Which Carburetor?

RIMike · Post by **RIMike** » Mon Oct 04, 2004 4:51 pm

I have a 79 Dodge Aspen R/T with 360.
.30 over 360 around 10:1 compression
202 heads with a lot of porting and 2.055 Chevy intake valves
a mechanical cam with 236 duration @.050 lift
1.6 roller rockers
A Mopar M-1 single plane intake
A 10" 3000-3400 stall converter
Manual shift valve body
4:10 gears

I use this car for high performance street driving, about 50-100 miles per month. I would like this car too idle somewhat and be very fast when I nail it. I have tried a few stock Holley carburetors and I can`t get any of them to idle or accelerate for sh1t.
What would you recommend for a carburetor?
I was looking at the Barry Grant "Speed Demon", "Mighty Demon" and the Proform 750 Double Pumper.

speedtalk · Post by **speedtalk** » Mon Oct 04, 2004 5:22 pm

Hi Mike, thanks for joining the forum. I purchased a 1000 demon a few months back and it's the best carb I've ever had. I'd say a 750 Demon for your combo

RIMike · Post by **RIMike** » Mon Oct 04, 2004 5:44 pm

Are using it on the street?

speedtalk · Post by **speedtalk** » Mon Oct 04, 2004 5:47 pm

Yes sir

tk · Post by tk » Mon Oct 04, 2004 6:58 pm

speedtalk wrote: I'd say a 750 Demon for your combo

Or a 750 HP series Holley

RIMike · Post by **RIMike** » Mon Oct 04, 2004 7:46 pm

tk wrote:
speedtalk wrote: I'd say a 750 Demon for your combo
Or a 750 HP series Holley

I have already been through 3 750 Holleys, they seem to be crap right out of the box. I would like to step up to something of better quality.

Speedtalk, I called Barry Grant`s tech line to ask which carb would be best for my set up and talked to some snot nosed kid who was reading from a menu of questions. He said I need a 650 Demon, I don`t know if I need that or a 750 Speed Demon?

speedtalk · Post by **speedtalk** » Mon Oct 04, 2004 9:00 pm

RIMike wrote:I don`t know if I need that or a 750 Speed Demon?

I know, I always love it when these guys read off questions their computer is spitting out. I actually think you need at least 750.

Guest · Post by **Guest** » Mon Oct 04, 2004 9:38 pm

I'm a little more extreme than some people but i would go with a 750. However, i prefer double pumpers and i also run a 1:1 linkage on my street cars.

RIMike · Post by **RIMike** » Mon Oct 04, 2004 10:54 pm

Speedtalk, do you think I could get away with using the 750 Speed Demon?

Speedy Goomba · Post by **Speedy Goomba** » Mon Oct 04, 2004 11:41 pm

a 750 holley is not even CLOSE in quality to a 750 HP holley. The HP series are very nice carbs and from what i've seen very close out of the box.

tk · Post by tk » Tue Oct 05, 2004 8:14 am

Speedy Goomba wrote:a 750 holley is not even CLOSE in quality to a 750 HP holley. The HP series are very nice carbs and from what i've seen very close out of the box.

Exactly , these are the old Barry Grant carb castings
( when they were called gold claws)
before they switched names due to a law suit from Holley.

HP series are 100% better than those plain double pumpers.

RIMike · Post by **RIMike** » Tue Oct 05, 2004 9:33 am

tk wrote:
Speedy Goomba wrote:a 750 holley is not even CLOSE in quality to a 750 HP holley. The HP series are very nice carbs and from what i've seen very close out of the box.
Exactly , these are the old Barry Grant carb castings
( when they were called gold claws)
before they switched names due to a law suit from Holley.

HP series are 100% better than those plain double pumpers.

But how do the HP Holleys compare to the Speed Demon and Mighty Demon?

ozrace · Post by **ozrace** » Tue Oct 05, 2004 9:34 am

Mike
A BG 650 Mighty Demon will flow about the same amount of air as a 750 Holley. The 750 Demon is closer to 900 cfm in Holley terms.
If you want something really punchy down low, the 650 is probably the way to go.
You will find the Mighty Demons will idle nicely because they come calibrated for ported heads, single plane, cam, etc - plus they have an adjustment screw on both shafts, as well as an idle bypass system that you adjust through the air cleaner stud hole, so you can keep the butterfly to idle slot relationship right.
From my experience with them, the only thing you might have to do is jet up a little for best power. Maybe 3-4 jet numbers front and rear.
The Holley pro series carbs are also a nice carb.

RIMike · Post by **RIMike** » Tue Oct 05, 2004 11:52 am

Thanks for the info ozrace.

andyf · Post by **andyf** » Tue Oct 05, 2004 1:00 pm

The Edelbrock AFB style carbs work great in street perf applications up to 600 hp. The fuel curve can be easily dialed in with the metering rods.

Here is an article I wrote for PHR on the Eddy 800 cfm carb: http://www.popularhotrodding.com/tech/0403phr_carb/