Printable Version of Topic

Posted by: Geezer914 May 20 2022, 11:53 AM

If I install a Mallory distributor in the stock location, with #1 at 11:00, the clips that hold the distributor cap interfere with the engine tin, making setting timing difficult. Just want to double check myself, if I rotate the distributor drive gear to one or two teeth so it lines up with 9:00 with the engine at top dead center, I can line up the rotor at 9:00 and be at top dead center for #1?

Posted by: rhodyguy May 20 2022, 01:07 PM

Did you dimple the tin to make room for the distr body? You pretty much have to. It doesn't take much. I just used a piece of 3/4" dowel and a hammer.

Posted by: cgnj May 20 2022, 07:52 PM

I reindexed the drive gear. I have one with vacuum advance and that was the only way it would fit.

Posted by: Jack Standz May 21 2022, 11:11 AM

I have both the centrifugal advance version and the vacuum advance version.

After I read Jake Raby`s experience with the vacuum advance version that can fail in a way that could destroy your motor, I use the centrifugal advance version only. This one fits better and no tin dimpling needed in my case.

Wouldn't it work and be a whole lot easier to just move each spark plug wire on the distributor cap either one position clockwise or counterclockwise? In other words, put the distributor body in a spot where the clips don't interfere with the tin and then adjust what you now call #1 (#2,3 &4) on the cap to where you have enough rotation to adjust the timing?

Your way looks like it'll work, but if you keep the distributor drive where it is and rotate the distributor body (will have to pull the distributor out of the hole, turn just the body, and then reinstall) either 90 degrees clockwise or counterclockwise from where your first photo shows, it looks like you'll have enough timing adjustment rotation.

Posted by: Geezer914 May 21 2022, 11:36 AM

I indexed the distributor las night so the clips are almost parallel to the sheet metal. If you rotate the cap and switch the wires, the opposite clip hits the sheet metal.

Posted by: Jack Standz May 21 2022, 12:24 PM

Bummer.

I looked at the difference (rough and dirty) between the vacuum advance and the centrifugal distributors and interestingly the rotor to distributor drive alignment, optical sensor, distributor cap, etc. are off between the two. So one might clear the engine tin while the other might not.

Posted by: Jack Standz May 21 2022, 12:24 PM

Posted by: VaccaRabite May 23 2022, 06:37 AM

Can you find Mallory dizzys again? They were NLA for years.

And, yes. You have to dimple the tin to make a Mallory work well.

Zach

Posted by: rfinegan May 23 2022, 07:09 AM

Mine looks a lot like fig 1...




Attached thumbnail(s)

Posted by: Jack Standz May 23 2022, 07:46 AM

Yes, you are correct, they are NLA for a long time. But, you can still find the optical sensor units, springs (i.e. grey, grey), and caps. It's a shame as they work great and can be tuned to your application.

Our 1.8 uses a centrifugal distributor without dimpling the tin, YMMV.

Posted by: Jake Raby May 23 2022, 05:25 PM

I have 3-4 of the 4554101 Mallory centrifugal advance units left. These were all dyno only units except for one that came from my wife's engine when I swapped it to a Bluetooth 123 unit.

If someone wants one, message me.

Posted by: Jack Standz May 23 2022, 07:02 PM

Message sent.