Can somebody tell me what I need to do to get the most out of this cam in terms of setup and adjustments?

I can't seem to get idle below 1000rpms (maybe thats OK?).

Power brakes are working fine.

Vacuum advance doesn't change the timing at idle-hooked up to ported vaccum (initial 18*, total 38*, w/no vaccum adv, 50*+ w/advance hooked up).

Engine seems run good - I spun up to 6000 cleanly, just seesm to run a little rough, and lacks low-end.

Thanks

I had a 300/300 in a 355 SBC and it idled real lopey at 900... sounds like a carb problem to me. check out this link (http://www.chevelles.com/forum/ultimatebb.php?ubb=get_topic;f=4;t=017709)

idles rough,lacks low end, spins to 6000rpm easily. yep, that's what this cam is designed to do!!!

I noticed that even if I back the idle screw all the way out to the point where it doesnt touch the throttle lever it still idles. The cable has enough slack, and the secondaries are fully closed. What am I missing here?

I would say you have something else going on.

I ran the 280 hydro cam in my mild 406 with 10 to 1 cr. I could get it to run at an easy 850 rpm. No power brake problems, etc either.

Rough idle yes...very nice.

smile.gif

I also have used it and had it idle around 850 in a decent 350. That cam has a sweeeeet idle sound!
But I agree the cam lacks low end, even with 3:73s. Not sure why you cant get it to idle down though, sure sounds like the throttle is up on the fast idle cam or something.

noticed that even if I back the idle screw all the way out to the point where it doesnt touch the throttle lever it still idles

sounds like you got a big vaccum leak.

either you have a vacuum leak or your secondary throttle blades need adjusted.

to adjust the secondary throttle position you will need to remove the carb and flip it over. there will be a set screw that runs through bottom of the baseplate near the secondary throttle shaft.

if you are certain there is no vacuum leak you will need to close the secondary throttle blades down. how much i dont know, you will need to experiment to get it right.

i suggest you purchase a good holley tuning book such as Holley Carburetors by Dave Emanuel. it has been a big help to me when tuning and diagnosing my holley carb.

If I apply pressure the the throttle it will go back some and the idle comes down. It seems as if something isn't letting it go down completely. I'll flip the carb over and check the adjustments.

First thing, hook up the vacuum advance to MANIFOLD vacuun, NOT ported vacuum. Ported vacuum will allow the advance to be well over 50* at rpm under power.... not good. The vacuum advance is used for part-throttle cruise to keep the advance high and maintain good part throttle response and decent mileage. When you go to full throttle, the vacuum should fall away and the total timing curve is then controlled by the springs, weights, and stop slot.

I'd check that the fast idle screw is not touching the fast idle cam on the passenger side of the carb. That will make it idle fast even with the curb idle screw all the way out.

Randy