No cross firing with the small cap in my experience.
FWIW, Ford says the big distributor caps are to reduce cross-firing both inside and outside the cap, and being vented (the odd protrudence between wire towers and coil) reduces ozone that's produced inside the cap from rotor sparking. Finally, big caps only take modern sparkplug ends due to the male-type cap connectors. Ford also once produced weatherproof rubber distributor boots for boats and cars with semi-exposed dizzy caps- but they only fit the big caps. Boots are nice for Panteras that are driven in bad weather.
quote:Originally posted by Bosswrench:
FWIW, Ford says the big distributor caps are to reduce cross-firing both inside and outside the cap, and being vented (the odd protrudence between wire towers and coil) reduces ozone that's produced inside the cap from rotor sparking. Finally, big caps only take modern sparkplug ends due to the male-type cap connectors. Ford also once produced weatherproof rubber distributor boots for boats and cars with semi-exposed dizzy caps- but they only fit the big caps. Boots are nice for Panteras that are driven in bad weather.
The cap boots were introduced on mid-80's Mustang GT's. They were infamous for containing moisture under them. I think they were discontinued as a result?
E6TZ-12252-A
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I purchased the 1976 Ford Duraspark rotor for the smaller 4" distributor cap, SMP p.n. FD-115, and checked it on a NOS Duraspark distributor with the 4 inch International Harvester (IHC) distributor cap, SMP p.n. AL-482.
The IHC cap is an inch smaller in diameter and about 5/8 inch shorter too. The cap in the pictures is actually a Borg Warner (BWD) cap, from their "select" line of auto parts. Notice the terminals are brass. BWD's part number is C200.
The terminal on the tip of the rotor, and the terminals in the cap have about 1/32 inch clearance, this was true for both the big Duraspark cap and the proper rotor for that cap, as well as for the IHC cap and the smaller Duraspark rotor. The small rotor also lines up with the IHC cap terminals height wise.
4V&Proud will be pleased to know the IHC cap is notched so that it is oriented on the distributor with the same terminal phasing as the Ford cap.
I'm happy to inform you guys that its a fit. A good option for Duraspark distributors in Pantera applications.
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quote:Originally posted by JAG13CAT:
PUNKDOG; Just completed a Duraspark II installation on mine. With the aforementioned comments, its the way to go. Purchased a rebuilt Motorcraft distributor, the module, coil, wire set and distributor cap from the local NAPA store for less than $200. One compelling reason for the Duraspark II is availability should a part fail. I will not be searching for some exotic ignition system that cannot be readily sourced. Local auto parts stores typically carry the parts.
Additionally, just go to "Find" at the top of the posting and type in Duraspark and George's wiring schematic and installation instructions are at your finger tips.
PUNKDOG here are the Duraspark items I purchased from NAPA a few years back after reading all the information on this forum.
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Duraspark distributor
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Comparison on internals, stock dual point vs. Duraspark
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Stock vs. Duraspark side by side.
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Hi George. Above you stated:
"I purchased the 1976 Ford Duraspark rotor for the smaller 4" distributor cap, SMP p.n. FD-115, and checked it on a NOS Duraspark distributor with the 4 inch International Harvester (IHC) distributor cap, SMP p.n. AL-482."
Searching online I can find the cap (AL482) in SMP's catalog and at Summit racing and other sites. I can't find the FD115 rotor on SMP's catalog. I find some available at Walmart.com, but not sure they really have them or not. Is the FD115 part number rotor still available or did the part # change? Just wondering where you found it and if it's still out there at most places. Good discussion in this thread and I'm looking to change to a smaller distro cap for my duraspark distro. Your recommendation on these parts based on your research was helpful! Thanks, Mike
FWIW, the versatile Ford electronic distributor's mechanical and vacuum advance curves can be tailored to your needs using stock or easily altered parts. The numbered pivoting weights and limit slots can be changed, in case the 460 Ford advance curve in most e-distributors is not to your liking, or they can be tailored with a gas welder and Dremel tool. I think there are 5 or 6 stock choices, besides changing advance springs. Stock Ford vac-advance cans are adjustable with an allen wrench. There are several articles in the POCA Archives on the details of this mod, including using a fail-proof e-coil in place of any of the can-of-oil coils.
You'll have to do some experimentation on your combination; for instance, with aluminum SVO closed-chamber heads & SVO flat tappet cam in our 10.5:1 351-C, I found best power with 16 degrees initial advance and 28 degrees total. I shifted the whole engine/ZF backwards 3/4" on swapped upper motor mounts and now have lots of room for a big vented dizzy cap and late wires. The small move backward also made changing to a flat firewall access door much easier.
I purchased the rotor via eBay circa August 2018.
I like using eBay because I can acquire SMP brand parts that way. There are no independent auto parts retailers locally here in Ventura, only chain outlets like O'Reilly, AutoZone, NAPA, and CarQuest. I have been burned by each of them. I've never been burned by an independent retailer selling SMP parts.
(SMP = Standard Motor Products)
Thanks George : )
...I went Distributor-LESS with Computronix. No more Rotor to Cap Spark Gap. Very Small/Short Timing Unit replaces the Dizzy. Full Voltage to 12000 RPM. No 'Spark Scatter', No Backlash. Note the difference, Runs 'Smoother' on the Freeway. I would change-over again, without hesitation. Look it up on the Net, and come out of the 'Dark Ages', in My Opinion. The Timing Unit I Received, came with the 'Steel' Gear Installed, compatible with Roller Cams.
MJ
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I kept mine because I want the car original. If you want improved performance then go electronic.
Australian Bosch copy, what's the module?
i think i heard these have a 2 piece shaft that can be an issue?