Carbs
 

I heard a couple of racer iat the allstar race had some problems with there holley carbs . true or flase ?? Jim Hanig

Hey jim,
Travis had a problem with the holleys on a couple of the BBC cars that had the '4 corner idle circuits'. They don't come that way but it really doesn't affect performance down track, it only helps driveability around the pits and idle.
He's right, but, is it a down track performance issue?

Thanks Bernie Terry is the one that said he had heard it . JHanig

What was the outcome ??

bp4133 Bob Pagano

That better idle and transition circuit is included on Holley race carbs for a reason. And it is not for better in town driving. And if it wasn't an improvement to a race car, those racers would not have applied the technology. Would be a waste of money. A clean leaving stocker does have an advantage. Nice try.

I don't think any of the "FACTORY" carbs had 4 corner metering blocks, If so you also get them for the 428 "735" Carb.

I have a 3310-1 780 carb that David Cook did. It is the Vac carb that is legal as a 750 in some comp & SS classes. I have done some testing with it in my SS/DS car. Before I paid David & started testing I had Wesley check out the carb. He made no mention of the carb having 4 corner idle.
I really don't see that it is a big thing because I have cleaned up the idle circuits on non 4 corner carbs when I do dyno testing of the engine. It is no big deal to change air bleeds & fuel bleeds. It just isn't as adjustable as with a screwdriver. I agree the screws & outside of the metering block don't look stock. (like the original carb) I would like to know the out come because I was about to let Kevin Helms try this carb on his 396 combo. I would like to give David a pat on the back. This carb had a very nice fuel curve, right out of the box...

Adger Smith

I wonder if that falls under the "new" rule that the carburetor must be the same brand and model, as well as having the same venturi and throttle plate size? I wrote a letter, and sent an email, to Glendora a while back, with a list of Holley carburetors the same size and model as the one required for the car, and they said any of them could be used. A couple were newer carburetors with 4 corner idle circuits. I think one or two may have even had a different type of booster venturi. In any event, we bought a carburetor with the correct list number for the car and had that one built. Just to make tech easier and prevent questions. It does not have 4 corner idle circuits.

Alan Roehrich


Bring "AA" classes to NHRA Stock Eliminator!

Alan,
I think the booster issue is avalid one. There are flow advantages to some types as well as signal & fuel mixing. I have seen photos in an NHRA Tech's book about correct boosters. I know the Hemi guys are having to use the correct boosters, Non down leg & Down leg, where they were originally used. I just don't see the 4 corner idle being as big an issue as the boosters. As I have said before, a good tuner can clean up the idle & response without 4 corner idle. It is just easier to retune for atmospheric & other changes with the metering block screws. What was the out come of the concerns that Travis had?

Adger Smith

Adger, I'm not sure, maybe they simply didn't look to see if the boosters were different. I agree, there is a real difference in flow between the three different booster designs. We were looking at what carburetors we could run as replacements rather than spend big bucks for the original number. We were wanting to find an accepted replacement that matched the original, so we could go through tech with no worries. Turns out some of our great racer friends took care of us with a killer deal on the right carburetor.

Alan Roehrich


Bring "AA" classes to NHRA Stock Eliminator!