I recently bought a hot rod Chevy. It has a 69 396 The guy who built it 20 years ago is no longer with us. The problem is I have no idea what was done to it. It has an old single plane Edelbrock intake with an old Holley. Mallory unilite dizzy, And rather larger cam. What iam wondering is timing issues it seems rather sluggish I checked the timing it was set at 25 initial. Seemed kind of high, so I backed it down to 18 the motor would not run. So I bumped it to 30 and it idles better. Check the balancer to be sure timing marks were not off, they are not. I have never had a motor that needed 25 - 30 timing at idle. Is this a BBC thing?
i thought the timing on a big block was 34 atc...do a search on google you will come up with the correct timing for that motor
I'm assuming no vacuum advance ?? 30 seems way high to me also. I set my racing big blocks to 36-38 total advance - less about 20 deg centrifugal advance - that's about 16-18 at idle. I would double check the timing mark - setting #1 piston at TDC and checking. Correct that, determine your cent. advance, and set to 36 degrees total. Should run pretty good at that.
When you installed the cam was there any making on the face of the cam so you could find out the specs ? That would surely help out but when I have timing problems with cams of un know specs , I just lined up the timing marks on the chain and crank gears , made sure the #1 piston was all the way up and set the distributor on TDC and when it started I did the timing the best I could , mostly by what ran the best and went from there . Are you sure the distributor is set on #1 , TDC ? Was the timing chain set correctly ? If it runs good then you should be OK . Retro Jim
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