Crab distributors makes my head hurt sometimes ????
 

Theres not a day goes buy that i don't learn something ???? Heres the point plate out of a crab ( 42-48 Ford distributor) with a very interesting modification on it . Some old racer figured this out .

I will just leave it here for discussion .. ?????????:eek::eek::D

Re: Crab distributors makes my head hurt sometimes ????
 

Was the slot in the housing hogged out as well?

Re: Crab distributors makes my head hurt sometimes ????
 

I guess it would have been, although i didnt have the housing, note the the brass contacts have been cut out etc. Gotta wonder what they were thinking, someday when we are just sitting around ask me about my early days at the gas station where we sponsored a very fast flathead dirt track car ( i was 14-15 etc).:eek:

Re: Crab distributors makes my head hurt sometimes ????
 

I guess with the contact altered and a modified a slot in the housing you could get one to run a V8 on a single set of points.. wonder what the most dwell you could safely get out of a single set of points would be... 32 degrees?

Re: Crab distributors makes my head hurt sometimes ????
 

Set up for alky-nitro blends. 35 to 45 degrees common.

Re: Crab distributors makes my head hurt sometimes ????
 

I have never been able to get one to run good on a single set of points , just can get the proper dwell.....????

Re: Crab distributors makes my head hurt sometimes ????
 

JWL you talking cranksaft timing or engine dwell....??????

Re: Crab distributors makes my head hurt sometimes ????
 

Jim,
Fooling around, 31 degrees is the most I’ve ever gotten and the gap was so tight it likely would never work.... I think JWL is certainly talking timing not dwell

Re: Crab distributors makes my head hurt sometimes ????
 

Yes, I was describing the reason for the extended tang was to allow for more timing advance without using the Harmon Collins plate.

Re: Crab distributors makes my head hurt sometimes ????
 

Yes the Harmon Collins adjustment plate fixed the issue of not having adjustable timing. ( at least not easily adjustable :))
The issue with all the early Fords was the case either helmet or crab wasnt movable once mounted. A good thing for the Ford service dept and service techs as the chevy guys was cranking the timing up and down in every gas station in the country.
Many figured out the mods to allow some increased spark timing and advance, but in reality there was another constraint, and that was "rotor phase" you can only move the point set so far until you have spark scatter with the rotor being out of phase with the cap contact! :eek:

Re: Crab distributors makes my head hurt sometimes ????
 

Is this why Chevy sixes had the vacuum advance move the whole distributor body? I've often wondered why they did that.

Re: Crab distributors makes my head hurt sometimes ????
 

Actually that was a terrible idea! We weld them up and make them solid......
:eek:

Re: Crab distributors makes my head hurt sometimes ????
 

How do you get spark advance in the Chevy six after welding up the vacuum advance? Is there an internal mod that you fit?

Re: Crab distributors makes my head hurt sometimes ????
 

No the chevy six uses a delco distributor with vacuum and mechanical advance. The mechanica:)l advance works very very good by its self....