The Ford Barn

Shoebox · 04-27-2014, 02:49 PM

I have built 2 nice running flatheads over the years, both being 49-53 engines. Now I am faced with the dist on my 39 Merc..... completely alien to me. Now I have a vintage Motor manual coming from that auction site, but in the mean time trying to learn as much as I can. I see more in print regarding the 41-48 crabs, are the pre 41 units substantially different? This car is very original, however not opposed to considering improvements with regard to reliability or better ignition performance. Planning on staying with 6 volts at this time.
Any comments or recommendations welcome guys!

Thanks,

Shoebox

Pete · 04-27-2014, 03:22 PM

Talk to Bubba on this forum.

scooder · 04-27-2014, 03:40 PM

Staying all stock, I don't think you'll get better performance or reliability than you have with the original ignition. This would be the "football" or "divers helmet" type, plus they look so cool. The later ignitions are also very good. With a completely stock flathead I feel there is no need to change out the ignition. Even the 8BA dizzy does s good job on a stocker, start changing things and all bets are off. These old flatheads have millions of miles under their belts, before all that electronic stuff turned up.
Martin.

Shoebox · 04-27-2014, 04:01 PM

Guys,
Thanks for the quick response. Pete, I have emailed Buba, Scooder you're probably right, maybe just having Buba thoroughly go through the "helmet" is all I may do. Still interested in hearing what else someone may have done.

Shoebox

alan · 04-27-2014, 04:25 PM

on the "helmet" distributor, I allways insulate the shaft under the rotor button with tape and or heat shrink tubing--I have found several rotor buttons that are leaking voltage and this cures it. otherwise my 40 wagon has over 20,000 miles with one of them

Bruce Lancaster · 04-27-2014, 05:16 PM

Sponsored Links (Register now to hide all advertisements)

The 1941 (if it is right it will have an "11" on rear of shaft) had the same upgraded advance as the crab type used 1942 to '48 with variations.
The main advantages of the '42 over the '41 that uses same points and advance is that it is a lot easier to R&R and to work on, plus all the plastic parts are more readily available in good quality.
Either distributor will generally allow significantly better performance than the '49 up distributors, which had very lazy advance systems.

Ol' Ron · 04-27-2014, 10:40 PM

Yes the 42 crab is the best dist for the early engines, You can buy an adapter or change timing covers, but you may need a spacer. However if you just building the engine , convert to an 8BA style cam and use the SBC dist, This can be set up with any advance curve you can think of.

04-27-2014, 02:49 PM	#1
Shoebox Senior Member Join Date: Jan 2014 Location: Holmen,Wisconsin Posts: 983	Crab Distributors I have built 2 nice running flatheads over the years, both being 49-53 engines. Now I am faced with the dist on my 39 Merc..... completely alien to me. Now I have a vintage Motor manual coming from that auction site, but in the mean time trying to learn as much as I can. I see more in print regarding the 41-48 crabs, are the pre 41 units substantially different? This car is very original, however not opposed to considering improvements with regard to reliability or better ignition performance. Planning on staying with 6 volts at this time. Any comments or recommendations welcome guys! Thanks, Shoebox

04-27-2014, 03:22 PM	#2
Pete BANNED Join Date: May 2010 Location: Wa. Posts: 5,423	Re: Crab Distributors Talk to Bubba on this forum.

04-27-2014, 03:40 PM	#3
scooder Senior Member Join Date: Jul 2010 Posts: 2,595	Re: Crab Distributors Staying all stock, I don't think you'll get better performance or reliability than you have with the original ignition. This would be the "football" or "divers helmet" type, plus they look so cool. The later ignitions are also very good. With a completely stock flathead I feel there is no need to change out the ignition. Even the 8BA dizzy does s good job on a stocker, start changing things and all bets are off. These old flatheads have millions of miles under their belts, before all that electronic stuff turned up. Martin.

04-27-2014, 04:01 PM	#4
Shoebox Senior Member Join Date: Jan 2014 Location: Holmen,Wisconsin Posts: 983	Re: Crab Distributors Guys, Thanks for the quick response. Pete, I have emailed Buba, Scooder you're probably right, maybe just having Buba thoroughly go through the "helmet" is all I may do. Still interested in hearing what else someone may have done. Shoebox

04-27-2014, 04:25 PM	#5
alan Senior Member Join Date: Jul 2010 Location: UPSTATESC Posts: 669	Re: Crab Distributors on the "helmet" distributor, I allways insulate the shaft under the rotor button with tape and or heat shrink tubing--I have found several rotor buttons that are leaking voltage and this cures it. otherwise my 40 wagon has over 20,000 miles with one of them

04-27-2014, 05:16 PM	#6
Bruce Lancaster Member Emeritus Join Date: May 2010 Location: Madison, NJ Posts: 5,230	Re: Crab Distributors Sponsored Links (Register now to hide all advertisements) The 1941 (if it is right it will have an "11" on rear of shaft) had the same upgraded advance as the crab type used 1942 to '48 with variations. The main advantages of the '42 over the '41 that uses same points and advance is that it is a lot easier to R&R and to work on, plus all the plastic parts are more readily available in good quality. Either distributor will generally allow significantly better performance than the '49 up distributors, which had very lazy advance systems.

04-27-2014, 10:40 PM	#7
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,985	Re: Crab Distributors Yes the 42 crab is the best dist for the early engines, You can buy an adapter or change timing covers, but you may need a spacer. However if you just building the engine , convert to an 8BA style cam and use the SBC dist, This can be set up with any advance curve you can think of.