost as nice when finished.

 

[paul67]

I should mention that I gave up on that Holley about mid-June. It was a plug-fouling nuisance that gave me no end of misery. I put on a new Edelbrock #1406 and I have been happy/happy since. The Edelbrock is a jewel in terms of reliability!

 

[brumbach]

Funny, I pulled the holley off when I first bought the car and installed the edelbrock 1406 too. The holley was really giving me fits. The edelbrock performed good but unfortunately due to its higher profile, it caused my breather to rub on the underside of the hood. I took a chance and applied a renew kit ($30) to the holley, reinstalled it and haven't had anymore problems. The holley causes a deeper exhaust tone than the edelbrock. I like the sound much better. I routinely check my plugs and haven't noted any fouling. Acceleration is relatively the same, regardless. I think the problems I initally had with the holley resulted from the car being stored for a long period before I bought it. I drive the car once a week to keep the metering blocks, etc from drying out or fuel going bad.

 

[paul67]

I kept the Holley and will have it rebuilt this winter. Summer is so short I just did not wish to fool with it any longer. Note that I went to a 2" air filter to get the hood clearance. That issue was made worse but my use of a 3/8" carb/manifold heat insulator/spacer. But it all works fine now.

 

[Tom Bryant]

Tin valve covers with PCV holes have a baffle to prevent oil from entering the hose. You shouldn't have any trouble with oil getting up to the air cleaner from the vent hose as thats where fresh air is drawn into the crankcase by the vacuum created on the other end of the system where the pvc valve is metering vapors to the carb base.

However if your rings are tired, excessive blowby at higher rpms could blow oil out of the vent end. You may be able to remove a baffle from a junk yard valve cover and adapt it to your valve cover watching for rocker arm clearance.

Tom

 

[JohnZ]

You can fabricate a small aluminum baffle and rivet it to the inside of the valve cover where you drill the hole for the hose to the air cleaner, or Moroso makes several rubber hose oil breather grommets with molded-in baffles that you could adapt to your setup.