Dual distributors
- Thread starter Ol' Ron
- Start date
tjw
Senior Member
tubman Thanks I have sold a lot of these Dual timing covers now, and I also have a new dual plug Flathead V8 head coming out soon.
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tjw
Senior Member
OI' Ron Very nice job.
rotorwrench
Well-known member
The old Elco/Nash dual fire that used to Autolite 16 distributor are likely hard to find parts for now days so that set up will do the trick without worrying about finding parts. One of Bubbas threads, https://www.fordbarn.com/forum/showthread.php?t=60169&showall=1
Ol' Ron
Well-known member
Well we bought one of these back a few years ago, and couldn't figger out how to make it work. The distributors didn't line up with the gear on the cam. Was also told we had to have a CCW distributor for the drivers side, so I got a Pontiac dist. I could see this was going to be to complicated to work for us. My stupid factor is pretty high. That cover is pretty expensive. just how much does a working dual distributor system like that cost?
With my system you could run two stock distributors, and with the right carb should work just fine.
With my system you could run two stock distributors, and with the right carb should work just fine.
tjw
Senior Member
Hi Ron I am sure you did not buy one off me, someone else was making something similar to mine at one stage.. I have never had any conversation with yourself about using a Pontiac distributor on one side and have never advised any one to use them [ the Pontiac distributor would most likely not line up with gears anyway as the length of it would be wrong ... I only use two 8ba distributors which line up correctly and I have a video of the test engine running using this set up. MESSAGE me your email address and I will send you a copy of the video to view. [ If any one else wants a copy of the engine running video please send me your email address. ] I will see if I can load it on here first .. As far as cost is concerned, I think they are fairly priced as it is not a cheapo item to manufacture, by the time you cost in the pattern to make them, cast it, machine it, ship it etc. I run an electronic ignition with both modules in the one distributor as you will see in the photo which has never given us any problems at all.
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Ol' Ron
Well-known member
I certainly apologize to you and your efforts here. The unit we had was from Texas. I see that you use a CCw rotation dist on the drivers side tho. I was the one that brought up the use of the Pontiac distributor. It has a CCW rotation and can be used in the SBC distributors we use in the fatheads. I wouldn't have used these Mallory dists as they are heard to modify the advance, where as the Chevy units have adjustable vacuum and N
Mechanical advances. I understand the cost of producing anything, especially a part for a small customer base. I wish you well. Yje unit I made wasjust an exersize , just to see if i could do it..
Mechanical advances. I understand the cost of producing anything, especially a part for a small customer base. I wish you well. Yje unit I made wasjust an exersize , just to see if i could do it..
Bored&Stroked
Well-known member
I have the same dual-magneto setup. I've always wondered what the original application was - as the mounting bolt-pattern does not match the flathead Ford timing cover. Was there a DIFFERENT timing cover in Europe that I don't know about?
My guess has always been an aircraft application of some sort - due to all the aircraft style shielding on the caps (metal covers over the STD Scintilla cap) as well as the original braided/shielded spark plug wires.
Bored&Stroked
Well-known member
This makes a lot of sense in that the second distributor can spin the opposite direction as all it is doing is transferring the spark to the second set of plugs. It is NOT involved in actually firing the coils. Therefore there only needs to be an advance mechanism in the one distributor (and a single points plate for that matter).
KiWinUS
Well-known member
Dale the first I purchased came from Denmark the other 2 from Sweden,I was told they came off Swedish military engines.When I received the second I believe I found the key.They had complete shielded plug wire sets with brackets &it looks to me the mags are turned 90*& straddle the left water pump. I determined this from lengths is wires&placement of bracketsThis would be possible if they weren't used in a regular vehicle or used in a boat. The bolt pattern lines up this way also. Makes sense.
Cheers
Tony
This is a casting I have had for a long time supposedly made by the late great Mickey Thompson
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Ol' Ron
Well-known member
Now B&S, that;s a great idea, fire both coils fron the lead distributor. Then both distributors would have the same advance curve, but could you delay the secondary distributor a few degs. I have to think about this. with the gears mounted in the system the secondary dist is CCW
KiWinUS
Well-known member
Ron am I correct in thinking to delay timing of secondary distributor would require the module that signals the secondary distributor be adjusted slightly from the primary module?
Bored&Stroked
Well-known member
Yes - you'd need to setup the second trigger or set of points to be "adjustable" so you could decide how close you wanted to sync it to the other set.
I'd probably do it on a distributor machine - though I'm sure real-world experimentation would come into play as well.
Also, you'd need to synchronize/time the rotor on the second distributor - so that it is in the right place (given the cap terminals) - such that you're not trying to jump too big of a gap (really hard on the coil and can cause a spark to jump to ground inside the distributor itself.).
Probably ZERO horsepower to be gained . . . only bragging rights! LOL
Yoyodyne
Well-known member
There's definitely power to be gained on some engines with dual plugs, but maybe not flathead Fords. Race Harleys have done it since the 70s, I had my first dual plug setup on a shovelhead about 77 or 78. Shovelheads have huge hemispherical chambers that resemble a Chrysler Hemi, race versions have big domes on the pistons. Putting a plug on each side of the chamber does gain power, and allows slightly reduced timing advance. Curent HD engines have much smaller chambers and gain less from dual plugs. Staggering timing has never been much help on any HDs I've dealt with. When Hemis were competitive in Pro Stock dual plugs were in popular use. All current fuel Hemis use dual plugs, there was even some experimentation with 3 plugs before it was outlawed by NHRA.
To use a Nash 16 plug distributor on a flathead requires a custom point cam, at least the one I've seen running did.
To use a Nash 16 plug distributor on a flathead requires a custom point cam, at least the one I've seen running did.
rotorwrench
Well-known member
Aircraft engines were hemispherical way back. The fuel mix swirls in them and the twin redundant ignition systems ignite the spark plugs at 180 degrees from each plug center inside the cylinder. The flathead has more than a swirl in the chamber due to it's design but the fuel mixture does get burned efficiently. That's one of the reasons it doesn't need as much advance as an overhead valve engine does.
The really large engines have two magnetos and two distributors. The magnetos provide the high tension and the distributors clock it to the correct cylinders. The big Wright R-4360 has 28 cylinders in 4 rows of 7 cylinders each. That makes for 56 spark plugs to fire for each double rotation of the crank. The really complex one was the Chrysler Multibank engine in one of the M4 Sherman tank models. It had five 6-cylinder engine blocks joined into one casting. That's 30 cylinders to fire in two rotations. It was an amazing design. You can imagine the 5 ignition systems on that baby.
https://en.wikipedia.org/wiki/Chrysler_A57_multibank
The really large engines have two magnetos and two distributors. The magnetos provide the high tension and the distributors clock it to the correct cylinders. The big Wright R-4360 has 28 cylinders in 4 rows of 7 cylinders each. That makes for 56 spark plugs to fire for each double rotation of the crank. The really complex one was the Chrysler Multibank engine in one of the M4 Sherman tank models. It had five 6-cylinder engine blocks joined into one casting. That's 30 cylinders to fire in two rotations. It was an amazing design. You can imagine the 5 ignition systems on that baby.
https://en.wikipedia.org/wiki/Chrysler_A57_multibank
BUBBAS IGNITION
Well-known member
How about longer plug wires on the second distributor to delay the second spark?
Theres way too much information in this thread and you have to add this statement.
JC Whitney sold a booster to slow down the spark when it was too fast!!
