Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 05-17-2020, 09:56 AM   #1
stude333
Member
 
Join Date: Feb 2015
Posts: 36
Default crab distributor on a 38 24 stud

is there an adaptor from 2 hole to 3 hole ditributor? I want to use the crab style on a 38ish 24 stud. I really dont want to pull the crank pulley and front cover unless that is the only way. what do you know? thanks for any ideas
stude333 is offline   Reply With Quote
Old 05-17-2020, 10:18 AM   #2
GaryU.
Senior Member
 
GaryU.'s Avatar
 
Join Date: May 2010
Location: Madison,Wisconsin
Posts: 527
Default Re: crab distributor on a 38 24 stud

Here's an adaptor from Speedway.

https://www.speedwaymotors.com/Flath...olt,25076.html
GaryU. is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 05-17-2020, 10:25 AM   #3
Kube
Senior Member
 
Kube's Avatar
 
Join Date: May 2010
Location: Wisconsin, USA
Posts: 6,050
Default Re: crab distributor on a 38 24 stud

Quote:
Originally Posted by stude333 View Post
is there an adaptor from 2 hole to 3 hole ditributor? I want to use the crab style on a 38ish 24 stud. I really dont want to pull the crank pulley and front cover unless that is the only way. what do you know? thanks for any ideas
I feel the need to ask: "Why do you want to go the crab style?"
__________________
"I can explain it for you. However, I can't understand it for you".
Kube is offline   Reply With Quote
Old 05-17-2020, 12:48 PM   #4
stude333
Member
 
Join Date: Feb 2015
Posts: 36
Default Re: crab distributor on a 38 24 stud

I changed to the 2 bolt cover this morning. but alas the snot on the camshaft is too long and the crab distributor won mount. looks like i would need something like a 7/16"spacer for it to work.
stude333 is offline   Reply With Quote
Old 05-17-2020, 12:51 PM   #5
Kube
Senior Member
 
Kube's Avatar
 
Join Date: May 2010
Location: Wisconsin, USA
Posts: 6,050
Default Re: crab distributor on a 38 24 stud

Quote:
Originally Posted by stude333 View Post
I changed to the two bolt cover this morning. But alas the snout on the camshaft is too long and the crab distributor won't mount. It looks like I would need something like a 7/16"spacer for it to work.
Gary, post #2, gave you the link for the adapter plate required.
I'd still like to know why you feel the desire to swap the original dizzy for the crab type.
__________________
"I can explain it for you. However, I can't understand it for you".
Kube is offline   Reply With Quote
Old 05-17-2020, 03:34 PM   #6
Mart
Senior Member
 
Mart's Avatar
 
Join Date: May 2010
Location: Solihull, England.
Posts: 6,539
Default Re: crab distributor on a 38 24 stud

If you've already swapped on a 2 bolt cover you need this spacer instead.

https://www.speedwaymotors.com/Flath...cer,25074.html

Mart.
Mart is offline   Reply With Quote
Old 05-17-2020, 11:13 PM   #7
35fordtn
Senior Member
 
35fordtn's Avatar
 
Join Date: Aug 2010
Location: McMinnville, TN
Posts: 1,739
Default Re: crab distributor on a 38 24 stud

Im with Kube. The three bolt 11a helmet distributor has the exact same advance curve as the 21a crab and performs the exact same and in my opinion given the distance between the bushings and the fact the rotor is in the middle of the shaft rather than attached to the end, I much prefer the helmet distributor as the bushings last longer in them over the crab.

But I can understand plug wire changes are much easier on a crab type as well as the cap and rotor.
35fordtn is offline   Reply With Quote
Old 05-18-2020, 08:09 AM   #8
Kube
Senior Member
 
Kube's Avatar
 
Join Date: May 2010
Location: Wisconsin, USA
Posts: 6,050
Default Re: crab distributor on a 38 24 stud

Quote:
Originally Posted by 35fordtn View Post
Im with Kube. The three bolt 11a helmet distributor has the exact same advance curve as the 21a crab and performs the exact same and in my opinion given the distance between the bushings and the fact the rotor is in the middle of the shaft rather than attached to the end, I much prefer the helmet distributor as the bushings last longer in them over the crab.

But I can understand plug wire changes are much easier on a crab type as well as the cap and rotor.
You have offered a much more insightful reason why there is little advantage to swapping to the crab type dizzy.
Yep, easier to change the cap and wires for certain. Still, just how often are they necessary to change?
Of course, having no response from the OP doesn't help us better understand what he (or she) is envisioning with this proposed swap.
__________________
"I can explain it for you. However, I can't understand it for you".
Kube is offline   Reply With Quote
Old 05-18-2020, 10:44 AM   #9
cas3
Senior Member
 
Join Date: Jan 2011
Location: sw minnesota
Posts: 2,289
Default Re: crab distributor on a 38 24 stud

if its going in an Av8, the crab is shorter. no room to spare in those contraptions.
cas3 is offline   Reply With Quote
Old 05-18-2020, 11:28 AM   #10
Juergen
Senior Member
 
Join Date: May 2010
Posts: 357
Default Re: crab distributor on a 38 24 stud

I found the crab, with external coil, easier to diagnose. The old saying, if it doesn't fire, it's usually spark or fuel. It is easy to take off the air filter to see if fuel is coming out using the accelerator pump. If there is no blue spark at the plugs, see if there is blue spark at the output of the coil. If so the problem is in the distributor mechanical rotor system; if not it is in the electrical system and it is a lot easier to change out the coil to see if the spark improves. Also, (and I say this in partial jest) since Henry went to this system, it must have been better to someone other than a restorer.
Juergen is offline   Reply With Quote
Old 05-18-2020, 12:58 PM   #11
Hoop
Senior Member
 
Hoop's Avatar
 
Join Date: May 2010
Location: Jacksonville FL
Posts: 1,096
Default Re: crab distributor on a 38 24 stud

Juergen,

Just because the design was changed does not mean it would create a "better" distributor. There were considerations other than performance and service.

A helmet uses twice as much aluminum as a crab.

Aluminum production at the begining of WW2 was nothing compared to war production needs ... by war end the story was different.

Do your own calculations and figure out how many P-51's could be built from the aluminum saved.

(I could be wrong ... and didn't they make some crabs out of cast iron to save on aluminum?)
__________________
"Remember that when it comes to intelligence, half of all of us are below average."
Hoop is offline   Reply With Quote
Old 05-18-2020, 01:20 PM   #12
frnkeore
Senior Member
 
frnkeore's Avatar
 
Join Date: Jul 2019
Location: Southern Oregon
Posts: 438
Default Re: crab distributor on a 38 24 stud

I would agree, knowing how Henry thought, that the Crab was at least 50% cost reduction but, I like them for 4 reasons. Looks (I grew up looking at them on all kinds of race engines), remote coil and they are easier to work on are 3. After market cams are another reason to use one.

I bought one and the aluminum gear, to put on my '36/'37, 21 stud stud engine, to use with the 59 style cam.
__________________
Frank
'35 Ford Model 51
'48 Ford F3

Last edited by frnkeore; 05-18-2020 at 01:25 PM.
frnkeore is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 04:10 AM.