single or dual distributors

I think a single distributor is preferable. This way there is only one advance mechanism controlling advance instead of two. With two advance mechanisms there is no way they are going to be synchonized all the time or for very long. That said if the dist caps and rotors are even more expensive than the duals or NLA, then I'd want to stick with the dual!

 

Stick with the single set up and yes its valuable. It can also be converted to electronic.

 

One more vote for one dist. Traded the twins and cash for a single and love it.
Tom

 

single.

 

I'd go single, for sure.

 

It should match the VIN of the machine......
NA versions were the ones requireing R1 R2 points but many are now 'lighter' somewhat.....

I run twin on all mine, but the 8 plug is a nice unit.....


I'm glad you guys are junking the old ones they are hard to find! LOL!


Once tested and installed my twins stay pretty well set..........

 

You would need fewer 400$ caps for sure.........

 

Geez. So many singles out there. O.k. I'll chime in. It is an exotic and so are the two dizzys. If you learn how they work, they work fine. It is factory equipment and really hard to go back. The wire routing is cooler IMHO. I tell friends "you see the two distributors, one for each bank?" and it always gets a "whoa" or "cool". Anyway, I'm for duals.

-Rjay

 

Going back just means putting the twins back in, which is why I didn't feel bad going single.
Tom

 

Thanks for the back up....LOL!

Interesting discussion here.........so few un modded cars out there, but....you gotta keep 'em runnin'!!!!!

 

That's exactly what it boils down to for me - if it's cost-effective, will minimize my stress, and will keep my car on the road more than laid up in the garage, I'm all for it. Factory originality is a concept that I appreciate in others' cars very much, and even in my own (to an extent), but it is by no means the rule which I live and drive by.

 

+1

 

It might look cool but it aint better and never will be because 2 of the same distributors will never advance at the same rate no matter how long you play with a distributor machine and it only makes it even more like 2 - 4 cylinder engines sharing the same crank and fighting each other. There is a certian appeal for me seeing the 2 distributors but once you know its pitfalls it becomes less attractive, at least for me.

 

Good luck with it and thanks for dropping in!

The Euro cars had a metal weathreshield over it....lost in the dual installation.....water just runs right in our louvers and washes the dust off!

Handy, for desert running...............

 

OEM 4 plug is $800......$500 to rebuild and calibrate.......

 

It's like a BenHur chariot Newman, ponies running every which way....

danger.....blood ............death.....

 

But as has also been pointed out, two distributors with thier own seperate points and advance mechanisms are going to be virtually impossible to syncronise. This is why the euro cars had a single unit with both banks points inside one unit. This was impossible to do when the cars needed idle retard to meet US emissions for idle speed, and thus four sets of points and dual distributors. But come on, they do look cool.

So in my case I simply "altered" one of my distributors so the second set of points is offset correctly, and use the second set of points to fire the front bank. I basically built a single distributor. The front distributor is gutted except for the main shaft and rotor, no advance wieghts, points, nothing, it simply delivers spark. When its time to play with ignition, I only have to deal with the one distributor. I keep the look and character of the car mostly original, yet have dramatically shortened the amount of labor required to keep it running good or trouble shoot it. Runs like a single, looks like a dual. Best of both worlds.

My next idea is to convert the other distributor the same identical way, and then run off one and keep the other diconnected. If I have an ignition fault away from home I could simply switch wires and be running again. The same thing could be done with Pertronix units.

 

OK, in the interest of banging my head against the wall, I'm sticking with duals. When properly set, they work great. I find it hard to believe that any of us would ever notice the two distributors being off by a couple of degrees whether at idle or while advancing or at full advance. The two banks aren't "fighting each other", and unless everything else in the engine is perfect (compression, valves seating fully, no leakdown by the rings, all plug wires and connections perfect, etc), only a dyno test would show any difference if one existed. I bought a distributor machine just to set up and check mine, and will help anyone else who chooses this route. Additionally, my '79 (US) has the "weathershield" which re-routes water from outside so it doesn't drip or run directly onto the coils or distributors. These older 2-valve cars will never match the newer cars in performance, so why not be satisfied with them as they were intended. As previously stated, properly maintained cars are not a reliability issue. Now, where's the excedrin???

 

There's a national shortage after all the ones I bought over the last year.

 

One thing I haven't heard discussed in point bounce. The first time I saw a V8 or V12 with dual distributors and points I assumed one goal was to reduce the number of times the points opened and closed per cycle. With a 7,700 RPM redline isn't point bounce a concern with a single distributor. With duals the points are running at half speed.

Also isn't the potential for crossfiring between poles is increased with 8 in the same space as 4. I seem to remember hearing somewhere that an 8 pole distributor limits total advance potential, but I don't know how that would be. If I remember correctly these reasons are why GM used a larger cap on the HEI distributors.

Does anyone out there have any real knowledge about these points, I have just heard these over the years.

 

my stock setup on the euro 308 GTS is a single distributor with NO points. a great unit, i used it until i bought the electromotive. still have it in a box stored away....

 

AND you can get more dwell with duals, since the points can be closed longer. In theory anyway, at high RPM this can give a better spark.

But of course the BEST answer to the question of how many dizzys to run is MY answer: NONE!

(Electromotive)

Birdman

 

Distributors w/MSD rock. Electromotives are for Kids.