Motorator Experts - Just rebuilt 350 sbc. Runs great in low rpm's not so good in higher rpms. Any ideas to fix the problem?

Motorator Experts

Just rebuilt 350 sbc. Runs great in low rpm's not so good in higher rpms. Any ideas to fix the problem?

This motor goes in a dirt track race car and needs to run strong around 6000 rpms. I have tried three dif. carbs and adjusted timing but it did no good.

Asked by: Ivan

User type: Enthusiast

Asked on: July 26, 2010 22:53

Vote on this question

Email this question

Save as Favorite

Flag as Inappropriate

Answers

Tri-5
User type: Enthusiast
Posted: 18 days ago

Flag it

I supposed this can be a number of things. First off, what do you mean by "doesn't run great" in high RPMs? Does it surge or bog down?

You're right in that it could be a lack of fuel (or too much) or losing ignition. The spark can be blowing out. You could also be floating valves, which might mean you have bad valve springs or need higher pressure springs. It could also be a vacuum leak, one that only occurs as vacuum increases at high RPMs.

Give us some of the specs on the motor and I'm sure we can help you more.