right now im running a 600 AFB, I need a double pumper and I can get a good deal on a 750

the car has run 13.65@103.67 and has trapped as high as 104.97 with the current carb.

it has a single plane manifold.. you think a 750 DP would be too much?

 

750 DP would be too much for a 305. A 600 or 650 would be a much better carb to use.

 

It'll work fine if the jetting, accelerater pumps, and opening of the rear throttle plate is right.

I know it seems obvious, but a carb will only flow what the engine wants. Put a 750 on a 267 SB and it'll only flow 502 cfm (100% VE) @ 6,500 RPM. It doesn't force feed an engine. That's a supercharger's job.

It may not be a "snappy" as a smaller carb, but it'll work.

 

thanks, believe it or not, I knew that


what im asking is if anyone has any experience with a similar buildup and not had enough booster signal thus making the carb unresponsive.


Maybe i shouldnt have mentioned the engine size because c.i. doesnt matter that much, the amount of power the engine generates does

so anyone have any experience with a 750 on a single plane in a car that traps 103-105 and runs mid 13s?

 

Where CI matters is lowest RPMs at which you go WOT.

Keep that high, you can get away with a larger DP than "necessary". Let it go too low, you'll bog.

 

exactly

 

Thats exactly what I was trying to say.

 

ok, so, anyone have any practical experience with a similar setup? im bogging right now with the 600 afb which is why i ran a 13.6 with a 2.2 60 foot time

 

In days of yore I had a .060-over 327 block with 283 crank (w/stock 4" bore, that's a 302...). It had LT-1 2.02/1.60 heads, LT-1 solid lifter cam, 12.5:1 pistons, Torker intake, Powerglide from a '65 Biscayne 283 with stock converter.

With 1200 stall and 310 CID, Holley's chart doesn't even go small enough. Therefore, with a 600 DP, it would bog if I floored it below 2000 RPMs. Besides, with that cam & intake it didn't have any guts until RPMs were well over 2500 RPMs, anyway.

I always wanted to get a TH350 or 400 and higher stall converter, but being Army enlisted and therefore poor during the Carter inflation years, it never happened. And, I wasn't too savy about carb tuning back then, so it surely suffered more than necessary. But, when I swapped that engine over to another '57 with 3-speed manual and 3.55 gears, it was a whole different animal.

Still couldn't floor it below 2500 RPMs, though. In 1978 I took it out to the 1/8 mile drag strip once; with peg leg and bald bias ply tires, I'd launch at 2500 RPMs, only taking the throttle to the beginning of the secondary opening, and when the right rear tire stopped spinning, I'd floor it. They didn't provide little details like RT & 60' back then (time slips were hand written), but it ran 10.25's in the 1/8 @ 75 mph at 6000' elevation.

You'll be better off with a 600 DP, but you can "live" with a 750 if you taylor your driving habbits accordingly. Most likely will run better than with a Performer/AFB either way.

 

thank you, that was more or less the information I wanted.