Timing issue

[Jac Mac]

Originally Posted by 951mat

I'm stumped on the mechanical advance of my MSD on my 427. Very simply my initial timing right now is +/- 12 degrees. I have the 2 light silver springs and the red bushing in my MSD distributor. The red bushing should deliver 28 degrees of additional advance for a total of 40ish.

My timing all in is only 25 total at 2300+ rpms. What gives????? By the way, if I set my initial timing much higher, starting is much more difficult and the engine "runs on" after shutting down, I assume because of the pump gas its on. I don't think any of that really matters with the main problem of my total timing not adding up. Any way to trouble shoot this?

Thanks for any advise.

Mat

If you are 'only' getting an indicated 25° total advance @ 2300+ RPM and higher ( I would check @ 4000 RPM ) then it is obvious that the mech advance is sticking or being prevented from functioning. You have already confirmed that by stating that the engine becomes hard to start when you advance the distributor manually to obtain that 36°/40° Total and the over advanced state which raised the cyl head temp to provoke run on after shutdown. The talk in other posts about rates of advance dont make a lot of sense if the advance mechanism was free as the weights would be returning to the 0° position for startup cranking speed which is clearly not the case.

Jac Mac