crab dist parts Q...

hardtimes said:
Hey Mart,
Thanks for confirming that that brown color inside my crab cap is not just someone messing with paint:) !

I guess that there is no one in the Ford world who knows the 'skinny' on why these caps are BROWN inside, and/or if that paint was some kind of improvement..against say carbon tracking/whatever! Guess we'll never know,eh.
Click to expand...


Actually the brown paint is a "dielectric" and is used in lots of old distributors by many companies.
Helped prevent spark arch over and carbon tracking...
 
BUBBAS IGNITION said:
Actually the brown paint is a "dielectric" and is used in lots of old distributors by many companies.
Helped prevent spark arch over and carbon tracking...
Click to expand...

Thanks much! Hm , learn something new every day:)!
So, am I doing the ok thing when I use 'dielectric' grease on all of my electrical contacts, i.e.- rotor end; cap contacts, wire ends; etc ?
 
BUBBAS IGNITION said:
There seems to be two crabs out there from 42 to 48 , one is aluminum and the other is cast iron.
I believe ( someone may know) that the cast iron ones are truck units from a given model year, the inside seems to all be 11A units and offer 11 degrees of advance or 22 degrees of engine advance curve.

The stock springs ( assuming they are in good shape and havent been modified etc) work very well with a slight drag on the vacuum brake.
Could very well be one of the best Ford ever used especially after a complete clean and lube. The best most accurate adjustment is on a distributor machine running at approx 2000 rpm..:eek::)
Click to expand...

A number of years ago, Carpenter was selling NOS '42-'44 cast iron distributors, said at the time they were military surplus. I bought one then (about 198?) just today transferred it to another engine.
 
I am having the same problem, breaking rotors, or cracking them. I see somebody said file off .020 and another says .125. That is quite a difference. Will it still jump spark at .125? Not knockin it, just like to know how much is too much.
Thanks, Lee
 
42merc,
Iron....Interesting and pics to share, never seen one! Does the iron dist have any advantages over the aluminum dist ?
 
Ive had a dozen of them over the yrs and they rebuild well,accuately more resistent to nicks and burrs around the edges where the cap fits which have to be filed off on alum ones.Would rather work on those than alum ones. ken ct.
 
I wouldn't use dielectric on any high voltage eg inside the distributor .I would go along with sometimes using the old parts polish up the points on .
hard times said:
Thanks much! Hm , learn something new every day:)!
So, am I doing the ok thing when I use 'dielectric' grease on all of my electrical contacts, i.e.- rotor end; cap contacts, wire ends; etc ?
Ford recommends 1/32 clearance on the rotor so the coser the better .trial and error
Click to expand...
3quarter32 said:
I am having the same problem, breaking rotors, or cracking them. I see somebody said file off .020 and another says .125. That is quite a difference. Will it still jump spark at .125? Not knockin it, just like to know how much is too much.
Thanks, Lee
Click to expand...
 
I took off the distributor, put a thin layer of clay on the lower contacts of the cap. Rotated the cam by hand and felt some resistance, other than points functioning. When I removed the cap, I found the rotor was hitting #4 and #8 contacts on the cap. I removed about .020 from the end of the rotor, and no more interference.
Going to replace cap and rotor, but will repeat process before firing up the engine again. Also, I did not have the gasket for the cap.
 
Iron crabs were I believe Canadian, and lots of Canadian military parts reached Carpenter and others from WWII Indian army stocks.
The innards seldom need replacement, just careful cleaning and lubing.
Coupla things...be sure to slide the cam off of shaft, clean and lube where it pivots. This area MUST move, and it is oft stuck with petrified grease.
The front bearing is lubed through hollow felt filled shaft from rear bearing area...after you have cleaned the shaft that area will be full of murky solvent and it will be a long time before it cooks and oozes out to be replaced by oil.
I simply put mine on top of the exhaust from house water heater until solvent has evaporated through the itty bitty holes.

(the various cap gaskets in the Ford schematic generally cannot be used with non-original caps)
 
Bruce ,

The front bearing is lubed through hollow felt filled shaft from rear bearing area...after you have cleaned the shaft that area will be full of murky solvent and it will be a long time before it cooks and oozes out to be replaced by oil.

We actually remove the felt and clean and relube it....a real pain but we feel its worth it...:eek:
 
3quarter32 said:
I am having the same problem, breaking rotors, or cracking them. I see somebody said file off .020 and another says .125. That is quite a difference. Will it still jump spark at .125? Not knockin it, just like to know how much is too much.
Thanks, Lee
Click to expand...

.020-.o30 is plenty , i mistakenly said .125 thats 1/8 of a inch and too much for sure.
It should jump the .030 with no problems at all.......
 
hardtimes said:
Thanks much! Hm , learn something new every day:)!
So, am I doing the ok thing when I use 'dielectric' grease on all of my electrical contacts, i.e.- rotor end; cap contacts, wire ends; etc ?
Click to expand...

Yes dielectric should be used at every connection as well as spraying WD40 on the cap and wires to help water/moisture proof the system...inside the distributor as well as outside....
 
Bubba rebuilt 2 for my 37 and they look great. One of these days I'll get to start the damn thing too.


hardtimes said:
I've taken several pics of a 'crab' dist. Need source of parts to 'rebuild'.
Are there any parts vendors for this type dist?

Also, the inside of the black cap is brown colored...is this normal or what's up with this?
Click to expand...
 
BUBBAS IGNITION said:
.020-.o30 is plenty , i mistakenly said .125 thats 1/8 of a inch and too much for sure.
It should jump the .030 with no problems at all.......
Click to expand...


I just looked at mine again after 100 miles and decided to take another .005 off the rotor. I could still see slight contact on the cap terminals. Started by taking .020 and now another .005. I also found a NOS mallory crab cap for the Ford dist. and it fits a lot better than the ones available now...
 
BUBBAS IGNITION said:
Yes dielectric should be used at every connection as well as spraying WD40 on the cap and wires to help water/moisture proof the system...inside the distributor as well as outside....
Click to expand...

Hey Bubba,
Thanks much for sharing your vast knowledge/experience regarding distributors and their use in our hobby:)! You have validated my use of dielectric grease and belief in its benefits. I've used it for any and all electrical connection work that I do. I've never experienced any of the oxidizing and blackening of electric contacts/connections that you normally see in those after prolonged use. I also have increased auto and house bulb life with its use. I understand WD40 and will take your advice that way also. Hey, you may not know it but that wd40 is also excellent sprayed on fish lures/bait as attractant too,eh:D
 
Re the .020/.025" clearancing, can you say exactly which rotor and cap? Are these the Napa Echlin parts?

Mart.
 
Hey, you may not know it but that wd40 is also excellent sprayed on fish lures/bait as attractant too,eh:D[/QUOTE]


Really? I'll have to try that. Anything I can do to hook up with some big ones I'll try.
 
You must log in or register to reply here.
Back
Top