Which aftermarket distributor to buy, 351C 4V

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My Car
1971 Mustang Mach 1, M code, 4 speed.
There are a lot of opinions as to which aftermarket distributor is best for the 351C 4V. I had my reman. dist. supposedly re-curved for my application returning to points at this time, but it seems no better than before. It could be that I am misreading my brand new timing light, which definitely could be the case. To get a total advance of 34 deg. with vacuum attached, it appears to be 0 deg. mechanical, vac off. At 6 deg.,  factory setting, I get 41 deg. total @ 2500 rpm and that seems too much. Perhaps I need someone who knows what to do before I 'F' it up!!

I found that Cardone seem to build 1 replacement to cover a load of applications, I mean a dozen or more. (look it up on Rock Auto for example) The factory ID for my manual trans is D0OF-V.

I'm at the point where authenticity is somewhat out the window, so IF I replace it, what is the best, but close to stock distributor. I have a Pertronix 3 unit already, but I'm told by my local guru that the Pertronix dist. itself is no good and that particular store no longer sells them. I see in Mustang Monthly that Performance Distributors offers a custom built DuraSpark dist. that will be built to my engine specs. Any thoughts??

What I DON"T want is an ugly MSD type "box" bolted anywhere it can be seen, even though it may be a good replacement. I know we have been over this before many times, but products changes and so do thoughts on what's good and what's not.

Thanks,

Geoff

 
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There are a lot of opinions as to which aftermarket distributor is best for the 351C 4V. I had my reman. dist. supposedly re-curved for my application returning to points at this time, but it seems no better than before. It could be that I am misreading my brand new timing light, which definitely could be the case. To get a total advance of 34 deg. with vacuum attached, it appears to be 0 deg. mechanical, vac off. At 6 deg., factory setting, I get 41 deg. total @ 2500 rpm and that seems too much. Perhaps I need someone who knows what to do before I 'F' it up!!

I found that Cardone seem to build 1 replacement to cover a load of applications, I mean a dozen or more. (look it up on Rock Auto for example) The factory ID for my manual trans is D0OF-V.

I'm at the point where authenticity is somewhat out the window, so IF I replace it, what is the best, but close to stock distributor. I have a Pertronix 3 unit already, but I'm told by my local guru that the Pertronix dist. itself is no good and that particular store no longer sells them. I see in Mustang Monthly that Performance Distributors offers a custom built DuraSpark dist. that will be built to my engine specs. Any thoughts??

What I DON"T want is an ugly MSD type "box" bolted anywhere it can be seen, even though it may be a good replacement. I know we have been over this before many times, but products changes and so do thoughts on what's good and what's not.

Thanks,

Geoff
You should not be setting the timing with the vacuum advance connected. Disconnect the advance hose and plug it. Set initial timing with your timing light to whatever you think it should be. After that is done you can check total timing (initial + mechanical advance) by increasing the engine rpm while checking with your timing light until the timing stops advancing. This will typically be somewhere between 2500 and 3500 rpm. If that total timing value exceeds about 36 degrees you need to either reduce your initial timing or reduce how much mechanical advance is being added.

After all that is sorted you can check how much vacuum advance your advance unit is adding by pulling a vacuum on the advance unit while checking with a timing light. You will want to limit the vacuum advance to about 10 degrees to avoid pinging.

 
You should not be setting the timing with the vacuum advance connected. Disconnect the advance hose and plug it. Set initial timing with your timing light to whatever you think it should be. After that is done you can check total timing (initial + mechanical advance) by increasing the engine rpm while checking with your timing light until the timing stops advancing. This will typically be somewhere between 2500 and 3500 rpm. If that total timing value exceeds about 36 degrees you need to either reduce your initial timing or reduce how much mechanical advance is being added.

After all that is sorted you can check how much vacuum advance your advance unit is adding by pulling a vacuum on the advance unit while checking with a timing light. You will want to limit the vacuum advance to about 10 degrees to avoid pinging.
Thanks TommyK, Just to be clear, I was setting initial without vacuum. I'll retry as you suggest, but I really think this distributor has waaaay toooo much mechanical from the get-go. I think the base plate limit stops need to be changed or reworked. This is why I'm about to just go buy a better distributor and chuck this one in the junk box.

Geoff.

 
You should not be setting the timing with the vacuum advance connected. Disconnect the advance hose and plug it. Set initial timing with your timing light to whatever you think it should be. After that is done you can check total timing (initial + mechanical advance) by increasing the engine rpm while checking with your timing light until the timing stops advancing. This will typically be somewhere between 2500 and 3500 rpm. If that total timing value exceeds about 36 degrees you need to either reduce your initial timing or reduce how much mechanical advance is being added.

After all that is sorted you can check how much vacuum advance your advance unit is adding by pulling a vacuum on the advance unit while checking with a timing light. You will want to limit the vacuum advance to about 10 degrees to avoid pinging.
Thanks TommyK, Just to be clear, I was setting initial without vacuum. I'll retry as you suggest, but I really think this distributor has waaaay toooo much mechanical from the get-go. I think the base plate limit stops need to be changed or reworked. This is why I'm about to just go buy a better distributor and chuck this one in the junk box.

Geoff.
Are you up to taking it apart? You need to see what slot widths you have in the limiter. It may be possible to flip the one you have to limit the mechanical advance. Alternatively you can weld the slot up to whatever dimension is needed for the amount of mechanical advance required.

This tutorial is for a Duraspark but the principles apply:

http://www.reincarnation-automotive.com/Duraspark_distributor_recurve_instructions_index.html

 
You should not be setting the timing with the vacuum advance connected. Disconnect the advance hose and plug it. Set initial timing with your timing light to whatever you think it should be. After that is done you can check total timing (initial + mechanical advance) by increasing the engine rpm while checking with your timing light until the timing stops advancing. This will typically be somewhere between 2500 and 3500 rpm. If that total timing value exceeds about 36 degrees you need to either reduce your initial timing or reduce how much mechanical advance is being added.

After all that is sorted you can check how much vacuum advance your advance unit is adding by pulling a vacuum on the advance unit while checking with a timing light. You will want to limit the vacuum advance to about 10 degrees to avoid pinging.
Thanks TommyK, Just to be clear, I was setting initial without vacuum. I'll retry as you suggest, but I really think this distributor has waaaay toooo much mechanical from the get-go. I think the base plate limit stops need to be changed or reworked. This is why I'm about to just go buy a better distributor and chuck this one in the junk box.

Geoff.
Are you up to taking it apart? You need to see what slot widths you have in the limiter. It may be possible to flip the one you have to limit the mechanical advance. Alternatively you can weld the slot up to whatever dimension is needed for the amount of mechanical advance required.

This tutorial is for a Duraspark but the principles apply:

http://www.reincarnation-automotive.com/Duraspark_distributor_recurve_instructions_index.html
I've been thinking along those lines. I'm sure that the slot width is wrong for my app. It was supposed to have been 'curved', but I'm getting less confident in the guys ability. It may come down to the old adage "if you want something done right, do it yourself". I was thinking that if I can get a better alternative for the time being, I would tackle doing the D0OF-V later when it's not so critical.

What do you think about the Dura-Spark mentioned before for use in the 351C 4V??

Thanks for your help here, much appreciated.

Geoff.

 
Clevelands like a little more initial timing than what is normal like 16 to 18 degs, but the mechanical advances to much. So you have to weld the slot some and grind to what you need.

 
Clevelands like a little more initial timing than what is normal like 16 to 18 degs, but the mechanical advances to much. So you have to weld the slot some and grind to what you need.
Thanks Red351, I'll have to look into doing that. Just more pi**ing around than I need right now. It's been a long time getting the engine re-rebuilt and back in. I just want to go drive the **** thing!! Summer will be over before I get to enjoy it.

It's very frustrating when one doesn't get what one expected. I'll be talking to the shop tomorrow for sure.

I do have a 302 dist. that I can play with and get a look at the internals. May get a better idea from that.

Geoff.

 
I have a Cardone Duraspark-ready distributor wired up to a Duraspark (blue grommet) box with and Accel Super Coil, and mine runs like a champ.

Pretty much just dropped it in, timed it, and there it is.

Got the dizzy and Duraspark box from Summit Racing, and my conversion wiring harness from NPD, but Summit has them as well:

Dizzy: http://www.summitracing.com/parts/aaz-30-2893/overview/

Duraspark Module: http://www.summitracing.com/parts/smp-lx203/overview/make/ford

Conversion wiring harness: http://www.summitracing.com/parts/aww-500918

There are some pretty thorough threads elsewhere on the site regarding Duraspark swaps. Easy enough to search for.

Hope this helps!

 
I have a Cardone Duraspark-ready distributor wired up to a Duraspark (blue grommet) box with and Accel Super Coil, and mine runs like a champ.

Pretty much just dropped it in, timed it, and there it is.

Got the dizzy and Duraspark box from Summit Racing, and my conversion wiring harness from NPD, but Summit has them as well:

Dizzy: http://www.summitracing.com/parts/aaz-30-2893/overview/

Duraspark Module: http://www.summitracing.com/parts/smp-lx203/overview/make/ford

Conversion wiring harness: http://www.summitracing.com/parts/aww-500918

There are some pretty thorough threads elsewhere on the site regarding Duraspark swaps. Easy enough to search for.

Hope this helps!
Thanks, I'll check it out. My thought is that the DuraSpark would be a big step up from the crap reman I have even though it does not look exactly stock. Most would never know anyway!

Geoff.

 
Stanglover,

A very good thread on another distributor solution.

I am running the Mallory Unilite distributor with mechanical advance with Mallory Hyfire and Pro Master Coil. I mounted the spark box on a custom made aluminum plate and installed it where the glove box insert was. I can state that my 351C idles/runs very well with this setup. One thing to mention, I installed this setup some 20 years ago. I sometimes wonder if I should have used the vacuum advanced Unilite verse the mechanical version.

I believe the Dura-Spark distributor system is a good system to install. It is clean, compact and provides a good spark source.

http://www.reincarnation-automotive.com/Duraspark_distributor_recurve_instructions_index.html -Good site to keep-

A bit more on the expensive side. http://performancedistributors.com/product/ford-duraspark-distributors/

Look forward to your progress in the installation-

mustang7173

 
Stanglover,

A very good thread on another distributor solution.

I am running the Mallory Unilite distributor with mechanical advance with Mallory Hyfire and Pro Master Coil. I mounted the spark box on a custom made aluminum plate and installed it where the glove box insert was. I can state that my 351C idles/runs very well with this setup. One thing to mention, I installed this setup some 20 years ago. I sometimes wonder if I should have used the vacuum advanced Unilite verse the mechanical version.

I believe the Dura-Spark distributor system is a good system to install. It is clean, compact and provides a good spark source.

http://www.reincarnation-automotive.com/Duraspark_distributor_recurve_instructions_index.html -Good site to keep-

A bit more on the expensive side. http://performancedistributors.com/product/ford-duraspark-distributors/

Look forward to your progress in the installation-

mustang7173
Thanks, I called Performance Distributors today. Yes quite expensive, BUT you're getting a custom built to the car's specs distributor. Complete kit, $464 or 265 for the dizzy alone. Still not bad considering. The dollar exchange is what will kill me right now, so I may get through the summer and hope things improve by next year.

Has anyone an opinion on the PerTronix distributor? My local supplier has dropped that line because of issues, so I am hesitant to go that route.

I appreciate all the comments and advice.

Geoff.

 
Probably should post this in Want Ads. The budget is all but up for now on this issue, but, does anyone have a correct bottom plate, the one with the limit slots, for a D0OF-12127-V distributor they would sell me?? This would be off a 71 351C 4V manual trans, dual vac. I only need the correct plate, not the whole distributor. OR as an alternative, does anyone know the exact slot dimensions for said dizzy? I could then re-machine my plate accordingly.

Please PM me if you can help.

Thanks,

Geoff.

 
Sorry for revisiting this post again. After much deliberation and consideration of the comments, suggestions made about what I could or should buy, I have decided to rebuild the distributor I currently have. To do this, I bought a cheapo dizzy just so I can run the car while I play with the good one. It will work about as good as it does presently. To be on the safe side, I am going to use the drive gear from the Cardone reman. as I have no idea what garbage the Chinese one is made of.

I am going to rework the slot plate starting with a 10L, about .410" slot width and go from there. If I'm correct, that will give me 20* advance plus an initial setting of about 14*, will give me 34* total mechanical. Now, here's where I'm getting lost. I only want about 34-36* TOTAL, so how do I figure in the vacuum advance?? I have read through lots of posts and I do have a far better idea, but somehow the numbers just don't add up in my head. I am also thinking of going back to the PerTronix 3 I already have instead of the points that were put in by the engine builder. I have NOT ruled out going to a DuraSpark later if I don't get what I want from what I already have.

A quick and brief explanation would be very much appreciated.

Thanks to all for your past assistance,

Geoff.

aka, Stanglover.

 
Sorry for revisiting this post again. After much deliberation and consideration of the comments, suggestions made about what I could or should buy, I have decided to rebuild the distributor I currently have. To do this, I bought a cheapo dizzy just so I can run the car while I play with the good one. It will work about as good as it does presently. To be on the safe side, I am going to use the drive gear from the Cardone reman. as I have no idea what garbage the Chinese one is made of.

I am going to rework the slot plate starting with a 10L, about .410" slot width and go from there. If I'm correct, that will give me 20* advance plus an initial setting of about 14*, will give me 34* total mechanical. Now, here's where I'm getting lost. I only want about 34-36* TOTAL, so how do I figure in the vacuum advance?? I have read through lots of posts and I do have a far better idea, but somehow the numbers just don't add up in my head. I am also thinking of going back to the PerTronix 3 I already have instead of the points that were put in by the engine builder. I have NOT ruled out going to a DuraSpark later if I don't get what I want from what I already have.

A quick and brief explanation would be very much appreciated.

Thanks to all for your past assistance,

Geoff.

aka, Stanglover.
The vacuum advance is not figured in the total advance equation. Vacuum advance should only be active during part throttle, high vacuum low load engine operation. The fuel mixture is leaner at part throttle. Sometimes as lean as 15-17:1. Leaner mixtures require the spark plug to fire earlier to properly ignite than richer mixtures due to the greater percentage of oxygen. The vacuum advance provides the earlier spark firing and makes it possible to run leaner mixtures thus improving fuel economy. When you put your foot in it, at about 70% of load, the mixture needs to richen (power valve open or metering rod retracted) to provide power and prevent engine damage and the additional spark advance is no longer needed. This is where the vacuum the engine makes will begin to drop and where the vacuum advance should no longer be adding advance. The exact vacuum reading where this should occur varies from engine to engine. Generally a high compression high performance engine will want to be rich and retarded sooner than a low compression low performance engine.

As to how much vacuum advance should be added, in general you should run as much as the engine will tolerate without pinging. This takes some trial and error to determine.

 
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