The Ford Barn

hdmike · 04-25-2015, 06:05 AM

What is the best way to remove material from the rotor to properly set the air gap? I just don't want to remove to much at one time.

James Rogers · 04-25-2015, 06:13 AM

You don't remove any material. The end of the brass is bent up or down to increase or decrease the air gap.

BudP · 04-25-2015, 06:45 AM

When I used a new distributor body and a new rotor, I found that the contacts inside the body were uneven distances from the rotor. I filed each long contact down to the length of the shortest. I also filed a little off the end of the rotor. I used a feeler gauge to insure a uniform gap between the end of the rotor and the contact. I filed each until I had a uniform gap of .025 between the end of the rotor and each contact.

Mitch//pa · 04-25-2015, 08:09 AM

BUd P has it right file each contact to get your gap. if you try and bend the rotor contact it will break off the plastic rotor most of the time. as long as your not rubbing the dist body contacts you should be good. how often did we set the gap on later points style cars? do you remember a spec for those later cars? i dont.
probably the most important thing is to have no play in the distributor shaft which causes variable point gap and rotor contact gap

BILL WILLIAMSON · 04-25-2015, 09:05 AM

Quote:

Originally Posted by Mitch//pa

BUd P has it right file each contact to get your gap. if you try and bend the rotor contact it will break off the plastic rotor most of the time. as long as your not rubbing the dist body contacts you should be good. how often did we set the gap on later points style cars? do you remember a spec for those later cars? i dont.
probably the most important thing is to have no play in the distributor shaft which causes variable point gap and rotor contact gap

Only with X-RAY vision, could we check a "modern" cap Anyone remember having one HIT? I don't.
Bill W.

Mitch//pa · 04-25-2015, 09:28 AM

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Quote:

Originally Posted by BILL WILLIAMSON

Only with X-RAY vision, could we check a "modern" cap Anyone remember having one HIT? I don't.
Bill W.

EXACTLY my point

Kurt in NJ · 04-25-2015, 10:22 AM

It is something I never looked at on my car, it runs fine, but I took a look, found one contact almost touching, opposite side about .025, found the locating pin holding th cap a little off dist base, filed the notch, now the cap sits square, still some gap variation, car still runs the same , found a cap that has same gaps, car still runs the same, put original cap back on, car still runs the same--- my conclusion-- it doesn't matter that the gaps are somewhat different if there are no other problems--- perhaps a large gap helps if you have rich mixture plug fowling problems

hdmike · 04-25-2015, 01:07 PM

The reason I was asking i bought a new rotor from Snyders and it was to long and hit the body and broke the rotor. I don't remember years ago when I had a two door sedan worrying much about the rotor hitting the body. I just put it on and was good to go. But, that was over 30 years ago.

Tom Wesenberg · 04-25-2015, 01:22 PM

I wonder if the body contacts were too long. I've seen some repro bodies that fit loose on the distributor and can shift around. The bodies I bought from Bratton's, Snyder's, and Little Dearborn all fit nice and snug.

Mitch//pa · 04-25-2015, 01:24 PM

do you have side slop in your dist shaft?

mshmodela · 04-25-2015, 01:29 PM

Funny I was checking my rotor gap a few weeks ago --it was a whopping 0.061" I replaced the body with a new one (the old contacts had some major signs of arching). I happen to be using a clear distributor top and the difference in the new body resulted with a a gap of 0.035" on each as opposed to the 0.061" is that the spark at the contacts is now much less. Given gap is resistance, more gap, more resistance, I would think more of the coil's energy is now going to the plugs and maybe a larger spark there... My car idles smoother, less little odd random miss... (for what this newbie has observed).

Mike V. Florida · 04-25-2015, 11:11 PM

Quote:

Originally Posted by hdmike

The reason I was asking i bought a new rotor from Snyders and it was to long and hit the body and broke the rotor. I don't remember years ago when I had a two door sedan worrying much about the rotor hitting the body. I just put it on and was good to go. But, that was over 30 years ago.

When I buy parts for spares I test fit them on my car first. I have found bodies that the "original" rotor hits and I have found rotors that have hit "original' bodies.

I make the adjustments to the new part installed.

hdmike · 04-26-2015, 05:09 AM

There is no slop in the dist. shaft. I'm just lucky that my old one was still good, till I can order another one from Snyders. I want to thank you, for all of your comments it really helps.
Mike

kenparker · 04-26-2015, 08:14 AM

No offense meant Kurt, but "It does matter". As msh said "the more gap the more resistance". If one wants their cars engine to fire and run smoothly all four plugs should fire evenly. To do so requires the same voltage to each plug in order to get he same explosion in each cylinder.

... and I hope I got my grammar right. I am to lazy to do much proofreading.

04-25-2015, 06:05 AM	#1
hdmike Junior Member Join Date: Jan 2015 Posts: 10	New Rotor What is the best way to remove material from the rotor to properly set the air gap? I just don't want to remove to much at one time.

04-25-2015, 06:13 AM	#2
James Rogers Senior Member Join Date: May 2010 Location: Asheville,NC Posts: 3,104	Re: New Rotor You don't remove any material. The end of the brass is bent up or down to increase or decrease the air gap. __________________ http://www.model-a-ford-4bangers.com/

04-25-2015, 06:45 AM	#3
BudP Senior Member Join Date: Jun 2011 Location: Oakton, VA Posts: 437	Re: New Rotor When I used a new distributor body and a new rotor, I found that the contacts inside the body were uneven distances from the rotor. I filed each long contact down to the length of the shortest. I also filed a little off the end of the rotor. I used a feeler gauge to insure a uniform gap between the end of the rotor and the contact. I filed each until I had a uniform gap of .025 between the end of the rotor and each contact.

04-25-2015, 08:09 AM	#4
Mitch//pa BANNED Join Date: May 2010 Location: Bucks County, PA Posts: 11,454	Re: New Rotor BUd P has it right file each contact to get your gap. if you try and bend the rotor contact it will break off the plastic rotor most of the time. as long as your not rubbing the dist body contacts you should be good. how often did we set the gap on later points style cars? do you remember a spec for those later cars? i dont. probably the most important thing is to have no play in the distributor shaft which causes variable point gap and rotor contact gap

04-25-2015, 10:22 AM	#7
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,159	Re: New Rotor It is something I never looked at on my car, it runs fine, but I took a look, found one contact almost touching, opposite side about .025, found the locating pin holding th cap a little off dist base, filed the notch, now the cap sits square, still some gap variation, car still runs the same , found a cap that has same gaps, car still runs the same, put original cap back on, car still runs the same--- my conclusion-- it doesn't matter that the gaps are somewhat different if there are no other problems--- perhaps a large gap helps if you have rich mixture plug fowling problems

04-25-2015, 01:07 PM	#8
hdmike Junior Member Join Date: Jan 2015 Posts: 10	Re: New Rotor The reason I was asking i bought a new rotor from Snyders and it was to long and hit the body and broke the rotor. I don't remember years ago when I had a two door sedan worrying much about the rotor hitting the body. I just put it on and was good to go. But, that was over 30 years ago.

04-25-2015, 01:22 PM	#9
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: New Rotor I wonder if the body contacts were too long. I've seen some repro bodies that fit loose on the distributor and can shift around. The bodies I bought from Bratton's, Snyder's, and Little Dearborn all fit nice and snug.

04-25-2015, 01:24 PM	#10
Mitch//pa BANNED Join Date: May 2010 Location: Bucks County, PA Posts: 11,454	Re: New Rotor do you have side slop in your dist shaft? Last edited by Mitch//pa; 04-25-2015 at 02:07 PM.

04-25-2015, 01:29 PM	#11
mshmodela Senior Member Join Date: Mar 2014 Location: Cleveland, Ohio Posts: 2,763	Re: New Rotor Funny I was checking my rotor gap a few weeks ago --it was a whopping 0.061" I replaced the body with a new one (the old contacts had some major signs of arching). I happen to be using a clear distributor top and the difference in the new body resulted with a a gap of 0.035" on each as opposed to the 0.061" is that the spark at the contacts is now much less. Given gap is resistance, more gap, more resistance, I would think more of the coil's energy is now going to the plugs and maybe a larger spark there... My car idles smoother, less little odd random miss... (for what this newbie has observed). __________________ -Mike Late 31' Ford Model A Tudor, Miss Daisy I don't work on cars --I'm learning about my Model A. Cleveland, Ohio Last edited by mshmodela; 04-25-2015 at 11:14 PM.

04-26-2015, 05:09 AM	#13
hdmike Junior Member Join Date: Jan 2015 Posts: 10	Re: New Rotor There is no slop in the dist. shaft. I'm just lucky that my old one was still good, till I can order another one from Snyders. I want to thank you, for all of your comments it really helps. Mike

04-26-2015, 08:14 AM	#14
kenparker Senior Member Join Date: May 2010 Location: Van, Texas Posts: 1,122	Re: New Rotor No offense meant Kurt, but "It does matter". As msh said "the more gap the more resistance". If one wants their cars engine to fire and run smoothly all four plugs should fire evenly. To do so requires the same voltage to each plug in order to get he same explosion in each cylinder. ... and I hope I got my grammar right. I am to lazy to do much proofreading.