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Help me pick some carbs for 572 HEMI

Posted By: Bishop

Help me pick some carbs for 572 HEMI - 07/10/12 11:59 PM

I'm replacing a single 1250 4500 Dom. carb on a single plane Ray Barton that made 950 HP with a Ray Barton cast alum crossram. It has 13:1, .805 roller cam I've been told I need vaccum secondaries for the 4150 style carbs any advice on brand & size?

Thanks Brian

PS The motor is going down in a 68 dart with a tranny break

Attached picture 7286522-57268HEMIDart.jpg
Posted By: EvilB1Dart

Re: Help me pick some carbs for 572 HEMI - 07/11/12 01:06 AM

You have the best or one of the best in your home state. Love his stuff; Dale Cubic of CFM.

http://cfmperfcarbs.com/
Posted By: rickseeman

Re: Help me pick some carbs for 572 HEMI - 07/11/12 03:14 PM

The original crossram carbs were vacuum secondary but I don't guess you have to run them that way. I think you can still buy the original new 4235/4236 Holleys for about $750 each.
Posted By: AndyF

Re: Help me pick some carbs for 572 HEMI - 07/11/12 03:25 PM

Just depends what you're trying to accomplish. I don't see any reason to put original carbs on there unless the rules require it. Do you have a budget limit? Are you trying to make as much power as possible? Without any idea of what you're doing with the engine it is hard to make a recommendation.
Posted By: Slingshot383

Re: Help me pick some carbs for 572 HEMI - 07/11/12 05:02 PM

A pair of HP 950's would really wake that big motor up!
Posted By: Bishop

Re: Help me pick some carbs for 572 HEMI - 07/11/12 05:05 PM

Andy
No they don't have to be orginials and of course I'm wanting to make as much HP as possible, what do you suggest? This is a 100% race car

Thanks Brian
Posted By: AndyF

Re: Help me pick some carbs for 572 HEMI - 07/11/12 05:58 PM

My recommendation would be a pair of the new all aluminum Holley carbs. You'll save a bunch weight and they are fully adjustable. Most people don't even understand all the new adjustment capabilities on the new Holley carbs since they haven't been out very long. The new carbs are so much better than anything in the past that there just isn't much reason to use anything else anymore unless the rules require it.

Size is a little tougher choice, a pair of 750 carbs would probably be my choice.

If you're comfortable with carb tuning and have a wide band setup on the car then I'd recommend just buying a pair of new aluminum 750's from Summit and bolting them on. If you don't want to mess with tuning then give a carb tuner a call and have them tweak a pair of carbs for you. BLP is who I work with but there are other tuners out there.

If you are a really super serious racer with a big checkbook then call someone like Braswell and have them build you a pair of carbs. But I wouldn't spend that kind of money unless I had a racepak on the car and I could tell Braswell exactly what the car is doing at each gear change going down the track.

I've dyno tested super expensive Braswell carbs back to back against the new Holley aluminum carbs and there isn't a difference on the dyno. But, that doesn't mean that a Braswell won't get you down the track faster. There is a lot of stuff going on during the gear changes and such that you don't see on the dyno.

The cross ram is a bit of an issue for carb tuners. You might have to call around a bit before you find someone who knows what works on those things. A really serious setup would require O2 bungs in each pipe. If you aren't that serious then just jet it a little rich and go have fun.
Posted By: Bishop

Re: Help me pick some carbs for 572 HEMI - 07/15/12 04:09 PM

What about a pair of these for a Hemi crossram?

http://www.facebook.com/l.php?u=http%3A%2F%2Fwww.holley.com%2F0-81870&h=mAQFfwqlZ
Posted By: racerbychoice

Re: Help me pick some carbs for 572 HEMI - 07/15/12 06:13 PM

Quote:

You have the best or one of the best in your home state. Love his stuff; Dale Cubic of CFM.

http://cfmperfcarbs.com/




^^^^^this^^^^^

the best advice so far. call him you will not be sorry. plus you get unlimited service after the sale. you buy one of dale's carbs, you buy him too. plenty of hemi experience.

nhra/ihra pro stock, sportsman and serious headsup racers don't use this guy for nothing. right up there with braswell, gary williams and bob book racing carbs, if not better.

dj
Posted By: AndyF

Re: Help me pick some carbs for 572 HEMI - 07/15/12 07:20 PM

Quote:

What about a pair of these for a Hemi crossram?

http://www.facebook.com/l.php?u=http%3A%2F%2Fwww.holley.com%2F0-81870&h=mAQFfwqlZ




No, I think you're way off with that choice. The new aluminum carbs are fully adjustable. There is no good reason to buy anything else if you're going to be doing a lot of tuning. And with a cross ram, I'd expect a lot of tuning.
Posted By: DusterDave

Re: Help me pick some carbs for 572 HEMI - 07/16/12 12:57 AM

I suggest giving Quick Fuel a call and talk to them about your combination. They are good people.
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