Changing points crab shell.

Licensed to kill

Licensed to kill

Well-known member
So, I just purchased my first flathead 8 (has a crab shell dizzy) and am in the process of getting it running. It hasn't run in about 7 years, the guy said it ran good then lost spark and he just didn't get around to looking into it but suspected the points. I removed the dizzy cap and found that a bit of water had gotten in there and there was rust in the bottom of the cap. I have a new cap, condenser and points coming but am having issues getting the points out. My observations are this. each set of points have 2 screws that secure them to the body, one upper and one lower and the points pivot on a post that has a small bail wire keeping them from walking up the post. First, am I understanding this correctly?. If so, The points are seized on this post. If this is so, what is the tried and true method of getting them off without damaging anything?. BTW, I USED to think that Henry Ford was a pretty smart guy until I saw where he chose to locate the distributor on theses early flatheads. What a putz!.
 
Hold on Ltk,
Once you understand flatheads you will come to appreciate one of the most

innovative and effective distributors ever designed the '42 thru '48 'crab'.
Remove the snap ring that holds the breaker plate in the dist housing, remove

the connector that the coil wire attaches to ,remove the timing tab. With that out of the way you can remove the breaker plate. With the help of penetrating oil the

points will eventually loosen enough to be removed , overnight at most. Don't forget to remove the
small cap screws that attach the point springs to the insulation block. With the plate out and in a vise removal and replacement goes lots easier.
Charlie ny
 
You might also be interested to learn that it was never intended to service the points on the vehicle. The idea is to remove the distributor and set it up on the bench using a timing fixture.

Mart.
 
Licensed to kill said:
BTW, I USED to think that Henry Ford was a pretty smart guy until I saw where he chose to locate the distributor on theses early flatheads. What a putz!.
Click to expand...

Might be a lot smarter than you think! It is a somewhat fixed distributor (mounted on the engine). It is a good example of a simple (and smart) design. The distributor can be set up on the bench and then just bolted on.
 
JSeery said:
Might be a lot smarter than you think! It is a somewhat fixed distributor (mounted on the engine). It is a good example of a simple (and smart) design. The distributor can be set up on the bench and then just bolted on.
Click to expand...

Just stay out of water. When the fan picks up water, you are dead in the water! This was one of GMs better ideas, to put distributors in the back on most engines.
 
philipswanson said:
Just stay out of water. When the fan picks up water, you are dead in the water! This was one of GMs better ideas, to put distributors in the back on most engines.
Click to expand...

In 25 years of driving my car in all kinds of weather, I have never had a moisture problem with my crab distributor.
 
Charlie ny said:
Remove the snap ring that holds the breaker plate in the dist housing, remove

the connector that the coil wire attaches to ,remove the timing tab. With that out of the way you can remove the breaker plate.
Click to expand...
Cool. I assume that the screw at 1 o'clock is the timing. Got the plate loose but am not sure how to get that coil wire connector out and i suspect that it is preventing the plate from coming out. If so, how does the connector come off?. I sprayed the base with some penetrating oil an tried a punch in one of the two notches on the perimeter to try to unscrew it but it seem pretty solid and i didn't want to hit it too hard in case that was not the thing to do. Don't want to create more problems LOL.
 
The brass wire connecter doesn't need to come of to free the points plate but there is a large spring clip around the edge holding it ,sometimes the condenser screw can hold it also ,you can lever up the points with a screw driver ,Ted
 
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Ltk,
Take a close look at the connector , you will see 2 notches 180 degrees apart.
The connector is threaded into the housing. Using a small spanner wrench or a punch and small hammer and with bit of a twist the connector will spin out. It is my choice to

remove all the parts to be sure all are in reusable shape. When reassembling I use
allen head cap screws in place of the funky slotted head screws that attach the

points to the breaker plate, better leverage.
Charlie ny
 
Note that most "complete" gasket sets for engines include a gasket to install between the distributor cap and body of the crab distributor. However, both Bubba and Charlie NY told me that installation of the gasket isn't essential and apparently they don't use them. Regardless, if used, to extends the cap outward from the crab body by a minor amount. I have and have not used the gasket without effect, but I also have not had radiator leaks etc.

It also should be noted that the gap between the outer tip of the rotor and the inside cap lugs should be checked (there is a spec for this). Some new rotors may hit and damage the lugs inside the cap or even break the rotor. Generally the brass tip of the rotor can be filed-down to correct this.
 
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Got the plate out, just need to clean it all up and wait for the new points. One of the bail wires is stuck fast and am soaking in penetrating oil to get it out without breaking it. Otherwise I think i should be OK but I may be back if I run into other issues/questions. Thanks to all for the help. Very much appreciated.
 
Ltk,
Now is a good time to replace the bushings if they are worn.....anything over
.003 on the big bushing is excessive. Sloppy or off center bushings is the main reason
for rotor to cap interference. It's the obscure little details that when ignored can

bite you where it don't show.
Charlie ny
 
Licensed to kill said:
BTW, I USED to think that Henry Ford was a pretty smart guy until I saw where he chose to locate the distributor on theses early flatheads. What a putz!.
Click to expand...

OK, so I just thought I should mention that, as a couple of you suggested, after playing with this motor for while, I no longer find the location of the dizzy such a bad thing. Just don't BE a putz and try to work on it ON the engine (as some mentioned in a much kinder fashion). I owe Henry an apology. ;). BTW, as an interesting side note, a buddy of mine has a mid 90's camaro and the dizzy is also mounted on the end of the cam like the crab.
 
You may already be aware of this but when you go to install the distributor, the slot on the end of the cam is offset so it only goes on one way. You'll know if your 180 degrees off as the bolt holes won't line up.
 
LTK,
If we know where in the USA you live one of us will contact you and come over and show you all the things you now have questions about and more.
Not all of us have distributor set up equipment so have for decades been replacing points and setting initial timing with a screwdriver, a set of feeler gauges and a scale (ruler). Buying a 42 -48 repair manual or a Motor manual covering your year will help a lot.
You own a great piece of history.
 
LTK, I made a couple of videos lately covering some of the things you are talking about.

In this thread https://www.fordbarn.com/forum/showthread.php?t=256334 there is a link to a video which, if you can stick with it, shows the distributor being fitted.

In this thread https://www.fordbarn.com/forum/showthread.php?t=256277 there is a link to a video where I have a crab distributor on a timing fixture. Ok, that might not be what you have, but maybe you might be able to see how it should be set up and what you are trying to emulate when trying the two ruler method for example.

Hope these may be helpful or interesting to you

Mart.
 
Licensed to kill said:
Cool. I assume that the screw at 1 o'clock is the timing. Got the plate loose but am not sure how to get that coil wire connector out and i suspect that it is preventing the plate from coming out. If so, how does the connector come off?. I sprayed the base with some penetrating oil an tried a punch in one of the two notches on the perimeter to try to unscrew it but it seem pretty solid and i didn't want to hit it too hard in case that was not the thing to do. Don't want to create more problems LOL.
Click to expand...

Buy the reprinted Manual for Service.. It has step by step instructions & photos.. :D
 
I guess I'm okay with help. We are a team of special talents (which I have little of). it's not expensive to send a dizzy or carb out. Besides it funds people that know their sh*t. not sure why you need to get the bail out to replace points :) weights yes. Bubba is good, Skip also does dizzies as well as Charlie. Probably someone local to you also.

Send the dizzy off to a guy with a Sun machine (why they where invented). Granted single carb also... or not. I can make a flathead run but till these services don't exists I'll send them off and work on something else that needs to be done.

yes you can bench it too, and it's good to know how to do it to get it running. Truly a treasure of a site.
http://www.vanpeltsales.com/FH_web/flathead_engines_distr-timing.htm
 
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