new dist body,s

sorry if im missing the point
but if the rotor dosnt clear the contacts in the body
maybe the rotors wrong?
wouldnt it be easier to file the rotor to get the gap?
and then if one or more is wrong file that one,instead of the akward filing of four contacts
tom
 
SAJ said:
I think we are talking about different gaps. I am referring to the gap inside the distributor beteeen rotor and electrodes in the body. For plug gap, standard coil and high compression I use .030 for the plugs. But I use .035 for the 40000 V coil for both plugs and rotor gap. Both my cars now use a stipe points cam and Flame Thrower coil on Purdys recommendation. I cannot personally say if they go better because I am always changing things. They pull cleanly up to well over 70 mph on my GPS which is too fast for the hard skinny tires I have.
SAJ in NZ
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Yes, I was referring to the spark plug gap in my other post. However, there's no reason to think that a larger gap between the rotor and the electrodes would make hotter spark at the spark plug. The only way to make a hotter spark is to increase the dwell time of the coil or change to a more powerful coil.
 
mot said:
sorry if im missing the point
but if the rotor dosnt clear the contacts in the body
maybe the rotors wrong?
wouldnt it be easier to file the rotor to get the gap?
and then if one or more is wrong file that one,instead of the akward filing of four contacts
tom
Click to expand...

By filing the body contacts keeps the rotor contact center since the rotor contact is on a downward angle.
 
edmondclinton said:
Yes, I was referring to the spark plug gap in my other post. However, there's no reason to think that a larger gap between the rotor and the electrodes would make hotter spark at the spark plug. The only way to make a hotter spark is to increase the dwell time of the coil or change to a more powerful coil.
Click to expand...

Sorry, not quite true. When the points open, the voltage from the coil due to the changing flux in the coil takes some small time to rise to a maximum. By using the methods that Purdy S. talked about, the voltage has risen to it's highest value and then jumps the spark gap. What the gap in the distributor or in the wires does is let the voltage rise to a higher value by stopping the first spark that could happen. I.E. the gap inhibits the early, weaker, spark and causes the later stronger spark to jump the plugs.

It's a nice trick with the original spark system.

Marc
 
marc hildebrant said:
Sorry, not quite true. When the points open, the voltage from the coil due to the changing flux in the coil takes some small time to rise to a maximum. By using the methods that Purdy S. talked about, the voltage has risen to it's highest value and then jumps the spark gap. What the gap in the distributor or in the wires does is let the voltage rise to a higher value by stopping the first spark that could happen. I.E. the gap inhibits the early, weaker, spark and causes the later stronger spark to jump the plugs.

It's a nice trick with the original spark system.

Marc
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The voltage may be slightly increased but a lot hotter, no. The original distance as made by Ford is the best for a variety of RPM especially when one does not quite have the timing advanced far enough for a particular higher speed as the spark would stretch out when jumping a greater distance with a wider gap which could cause a weaker spark at the plugs.
 
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The "offshore" distributor body is machined after molding to provide 3 concentric surfaces.
The 3 surfaces are: 1) where the distributor body interfaces with the distributor base, 2) the 4 contacts, and 3) where the distributor body interfaces with the distributor cap. No filing is required unless the rotor tab is longer than stock.
 
edmondclinton said:
Sorry I disagree. Opening the gap merely presents a larger spark which will maximize the efficiency of the burning fuel but the spark itself is cooler or less intense; that's why when performance people go with large gaps they will have extremely hot coils. Moreover, after raising up the compression on a engine with the same stock ignition a smaller gap is often required to ensure the best ignition in the denser mixture whereas a larger gap can cause a misfire.
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It takes a hotter spark to jump a larger gap!
Bill
 
By lifting the wire up a bit the coil needs to build to a higher voltage to jump the gap. This higher voltage can then jump the spark plug gap before it has time to bleed off due to a wet or carbon coated center electrode.
 
those having trouble with what Purdy wrote (which is true) might google 'booster gap' and enjoy some reading. There are some really old time spark plugs with a hollow glass top and a lever whereby you could change a gap setting in the top of the plug, or have no extra gap there. I have one such plug in my archives. This concept was discovered a long time ago. Even in the 70s it was common to have modern plugs with booster gaps in them; just no glass top to see it
 
bbrocksr said:
It takes a hotter spark to jump a larger gap!
Bill
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Maybe the following from the NGK company's web site will help you to understand my point of view:


A spark plug's voltage requirement is directly proportionate to the gap size. The larger the gap, the more voltage is needed to bridge the gap. Most experienced tuners know that opening gaps up to present a "larger spark" to the air/fuel mixture maximizes burn efficiency. It is for this reason that most racers add high power ignition systems. The added power allows them to open the gap yet still provide a strong spark.
 
Post 14 & 15 & 27 : Purdy Swoft: "Doesn't Terry Burts produce an accurate model A distributor cap body?
__________________________________

Is there a source to buy the Terry Burts Distributor Cap Body ?
 
pgerhardt said:
I have a nice ford script distributer body and cap I would like to use. Are there any visible signs of a bad body/cap I should I should look for before just giving it a try?
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Both the top & body are after market reproductions, not used by Ford when new.. They may work just fine ??..
 
DougVieyra said:
Post 14 & 15 & 27 : Purdy Swoft: "Doesn't Terry Burts produce an accurate model A distributor cap body?
__________________________________

Is there a source to buy the Terry Burts Distributor Cap Body ?
Click to expand...

Also, Is it the first type or 2nd ??
 
Getting a hotter spark when there is a wider air gap in the distributor seems counter intuitive to me. The wider the gap, the more voltage is required to jump it, leaving less to give a spark at the plug seems more logical. For example, if the coil puts out 20,000 volts and it takes 5,000 to jump a 0.035" gap in the distributor, that leaves 15,000 volts of spark at the plug (in a perfect world). If the distributor gap is say, 0.025", it will take let's say, 3,000 volts to jump it, leaving 17,000 for the plug and hence a hotter spark (assuming the plug gap is the same).
Can somebody please explain what I'm missing?
 
that is not how it works. spark is not really 'used up' like that

i would google things like, ignition voltage, spark plug gaps, booster gap, etc for greater detail.
 
Synchro909 said:
Getting a hotter spark when there is a wider air gap in the distributor seems counter intuitive to me. The wider the gap, the more voltage is required to jump it, leaving less Where do the electrons go? to give a spark at the plug seems more logical. For example, if the coil puts out 20,000 volts and it takes 5,000 to jump a 0.035" gap in the distributor, that leaves 15,000 volts of spark at the plug (in a perfect world).Once again where do the electrons go? Well they wait. The coil continues to build up voltage to its design maximum. The voltage builds up and finally jumps the gap. The larger the gap the more voltage that builds up in the coil before it jumps the gap and continues on to the plug with no loss due to the jump. If the distributor gap is say, 0.025", it will take let's say, 3,000 volts to jump it, leaving 17,000 for the plug and hence a hotter spark (assuming the plug gap is the same).
Can somebody please explain what I'm missing?
Click to expand...

Of course what I wrote above is a simplistic version as there are other variables that come into play such as dwell and design specifications of the coil. So, no a one inch gap will not work as the coil is not designed to build up to the required voltage to jump that gap nor does it have time to do so (dwell).

Hope this helps.
 
Doug and Fred,
The Bakelite distributor body is available from most parts dealers including Snyder's, Bratton's, Bert's, Mac's, and others.
It is the early style and correct for cars manufactured up until Dec '30. After Dec '30, the window was changed and Ford script was added.
 
Terry Burtz said:
The "offshore" distributor body is machined after molding to provide 3 concentric surfaces.
The 3 surfaces are: 1) where the distributor body interfaces with the distributor base, 2) the 4 contacts, and 3) where the distributor body interfaces with the distributor cap. No filing is required unless the rotor tab is longer than stock.
Click to expand...

Thanks for your answer. In both cases they had a new body and rotor. The body did fit well but the rotor hit every post lightly.
 
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