Edelbrock 1407 carb tuning [Archive] - Chevelle Tech

: Edelbrock 1407 carb tuning


Brucelee
Mar 23rd, 04, 1:39 PM
I just rebuilt most of my engine, I now have it running decently, but I could use some help with tuning my Edelbrock 1407 carb. Here is my combo:

1992 350 block w/L2256 forged pistons
AFR 190cc heads
CC 280H cam w/1.6 Erson rockers
Performer RPM Air Gap intake
Edelbrock 1407 (750) carb (stock rods, springs) with 1" spacer
3" exhaust
T350 w/3.73 posi

I know how to set the idle screws with a vaccumm gauge, but I don't know much beyond that. Right now when I punch the gas from Idle it kind of bogs or hesitates for a second. Does this mean i'm too rich or too lean?
I guess my timing isn't perfect yet either. Any advice on getting this right would be appreciated. If I need new metering rods or springs I'd like to buy just the size I need, instead of the $50+ kit.

Thanks for any help,
BL

Pat Kelley
Mar 23rd, 04, 11:42 PM
You need to get the timing set first or you'll never get the carb right. Off idle problems are often the accelerator pump issues. On the driver's side fromt you;ll see an arm with w link in it. this is the pump link. Try moving to one of the other holes. If the one you try doesn't fix it, try the other one. If neither fixes it you may need to change the squirter. A vacuum leak will cause similar problems, so check that. As for jetting, you can buy the parts individually. Check your manual for the sizes needed to richen or lean. Go up or down about 8% at a time.

MarkM
Mar 24th, 04, 9:06 AM
I agree with Pat.

I've had this happen before. It's usually cause by not enough pump shot, which makes it too lean. If you move the pump arm to the top hole, this will give you a quicker shot of fuel, and richen things up. If you get it to the top hole, and it's still doing it, it could be another problem, or you need a bigger squirter, as stated. I've seen someone modify the pump arm, and carb body to give an even quicker shot too.