Inside of the distributor

[MBI Houston]

Hi Folks:

I am putting a new distributor in my 30 Coupe. (no prior experience with the distributor) My question is about the correct placement of the upper plate in relationship to the lip on the distributor body. Should the three tabs on the upper plate fit under the lip. If so, is there a trick to get all three tabs under the lip? Any insight will be of great value. Thanks, Marshall

[RonC]

yes all three tabs will fit in three slots in the distributor casting. rotate the plate until it aligns with the slots.

[Tom Wesenberg]

Don't forget the tension spring under the top plate. All three pictures show the stamped steel top plate, but most of the 1928's had a forged upper plate. I like to keep all moving parts lubed and that means grease for the three tabs and in the center hole of the top plate, and one drop of oil on the points pivot. Also use cam lube on the rubbing block of the points.

The forged plate has the points located in a different position than the steel plate, but the points gap and timing for both is identical, no matter who's method you use to time it.

The third picture shows the rotor I balanced for my distributor.





Here's a couple pictures showing the forged upper plate, which is copper plated on my 28.

[Steve Wastler]

Have not heard of a balanced rotor before, does it make a difference?

[Glen in Hillman MI]

Had one come into the shop last week that i had to tilt it puttihg one tab into the slot then other two tabs fell into place. It look like a new unit.

[Jim/GA]

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Borrow the DVD called "Dial D for Distributor" from Bryan Perkins. It walks you through everything. Good basic info for a person who has never done anything with the distributor.

[Tom Wesenberg]

Originally Posted by Steve Wastler

Have not heard of a balanced rotor before, does it make a difference?

Yep, balancing any rotating part helps.

I put a distributor shaft with cam in a small 1000 RPM drill and slip on an unbalanced rotor and spin it. I then switch to the balanced rotor to demonstrate the difference. The shake you feel with the unbalance rotor is the same force the distributor bushings feel.

[Ron Lowe]

IN the third photo what is that clear plastic thing on the rotor? Ron

[Tom Wesenberg]

Ron, As Timothy said, it's what I used to balance the rotor. I cut 4 pieces out of 1/8" thick plexiglass and used super glue to hold them in place. After 3 years the glue let loose, so I have since locked them in place with the 1/4" blue fiberglass rod you see in the picture.

I have another rotor I balanced by drilling 2 holes on the light side and using 2 screws and nuts to balance it.

[josh1331]

WHAT IS ALL THAT RED STUFF ON THE BOTTOM SPRING PLATE AREA" THAT SURE WILL CAUSE A PROBLEM i BELIEVE WITH THE PT GAP. AS IT WILL SPI N AROUND AND LAND ON TOP PLATE...YES?

[MBI Houston]

I solved my problem with the top plate not fitting into the body!!!! Damn repo parts! I switched to a Nu-Rex plate and it easily slipped right into the slots. To make the other plate work I needed to trim one of the three tabs.

[Tom Wesenberg]

Originally Posted by josh1331

WHAT IS ALL THAT RED STUFF ON THE BOTTOM SPRING PLATE AREA" THAT SURE WILL CAUSE A PROBLEM i BELIEVE WITH THE PT GAP. AS IT WILL SPI N AROUND AND LAND ON TOP PLATE...YES?

That's Mystik JT-6 High Temp grease and keeps the spring and top plate lubed. There's no way for it to get to the points and mess them up. I've got over 6 years on it now. I always use original top plates and lower plates for the best fit and function.