distributor differences 1950 8BA

[cobra5laddict]

I am nearing completion on my f1 project. I contacted Bubba to rebuild my original Load o matic distributor. I had 2 so i figured I would send both in case parts were needed to put a good one together. The unit on the top (greasy one) was pulled from a running 8ba 10 years ago. the distributor on the bottom of the photo was also pulled from a different 8ba recently. obviously there are housing differences as well as shaft differences. the greasy distributor came from a 8ba with a cast iron timing cover. The clean distributor came from a 8ba with an aluminum cover. is that the difference between the 2?

in my other post about how the housing seats into the timing cover i questioned the gap between the housing and the timing cover.





i want to get the correct one rebuilt.. help?

[flatheadmurre]

The one with a supporting shaft sticking out under the gear is for an aluminum cover with a support.
There are aluminum covers without the support to accepting the other style only.
So its up to if your timing cover has the support or not.

[V8 Bob]

The aluminum distributor should only be used with the aluminum front cover "A" with the lower support, because of it's short upper housing. The cast iron distributor with the longer stepped support should be used with alloy cover "B" or cast iron cover styles "C" and "D". The pictures below should help with understanding the differences.

[cobra5laddict]

excellent resource and explanation.

[CT AV8]

Nicely done, V8 Bob. Couldn't be any clearer. I am filing it for future reference.
Thanks for the detailed pics.

[scooder]

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That's some good pictures there.
I've not seen them all laid out next to each other.
Notice the timing pin? It's in different places, be nice to know what that difference in timing is. On an 8BA l line up the dot with the pin using a timing light, that's the correct way to time these, but with that pin not being in the same place, the timing is gonna be out some times.
Or is the timing cover has to match the correct pulley? And therefore with the right pulley and cover your golden. If so how do you know you got the right combination?
What's the story with these?
I went and checked the ones I have, and there all identical cast iron covers that came from pickups.
I love learning new stuff, thanks for the pics.
Martin.

[V8 Bob]

The upper timing pin location on both alloy covers and the cast iron covers is for use with the larger diameter sheet metal crank pulleys found on '48-'53 trucks and '49 Fords and Mercs. The lower position on the alloy covers is for the '50-'53 cast iron car stepped pulley. Either location results in 2 degrees BTDC when aligned with the the dot on the pulley.

[Ross F-1]

The truck pin is also a different length than the car's. Pin location is cast into the cover (hard to read, but it says 8RT and 0BA)

[jack orchard]

The aluminum front covers tend to wear faster than the cast ones. You might want to check cam end play before using. However, end play should be measured with any cover - not just aluminum ones.,...jack

[CT AV8]

Talk about learning new stuff, thanks for bringing this up Martin.
Bob, I put the stamped wide belt truck pulley on the 8BA in my AV8 that had the passenger double pulley. It's got the cover type D, so my timing must be off.
Should I set it so it's set just a bit to the passenger side?

[V8 Bob]

Originally Posted by CT AV8

Talk about learning new stuff, thanks for bringing this up Martin.
Bob, I put the stamped wide belt truck pulley on the 8BA in my AV8 that had the passenger double pulley. It's got the cover type D, so my timing must be off.
Should I set it so it's set just a bit to the passenger side?

Cover B and C have the pointer located high which is correct for your sheet metal truck style pulley. The wrong pulley was on before. The pointer should line up easily with the "bump" on the pulley, giving 2 degrees BTDC. This can be verified with a adjustable dial type timing light.

[CT AV8]

Originally Posted by V8 Bob

Cover B and C have the pointer located high which is correct for your sheet metal truck style pulley. The wrong pulley was on before. The pointer should line up easily with the "bump" on the pulley, giving 2 degrees BTDC. This can be verified with a adjustable dial type timing light.

Bob, I have cover type D and it looks like the pointer is mounted lower than B & C in your photos.

[V8 Bob]

Originally Posted by CT AV8

Bob, I have cover type D and it looks like the pointer is mounted lower than B & C in your photos.

Looks are deceiving. Measure the distance from the bottom of the pointer straight/vertical to the bottom of the cover, and it should be very close to 3". All of mine do.

[Ol' Ron]

Before I'd spend any money on a rebuilt Loadamatic. I'd buy a converted GM unit from Bubba. Much better investment along with more performance and economy.

[scooder]

V8 Bob,
Thanks for your replies. Got it now, keep the right pulley with the right cover, and your golden.
Cheers,
Martin.

[Ol' Ron]

I don't want people to think I'm on Bubba's Payroll, Charley NY and several others offer the same service.

[CT AV8]

Originally Posted by V8 Bob

Looks are deceiving. Measure the distance from the bottom of the pointer straight/vertical to the bottom of the cover, and it should be very close to 3". All of mine do.

Yes, 3" to bottom of cover. I now understand the pointers are both clocked the same way from crankshaft centerline but with different radii. I've got my timing set correctly.
Thanks for your help, V8 Bob.

[scooder]

Originally Posted by CT AV8

Yes, 3" to bottom of cover. I now understand the pointers are both clocked the same way from crankshaft centerline but with different radii. I've got my timing set correctly.
Thanks for your help, V8 Bob.

And thanks to you for posting this response, I get it now, it's the radius that's compensated for with the pin move, cus of the pulley diameter. You could have heard the pin drop from over there.
Cheers,
Martin.