Too small a carb?

[Brian Sisson]

Alright,

I called Edelbrock and the tech guy said that that carb is fine, but will not support a high-rpm use. I asked what that was and he said over 5K it would start to perform poorly.

Said my jets were fine, and my needles were fine. Said that the problem I'm having is probably from a vacuum leak and I should check that. I had 15 psi of vacuum at idle....so I dunno.

He also said that the problem I was having where I'd stomp the gas and it woudl bog down was from the accelorator arm being in the wrong hole. He said it needs to be in the top hole, so that's an easy fix.

I'm gonna install a carb spacer to cool out the gas in the bowls and see if that fixes it. He said that should as if you are running a steel manifold you always want to run an insulator.

I dunno.
-B.

[Swampthang]

B, you mentioned intake gaskets blown when you got the motor. Could it be leaking again? if heads have been surfaced or block decked it can create an angle difference between intake and heads. this might explain the oil in intake ports on teardown. angle opens up on bottom side of intake...sucks oil from galley and creates a vac. leak. Just a thought.

[Doug]

DaveA stole my words.....

15 Inches, not PSI........Not trying to be smart, you will command more respect from the tech line if you use the correct terminology.

[Brian Sisson]

Ahh...inches. Thanks.

I dunno about the heads surfaced. The plugs looked good, and if what you suggested is true then it would have smoked or fouled plugs...right? Wouldn't it have a little vacuum at the oil fill plug? I could test that with a baggie or something. What should my vacuum inches be? Any idea?

I put silicon on the gasket, so a little surfacing wouldn't effect them.

I dunno. I think that I need to put my old carb back on and test it out again. I don't trust the garbage one as there seems to be no reason it was thrown away and that makes me scared.

-B.

[LuckyPabst]

Take it to the modified tech!!!! Darnit!!!

Chris

[Ronner]

Hey B., I'd have to go dig out one of my Edelbrock carbs to be sure, but don't they have idle circuit adjustment screws? Open them up and you get more fuel, not just at idle, but also during non throttle cruising. As for the vaccuum leak - start it up and fog some starting fluid around the base of each intake runner base, if it perks up you found your leak. You also don't need to change out the needle valves(?) just put lighter springs in - nice thing about that style, no jets to change. Get a 1" phenolic spacer on there with a heat shield and make sure your fuel lines are routed well away from any heat source. On top of that you could booty-fab a cold-air intake out of some 3" rubber hose and a K&N bullet style air filter. Combine cold air with non-boiling fuel (and more of that fuel) and those large pistons and you can forget about pre-iginition problems. personally I'd crank the timing back up to 10-12* as that fat piston gives you a larger area to have to ignite the mix. And get all of your timing in by 2k or so to take full advantage.
On a big block even you cannot hurt it too much by tuning it up a little. Apply semi-hot sb standards to a bb and you're just getting it in tune.

Ron

[dave]

you could put an 800+ cfm carb on it and never over carb it
. I made my truck rt hnd drive over the weekend with my booty fabbed seats. LOL!