[Old Goat Racer]

Originally Posted by coonhunter70

I was just looking on ebay at the L-88 valves mentioned above they appear to be valve cover applications. What # was the original Ram Air IV valve?

Pontiac parts catalog lists 1 valve cv679c for 57-79

[David Jones]

Originally Posted by Old Goat Racer

Pontiac parts catalog lists 1 valve cv679c for 57-79

cv679c is for a stock engine only, if I remember correctly.

Effective in a modified Pontiac, probably not.

[Tom Vaught]

Well the Pontiac Engineers released the cv679c valve for production on the RA-IV (the 455 SD used a smaller camshaft) so apparently it met their needs for the limited production run of the RA-IV engines.

If you actually put a decent camshaft in the engine then the L-88 valve, (396/375 and 427/435 camshaft were not that big) would work better. Even better is a Ford PCV Valve
as Ford has a list of about 20 different valves for their engines vs the ONE "generic" valve for everything Pontiac. I never looked at the Z-28 PCV valves to see if there was a different offering for the bigger camshafts. Probably most stripped the PCV stuff off the engine and ran open breathers (with oil all over the firewall).

Tom V.

[Old Goat Racer]

Originally Posted by Old Goat Racer

Pontiac parts catalog lists 1 valve cv679c for 57-79

But, I don't remember seeing a PCV valve on 57,58,59............not sure when they started using them ?

[post toastie]

thanks for the info my pcv valve was creating a vacuum leak replaced it with a fram one engine is happier now.

[69FIREBIRD76MM]

Mr. Tom, what pcv valve you recommend for a turbo boost ls1? I was also looking at that expensive pcv valve, friend is using one on his 1100 rwhp ls street mustang, a cheaper alternative will be a better choice for me. Thanks

[straycat]

If I'm running dual AFBs with a factory pushrod cover would it be best to split the hose from the PCV to both carbs therefore not upsetting AFR? Or too miniscule to make a difference?

[SD421]

In the TriPower Forum I posted my results from having my engine tuned.
I had to have a slower PCV valve installed.
Engine idles smoother and less fuel smell cause the carb could now be leaned out more.
Heres a pic of the box.
Don

[rtanner]

Originally Posted by Tom Vaught

Well the Pontiac Engineers released the cv679c valve for production on the RA-IV (the 455 SD used a smaller camshaft) so apparently it met their needs for the limited production run of the RA-IV engines.

If you actually put a decent camshaft in the engine then the L-88 valve, (396/375 and 427/435 camshaft were not that big) would work better. Even better is a Ford PCV Valve
as Ford has a list of about 20 different valves for their engines vs the ONE "generic" valve for everything Pontiac. I never looked at the Z-28 PCV valves to see if there was a different offering for the bigger camshafts. Probably most stripped the PCV stuff off the engine and ran open breathers (with oil all over the firewall).

Tom V.

ive used the motorcraft pcv valve in all my engines since the 80s, discovered it had little more bypass in it by accident, really helped the idle with all my junk, cant remember to motorcraft # right now, will have to look, I need one for my buick any way

[Tom Vaught]

The CV881C valve is a generic valve ised by GM across the whole line in the 80s and mid 90s. The valve will work on a 4 cylinder or a smaller stock SB chebby size displacement very well. So if you need a bit less flow (because the 4 cylinder stuff is sized more towards the lower flow spec (2.5-3.0 cfm vs the old Pontiac 4.0-4.5 cfm spec) the valve will work well and still remove corrosive gases from the engine.

When I looked that valve was about $4.00 in stores.

So still many $$$ less ($125.00) than the high dollar valve and as was posted will do the job well on Pontiacs like SD421's engine.

Tom V.

[TXSTARFIRE]

But, I don't remember seeing a PCV valve on 57,58,59............not sure when they started using them ?

1963 Was first year for PCV valve. Pontiac had kits available to convert early cars to a closed crankcase vent system. Kits for V-8 cars also used the CV679C valve.
Interesting old thread, I have always used the CV679C valve in my car.

[PontiacHO]

Now open the hood and look at the dipstick. You have a PCV problem if the dipstick is pushed-up out of the tube, like a pencil tire gauge. If you don't see or smell any oil, the dipstick is firmly in the tube, the engine idles smooth, save your $129.00. Not saying the part described is stupid or overpriced, but only a very tiny % of street engines need or would benefit from it in my opinion.

Or-you have blow by and need rings. No PCV valve will help…

[Formulas]

The CV679C has a higher CFM rate than alot of PCV valves.. ... When they started using them i cannot accurately say but pretty sure when the road draft tube went away the PCV valve was soon to show up

[P@blo]

Only fixed orifice PCV valves used here for years. Not very confident in the current offerings and looks like they build valves that look correct but do not function like the originals.

I use the Standard V372 fixed orifice PCV valves for $5 and will never wear out. Then you can spend the other $125 you saved on fuel.