Custom Distrubutor Cap

Anyone know someone who can make a custom distributor cap? I'm building a 2 engine car and one to run just one distibutor. What I'd like to have is a cap that will fire two terminals at a time (thus igniting two cyliders at a time, one for each engine).

Why not run EDIS, or similar.
Uses a 36-1 trigger wheel,then you don't need distributors.

If you are running a pair of 4 cyl motors, for some reason ,
some Japanese 4 cyl motors ran two plugs per cyl.
You could get one of those distributor caps.


Much simpler and easier to run two distributors.

I've seen some people modify a large diameter MSD
cap and rotor, to create a custom twin plug cap.

But, unless you have both engines indexed to TDC
at exactly the same time, your timing won't be accurate,
if you are running only one distributor.
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One coil probably won't have enough juice to fire two plugs
at once. OEM dual plug ignitions typically run two coils.

The fuel drag race guys run two plugs per cylinder, but use
two distributors and two coils.Each system is independent.
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The more I think about it, the more I would be inclined
to run two distributors. Keep it simple.

This can be done but it will be tricky,

Are the engine going to be hooked together or use a gear box to couple them to the drive train?

Depending on the engine, a mag is probably the way to go. two mags would be easier to use and Hemi offset drives are available and easy to modify so both will spin together but carry enough fire to light all 16 candles.

I put my rat project on hold to spend the summer getting ready to retire from racing and was racing nostalgia races all year long, you will be suprised what these old guys can build so im sure its been done...

Nice FED Troy.

Simplest solution would be to use a regular cap, run a wire to a plug and then from there to the corresponding plug on the other engine............not sure if you will lose voltage......

Getting TDC on both engines would be crucial.

Thanks for the suggestions, however I'm looking for something a little simpler. The engines are coupled together, 180 degrees apart, so when #1 fires on the front engine, #6 will fire on the back. What I'm looking for is a cap that will allow me to fire 1 & 6 at the same time, and so on, basically a cap that fires two wires at-a-time instead of one. I'd run all 16 wires off of the same cap like you would see on a V-16. I'm running two 360 Mopars, so I'd use the stock style small block chrysler electronic distributor. This is not a race car, so a built up electronic distributor should give me enough fire. I just need the cap.

You can see the car via the attached youtube link.


http://www.youtube.com/watch?v=b8fHyQn5KyI

If a cap can't be found or created, I wonder if the spark plug wires can be spliced. I know there is high voltage but if the insulation thickness was duplicated with RTV silicone, it might work. Wouldn't cost much to make a test set up on a running engine.

maybe this will help

take a look online for companies that build racing aircraft engines, someone builds an engine that is 2 small block chevies mated together, not sure who they are, but they have an audio sound of one of these monster at full throttle and it sound awesome,,,hope it helps,,,tk

tkkruzer - I been searching for that mated small block you mentioned but can't find it. If you can find it or think of any other clues please let me know.

oil pumps

Don't forget that you still will have to modify a distributor to put in the other engine so that its oil pump shaft stays put.

Why not run two distributors, again? It will be easier to time each engine and compensate for differences in timing chain stretch, camshaft variations, and carburetors.Tuning each independently will maximize performance - the ignition timing relates to the vacuum developed and thus carburetor tune, especially idle speed.

Even the GMC Twin Six ran two distributors, although it had one common crankshaft and camshaft.

Food for thought, anyway.

440shorty

bob w said:

If a cap can't be found or created, I wonder if the spark plug wires can be spliced.

Click to expand...

I agree with bob w on this one. The cap is nothing more than a way to connect the wire to the electrode that the rotor passes current to. We've all built custom wires. Trim down the insulation on some wires, combine the core and crimp them into a single connector. Slide them into the cap and seal the boot.

Since in your application one of each pair of plugs will be a wasted fire due to TDC overlap it would draw no current so I agree that a stock, late model ignition system will suffice in output.

The 4 cylinder dual plug engines (Nissan NapZ motors) had bi-level caps with bi-level rotors and ran two coils because the second plug fired trailing in timing so adapting one of those would work poorly.

The two-wires-in-each-hole method would get it running until you could build a cap.

- Mike

I think if you ran two plugs off one distributor terminal,
there is a good chance that only one of them will fire.

As soon as the first plug fires, the electricity will follow the path of least resistance, instead of jumping the gap on the other cylinder.

TKKRUISER

Tkkruiser is right..aircraft engines have 2 plugs per cylinder..and dristributers are made....i have only found em for vw and covair engines....check the mudders site too..i have seen them with 2 plugs per cyl...good luck keep us posted

I have added dual plug heads on several of my H.D.'s by machining another plug hole on the right side of the head and used a dual point single fire[two individual sets of points on a single lobe point cam] or electronic single fire and ran dual coils - one per head.Adding another plug must be done in such a way that it does not interfear with the combustion pattern of the stock plug,but adds to it, if done improperly it can cause you more damage than help.Running two V-8's sounds like it could get rather costly.Running two distb. sounds easier.

Just a passing thought, but how do the tractor-pull guys go about it? They run a lot of dual motors in that sport.

i tryed to run 2 plugs at the same time and found that you cant get the gap the same and only one will fire not both had the bright idea for my flame throwers and ended up with 2 coils one for each plug

2rustee said:

i tryed to run 2 plugs at the same time and found that you cant get the gap the same and only one will fire not both had the bright idea for my flame throwers and ended up with 2 coils one for each plug

Click to expand...

Electricity follows the path of least resistance.
Once the spark jumps to Ground on one plug, it can't jump on another that is wired in Series.