Carb Size - BBC

[JLSTOEC]

Im wondering what carb you guys think would work best for my combo listed below. Im assuming a Dominator, but what size, company? Thanks for the help.

1970 Chevelle
Drag Race Only
3200 Pounds with driver
29.5 x 11.5W Hoosier slicks
Southside Machine lower control arms and adjustable upper control arms
4.11 gears in 12 bolt Spool
Turbo 400 Trans with Transbrake
540 CI Big Block 4.50” Bore 4.25” Stroke
12.8:1 Compression
Bullet Roller Cam 4/7 swap. 276, 280 duration at .050. .757 .737 gross valve lift
AFR 357 CNC cylinder heads.
Brodix HV Intake
MSD Digital 6 Ignition

[JLSTOEC]

Oh yeah, The Brodix HV is the intake I have for it but I would be willing to change. Any suggestions on that would be helpful as well.

[hammertime]

1050 is what I'd put on it, for the best GAS carbs check out either a APD or a Pro Systems.

[OneBadGMC]

http://www.timmcamis.com/cool_stuff.html

There's a carb calculator on McAmis' site.

[adjones419]

1050 Quick Fuel Dominator

[lanham]

If you are buying an out of the box carb then go with a Holley Dominator 1150 cfm,but for the price go with Pro Systems and they will recommend what you need.

[scuncio]

Look into Dale Cubic @ CFM carbs, He makes a real nice carb.

[Tod74]

I have a 540 similar to yours with smaller heads than you have in a 3050 lb car with a 8896 1050 and it works great.

[JLSTOEC]

Thanks for the responses.. I have a 1250 dominator and have heard it is too big. How much power/ET do you sacrifice running a carb that is too big? Also, what intakes do you guys like for a BBC making 825 HP?

[lanham]

I like a super victor intake.Call pro sytems and ask if the 1250 is too big.A buddy of mine just got a pro systems carb and they recommended a 1200cfm for his motor and it is a 540.He had a 1050 quickfuel and put the pro systems carb on and picked up about a half a tenth.

[JLSTOEC]

Do you guys have any thoughts on intake manifolds for a setup like mine? I hear alot of guys running Edelbrock intakes. My Brodix HV is basically untouched so Im wondering if I should have it worked on or buy something different.

[lanham]

I would clean some of the casting up and gasket match and use the intake you have.

[Tod74]

I like a super victor intake.Call pro sytems and ask if the 1250 is too big.A buddy of mine just got a pro systems carb and they recommended a 1200cfm for his motor and it is a 540.He had a 1050 quickfuel and put the pro systems carb on and picked up about a half a tenth.

damn...probably spent 1100 bucks and picked up half a tenth. :?

[johnracer]

Here's my 2 cents. The 1250 is probably a LITTLE to big, but since you already have it it's free. Right? It might actually run a little quicker and faster with a little too big carb, but consistency will suffer. A 1050 would be more consistent. JMO. I'd try the 1250 and see if it does what you want after proper tuning.....

[lanham]

Tod74 the carb was just a little over $900 and picked up a half tenth on an already perfectly tuned engine.The car runs 5.30's 1/8 at 2500lbs on gas.The engine is a n/a conventional head 540ci.Just think if he went to alcohol.

[hammertime]

Tod74 the carb was just a little over $900 and picked up a half tenth on an already perfectly tuned engine.The car runs 5.30's 1/8 at 2500lbs on gas.The engine is a n/a conventional head 540ci.Just think if he went to alcohol.

How do you pick up a half a tenth of a perfectly tuned motor :?: :lol:
I am on board to get this answer :D :shock:

[lanham]

It had a 1050 Quickfuel carb, was perfectly tuned the car ran 5.40s, then switched to the 1200 pro systems carb and after that it ran in the 30s with only a carb swap.I am not trying to sell their carb,this is just the good experiences i have seen with pro systems.

[hammertime]

Good tuned 1150 gas carb on 565 sent it to APD to work there magic picked up .15 ... both Pro Systems and APD have there stuff together on gas stuff ...

[SPEEDNEEDS1]

I may also need a little help, I have a 468 (4.310x4.000) Edelbrock square port heads, 2.25-1.90 valves, 13.3 comp, .722-.722 lunati cam, all in a 3500lbs 66 Chevelle, 400 turbo, 5500ati, and a 5.38 gear....What do I need for carb. I have a 830hp and it ran good on my last 468 but with much less compression?????????? I also run 1/8 mile ONLY (5.38)

[tcarda]

I may also need a little help, I have a 468 (4.310x4.000) Edelbrock square port heads, 2.25-1.90 valves, 13.3 comp, .722-.722 lunati cam, all in a 3500lbs 66 Chevelle, 400 turbo, 5500ati, and a 5.38 gear....What do I need for carb. I have a 830hp and it ran good on my last 468 but with much less compression?????????? I also run 1/8 mile ONLY (5.38)

Call Pat at Pro-Systems. I bought a new one from him in December for my 540. I won't have my motor on the dyno until April and I can't wait to see the numbers. Good luck! http://www.prosystemsracing.com

[SPEEDNEEDS1]

I will call and see if he has an idea

[hammertime]

Call APD also .. both Pro System and APD have very good gas setups.
www.apdracing.com

[jmarksdragster]

It had a 1050 Quickfuel carb, was perfectly tuned the car ran 5.40s, then switched to the 1200 pro systems carb and after that it ran in the 30s with only a carb swap.I am not trying to sell their carb,this is just the good experiences i have seen with pro systems.

Is it possible the added CFM made the car go quicker?
My take is this, the largest carb that will CORRECTLY meter fuel on the intended car/engine/ RPM range will run the fastest ET. Not to take away from any carb rebuilder, they make changes to correct metering issues over the entire operating range of the carb. This will help on throttle stop cars and footbrake cars. On a wide open/transbrake type car, I think the advantage of a "Professional Built" carb over a stock, unmodified carb is diminished to less than a tenth with flow rates being equal and correct jetting for the app. The 9375 or 9377 Dominators (1050 or 1150) would work fine for your car if you take the time to get the jetting correct. If you have money burning a hole or don't want to set it up yourself, any of the above are fine, another is BLP carbs. Just remember, you still may have to change jets on anyones carbs to match your combo.

[cepx111]

I may also need a little help, I have a 468 (4.310x4.000) Edelbrock square port heads, 2.25-1.90 valves, 13.3 comp, .722-.722 lunati cam, all in a 3500lbs 66 Chevelle, 400 turbo, 5500ati, and a 5.38 gear....What do I need for carb. I have a 830hp and it ran good on my last 468 but with much less compression?????????? I also run 1/8 mile ONLY (5.38) A Holley 1050 dominator is what I would recomend but most will say they are junk out of the box, but I beg to differ, I have had excellent results with them just playing around with the jetting to the motor's liking and consistent E.T."S and didnt spend a grand or more in the process either.
JMO ><CHarles

[farrigno]

since were on the subject of carbs what is everybody's opinion/experience on my combo for carb size?; 565 bbc,15-1 comp,bmf350-heads,bullet roller808/775 282-in/294-ex,have a victor454-r-with a box stock 1050/8896 hp-model,car is a 3500 pound chevelle 10-inch tire t-brake,probably see a max of 7800-8000 max trap rpm with a 76-7800 shift point, on a n/a deal,any help would be appreciated.

[topsportsman1]

For that 565 and RPM's your turning,you'd need a 1400 to 1450 cfm carb

[hammertime]

since were on the subject of carbs what is everybody's opinion/experience on my combo for carb size?; 565 bbc,15-1 comp,bmf350-heads,bullet roller808/775 282-in/294-ex,have a victor454-r-with a box stock 1050/8896 hp-model,car is a 3500 pound chevelle 10-inch tire t-brake,probably see a max of 7800-8000 max trap rpm with a 76-7800 shift point, on a n/a deal,any help would be appreciated.

1150 Alky Carb
1250 gas
www.apdracing.com

I had them redo a 1150 on a similar 565 and it picked up .15 after they were done.

[procitation]

Look into Dale Cubic @ CFM carbs, He makes a real nice carb.

We run only Dale Cubic Carbs. Definetly recommended!. Dale is a very seasoned carb builder. He has built carbs for some of NHRA prostocks top contenders. He is also a nice guy, easy to work with, and attentive to questions. I learned tons of info from him 8)

http://www.wforacingandmachine.com/images/07wfpskelly-300_t3yj.jpg

[topsportsman1]

since were on the subject of carbs what is everybody's opinion/experience on my combo for carb size?; 565 bbc,15-1 comp,bmf350-heads,bullet roller808/775 282-in/294-ex,have a victor454-r-with a box stock 1050/8896 hp-model,car is a 3500 pound chevelle 10-inch tire t-brake,probably see a max of 7800-8000 max trap rpm with a 76-7800 shift point, on a n/a deal,any help would be appreciated.

Give Patrick a call he'll get you fixed up

http://www.pro-system.com/

[Tod74]

since were on the subject of carbs what is everybody's opinion/experience on my combo for carb size?; 565 bbc,15-1 comp,bmf350-heads,bullet roller808/775 282-in/294-ex,have a victor454-r-with a box stock 1050/8896 hp-model,car is a 3500 pound chevelle 10-inch tire t-brake,probably see a max of 7800-8000 max trap rpm with a 76-7800 shift point, on a n/a deal,any help would be appreciated.

RON'S TERMINATOR !! Alchohol injection. They have I think 3 different sizes of throttle body.

[farrigno]

not interested in going to alchohol, but thanks for the replies, i sent patrick @ prosystems a tec sheet waiting to here back from him if my 1050 is not going to work...if i need bigger anybody interested in a 8896-1050-hp model it brand new/ may trade up for a 1150 or bigger model. :D

[jaht1320]

Here's my 2 cents. The 1250 is probably a LITTLE to big, but since you already have it it's free. Right? It might actually run a little quicker and faster with a little too big carb, but consistency will suffer. A 1050 would be more consistent. JMO. I'd try the 1250 and see if it does what you want after proper tuning.....

Why would a bigger carb be less consistant? Just curious, I think mine is a little big too.

[jaht1320]

carb that is! :oops:

[hammertime]

Here's my 2 cents. The 1250 is probably a LITTLE to big, but since you already have it it's free. Right? It might actually run a little quicker and faster with a little too big carb, but consistency will suffer. A 1050 would be more consistent. JMO. I'd try the 1250 and see if it does what you want after proper tuning.....

Why would a bigger carb be less consistant? Just curious, I think mine is a little big too.

No in theory it shouldnt be it should be show less et change with more air.

[jaht1320]

Here's my 2 cents. The 1250 is probably a LITTLE to big, but since you already have it it's free. Right? It might actually run a little quicker and faster with a little too big carb, but consistency will suffer. A 1050 would be more consistent. JMO. I'd try the 1250 and see if it does what you want after proper tuning.....

Why would a bigger carb be less consistant? Just curious, I think mine is a little big too.

No in theory it shouldnt be it should be show less et change with more air.

So in theory a larger carb should be more consistant???

[jmarksdragster]

If both are metering fuel correctly the larger carb should be more consistent and make more power. I would run the 1250 and let us know how it works. There tends to be some issues with the factory metering on 3-circuit Dominators, they tend to run fat at low and midrange and lean up top. If yours does, I can send you to a site to help you fix it.

[JLSTOEC]

Guys,

Thanks for the thoughts. I was out racing today and happened to try 3 carbs. An old style #9375 1050, a new HP#7320 1150, and my HP#80532 1250. I jetted them similar and only took the time to set the idle speed and that was it. I wasnt sure if the jetting should be different based on the cfm so it wasnt the most thorough test....but anyway the 1250 actually gave me the best ET and MPH. Like I said it was an untechnical test but I had to try something. The 1050 felt like it ran out of steam near 3/4 track. It could be because I was way off on the jets (93 square on all carbs) or that it was to small. I ran 9.88 at 137 with terrible 1.50 60's due to a poorly prepared starting line (typical short time 1.33) If anyone has thoughts I would like to hear them. How would you jet this? I used the 1250 on the dyno and we had a hard time getting the back cylinders to be rich enough. I would figure the smaller cfm would provide better fuel distrubition compared to the 1250 but the results today were different.

[jmarksdragster]

I have the 80533 1250, factory jetting is 97 for yours and mine and you should run 99 in back if you are lean. It may be a manifold distribution issue. You will jet according to carb size usually. The old 9375 is the best 3-circuit from Holley as far as metering and 93's are OK, but there are things you can do to the 1250 to help. Take out the intermediate bleeds (center ones) and put around .025 in the main air bleeds as well as jet it up. This will help an excessively rich bottom and midrange that is typical on 3-circuits. Invest in an AFR meter, dual O2 is best. I have a FAST but wish I had spent the extra for the Innovate system. If you find you are still lean up top, and good reading anyway, read the following. Mine has been converted to 2-circuit.
http://speedtalk.com/forum/viewtopic.php?t=9934
http://www.motorsportsvillage.com/forum/viewtopic.php?t=3742
http://www.motorsportsvillage.com/forum/viewtopic.php?t=3811

[TheRabbit]

Carb, go to BLP, (Bo Laws Products), http://www.blp.com/
but when you get it it will be a little rich. Gotta understand they are not going to sell you a lean carb and hurt your motor. extra jets will come in the kit. ONLY ONE INTAKE FOR A BBC (24* HEADS) AND IT'S THE PRO-FILER SNIPER.
http://www.profilerperformance.com/bbc-singleplaneintake-206.html