The Stovebolt Site Forums The Shop Area The HiPo Shop Poor Engine Acceleration

I have a recently rebuilt Chevy 350 SB with an Edelbrock 650 CFM 4 bbl carb and a Crane cam with 260 duration, Carter mechanical fuel pump (for 4 bbl). I have a 350 Turbo auto transmission. I am at the stage where I can drive my truck, but I get poor engine performance on acceleration. In the driveway under no engine load, I can get smooth acceleration from idle to WOT. However, when I am on the road and I stomp the pedal (not that I plan to do that a lot) the engine bogs down and I get no power. However, when I slowly accelerate the engine seems to ramp up to higher RPMs. I am at 10 degrees BTDC on my timing (since I do have a slightly higher performance cam).

What do you think the problem is? I do have a new distributor, wires, etc.

Is the advance working, I throw the timing light on it and see if it advances as RPM goes up.

Sounds like little secondaries action. Maybe a weak accelerator pump. I don't know that much about them carbs, just an educated guess on my part,
Scott

Hi,
It might be your rear gears, I have city gears that makes it accelerate fast but slow highway. You might take a look at that. Hope I helped

Is there a TV cable and the proper bracket hook up to the transmission?

52pu

Did you check all your vacume hoses?

Oops. Never mind -- I just saw you said it idles fine.

Sounds to me that your carburetor is "loading up"(too much gas under acceleration...I had this problem with a Holley 600)... that is unusual for an Edelbrock carb which tends to be very smooth. Check/reset your floats...should fix the problem.

We run 650's on a dodge, and race car, my 59 has a 750. Sounds and act like accelerator pump, but also moving throttle slow to fast easy, could very well be filter. popcorn The Truth is Out There ( Your mechanical fuel pump should read 7 to 15 psi)