Thread: Supercharger Help...

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I am in search of information that can lead me to getting my motor to run properly.

I'm running a 350 Crate engine, Comp Cam 262, Shortie Headers, Weiand 144 Supercharger, and a Holley 700 Cfm DP.

First of all... what should be vacuum inches be at while idling? Currently it seems to be at about 11 inches in Park, and about 8 inches in drive. Is this ok?

While in drive, say at a light, the inches seems to vary from 8, sometimes lower and the motor wants to stall out. I'm thinking that I have a vacuum leak somewhere?

also I set the timing, and went to better octane gas, but the motor still pings, and the only way to get rid of the ping is to have the timing way back from where it should, and I don't know what to do, get a boost referenced timing retard control? Or is there more to my problem that I don't know about. I think the last time I set the timing (car has been sitting for awhile) the total timing was only in the low 20s, not the 34 degrees I was aiming for, just so the motor didn't ping.

Can anyone lead me in the right direction? tear it back off my motor and reassemble to make sure there are no vacuum leaks and then go from there or what?

Any help is appreciated, this problem has been driving me totally crazy, I just want to drive the car, heh.

Thanks.

You need to check for a vacuum leak. Put your hand over the carb and see does it smother out or continue to run. You may also need to fatten the jets in the carb. You should be able to run at least 32* timing no problem. Seems to me you should be pulling a little bit more vacuum, but I don't know the LSA of your cam. I think it's 10, It should be at least 12 and even better at 14. The blower is going to kill some of your vacuum because its still putting out a positive pressure, just not enough to overcome the engine's vacuum. It can't pull enough air with the throttle shut. I really think it'll run better if you put the stock crate engine cam back in it.

Tech should be able to give you a lot more info, I'm still new to the blower technique myself.

Hi there, do a search on blowers, there is a thread not long ago that had lots of discussion. Timing should be boost referenced to avoid detonation. Carby needs to be set up to supply enough fuel for the air being rammed into the motor. Also need to avoid having to high a static compression on the motor as it will give you problems. Blowers heat the air during compression which can cause detonation if there is hot spots. Lots of variables, a cam with excessive overlap will bleed dynamic compression out of the cylinders which which will prevent detonation, reducing overlap will give more power but will make detonation more possible.