Hey guys I wonder if you can help me, A friend of mine just had a 406 small block built for his car, the problem is it idles the best when the initial timing is 40 deg adv.? if we back the timing down to about 18 deg it runs like crap and starts running hot and clattering, what could be up with this motor everthing is new, msd vacuum advance dist, 6al box, Initial timing was set with the vacuum advance plugged, any suggestions?
thanks jeff

i would be double checking the balancer and timming tab.............make sure tdc is tdc..............with the current balancer and timming tab

That's what I was thinking but it did come from the engine builder with the timing tab and the balncer installed set at top dead center?

To be honest I don't know my car has been doing the same thing for 5 months and it's not my balancer, So if you find out what it is let me know I have been stugling with this forever.

Jeff,
First of all what type of timing light are you using ? If it's a "dail back" type light, MSD says not to use them with thier systems. I have seen one read 20 degrees different than my old Sun light.

What is the total timing ?

Is he running ported or manifold vacuum to the dizzy? try manifold vac if you aren't already. That way, you can run initial of 18* + 20* vacuum = about 38* at idle.

Sounds like he may be running ported at this time (no vac advance at idle). Mine runs like a$$ too w/only 16-18* intial - needs that extra timing from the vacuum advance to run good.