Hi all!
Long time reader, first time poster. I wanted to check on a modification I made to see if you all think it was done properly.
I have a '64, RE (365 hp). Previous owner replaced carb with an Edelbrock 1406. When it was done, the vent hose from outlet on Oil fill to metered orifice in carb was removed. I had noticed some oil inside my aircleaner and some misting on the engine under the breather tube to the air cleaner.
After looking at the shop manual, and reading the posts here on crankcase ventilation and pcv valves, I realized the cause of the misting and the importance of correcting the problem.
What I did is this: I got a pcv valve designed for a sb chevy (which is designed to be inserted into a grommet in the valve cover), and I made a custom hose from the outlet on the oil fill to the pcv vacuum outlet on the Edelbrock carb. I used a small piece of heater hose, with a proper inside dimension for the pcv valve to fit into, attached the hose to the outlet on the oil fill, and continued the connection from the pcv valve to the pcv vacuum outlet on the carb.
Checked the vacuum on the motor last night, and all looks ok. Any opinions as to if this is a proper solution for adding a pvc valve to a 64?
Thank you for your help.


[Modified by drascombe, 1:20 PM 8/27/2002]


[Modified by drascombe, 1:36 PM 8/27/2002]

 

Do you have an air breather oil cap or tube into the air filter? The PVC system needs an air intake on a valve cover or oil fill tube.

 

Joe,
I have the original clean air supply that came on the 365 hp version. (a connection from under the aircleaner that attaches to the block back near the distributor, so that's ok... I was missing the hose from the oil fill to the metered orifice of the original holly carb for the 365 hp version, and seeing the replacement carb doesnt have a metered orifice like the original holly, I made the a hose that can contain a pcv valve to take its place.

 

that will work as long as air can get in to complete the loop. :chevy

 

Yes, you indeed need in the opposite valve cover a vented breather cap to complete the loop. :cheers:

 

It sounds like you have a PCV design that is reasonable. The only issue I question is the use of "heater hose". Heater hose material is not designed to handle hydrocarbons. Replace it with "fuel/evap/PCV" hose. This is available in 7/16" and 1/2" diameters for PCV lines, but you might have to look around to find it. NAPA is usually a good source.

Duke

 

Clem & MasterDave
I guess my original post wasn’t clear… there’s no problem with clean air inflow into the crankcase.
The crankcase ventilation setup for the 64 365hp motor is a breather tube from the air cleaner to the back of the block (inflow into the crankcase) and a hose from the oil fill to a metered orifice on the original holly carb (outflow from the crankcase). What I was missing was the outflow hose from the oil fill to the carb, and seeing that the Edelbrock carb doesn’t have a metered orifice like the original holly, I constructed a hose that allowed me to place a pcv valve in the hose between the oil fill and the pcv vacuum connection on the new carb. Just wanted to know if it was ok to use a pcv valve inline to take the place of the metered orifice that's no longer there.

And thank you Duke for the information,
The piece of heater hose actually never comes into contact with the airflow of hydrocarbons, as it is just an outer shell to hold the valve, and has an inner hose of proper pcv line (the pcv valve holder and adapter to fit the vent on the oil fill is maybe 2" total in length). But I will check out Napa for a piece of pcv line to replace that outer shell just to be on the safe side.

 

Sounds like an OK solution to me - you have the production air intake from the air cleaner into the back of the block, and the PCV outlet from the oil fill tube to the carb with a valve instead of the metered orifice fitting in the air horn. Should work fine.

 

Again, I agree with JohnZ, sounds like you created the equivalent of a 65 and up PCV system. No problems that I can forsee with that setup.

 

Thanks for the input John & Denney,
I had known that post-64 C-2's had started using actual pcv's in the crankcase ventilation flow, but never checked to see how... but upon looking at Long Island Corvette's catalog online, I see what you mean. I guess I could have just purchased a post-64 oil fill with the pcv valve attached instead of making my own adapter.
Thanks again for the help and info.


[Modified by drascombe, 8:19 PM 8/27/2002]