justanothercar

i have a 355 with edelbrock 600 on it,runs great and pulls hard but when i floor it and open the vaccum secondarys it bogs for a second then kinda surges. i have no clue what it could be.....

F-BIRD'88

First, Edelbrock carbs do not a have "vacuum secondaries"

The secondaries have a velocity air valve. Opens by air flow working against a counter weight.
It's non-adjustable. The velocity valve should open smoothly against the weight of the counterweight if you open it by hand. Sounds like the accelerator pump needs adjustment. You can buy different sized shooters to adjust the pump shot. You can also move the pump linkage link to a different hole on the arm..
More initial timing advance will help too. Recurving the distributor advance curve will allow this while maintaining the same total advance at high rpm..

justanothercar

I tried all 3 linkage holes on the accelorator none of them did any good,i also changed the timing curve that did'nt help either,how do i find the right "shooters" for it?

F-BIRD'88

You can buy a accelerator pump shooter kit with different sizes from Edelbrock. Look in the online listings.
You can get them from many well stocked performance speed shops and auto parts stores or from Jegs or Summit etc.

Look for a vacuum leak around the carb and manifold.
Power brake booster etc.
Propane is good for finding vacuum leaks. With the motor fully warmed up spray the propane in and around the carb and intake. If the motor changes tune or rpm
you have a air leak. pinch off all vacuum lines one at a time. Then pull one plug wire at a time.
The plug wire that does not effect the idle when disconected is the bad cylinder.

Need to know more about your engine combination
(intake, cam ignition timing {initial, total} etc)

Bogs are caused by the airfuel ratio momentarily going
lean (lack of fuel) But if one cylinder is already running lean because of a vacuum leak, no amount of tuning will get rid of it.
A weak spark, retarded timing or fouled plugs will contribute to poor throttle response too.

justanothercar

the motor is a stock short block with .100 dome pistins,882 heads,465/488 summit cam,wiend two plane intake. it has a msd hei,brand new plugs and wires.
I found a vaccume leak and fixed it but did'nt see any change in the bog/surge problem,did make it run a little better though.
initial timing i sat 15* advanced and i think total is about 35*.

JMD83

Reviving an old thread here. What was the end result? Were you able to identify the cause of the bog and how was it repaired?