Just installed new Edlebrock intake, Holley Avenger carb with vacuum secondary’s, new clutch, and lightweight flywheel on a 1968 400 BB with W30 spec cam and approximate 10.5-1 compression. I have a Pertrionix electric ignition with vacuum advance and set the RPM rev limiter to 6200.

I dialed in the timing 15 degrees advanced. Motor is running smooth (750 RPM) at idle.

Im noticing some starter kickback at startup…usually 1-2 times prior to start up. The starter is new (Powermaster) Can anyone suggest some diagnostics for the starter? I’ve read it could be too much timing advance, issue with vacuum advance, or mechanical advance?

Thanks,
Chad

 

My question is, what kind of distributor ? Points type distributor with Pertronix electronic or HEI type Pertronix ?

What "W-30" spec cam are you using ? 308 degrees or 328 degrees, or something different ?

 

Make sure you have at least 11 V at the solenoid, and then do a starter draw test as well. If you’re not getting full voltage/amperage to either one, it may do what you’re describing.

 

copy that...I'll check that tonight! TY

 

It's a bullet racing cam custom grind with following specs:

Intake / exhaust
duration 228 236
lobe lift. .3000. .3000
duration @006. 274 284
Gross valve lift. .480. .480

Distributor is Pertronix electronic ignition flamethrower III coil. I assumed that was HEI??

 

So cam specs really have nothing to do with W-30 ... probably would have been best just to post the actual numbers in OP. Also, not that it likely has any bearing on your problem, but I'm curious about what size Street Avenger you're using.

As for the distributor, you can tell an HEI from conventional points because HEIs have a really, really big cap.

 

HEI is the GM cap-in-coil system. People mistakenly refer to any electronic ignition conversion as "HEI". They are not the same. Pertronix does sell a Flamethrower HEI-style distributor for Oldsmobiles.

 

It’s not the vacuum advance (since there is no vacuum when the engine is not running), it’s not the mechanical advance (since that comes in at higher than idle RPM), so what’t left is the initial advance.

Most high compression engines use a low initial advance setting in order for the engine to crank over easily, and the total advance is made up with the mechanical advance.

So you can reduce the initial and stop there, or go further and modify the mechanical advance to add the amount needed to achieve the same total advance

Or do as some racers do and add a toggle switch to the coil power feed - turn the switch off, crank the engine, and once it’s spinning turn the switch on so the engine fires. The switch can also double as a home made anti-theft ignition kill.