single carb NSS racing deal

I want to race in NSS this summer but I really don't have the coin to do it right with an Indy intake or a worked cross ram.
So I am looking at the 11.50 class with a single Edelbrock and I'm not sure a 750 will do the job. I have been looking at the 800 AVS Thunder carb but I can get a 750 Performer for about half the price. Do you think 50 CFM will be that much differn't
Has anyone ever run this class with a single Carter/Edelbrock style carb?
Thanks
Gus

the 750's don't flow near 750, probably a little over 700. 800's probably don't flow 800 but i'd bet around 780. the extra venturi area of the 800 is what i'd be looking for. i'd do the 800; they can be made to work.

I have seen several racers with single 600 or 750 afb's.
Remember you will be racing on an index, just need to be consistent not the fastest. Heck all the manifold test I've seen show the crossram down 90+ horsepower.

Don't they also allow the use of a single Holley in 1 of the classes

I know a single 800 will work. That is what we run on our 67 coronet wagon in NSS. Corky Bumpus on a mopar and Jim Netherland on a buick also run a single 800.

We worked with an avs and the hesitation is hard to get rid of. Not a bog but a slight hesitation. I would go with an old style 800 performer series carb.It will work with some tuning.

Something else worth looking into. There is a new edelbrock carb. It has annular boosters to help it during the transition. I have not looked at the sizes available but its worth looking into.

Indexes are on a .25 second scale now instead of .50 second. The 750's are pretty inexpensive used. I'd try 750.
Doug

I got rid of the 800avs hesitation by getting rid of .113" primary jets and going to a smaller squirter. playing with step-up springs can help.

I believe only the NMCA nostalgia super stock classes allows single carb combos. Victory and NSS Inc. only allow dual carbs. Not sure about the other groups. The Modman from Indy seems to work OK, a lot of guys used to run the older edelbrock 2x4 manifolds. And as mentioned you pick an index, so if its a few tenths off, no big deal. I ran a 63 factory cross ram for several years, it was 4 tenths slower than a edelbrock victor Jr , I modified to run 2 carbs. Rules state you must run a as cast manifold but are allowed to modify the top. I have access to a spool gun to weld alumninum, I got $350 in my intake and two used 750 federal mogul AFB carbs off ebay for $75 each, car has run a best of 9.65 @ 140mph. The best I got the cross ram to run was 10.01 & 138mph, same engine only manifold change, the same carbs on both manifolds.

Run the AFB's a 750 will work good - 800 is little better up top but lots of 750's out there for sale - there are a few tricks you can apply to them to make them work better and be real consistent - but they are easy to tune - glad to help you out to get you to the D42 race

Thanks a lot guys I think I will get a 750 and tune it from there. I have an AFR meter that I'm putting on the car this year too so that should at least tell me where the tune is.
The car has run 10.91 with a big Holley so it will probably slow down some with a 750 but maybe not I might be overcarbed.
So I'll be looking for a Performer 750 that hasn't been touched yet so I have a good base to start tuning with.
Being a stick car I don't think I will have a bog issue because I leave on the 2-step at 4500 with the pedal on the wood.

Gus

Sounds like fun!!

Yeah let the clutch fly and start rowin gears fast because I'm sure you know how fast these 493 Indy head engines rev.

Well I got a line on a few carbs already One is an older Competition Series Carter AFB and he also has a few Eddy carbs but not sure which ones.
So I'll pick up a 12 pack and go check them out tomorrow

Gus

Lots of guys that run trans brakes and sticks with AFB's run with the rear air door wedged open. It's easy to try with a couple of pieces of 1/4" vacuum line stuffed into the upper corners of the rear casting above the door weights. Doesn't work well with foot brake or low RPM full throttle leave.
Doug

Thanks Doug I was wondering how that door reacts when on the rev limiter for a second. Will it flutter on the 2-step and not work correctly Maybe someone filmed it with a Go-pro to see what happens.
I'm looking forward to testing as soon as the snow melts around here.

Gus

A mate with a cross ram 409 chev stroker took the air door and weights out completely . Drives it on street a bit said no issues

Tex

Pick the one with the longest Booster. If there is one.

A Genuine Carter 750 will have a longer booster than Later Federal Mogul or Edelbrock Carbs which places the Booster in the correct position of being at the Vena Contractor.

The later carbs got the Booster from the 625 series carbs which has the Vena Contractor mush higher.

Here are the 2 different lengths:
[img]https://photos.google.com/share/AF1QipP8...nR2cGFpRFIwMkFR[/img]

I have also installed holley air bleeds in the top of mine to make it more tunable.

Hysteric

It seems to me back in the late 60's we tightened the spring on the secondary door to get more fuel less air on the hit ? heck that's 50 years ago. Never heard of anyone back then taking it out. Maybe that was stone age thinking. If it wasn't in Hot Rod Magazine we didn't know jack schit.


Brain just had a recall that was AVS carb , 1968 model, Didn't think a AFB had a secondary door.

What RPM were you going through the traps at with the cross ram.

I am running an old heavily modified STR15 with a pair of Diamondback Engines modified 800 Eddies.

I launch at 5700 and shift at 7600 (Jerico.) Best 1/8th so far was a 6.13 with this combo.

-Dave

Gus I think you should hunt for an 800, you are definitely not over carbed right now. I sent you a text.

HEY GUS!!!

Now that's funny I was just making a "parade" lap to see how the new track felt and it feels smooth.
I cant wait until the mid Ohio show.
Just installed the new Strange driveshaft and finished up the transmission mount. New fuel lines and regulator tomorrow

Gus

A guy at the local track was kinda doing the same thing without a helmet or seat belts on for that matter. punched the throttle , it stuck and sent him careening into the wall, bounced off that into the other launching him into the halo bar where the start controls were shutting the car off with his head. . On the plus side the cat scan from the hospital showed no damage to the brain from the wreck but to his benefit they found a growth that did't look good. Wrecking the car probably saved his life.