Technical No mechanical timing advance

Timing checks out perfectly with the same light on a different car.

 

Strange thing about that is the action feels the same as the distributor I just put in the SBC in my 62 Bel Air. The only real difference is the location of the distributor on the engine.

 

I can only imagine the fit and finish of a distributor machine you might own... Pinstriped, Plated or Factory Fresh?

-rick

 

Have heard of some having issues with the rib on the backside of rotor contacting weights preventing weights from moving.
Actually 'locking' weights, so no advance.
Fix is to dremel/file rib down so weights can move with rotor installed.
Worth a look see.

 

I might not have explained it very well but I did check that out and they moved freely under the rotor. I wish it was that simple but that's not it.

 

I believe you have a distributor that is set up for CCW roatation. Look at this picture of a Delco rebuild 455 distributor. Flip the weight over with the number down and see what happens.
https://autopartsobsolete.com/1971-...yl-455-rebuilt-Delco-Distributor-1112104.html

 

I might try that, but that's a points distributor not HEI.

 

Points, HEI shouldn’t matter. Only thing that matters is the rotation and weights at the rotor.

 

Looking in Motors manual the weight are on backwards.

 

Just popped this photo.

 

Read the "NOTE" part at the top of the instruction sheet in your first pic in post #1.
Is your distributor a GM HEI or a MSD HEI...???You might be trying to fit the GM kit to your MSD.

 

Tell GM that I guess.



Another photo I found online

 

It's a GM distributor. I tried to make clear in my original post that I was having the issues before I recurved it.

 

HEI in ford 302 ccw

 

The motors manual shows the weights like your when the vacuum advance it coming in from the other direction and weights flipped side to side if the advance comes in like yours.

 

For a points distributor or HEI?

 

HEI

 

I looked it up in a 1976 39th edition.

 

I've got an HEI sitting on my bench. I'll run some experiments with that one.

 

Here is a pretty good article on the HEI, it doesn't solve your problem but has a lot of good information about them.

 

Can you quick twist the gear and make it advance? If you hold the housing down pressing the gear against the work bench, will the advance still move by hand? I've had to pry up the center plate on a few after messing with them to get the lower advance plate freed up. Do the stock weights have polish marks on them where they rub the plastic bushings? I've seen points distributor not advance right because the upper bushing was rubbing on the under side of the advance plate.

 

Wow, lots of information! Thanks for that, I'll read through it in detail.

 

Yep, it twists easily and advances, there's no indications or feel of binding or rubbing.

 

Alright, I got home from a swap meet today and tinkered a little bit so I have an update.

Putting the lightest springs in with the light msd weights, the timing started coming in about 1,100 rpm and at 2,200 RPM I had 11 degrees of advance. I didn't run it up higher as it's late. I'm going to try it tomorrow with the heavier stock weights and the light springs and see what it does. It's less advance then I should get according to instructions, but at least it's actually doing something.

 

Just a suggestion, but check that the advance cam is in the right way and allowing the weights to move as they should.
In your pic the weights look like they are sitting a fair way out when at rest.

 

Now that you have it running and that distributor is in your face just for fun pull the cap and rotor and flip the weight and see what happens.

 

I think this is a big part of the issue. His weights are already a good bit out just sitting on the bench.

-rick

 

You might want to review all the HEI weight photos shown on this discussion.

 

I'll trust GM and others on the weight direction.