Technical Olds 324 Ignition Tips

Hi, Looking for some tips/hints regarding distributor set-up for a nicely built 324 Olds with 270 degree cam and Rochester tri-power. Specifically initial timing(factory says 5 degrees) and total advance. Should we use manifold, ported vacuum advance or none at all. Any help appreciated as this is a nice car but simply sounds terrible especially at an idle. The engine has the correct plug wiring and the Rochesters are not flooding and everything is nicely rebuilt. Thanks!

 

I have a '49 303 Olds with a distributor from a '54 324 going in my car. The factory manual for 1952 Olds says to use ported vacuum advance. Haven't run the motor yet so can't help with timing settings.

 

@Bcap55 Thanks for that info, gives us a place to start.

 

Do you have vacuum advance?

 

If it were mine I'd set it at 12 degrees and go from there

 

With any engine that is not bone stock, I set the advance at idle using a vacuum gauge. Plug the vacuum advance if any and get the car running. When it is warmed up and idling well I slowly advance the distributor until the vacuum reads the most and then retard it just a little. That sets the idle advance. You should at least check the total advance at speed with a dial-back timing light. Most OHV engines like a total advance in the mid-thirties. If an engine has been modified the ideal total advance can vary and can best be determined by the "seat of your pants". If you have access to a distributor machine and a dyno, the entire advance curve can be tailored to the engine. I don't have either of those, so I'll stop here.

 

Using the original dist there is a vac. adv. which is currently using manifold vacuum. I found any more that 10 degrees initial it would kick back on the starter. @tubman Thanks for that tip, I will give it a shot. Lots of time with Chev and Ford, not so much with an old Olds so any help is more than I have on my own. Thanks again to all.

 

Using manifold vacuum for the vacuum advance will give you a smoother idle. However, when you set the initial timing you need to have the vacuum advance disconnected. If you have a timing light that allows you to dial the timing in (reads advance on the light), I would disconnect the vacuum advance and set the timing at 30-32 degrees at 2500 rpm. I'm guessing at the total timing at 30-32 degrees as that's what most engines like. Someone out there should have the spec for the centrifugal advance on your Olds engine.

I'm running a 401 Buick with a mild cam. I have full vacuum advance at idle and it smooth's it out quite a bit. I always run vacuum advance. It's purpose if for part throttle fuel economy. It also makes the engine run smoother at cruise. As soon as you step on the throttle the vacuum advance goes away and you only have your centrifugal advance controlling the timing. Back off and bring engine vacuum back up, and you add the vacuum advance.

 

Thanks for that tip also, we'll start by setting full advance timing as suggested. Speaking of a 401 Buick, we have another coupe here with a 401 with similar tri-power using an original GM distributor and it runs like a watch, this Olds may be possessed.

 

@4wd1936 how did you make out with the Olds timing issue?