Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 02-16-2014, 07:20 PM   #1
oldscout
Member
 
Join Date: Jul 2011
Location: NEPA
Posts: 81
Default One for the books

Went to look at a 28 Sport coupe 3 weeks ago, it had been sitting for a couple of months. The owners son got it running, and it sounded fine. A week later I go with the trailer to pick it up, and it will not start. When it finally would start, it smoked and ran terrible then died. We cleaned the points, cleaned the plugs, won't start. Pulled the coil wire, hot Spark, it was getting gas, still won't start. Checked the cap and rotor looked fine, left the plug wires off of the distributor with a gap of about 1/8 inch, starts up and runs ! Now there is spark jumping from the distributor to the wires, then the plugs would fire ! Unfortunately, the owners son got a picture of it, but I didn't. So we put in a new set of plugs and it started fine and ran great. Has anyone ever heard of this happening? None of us could believe it, and I still get a laugh when I think of it.
oldscout is offline   Reply With Quote
Old 02-16-2014, 08:13 PM   #2
bbrocksr
Senior Member
 
Join Date: May 2010
Location: Yakima Washington
Posts: 595
Default Re: One for the books

Quote:
Originally Posted by oldscout View Post
Went to look at a 28 Sport coupe 3 weeks ago, it had been sitting for a couple of months. The owners son got it running, and it sounded fine. A week later I go with the trailer to pick it up, and it will not start. When it finally would start, it smoked and ran terrible then died. We cleaned the points, cleaned the plugs, won't start. Pulled the coil wire, hot Spark, it was getting gas, still won't start. Checked the cap and rotor looked fine, left the plug wires off of the distributor with a gap of about 1/8 inch, starts up and runs ! Now there is spark jumping from the distributor to the wires, then the plugs would fire ! Unfortunately, the owners son got a picture of it, but I didn't. So we put in a new set of plugs and it started fine and ran great. Has anyone ever heard of this happening? None of us could believe it, and I still get a laugh when I think of it.
Fouled Plugs, When you hold the wire away it increases the intensity of the spark until it jumps the gap on the fouled plug. OldTimer's trick to clean a fouled plug.
Bill
bbrocksr is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 02-16-2014, 08:20 PM   #3
Timsalways
Junior Member
 
Timsalways's Avatar
 
Join Date: Oct 2013
Location: Stockton CA. USA
Posts: 29
Default Re: One for the books

I had something like that happen to me when I replaced my points and condenser. I got a spark from the cable that goes to the firewall, it was shorting on the head. Either I let the wire on the bottom of the distributor plate ground out, or just had to replace the cap and rotor. Not sure.
Timsalways is offline   Reply With Quote
Old 02-16-2014, 09:11 PM   #4
Kevin in NJ
Senior Member
 
Join Date: May 2010
Location: South East NJ
Posts: 3,197
Default Re: One for the books

Putting some gap between the plug and plug wire causes the voltage to build up higher. This will burn through fouled plugs. It also does this at a cost in time. It effectively trades a delay in the spark for higher voltage. You do not get something for nothing.

At the flea markets there are these guys selling a spark enhancer. They have been around since the 40's. They make a gap to force the coil to build more voltage before current can flow. Inside there are some graphite disks if I remember correctly.

BTW, those guys get real upset when you point out the physics and why they are not good.
__________________
Cabriolet and Technical Hints
Kevin in NJ is offline   Reply With Quote
Old 02-16-2014, 09:47 PM   #5
Tom Wesenberg
Senior Member
 
Tom Wesenberg's Avatar
 
Join Date: May 2010
Location: Mpls, MN
Posts: 27,480
Default Re: One for the books

This is a very common problem with cold starts and little run time. In the late 70's I saw a lot of this with new car deliveries off the transport truck. And this was with the new electronic ignition.

It's even a worse problem with 2 stoke engines with oil in the gas. My neighbor asked for my help to get his weed whip started, so I removed the plug and got the electrodes red hot with a propane torch. He was surprised when it started on the first pull after the heating.

I've had to let some engines run for a good 30 minutes with the coil wire jumping a 1/4" gap before I could push the wire back in without the plug misfiring.

One bit of warning. In the late 70's we had a new Chevy running, fresh off the transport and a couple plugs were misfiring. The catalytic converter got so hot that the carpet inside the car started on fire. We got the fire out with no damage other than having to pull the seats and install new carpet.
Tom Wesenberg is offline   Reply With Quote
Old 02-16-2014, 09:57 PM   #6
QGolden
Senior Member
 
QGolden's Avatar
 
Join Date: Sep 2011
Location: Alton, NH
Posts: 1,216
Default Re: One for the books

My old 8N fouls plugs, I don't run it often enough to bother to fix it, it always starts, don't smoke much, but every so many hours of cumulative run time it will start to foul and will be all black and "fuzzy" with soot. I unplug the wires from the distributor, and just set them back on where the boots are just touching the top of the cap, and fire it up. After 4 or 5 minutes it's running good again. I can get away with this 2 or 3 times over several months before I have replace them.
__________________
It's not what people think they know that will hurt them, it is what they think they know that aint so! -Mark Twain.

It is the very things that we think we know, that keep us from learning what we should know.- Unknown
QGolden is offline   Reply With Quote
Old 02-16-2014, 10:01 PM   #7
MikeK
Senior Member
 
MikeK's Avatar
 
Join Date: May 2010
Location: Windy City
Posts: 2,882
Default Re: One for the books

Kevin, about the delay in spark- Using current science regarding spark propagation between charged points in the atmosphere I come up with an added delay of 0.00000037 seconds*(note 1) for an added 0.050" gap, likely a larger gap than one of those 'enhancer' thingies. I could punch more calculator keys and figure the delay in degrees at 2500 rpm, but with all those zeros I don't think it will add up to squat. Of course killing the coil is another story and reason enough not to do it long-term.

*Assuming a theoretical perfect air gap of zero capacitance. If there are two graphite plates as you state, the delay to breakdown will be longer as the plates charge, causing the coil voltage to rise even higher followed by a slightly higher amperage arc. Possibly the "secret" to their functionality? Anybody have a dizzy machine with a scope and one of those 'enhancers' handy? Both coil voltage and any readable added propagation delay would be interesting to see.
__________________
Mechanical engineering 101: If you put an adjustment knob, screw, bolt, or tolerance specs on something, some people will immediately fiddle with it. If you mark it DO NOT TOUCH everyone will mess with it.
MikeK is offline   Reply With Quote
Old 02-16-2014, 10:06 PM   #8
redmodelt
Senior Member
 
redmodelt's Avatar
 
Join Date: May 2010
Location: Portland OR
Posts: 5,162
Default Re: One for the books

Spark intensifiers have been around sense the 1910's or 1920's.
redmodelt is offline   Reply With Quote
Old 02-16-2014, 10:57 PM   #9
Drive Shaft Dave
Senior Member
 
Join Date: Dec 2011
Location: New hope Minnesota
Posts: 742
Default Re: One for the books

Back in the seventie's an old time mechanic friend of mine gave me one of the spark intensifiers, I put it on an old 6cyl chev. And drove around with it for a summer, then took it off. I couldn't tell any difference, theoretically the way it introduces a secondary gap may have some benefit.
Drive Shaft Dave is offline   Reply With Quote
Old 02-16-2014, 10:58 PM   #10
oldscout
Member
 
Join Date: Jul 2011
Location: NEPA
Posts: 81
Default Re: One for the books

I knew I'd get the right answer here, I've never seen it before. When we hooked the wires back on to the distributor though, it still wouldn't start. Also we put a propane torch on the plugs, and that didn't help either. We had to put in new plugs in before it would run right.
oldscout is offline   Reply With Quote
Old 02-17-2014, 12:09 AM   #11
700rpm
Senior Member
 
700rpm's Avatar
 
Join Date: May 2010
Location: Portland, Oregon
Posts: 5,290
Default Re: One for the books

I love it when I learn something new.
__________________
Ray Horton, Beaver Chapter, MAFCA, Portland, OR


As you go through life, keep your eye on the donut, not the hole.
700rpm is offline   Reply With Quote
Old 02-17-2014, 01:06 AM   #12
pooch
Senior Member
 
pooch's Avatar
 
Join Date: Sep 2010
Location: South Coast NSW Australia
Posts: 2,596
Default Re: One for the books

I have used those spark enhancers for years.

They DO work and are not snake oil.

They are old history now with computerised cars but they were great in their time.

I fitted them to others cars and told them to drive it and tell me what they think.

I did NOT tell them what I did.

In all cases, they noticed a slight improvement.

It was noticeable in pulling power, when a car can just not quite get up a hill without changing, fit the gizmo and it gets up without changing.

I did some zero to 60 times, but could not get anything to note in faster times on the flat, just pulling power.

And I am very much a skeptic on most things.
pooch is offline   Reply With Quote
Old 02-17-2014, 06:53 AM   #13
Wick
Senior Member
 
Wick's Avatar
 
Join Date: May 2010
Location: Gwynn's Island Va
Posts: 1,226
Default Re: One for the books

one tip; Run the engine at night and look for wires shorting out.
Wick is offline   Reply With Quote
Old 02-17-2014, 08:04 AM   #14
oldscout
Member
 
Join Date: Jul 2011
Location: NEPA
Posts: 81
Default Re: One for the books

I'm running the stock setup, but it has V8 points and condencer. Brass wires, stock distributor body, 6V. That's why it was so easy to gap the wires at the distributor. And your right 700rpm, there's always something new to learn here.
oldscout is offline   Reply With Quote
Old 02-17-2014, 09:17 AM   #15
Growley bear
Senior Member
 
Join Date: Apr 2012
Posts: 777
Default Re: One for the books

My father told me that they used buttons as spark intensifiers.
Chet
Growley bear is offline   Reply With Quote
Old 02-17-2014, 12:02 PM   #16
1930artdeco
Senior Member
 
1930artdeco's Avatar
 
Join Date: May 2010
Location: Oakland, CA
Posts: 2,763
Default Re: One for the books

So if I understand this right, one takes the strap off of the distributor just about a 1/4" or so and it should run? This will 'intensify' the spark and help clean the plug off-used in short duration of course. Or am I missing some part of the picture.

Mike
__________________
1930 TownSedan (Briggs)
Still learning after all these years....
1930artdeco is offline   Reply With Quote
Old 02-17-2014, 12:14 PM   #17
Mikeinnj
Senior Member
 
Mikeinnj's Avatar
 
Join Date: May 2010
Location: Northern New Jersey
Posts: 1,235
Default Re: Spark Intensifier Explained

http://www.steamengine.com.au/index....rk-intensifier
Mikeinnj is offline   Reply With Quote
Old 02-17-2014, 12:19 PM   #18
bbrocksr
Senior Member
 
Join Date: May 2010
Location: Yakima Washington
Posts: 595
Default Re: One for the books

Quote:
Originally Posted by 1930artdeco View Post
So if I understand this right, one takes the strap off of the distributor just about a 1/4" or so and it should run? This will 'intensify' the spark and help clean the plug off-used in short duration of course. Or am I missing some part of the picture.

Mike
Right.
Bill
bbrocksr is offline   Reply With Quote
Old 02-17-2014, 12:27 PM   #19
Jerry in Shasta
Senior Member
 
Jerry in Shasta's Avatar
 
Join Date: Jun 2010
Location: (Old)Shasta (Redding) CA
Posts: 341
Default Re: One for the books

Sooo, why not just file the rotor and create a larger gap there?
Just my WAG at the question

JB
Jerry in Shasta is offline   Reply With Quote
Old 02-17-2014, 12:53 PM   #20
clinton perry
Junior Member
 
Join Date: May 2010
Posts: 10
Default Re: One for the books

This happens often when you sand blast the plugs. You remove all the glaze from the porcelain and plug shorts from gas saturation. 30's and 40's this was common with rebuilt plugs from Western Auto and other suppliers. Would drive people crazy after changing the plugs, no start. Clinton
clinton perry 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 10:52 AM.