I may play around with that just for the sake of it making it easier to start at 22 degrees initial. My pertronix distributor came with some bars that are like +10, +12 etc.

I made some huge progress tonite! I tried some drilled out idle air bleeds that were bigger than the four .067's that were in the carb and it made the motor run terrible.
So I put new .061's in the front and some drilled out .064's in the rear and it's much better! Idling at 1100 in park and 900 in gear. I'm heading to Summit right now to buy .061's for the rear of the carb and I think it will be pretty darn good.

It's suppose to rain for a couple days so once that's all dried up I'll take it for a spin friday.

That`s a big jump and I usually start at .070 and go from there on MOST 4-corner idle stuff.......

Your kidding right? Give the Holley a shot and keep the more TUNEABLE carb and those calibrations are generally WAY off and as Andy said, you can check the ifr`s but start w/the idle bleeds and you`ll be amazed.......Then after that you`ll find there`s too much emultion so plugging and moving becomes my norm. Oh ya, lower the ifr`s while your in there for a more stable idle/fuel curve.......

Well the car motor wasn't happy with the new .061's in the rear so I went back to the drilled (.064's)back in the rear and ended up setting the air/fuel mixture screws at 1.5 turns and it seems to be running great.
Also, the timing does not move when going from neutral to drive, it stays at about 28, total timing is set at 32.
It's idling at about 1050-1100 in park, and 900 in gear so I'll keep playing with it but I'm pretty happy with that! To me it's annoying when it idles at 1200-1300 in park for this particular street car.

Andy, next time I pull the bowls I'll check for idle jets in the metering blocks, I'm not sure if these are billet or just really clean cast blocks.
I figured I'd start with the idle bleeds since they're so easy to change.
Once I start leaning over the fenders for hours trying different idle jets in the metering blocks I'll probably have to wear a back brace the next day!

Oh and I appreciate the info on the Eddy 800 carb but this ProSystems carb on my 500" motor is killer when I'm out driving and playing with the loud pedal, it seems like it is tuned spot-on. I just drove it so much this summer that I didn't have time to mess with the idle RPM til now.

I would drop the initial timing from 28 to about 14 to 18 for starters.

I honestly don't know how yet with the Pertronix distributor but I'm gonna try what Sixpackgut mentioned earlier, my distributor came with bars to limit advance.
It's running fine though, it doesn't ever have any problems firing up at all, or anything else goofy.

First off where are the throttle blades in relation to the transfer slots? Should just see them from bottom. Idle speed and quality comes from the air and fuel bleeds(95%) if you want the idle around 600 rpm those air bleeds need to be smaller, That makes more fuel come out the fuel bleeds. The problem you have is the cam gives you a very weak signal then it will pull more air(lighter) than fuel with the stock bleeds. You need the mixture on the fat side since the whole mixture is moving slower. If your metering blocks have the pressed in brass bleeds I would open it up 1-2 drill sizes to start.if you have the removable ones better yet. Use .030 air then start drilling them open till the throttle response is crisp, just the fronts not the back. It helps to have timing at full advance at idle while doing this, then put back when everything is set correctly. Went through this process many times with no vacuum cams. Had a 588 ci shotgun engine with two 4500s on a tunnel ram idle 500 with instant response in gear.

I would maybe go 20-22 base with one light springs and limit the advance to 10-12 degrees. With my Firecore distributor I set the base at 22 and total 34 and my particular combo runs perfect with that timing.
I think you really need to get your timing dialed in before even trying to tune the carb.
Gus

Thanks, I'll check the metering block idle jets when I have time to pull them off this weekend. The transition slots are fine I'm sure since both butterflies are not open very far, I remember checking it before installing the carb, I'll check it though when I pull the carb back off.

I have no desire to idle this motor at 500-600 RPM, 850-900 in gear is where I want it and it's pretty much there now, but I do want to learn more about the idle bleeds in the metering blocks.

Thanks Gus, I'm gonna try that for sure, just need to learn the proper way to do it with the Pertronix. When I tried heavier springs it didn't like it at all, but maybe with the light springs and a 12 degree advance limiter it will be ok? I'll let you guys know when I try it. Car is running very nice though, need some stickier tires before I hurt myself though lol.

The ifr`s supply fuel for the idle circuit and on yours hopefully they`re bet. .032-.034 and have seen em as high as .041 on 4150`s.......

Good info, thanks. How are you guys drilling your air bleeds, are you free-hand drilling or are you making a jig for a drill press?

I have a tall nut/all thread connector that I thread the bleeds into, then chuck into the drill, holding the drill in the bench vise. Hold the drill bit in a pin vice. Think of using it like a lathe. Has worked out so far. Think I borrowed this method from Mark's site...

Bought the tall nuts and a bunch of set screws from McMaster, 10-32 for air bleeds and Transfer slot restrictions, 6-32 for emulsion, idle and power valve restrictions.

I made an alum. drill plate and drilled and threaded it for 6-32,8-32 and 10-32 sizes and just use a regular cord drill to drill em w/wd-40 or cutting oil. It can be tricky at first especially w/the smaller .024-.026 bits.......

This is the best method if you don't have a lathe. If you have a lathe, you can make a fixture to hole the bleed like above, ot, you can just grab the bleed in the chuck and then hold the drill in a pin vise and drill it out. I try to use as much speed as possible and a light feed to keep from snapping those tiny bits.

So I ASSume you figured your carb out.......

This sounds like the best way for me to do it, I don't really have the tools or knowledge to do it the other way mentioned.


Yes Thumper, I think it's much better now, air/fuel mixture screws are 1.5 turns out, butterflies are not open very far, idles at 900 in gear and 1050-1100 in park. You guys have given me more ideas to work with, I'll mess with the distributor next. Suppose to be sunny tomorrow so I'll be cruisin!

Glad it`s coming around and my method works well for me..........

One more question, does a smaller number power valve help the idle? I'm only asking cuz I saw someone mention to someone else on a different site that a 3.5 power valve might help with their big cam/tight converter combo.