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Author Topic:   manifold & carb. help
Doug 86
Dirt Roller

Total posts: 12
posted June 10, 2002 10:30 PM UIN: 77655541
I am going to start racing on a 3/8mi.dirt track with a 79 nova 350 engine.The rules say i have to run a OEM 2barrel intake and stock carb.Also stock exhaust manifolds,no center dumps.I was wondering which would be the best to use?Also has anyone tryed the speedway 500cfm.rochester carb?Any help would be appreciated.

Dirt Full Roller

Total posts: 69
posted June 11, 2002 01:08 AM
Make sure that the Speedway carb is legal in your class. In IMCA Hobbystock it is considered an illegal carb.

Dirt Forum Racer

Total posts: 87
posted June 11, 2002 01:51 AM
There are "big" 2 bbl Rochester carbs around + or - 450 cfm and smaller 2 bbl Rochester carbs that are about 350 cfm. If they don't specify a CFM rule on a 2 bbl go with the biggest OEM Rochester you can find. If they allow that Speedway 500 cfm Rochester that's your ticket!!

Dirt Freak

Total posts: 408
posted June 11, 2002 08:28 AM
FWIW, keep in mind that the "big bore Speedway carb" is a mass-produced stock rebuild of the older 2G's. Some were large bores, some are just small bore carbs that have been "punched" to appear to be large bore carbs. They are FAR from a
custom built racing carb. They buy tons of them from a rebuilding house and market them as oval track racing carbs when all they are doing is "blowing smoke" at you guys.

There are no special purpose racing parts in those carbs, and all they are doing is putting in the larger needle and seats (hardly beneficial), running a jet tap in them for Holley jets, and throwing fresh gaskets in.

Like I said....spend your $ if you want get what you get there, and take your chances. Might be a good carb, might be a slug. Ya never know with "mass produced" carbs out of a magazine....

OK, so I'm biased....LOL!


Doug 86
Dirt Roller

Total posts: 12
posted June 12, 2002 05:23 AM UIN: 77655541
KPlugnut do you no where i could get a good race carb?My car did have a stock 4bbl.I ask the guy i bought the car from what size cam it had he said it had a firerball cam but had no spec.Also i was wondering is there a certain intake that works better than the others.Thanks

Dirt Freak

Total posts: 408
posted June 12, 2002 09:24 AM
As for where to get a good carb, my answer would be come to me. Kinetic Performance builds custom carbs for any level, any rules, any application from mild street to radically custom.
Since your rules pretty much limit you to the Rochester 2G (unless a quadrajet is allowed), we can build you a very nice carb that will out-flow anything out there if there is no limits. If you're limited to an untouched big bore 2G, we can supply that as well.
As for the intake, if you aren't allowed a
4bbl cast iron intake, then get either a 2bbl cast iron intake from a 400ci chevy, or the Canadian 2bbl intake (says "Canada" on it). Another option is the more expensive marine 2bbl intake that comes on Mercruiser engines). Hard to find, but VERY nice.
As for exh manifolds, the 2 1/2" truck manifolds will be your only choice.

Hope that helps,
KPLugnut aka,
Dayton Umholtz, owner
Kinetic Performance

[This message has been edited by KPLugnut (edited June 12, 2002).]

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