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Author Topic:   Rule change on carb and intake
Dixon
Dirt Full Roller

Total posts: 45
posted March 10, 2003 12:11 PM
I'm running a '80 Camaro at a high-banked 3/8 mile usually damp track. Rules changed for my class this year.
OLD: Any carb (execpt Dominator) and Performer RPM intake
New: Any single pump 4 barrel 750 CFM max, no milling of choke horn and cast iron intake
I know I'm going to run the cast Z-28 intake, but I don't know which carb to run.
Motor info: 355 w/ 487 heads(2.02,1.60) Crane .512" lift, 106 lobe seperation, 270/276 duration
Any suggestions would be greatly appreciated.

outlawstock17
Dirt Forum Champ
Total posts: 620
posted March 10, 2003 01:37 PM
race prepped q-jet.

KPLugnut
Dirt Freak

Total posts: 408
posted March 10, 2003 02:42 PM
For ease of tuning, I'd go with the 3310 Holley. It's easy to convert it to a single feed carb, and kits are available to convert the rear to jets for ease of tuning.

Hope that helps,
KPLugnut

superdave
Dirt Forum Racer

Total posts: 89
posted March 10, 2003 05:47 PM
I like the Qjet idea. No adapter plate is better than trying to get a square bore Holley on it. Love the looks it gets and the more they look at it the less they look at the rest of your car.

Good luck,

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Superdave
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Donnie Ross
Dirt Maniac

Total posts: 109
posted March 10, 2003 07:07 PM
i believe the marine cast high rise is holley
bolt pattern the early z28s used holleys not qjet so an adapter would be required for the quad cutting down on airflow.

superdave
Dirt Forum Racer

Total posts: 89
posted March 11, 2003 03:00 PM
The latest cast iron version has dual pattern for the carb I think.

Good luck,

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Superdave
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Dixon
Dirt Full Roller

Total posts: 45
posted March 11, 2003 05:07 PM
Thanks for the input everyone! I forgot to mention that we are allowed to have a 1" spacer. That should help me adapting carbs. I've never thought of running anything other than a Holley, could you guys tell me more about the Q-jet?

outlawstock17
Dirt Forum Champ
Total posts: 620
posted March 11, 2003 06:19 PM
the smaller primaries of the q-jet will get you off the corner quicker, while the HUGE secondaries give you long legs to get down the straightaways faster. the key is tuning the q-jet to open the secondaries at the precise time. kplugnut might be of some help here. he could build you what you need.

the other guys will be scratching their heads wondering how you're outrunning them with a "quadra-junk", lol.

Monster
Dirt Maniac

Total posts: 135
posted March 11, 2003 06:23 PM
Back in my drag race days, I remember replacing a 715cfm vac Holley with a 650 mech secondary model, and dropping et and gaining mph. My thoughts at the time were that the smaller carb, even though rated at less cfm, was actually less restrictive. Per your rules, you can't use a dbl pumper, but Holley makes a 660 center squirter(4224, I think) that only has 1 big pump, but squirts that shot down all 4 bbls, so technically, it's still a single pumper. Would drive the tech guys nuts!

outlawstock17
Dirt Forum Champ
Total posts: 620
posted March 11, 2003 06:57 PM
yeah, i tried one of the center squirters once on a factory stock. it was a dog off the corners as all 4 barrels open simultaniously and with it being a center squirter, you can't stage the opening of the secondaries. they work good drag racing on a tunnel ram in pairs though.

[This message has been edited by outlawstock17 (edited March 11, 2003).]

Donnie Ross
Dirt Maniac

Total posts: 109
posted March 11, 2003 09:04 PM
one other thing do not let any carb experts
tell you to put a ***** in the linkage to open the secondaries on a holley instant dog.

Dixon
Dirt Full Roller

Total posts: 45
posted March 12, 2003 07:18 PM
I was looking through a P.A.W. catalog and found a Holley Model 4160HP, #80529 that has no choke tower (rules don't say anything about not having one, just can't remove it) and is single pump. I was wondering if this is a misprint or if anyone knows about that model. It looks pretty nasty and has the price tag to go along with it.
KP, I also looked at the 3310, and the catalog said it already had vac. secs. I guess this could be a misprint too, I just haven't had a chance to call them and confirm. What do you think?
Thanks in advance.

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