Hey Steve,,    I know you did a lot of research on what PVC vale to run on your rig.  Have a little trouble getting idle right.  Believe the PVC valve is not right.  Running 4177 Holley, right now running 67 primary jets will go back to 71s seemed to be better, also using secondarys to control idle.  331 stroker, John's heads, Engle Cam #EP-20-Cam lift 321--duration 231--  lobe centers 110.   Blue Thrunder.   Pvc valve that I'm using is for a 289 Mustang. Maybe too big??     Thanks for all the help thru the years.   Still the Best site!!!    God Bless    Eddie

Eddie

Lake Forest, Ca. 92630

Hey Eddie! I started with the same as you and found it passed too much air.Wouldn't idle right.I went to a 78 4 cylinder Fairmont/Zephyr PCV and it was just about right.You can try restricting the one you have now and see how that works.Trial and error.

  

Thanks Mark, I pickup a 4cyl. valve.    Will let you know.   Many thanks    god Bless   Eddie

Eddie

Lake Forest, Ca. 92630

I've been away from my computer Eddie and overlooked your note.....

I used the PCV for a '64 292 cid truck and it bled way too much air into the intake. The engine acted like it would run on the PCV air alone. Rather than hunt down another, I orficed the line down to a better match.

Mark's choice of a smaller valve is probably the right way to go - but the orfice will work too.

 
 Steve Metzger       Tucson, Arizona

Let me ask you guys I am having idle problems too. I am running a 292 with g heads and a 3x2 offy with holly 94s. everything else stock idle it tends to idle fine in park but when coming to a stop it stumbles a bit. I have been chasing bogeymen like the PV and vapor lock on the fuel line. Do you think it could be the PCV? The pcv does rattle like a machine gun so i know it is working maybe too much. It might be a good quick fix to try a smaller valve I had never thought about that direction.

Mike Rizzo

1963 F100 "Rudy"

Daniel Island, SC

Steve;;    Thank You for returning the email.  Think I'll go with Mark's valve, if that is not good will try your restrictor.   Many Thanks and Merry Christmas!!!   God Bless    Eddie

Eddie

Lake Forest, Ca. 92630

I used one for a GM 305 in the past and it worked fine. I can't remember the specific application now. A pcv valve is not something you just put on and go. You will need to adjust the carb for it. If you're not able to adjust it because of too much flow, that's a different story but after you've eliminated vacuum leaks. A good way to start is to be sure you can get it running right with only breathers, no pcv.


Lawrenceville, GA

Riz - The troubles we were dealing with (downsizing the PCV) are a slightly different circumstance, my engine was acting like it had a big vacuum leak and the idle speed running high. After running out of places to look for a leak - I disconnected the PCV line and plugged it (both ways) and the "runaway" stopped.  So I got a piece of tubing and throttled the hose which helped a lot.

If your outfit stumbles when shifted into "drive" - it may have too little initial spark advance. Try raising the initial advance to something 10° or higher and see what the results are (at idle transfer). You may need to re-curve your distributor a bit so that you can have more initial advance - and then limit it to less on the top end. Because the two-barrels probably don't have a "ported vacuum" arrangement - you will most likely be needing to run "live" manifold vacuum to the can on the distributor. Because it may have too much travel - "adds" too much to the total when engaged - you may have to limit it as well after raising the initial static.   

 
 Steve Metzger       Tucson, Arizona

Steve

Thanks very much for the advice, this is my first y block. My previous project cars were imports or Sb fords that had a ton of data on them. I feel like I am often going one step forward and two back. Just grasping at staws.I get the idle straight and then tip in is junk. It has a mallory ignition so no vac only vac is for the AT. but great ideas on the timing, I will get back in it.

Well no one said hot rods made good sense.

Thanks again

Mike Rizzo

1963 F100 "Rudy"

Daniel Island, SC

I have a similar idle problem with my other hobby car. 65 Mustang with warmed over 302. Will try 4 cylinder pvc and see what happens.