CM Rules Question: Pertronix Ignitor III Distributor

[BRODA]

Hello,

I am new to CMod and new to FF. I am looking at options to add a rev limiter to my Kent-engined Formula F.

I know there are several popular options from MSD, Pertronix, and Microdynamics.

Lots of people seem to be using Pertronix Flame Thrower Ignitor II distributors and Pertronix Rev Limiters. The Pertronix Ignitor III has the rev limiter built into the distributor. It also adds multiple spark discharge.

From the literature:

Ignitor III Features:

• Multiple sparks thru the entire RPM range.
• Integrated digital REV limiter with LED feedback for precise RPM setting.
• Memory safe function stores settings eliminating unintended changes to Rev limit.
• Adaptive dwell maintains peak energy throughout the entire RPM range, reducing misfires while improving engine performance.
• Peak current level is reached just prior to spark for maximum energy without heat build-up, increasing coil performance and module reliability.
• Adjusts spark timing at higher RPMs to compensate for the inherent electronic delay.
• Senses startup and increases energy for quicker, easier starting.
• Thermal clad surface mount construction for superior reliability.
• Built-in reverse polarity and over current protection shuts down the system, preventing component damage.
• Not compatible with CD or Multi-Spark boxes

More details here: http://www.pertronix.com/catalogs/pd...me_thrower.pdf

FYI.. Here is the wording of 9.1.1.B.12.r from the 2016 GCR:

Electrical Equipment
Distributor: Distributors are unrestricted provided the original drive,
location, and housing are retained. The distributor is defined as the
component that triggers the LT current and distributes the HT current.
The ignition timing may only be varied by vacuum and/or mechanical
means. It is prohibited to use any other method or component to trigger,
distribute, or time the ignition. The vacuum advance mechanism may be
removed, and the distributor advance plate may be secured by soldering
or welding or by suitable fasteners. The advance curve and advance
springs are unrestricted. Generators/ Alternators: not required. All other
electrical components are unrestricted.

Does anyone see any reason why this would not be legal?

Thanks in advance,
Dave

[-pru-]

At first glance, I say it's legal. There is also a section in the GCR regarding RPM limiters that would be worth reviewing. That is, to see how they overlap. I do not think there's an issue, but I need to review...

[DanW]

The Pertronix distributor is legal, the built in rev limiter is interesting.

Troubleshooting a Pertronix is difficult. The only way I know how to check it is to take out the module and try a new one. If the new one works, the old one was bad. If the new one doesn't work, keep looking for the problem.

The distributor is Chinese made. Mike Summers had one on his Lotus 23B. The shaft broke the first day of the Monterey Reunion two years ago. It was quite a challenge to get the broken bits out and get it going again.

The Bosch distributor is a nice piece. A set of heavy duty points will serve you well. The microdyamics rev limiter works well as long as you install it correctly and have a good ground.

If you have a miss or non start, disconnect the rev limiter completely and retry. Simple as that. If that is not it, its easy to troubleshoot the points and condenser with a test light or a VOM.

The Motorcraft distributor is acceptable, easy to find heavy spring V8 Ford points that work easily to 7K rpm

Regards,
Dan

[bassracer]

I would only consider it it if was more reliable than the stand-alone pertronix rev limiter.

[na94]

I have a Bosch distributor with a Pertronix module and an old-school, spring-based rev limiter and I don't think anything has failed since 2000 when the car last had a frame-off.

[BRODA]

Thanks for all the comments guys.

I know from reading other threads that there have been reliability issues with all the different brands of rev limiters as well as the Pertronix electronic distributors. One thing I like about the Ignitor III distributor is that I think it will be very easy to swap out if I suspect it is not working, and I will have two spare Bosch distributors with me in the trailer.

At the moment, being new to the car and also planning to have a co-driver at some events this year, I am much more worried about over-revving the engine than I am about a DNF due to a failed distributor.

If someone has a suggestion for something more reliable, though, I would certainly be open to trying something different.

Thanks,
Dave

[Roland V. Johnson]

As referenced above, the simplest is to use a rev-limiting rotor. I think Ivey will still set one up for you (503-255-1123). Nothing though will stop the biggest over-rev problems, downshifting or missing a shift.

[chrisw52]

I use a regular bosch distributer with an MSD soft touch rev limiter. (this is not the loathed and hated MSD ignition system!!!)

I have had it in the car for about a year now with zero issues. It's cheaper than the pertronix rev limiter and it's more reliable than the micro dynamics rev limiter that pegasus sells.

https://www.msdperformance.com/produ...ols/parts/8728

[-pru-]

There is also a section in the GCR regarding RPM limiters that would be worth reviewing.

After reviewing the GCR, I have to retract the above in that for the FF Kent/Cortina engines, there is no mention of RPM limiters. Therefore, I believe, the final sentence of the noted GCR section applies. That is, "All other electrical components are unrestricted" implying that electronic RPM limiters are open.

[DanW]

I use a regular bosch distributer with an MSD soft touch rev limiter. (this is not the loathed and hated MSD ignition system!!!)

I have had it in the car for about a year now with zero issues. It's cheaper than the pertronix rev limiter and it's more reliable than the micro dynamics rev limiter that pegasus sells.

https://www.msdperformance.com/produ...ols/parts/8728

Chris,

That's great to hear. Mine lasted 1-1/2 race weekends.

Dan

[bassracer]

If your car is as bad with vibration as mine (RF85) it will eat a Petronix and MSD unit in 3 events. Dick had a lot of success with the Microdynamics in his RF85, but I could not get it to work with the Petronix II low-ohm ignition.

I started in CM without a rev limiter and went through the phase of "needing" one... after exhausting far too much energy trying out different units only to have them fail I've concluded that it isn't necessary. I found that spacing the gears correctly means you can up shift when it is convenient without losing the powerband.

[Robert J. Alder]

IMHO, rev limiters on a FF are just another piece of kit to go amiss (pun intended). If you can't learn to watch your tack and listen to your motor to develop the habit of shifting at the right time, other sport bekon. Frankly, most FF motors should be shifted long before they reach explosion levels. Learn what that shift point is and learn to do it instinctively by sound or at least with only a quick glance at the tach.

Just sayin'.

As Roland says, a rev limiter will do nothing to stop an over-rev caused by a bad downshift (the cause of most over-reves). And if you're chronically missing up-shifts . . . . hmmm. Not sure rev-limiters will really help.

[BRODA]

Thanks for all the comments.

This thread is quickly devolving to mirror every other thread about rev limiters in FF (i.e. they are all crap, and people should just look at the tach). I understand that advice, but I am not going to be looking at the tach during an autocross run. It just ain't gonna happen. Maybe for the 1-2 shift, but that's about it.

I also understand the feedback that most over-rev's are caused by a botched downshift, but that sounds like road race feedback. I don't see this being an issue in autocross, where I will rarely shift out of 3rd once I get there.

IMHO, the most likely situation where I would over-rev the engine would be during a high-speed slalom or across the finish lights. In neither of those scenarios will I be staring at my dashboard, and being able to bounce off the rev limiter while keeping my eyes up seems like a worthy goal.

I am very curious about this comment:

As referenced above, the simplest is to use a rev-limiting rotor. I think Ivey will still set one up for you (503-255-1123).

In my research on rev limiters, I haven't seen many comments on if this is a reliable solution. Does anyone else feel this is more reliable than the electronic rev limiters?

Also - if I let you all talk me out of an electronic ignition - can someone recommend a good book or website where I can learn how to maintain a points ignition?

Thanks again,
Dave

[Barry Ott]

Thanks for all the comments.

This thread is quickly devolving to mirror every other thread about rev limiters in FF ...

Yep, Rev limiters and gearing are two Autocross topics that always bring out strong opinions. I'm not convinced that either topic has a simple "right" answer or a "one size fits all" answer. So, I suggest you do what works for you, but keep an open mind as you gain experience in the car.

Personally, I used an MSD limiter in my Reynard for several years without any problems, but that was a while ago (my current car has it built in, Honda). I've found that I usually see my shift lights so that can help too.

Welcome and good luck!
Barry

[bassracer]

The negatives on the rotors is that they wear out over time from being run near their limit. It will slowly start reducing the limit. I figured it would make it though at least a season of Solo. I considered it but didn't want to go to points.


I think it is worth a call to Pertronix to see if they believe the III will be better suited for the harsh environment compared to the stand-alone unit.

Depending on a positive assurance from them, I would try it and have a points distributor backup with a rev-limiting rotor.

[BRODA]

Good idea Brandon. I called Pertronix and was able to speak with a tech, but he couldn't provide much concrete info on using the Flame-thrower distributor with the Ignitor III on a race car. He said the failures they have seen coming back from the field have not been related to the rev limiter.

Right now, I am leaning toward what you suggested: try the Pertronix distributor and also have a rev-limiting rotor in a Bosch distributor ready to go if the Pertronix fails.

I'm 2 months away from the start of autocross season, so I'll wait and see if any other suggestions come in before I place the order.

[Robert J. Alder]

Opps. My bad. I wrongly assumed you were running a FF in Road Racing. Indeed, autocross is a different kettle of fish. Sorry.

Still, I'd hope you develop and "ear" rev limiter, especially since there's little time to check the tach.
Cheers.

[DanW]

Thanks for all the comments.

This thread is quickly devolving to mirror every other thread about rev limiters in FF (i.e. they are all crap, and people should just look at the tach). I understand that advice, but I am not going to be looking at the tach during an autocross run. It just ain't gonna happen. Maybe for the 1-2 shift, but that's about it.

I also understand the feedback that most over-rev's are caused by a botched downshift, but that sounds like road race feedback. I don't see this being an issue in autocross, where I will rarely shift out of 3rd once I get there.

IMHO, the most likely situation where I would over-rev the engine would be during a high-speed slalom or across the finish lights. In neither of those scenarios will I be staring at my dashboard, and being able to bounce off the rev limiter while keeping my eyes up seems like a worthy goal.

I am very curious about this comment:


In my research on rev limiters, I haven't seen many comments on if this is a reliable solution. Does anyone else feel this is more reliable than the electronic rev limiters?

Also - if I let you all talk me out of an electronic ignition - can someone recommend a good book or website where I can learn how to maintain a points ignition?

Thanks again,
Dave

Dave,

Most electronic rev limiters work perfectly until they don't. The Bosch rev limiter rotor slowly goes "soft" over a long period of time. I actually like the Microdynamics rev limiter. Most last a long time though they are like troubleshooting the Pertronix when they fail.

If your distributor shaft is loose in the bushing, it doesn't help timing accuracy. There will be timing scatter with points or pertronix.

Maintaining points/condenser systems. A set of points and condenser will easily last 6000 miles or more, so buy a fresh set, along with a new cap and rotor when you rebuild your motor. Jay Ivey can also reset your rev limiter rotor for you, or sell you a new one.

A VOM with a "dwell" function tells you exactly if your point gap is in the right range without removing the distributor cap. https://actron.com/content/auto-trouble-shooter

As the points rubbing block on the distributor wear, the points gap gets smaller and your timing advances a couple of degrees. Easy to check with a timing light.

I have been tempted to find an early 80's bosch/volvo dizzy with the hall effect trigger and adapt it to a bosch distributor for the Kent. In all the time I owned my volvos, I never had to touch the trigger or timing, just replace the cap, rotor, spark plugs, and wires every 30,000 miles or so. http://www.ebay.com/itm/82-83-84-VOL...s=Make%3AVolvo

Google is your friend:
http://www.popularmechanics.com/cars...a6382/4338376/

[Unbalanced Engineering]

Hey Dan,

After killing another pertronix module this past event, I decided to purchase one of the Volvo distributors you mentioned. It really looks promising. The upper housing and upper shafts are almost identical. It appears that you only need to drill the holes in the housing to mount the Hall effect sensor in the FF housing.

The issue is this, the rotor shaft from the Volvo is for the opposite rotation and therefore won't mount to the FF shaft / mechanical advance. I don't want to machine the FF rotor shaft to match the Volvo without a backup plan.

Also, I assume the Hall effect sensor went to a module that told the coil when to fire. After looking at some wiring harness layouts, it appears that this is the case:

http://www.davebarton.com/240ignitionharnesses.jpg

Does anyone have any idea where I might get a dist with the same rotation direction as the FF and also the same upper / rotor shaft?

I'll upload a few pics when I get the chance.

Thanks!
Jason

[DanW]

Hello Jason,

I deleted some messages from my inbox and sent box, so it should work now.
You found the right photo. I had an 82 turbo and and 83 non turbo sedans.

Is there any way to adapt the hall effect kit from the volvo dizzy and install it in the kent dizzy? That way you would have the timing advance.

May I suggest contacting IPD in Portland, OR. They have a tech line and might be able to give some direction for you.

Regards,
Dan

[Unbalanced Engineering]

So here are a few photos to hopefully clarify. This is the Volvo dist with the cap and rotor removed:



The upper housing and the upper shaft are the same size as the Kent, shown below:



Here are the parts of the Volvo Hall Effects sensor disassembled:




And here are a couple of photos of the rotor shafts. The Volvo shaft has the two snap ring grooves and the Kent has the square points protrusion







So because of the different rotation directions, the "ears" are of the opposite hand and the volvo shaft won't work with the mechanical advance of the Kent. After taking some measurements, you can certainly have the Kent shaft machined to accept the Volvo snap rings and Hall Effects, but in doing so there is no going back. Does anyone have an extra rotor shaft they'd be willing to sell? Of know of another Bosch dist that is the same rotation direction and basic size of the Kent unit?

Thanks a ton guys. Hopefully I can help develop a better and cheaper Bosch dist for those of us still running the Ford. The cost and lack of reliability of the Pertronix modules is horrid, so hopefully this approach works.

Also, anyone who know anything about the Volvo ign module that the dist plugs into (shown in the link above) please chime in. For example, does it have a rev limit built in? If so at what RPM? Does it electronically adjust timing on the vac advance dist models?

Thanks again,
Jason

[Unbalanced Engineering]

Uh, apparently Apexspeed stripped out all the images. Are there size limits or something? Those I posted were trimmed down to ~100K

Thanks,
Jason

[Jerry B.]

Pertronics does supply a distributor with a built in rev-limiter with a small bowl dist. It uses an Ignitor III module inside. I believe that the Ignitor III is similar to their Ignitor II as that one cannot be diagnosed for good or bad and TDC cannot be found with the motor off.

The Pertronics "Ignitor" (call it the Ignitior I ) does have the capability to diagnose good or bad and you can use a light and wire, but only with the Ignitor 1.

They (Pertronics) rev limiter (PN 600) IMO, is too much $$$ and it does not allow some tachometers to work. The MSD Soft Touch (PN 8728) which uses single pills might be better. However, for example, using a 6500 rpm pill you MIGHT not get a 6500 stutter. The pills are off as much as 200 rpm plus or minus. I have never seen one that was on the mark. Maybe , as said above....by ear ??

I have found that the Pertronics complete new distributor for the Kent/TC/pre Cross flow (PN D196509) , which has the Ignitor I in it, might be the way to go. Not a lot of cash for what you get. I have never had a bad Ignitor 1, but I have had one Ignitor II go bad. What you have to do to these, is out of the box, and check the dimension of the drive gear and the body of the distributor. Look for .009" + or - .002" as they have way two much play in the gear. When removing the roll pin from the gear mark the gear to the shaft so you don't rotate the gear 180*. They have one shim above the gear....add as needed shims. YOU MUST use the correct ignition coil for the distributor. For the Ignitor I (Kent and 4 cyl) use a 3 ohm coil....if an oil filled coil use the coil wire end UP only. To use a 3 ohm epoxy filled coil , use any way. If you use an Ignitor II , use a .6 ohm coil. HT wires....NO wire core. Spiral core is best,,,,,,about 50 to 500 ohms per foot is best.

[Unbalanced Engineering]

Yeah, after killing at least 5 Pertronics modules, and one of their rev limit boxes, I'm done with them. They clearly do not make a quality product. The quest to eliminate them as a source of unreliability is where this started. It hopefully will end without a single Pertronix item on the car.... Including the coil I bought from them since that was supposed to be matched to the Ignitor II.... Nope, another failure in 5 events....

As for rev limit, I don't think by ear really works for Solo... When I was road racing it was a lot easier, I think partly because the gear ratios are much taller so you don't go from 5,000 - 7,000 nearly as fast and your ear can detect the diff between 6,000 and 6,800 pretty easily. Not so with the short solo gears, and not shifting may save the 0.005 seconds that I've won and/or lost by.

As far as rev limiters go, I'm pretty happy with the Ivey tuned Bosch rotor. BUT that, in addition to all the failures, precludes going with the Pertronix dist.

I did find that the early 80's BMW 320i used a similar Bosch dist and what appears to be the same Hall Effect sensor as the Volvo, but with the correct rotation direction for the Kent dist. Just bought one off Ebay, I'll keep everyone posted with what I find. It appears that it also requires a Bosch ignition module, and I don't "think" those contain any mods to timing or a rev limiter from what I've read on the BMW forums.

Thanks,
Jason

[Joe911]

Just skimming the thread, but I use a rev limiting rotor on my Kent FF/CF engine with Bosch dist and it works very well. Early Porsche (1969-70ish), 911T=6900; 911E=7100; 911S=7300. I use the 7100 version - on starts or when a slower car throws my off my rhythm is when I need to be reminded to up shift.

Also had a Pertronix DNF when cylinder 3 dropped out this weekend. After replacing plug and ignition wire with no effect, replaced the distributor and it runs fine.

[Unbalanced Engineering]

It looks like it will work, but some machining will still need to be done. Trying to figure out if its easier to adapt the whole dist to the Kent, or just the rotor shaft and hall effects sensor assembly.

Jason

[Unbalanced Engineering]

Hey guys,

I'm looking at this part of the GCR:

The ignition timing may only be varied by vacuum and/or mechanical
means. It is prohibited to use any other method or component to trigger,
distribute, or time the ignition.

Does that imply that I'm barking up the wrong tree with the hall effects sensor and the ignition control module. I thought they were analogous to the Pertronics module BUT the ignition control module from the BMW resides outside the body of the distributor. Is that an issue?

All the module does is take the incoming pulse from the hall effects sensor and tell the coil to fire, same as the pertronics module. BUT it is not inside the distributor. Is that an issue? It does not modify timing in any way, that was still done with mechanical and vac advance features in the Bosch dist.

Thanks for your thoughts,
Jason

[DanW]

Hey guys,

I'm looking at this part of the GCR:

The ignition timing may only be varied by vacuum and/or mechanical
means. It is prohibited to use any other method or component to trigger,
distribute, or time the ignition.

Does that imply that I'm barking up the wrong tree with the hall effects sensor and the ignition control module. I thought they were analogous to the Pertronics module BUT the ignition control module from the BMW resides outside the body of the distributor. Is that an issue?

All the module does is take the incoming pulse from the hall effects sensor and tell the coil to fire, same as the pertronics module. BUT it is not inside the distributor. Is that an issue? It does not modify timing in any way, that was still done with mechanical and vac advance features in the Bosch dist.

Thanks for your thoughts,
Jason

Hello Jason
An external module may provide the spark signal, such as the Crane Optical unit. The ignition timing advance must occur by either vacuum or mechanical means.

I don't think you are barking up the wrong tree, you simply may not be able to use a particular branch of the tree. That's why i suggested earlier to adapt the hall sensor to the Kent distributor and use its centrifugal advance.

Dan

[Unbalanced Engineering]

Hey Dan,

Thanks. It was the "external" part that was of concern. Yeah, the Bosch distributors are almost identical, other than the points / hall effect plate. If only the Kent dist was a little newer than the rotor shaft would also attach with a screw instead of the C clip. Then things would be a total bolt in swap. As it stands some machining will be required to get the BMW rotor shaft onto the Kent main shaft.

Thanks for the idea. I'll certainly keep you guys posted with my progress.

Oh, and has anyone tried the Crane Optical trigger?

Jason