The Ford Barn

36 ford · 10-01-2015, 12:48 PM

Bob and I have been attempting to get the 59A started in my 39' Deluxe. Seemed to want to start but wouldn't idle but then backfired. Tried different plug wires, set the idle up on the 97's. Pulled the cap and behold...metal shavings from the rotor spinning and grinding down the contacts in the cap. Never would have thought it was the wrong rotor. It came with the Bubba crab although not from Bubba. Bubba offered to check out the crab and I sent it to him and it checked out fine, What I didn't do was include the cap and rotor when I sent it off.
Now I need a new cap and correct rotor. Does NAPA offer a suitable replacement?

Phil

BUBBAS IGNITION · 10-01-2015, 01:07 PM

Yes napa part number FA65 and FA64, but even with the napa unit you need to grind a little off the rotor tip.
One of the best aftermarket caps out there with brass contacts etc but the rotor often ( almost every time) needs just a little material removed.....

You could probably just grind a little off the brown rotor you have , blow the cap out and spray a little wd40 inside the cap wipe clean with rag and it will work just fine....
The wd40 is a wd water dispersant...

ford38v8 · 10-01-2015, 01:09 PM

I don't have a crab, so can't advise on the exact rotor, but I've heard that new caps and rotors these days are all suspect, and should be dry run before installation.

Edit: Bubba beat me.

36 ford · 10-01-2015, 01:16 PM

Thanks, Bubba...So re-use the cap even though the rotor ground the inside of the cap and file the existing rotor down?

bbrust · 10-01-2015, 01:42 PM

The engine ran but would backfire occasionally. We took the cap off and noticed the metal shavings so I suspect we may have a hit and miss situation with the cap contacts. I also noticed that the cap didn't fit tightly which may have been the cause of the problem. Phil's buying a Napa FA65 cap as Bubba suggested and we'll reuse the USA made rotor after we grind it down a bit. Thanks all for your help. Bob

BUBBAS IGNITION · 10-01-2015, 01:58 PM

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Quote:

Originally Posted by 36 ford

Thanks, Bubba...So re-use the cap even though the rotor ground the inside of the cap and file the existing rotor down?

Sure , didnt appear to break anything. Theres a air gap or at the vary least some gap...

ford38v8 · 10-01-2015, 01:59 PM

Bob, Your backfiring was likely due to the brass shavings shorting out the path of the spark. If you wind up cutting too much off the rotor, build up the cap points with solder, which will be fine tuned by the passing rotor. Again, though, you'll have metal shavings to remove.

Lawson Cox · 10-01-2015, 07:24 PM

What happens when a wrong rotor is used in a crab ??

He will swim backwards??

Walt Dupont--Me. · 10-01-2015, 07:36 PM

Make sure the gasket is between the cap and the crab body. Walt

Walt Dupont--Me. · 10-01-2015, 07:51 PM

I forgot to say, install the rotor and cap with gasket on the crab and snap the clips on with the crab in you hand, turn the crab by hand with the tang and hear or feel if the rotor is hitting any of the tits in the cap, I have found 1-2 of them hitting, I then grind a little of the rotor, I know there hard figure if you have .010 or .015 clearance. Walt

cmbrucew · 10-01-2015, 07:52 PM

Quote:

Originally Posted by Walt Dupont--Me.

Make sure the gasket is between the cap and the crab body. Walt

Gasket, what gasket?
Bruce

Walt Dupont--Me. · 10-01-2015, 08:21 PM

Quote:

Originally Posted by cmbrucew

Gasket, what gasket?
Bruce

There is a gasket about 3/16in. wide that goes in the cap before you put the cap onto the dist. There is a pic of them in the Mac,s cat in the dist section. Walt

Bassman/NZ · 10-01-2015, 09:16 PM

Quote:

Originally Posted by Walt Dupont--Me.

There is a gasket about 3/16in. wide that goes in the cap before you put the cap onto the dist. There is a pic of them in the Mac,s cat in the dist section. Walt

About what thickness is that gasket? It doesn't seem to come in gasket kits these days, I might have to make one. I did notice my crab cap has a bit of play, and a gasket might tighten it up.

Mike in AZ · 10-01-2015, 09:40 PM

pretty diagram from MacVP's websote showing crab distributor parts....probably have to buy complete gasket set at one of the vendors to get that gasket, but there it is....Mike

http://www.vanpeltsales.com/FH_web/F...r_1942to44.JPG

zzlegend · 10-01-2015, 09:47 PM

Every time I went to put the cap on mine, that thin little gasket would drop down. After about the third time I got a tooth pick and my tube of silicon and just dabbed a few very small spots in the cap and place the gasket in there and let it sit for a little while and then snapped it back on the distributor. No more falling off. Just a thought.

Terry,OH · 10-02-2015, 05:49 AM

Suggest you remove the distributor and install a new cap then rotate the assembled distributor shaft by hand to find any of the CAP contacts that are hitting the rotor and file down just the interfearing contact. Sometimes it is just one or two cap terminal. why increase the gap of all for just a few.

bbrust · 10-02-2015, 06:07 AM

I didn't know about it either. Macs has it for $1.95 (plus $8.99 shipping!!!).

10-01-2015, 01:07 PM	#2
BUBBAS IGNITION Senior Member Join Date: May 2010 Location: SPEEDWAY INDIANA Posts: 4,148	Re: What happens when a wrong rotor is used in a crab Yes napa part number FA65 and FA64, but even with the napa unit you need to grind a little off the rotor tip. One of the best aftermarket caps out there with brass contacts etc but the rotor often ( almost every time) needs just a little material removed..... You could probably just grind a little off the brown rotor you have , blow the cap out and spray a little wd40 inside the cap wipe clean with rag and it will work just fine.... The wd40 is a wd water dispersant... __________________ If it Makes Spark, we do it !!!! www.bubbasignition.com [email protected]

10-01-2015, 01:09 PM	#3
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 6,635	Re: What happens when a wrong rotor is used in a crab I don't have a crab, so can't advise on the exact rotor, but I've heard that new caps and rotors these days are all suspect, and should be dry run before installation. Edit: Bubba beat me. __________________ Alan

10-01-2015, 01:16 PM	#4
36 ford Senior Member Join Date: Jul 2010 Location: Chambersburg, Pennsylvania Posts: 311	Re: What happens when a wrong rotor is used in a crab Thanks, Bubba...So re-use the cap even though the rotor ground the inside of the cap and file the existing rotor down?

10-01-2015, 01:42 PM	#5
bbrust Senior Member Join Date: Mar 2011 Location: Greencastle, PA Posts: 227	Re: What happens when a wrong rotor is used in a crab The engine ran but would backfire occasionally. We took the cap off and noticed the metal shavings so I suspect we may have a hit and miss situation with the cap contacts. I also noticed that the cap didn't fit tightly which may have been the cause of the problem. Phil's buying a Napa FA65 cap as Bubba suggested and we'll reuse the USA made rotor after we grind it down a bit. Thanks all for your help. Bob

10-01-2015, 01:59 PM	#7
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 6,635	Re: What happens when a wrong rotor is used in a crab Bob, Your backfiring was likely due to the brass shavings shorting out the path of the spark. If you wind up cutting too much off the rotor, build up the cap points with solder, which will be fine tuned by the passing rotor. Again, though, you'll have metal shavings to remove. __________________ Alan

10-01-2015, 07:24 PM	#8
Lawson Cox Senior Member Join Date: May 2010 Location: Above the gnat line in Georgia Posts: 7,009	Re: What happens when a wrong rotor is used in a crab What happens when a wrong rotor is used in a crab ?? He will swim backwards?? __________________ Life is like a roll of toilet paper. The closer to the end, the faster it goes. It is better to be seen, than viewed. "We sleep safe in our beds because rough men stand ready in the night to visit violence on those who would do us harm".

10-01-2015, 07:36 PM	#9
Walt Dupont--Me. Senior Member Join Date: May 2010 Location: Gardiner Me. Posts: 4,200	Re: What happens when a wrong rotor is used in a crab Make sure the gasket is between the cap and the crab body. Walt

10-01-2015, 07:51 PM	#10
Walt Dupont--Me. Senior Member Join Date: May 2010 Location: Gardiner Me. Posts: 4,200	Re: What happens when a wrong rotor is used in a crab I forgot to say, install the rotor and cap with gasket on the crab and snap the clips on with the crab in you hand, turn the crab by hand with the tang and hear or feel if the rotor is hitting any of the tits in the cap, I have found 1-2 of them hitting, I then grind a little of the rotor, I know there hard figure if you have .010 or .015 clearance. Walt

10-01-2015, 09:40 PM	#14
Mike in AZ Senior Member Join Date: May 2010 Location: Waddell, AZ Posts: 2,540	Re: What happens when a wrong rotor is used in a crab pretty diagram from MacVP's websote showing crab distributor parts....probably have to buy complete gasket set at one of the vendors to get that gasket, but there it is....Mike http://www.vanpeltsales.com/FH_web/F...r_1942to44.JPG

10-01-2015, 09:47 PM	#15
zzlegend Senior Member Join Date: May 2010 Location: Reseda, Calif. Posts: 2,188	Re: What happens when a wrong rotor is used in a crab Every time I went to put the cap on mine, that thin little gasket would drop down. After about the third time I got a tooth pick and my tube of silicon and just dabbed a few very small spots in the cap and place the gasket in there and let it sit for a little while and then snapped it back on the distributor. No more falling off. Just a thought.

10-02-2015, 05:49 AM	#16
Terry,OH Senior Member Join Date: May 2010 Posts: 4,743	Re: What happens when a wrong rotor is used in a crab Suggest you remove the distributor and install a new cap then rotate the assembled distributor shaft by hand to find any of the CAP contacts that are hitting the rotor and file down just the interfearing contact. Sometimes it is just one or two cap terminal. why increase the gap of all for just a few.

10-02-2015, 06:07 AM	#17
bbrust Senior Member Join Date: Mar 2011 Location: Greencastle, PA Posts: 227	Re: What happens when a wrong rotor is used in a crab I didn't know about it either. Macs has it for $1.95 (plus $8.99 shipping!!!).