New Distributor , Not Enough Advance

[redchev]

I bought a remanufactured original distributor for my '70, 350 cu in engine and I can only get 24 degrees full advance out of it. Has anyone else experienced this. I haven't taken it apart yet to see why it only gives 24* max but was curious if this is common on these remanufactured distributors. Thanks.

 

[Tom Bryant]

Is that 24 degrees in the distributor or 24 total including the initial advance?

Tom

 

[redchev]

Is that 24 degrees in the distributor or 24 total including the initial advance?

Tom

Hi Tom, That's 24 degrees total measured at the harmonic damper without Vacuum advance. It's been a while since I worked on this but if memory serves I think I was seeing only about 10 or 12 degrees of centrifugal advance. Base initial advance was set at 10 or 12.

 

[Tom Bryant]

Should go to around 34/36 total. You should see around 24 to 28 degrees of centrifugal advance in the distributor and it would be nice to see it all in @ 3000rpm. It may come in several hundred rpm later depending on the weight springs that are on it. You can get spring kits and change the springs to dial it in where you want it. Initial advance setting should be 12 to 16 depending on what your engine will tolerate before detonation. I wonder if there is something limiting the movement of the advance plate. I hate to suggest taking a newly remanufactured distributor apart but you may need to in order to see what is going on. It could be that the distributor was modified at some point to limit advance and the rebuilder didn't notice it.

Tom

 

[redchev]

Thanks for your response Tom. Logic would say you are right. I was hoping some might share a similar experience that way I could go straight to the problem. I have been so confident that a new distributor wouldn't do this that I started to doubt my timing light. But I have checked it on two other cars and it seems right on. I'm not afraid to take this distributor apart, I've rebuilt them before including align reaming new bushings. I have other work and I'm not ready to tear into this yet. But before good driving weather arrives I want to straighten this out. I started to theorize that maybe it is intended to be this way. I ordered it for a 350/350hp engine and I noticed that in the cataloges that the same distributor number is offered for everything from 1970 to '72 or maybe even later. Knowing that the later engines had less hp and cammed differently I thought maybe the suppliers are offering a milder distributor for all engines. Not what I wanted, of course. But no one seems to have noticed the phenomenon I am seeing. So I'm still searching for any logic in this. But soon I hope to get time to work on it, we'll see. Thanks, always interested in any thoughts.

 

[Halfmoon]

Hi Tom, That's 24 degrees total measured at the harmonic damper without Vacuum advance. It's been a while since I worked on this but if memory serves I think I was seeing only about 10 or 12 degrees of centrifugal advance. Base initial advance was set at 10 or 12.

That would mean that there is only about 6 degrees in the distributor. I would think there must be a stop bushing in there that is limiting the advance pin in the slot?