Tuning a Holley 600 for a street ported 12a
 

Iam looking for any info on tuning a Holley 600 for a street ported 12a.
The only starting point I have is to start with 58 jets for the primaries
and 56 for the secondaries.

i just installed a 600 cfm vac sec on a street ported 12a
what i used on the primaries was 61 and they r working real good far as secomdaries i had them open with a screw wich i put in the little piece of metal that connects the primaries to the secondaries, if u have a a carb with jets on sec i probably would use some 64 or 65m let me know

Doesnt sound bad.
I put my 600 on my stock port 12a over the weekend. I have 57
jets all around. Yeah, the screw thing is in effect, for the
"mechanical secs". Also the choke is history! She is running damn
good considering I have had it on for 4 days with no tuning.

if you make the linkage sloppier, and make the secondaries come on slower it will run much better and harder when you smash it...

Heh, the "screw thing". I've got that too.

Which linkage? And with sloppy linkage will the secondaries fully open.
Also is that with the vac sec hooked up or changeing over to the
mechanical, with the screw trick? I have a stumble when first
accelerating, then again when the secs start to kick in. But if I
accelerate with authority applying even and constant pressure it
will perform fine? That is not just slamming the gas. This is with 57
size jets in all fours. I think I might need bigger secs?

"accelerate with authority"

Which car comercial was that phrase from? Or was it for Splitfire plugs or some other aftermarket gimmick? There's this other one where a guy says "you hit the passing gear and you're gone!" or somesuch. Heh, that's automatic-speak right there.

To get back on topic, a quick fix you could do would be to do the screw trick if your secondaries aren't opening as soon as you'ld like, but it's just a quick fix.

Having said that, I need to learn more about Holleys because I'll be rebuilding my first one pretty soon. Any info and tips/tricks you've got will be apreciated.

I cant believe there is not more info out there about Holley's on Rotories. I guess
I need to step up and study up on the Holley and tuning it. I need to figure out the
correct terminology, so I can say what I mean and mean what I say. I do know I
need less gas in the low rpm's and more gas in the high rpm's. I think our rotory
group is slipping in the Holley catagory!

I brought my secondaries up to 62's and it runs better. Iam currently running 57 jets for
the primaries and 62's in the secondaries. The only problem I have now is trying to figure
out how to reduce the initial squirt of gas in the primaries. When lightly depressing the
accelerator it will stumble in the beggining especially when running the a/c. I have
assumed the stumble is comming from the gas squirting from the brass tubes in the primaries.
I think when I get a holley book, I can figure this problem out quickly?

Now, street ported, just brakeing it in. Runing like a champ. Got 57 jets in the primaries and 62 jets in the secondaries. Still need to get the center hung float bowls or notched float bowls with jet extensions? Not sure on which one works better. Any suggestions?

I have changed out my primaries to 62's. My car is running alot better with the richer primaries and I am thinking about trying 65's, like my secondaries. I have also found out the 600's with th vac secondary dont have adjustable air bleeds, I now need to look into how to tap them and make them adjustable. Good thing I have an extra 600 laying around! I think since the air bleeds are supposed to richen higher rpms it should make my engine really open up the way it should?