FSI distributor issue

[Corley]

Railcarmover, I think you may be confusing "Lean Burn", with normal cruise conditions. "Lean Burn" only became possible/practical with the introduction of Fuel Injection, when mixtures could be controlled more precisely. "Lean Burn" as implemented in many modern vehicles with EFI, is activated after a cruise situation has been detected and maintained for a few seconds, when mixtures are leaned out to as much as 18:1, which causes a much slower burn, and timing is further advanced to account for that. You might be surprised to find as much as 50 degrees of advance at cruise on some modern EFI controlled cars that have implimented "lean burn".


This is not the same situation at all as normal cruise, (and a model A at cruise), where we have not influenced the mixture at all, just increased the timing advance by a few degrees when not under heavy load. This does NOT increase combustion temperatures, in fact as the engine's optimal pressure vs the time when the pressure is needed (15 - 18 degrees after tdc) is more closely reached, when these times match more perfectly than without this advance, temps go down, and the engine isn't fighting itself, and is better able to expel the hot gasses. This is all win-win.




So, I don't agree with your premise that more advance creates more heat. However, In the case of the model A, the biggest benefit from the vacuum advance is probably at idle speeds and slower car speeds, when the excessive retard of the FSI distributor does in fact cause overheating in situations like parades. Excessive retard causes overheating, excessive advance causes detonation. Either one can be disastrous to your engine.






The biggest advantage I see in the Honda dizzy is it is a cheap way to get both centrifugal advance and vacuum advance. But like I've said, I'm a CAMO.

[Railcarmover]

Im not a fan of FSI/pertronix,its basically a chinese copy of an industrial distributor with a pertronix module,the partner in the FSI company that did mapping and used a distributor machine with skill passed away,the remaining partner basically sells parts so the basic research has stopped. I have experience with combination distributors,and the ones used in the 70's-80's were mapped for a cleaner,hotter burn.That is my only question with your experiment,and I hope it doesn't create an issue,I'm a CAMO man myself.

run it hard, check your plugs for soot and measure your engine temp is my advice..or if your ambitious,pull your head after a few hundred miles see if your getting enough upper cylinder lubrication.Accelerated valve wear is a result of cleaner burn,if you have modern valves and pressed seats your golden.

[Corley]

"I have experience with combination distributors,and the ones used in the 70's-80's were mapped for a cleaner,hotter burn."


When Detroit went nuts with emmissions in the 70s and 80s. They went with ported vacuum for the distributor. Basically, ported vacuum does as you say, creates a hotter burn, by retarding the spark under various conditions. They also put various controls to further restrict when vacuum was applied to the advance chamber. A big part of their motivation was to get things hot enough so that the cat converter would light off. What a disaster that turned out to be. Greater retard meant higher temps, crappy mileage, and tuning issues, often making more pollution than without all that crap. The distributors sometimes even had a vacuum chamber to retard timing even further. A lot of decent engines went to the dumper because of that fiasco.


I assure you that we are not implementing anything like that with this dizzy. For all practical purposes, it is just like something from the 30s-60s, and very basic in design. You will not see any additional heat generated from this whatever.

[Beater]

I'm already a bit worried about burning valves and such, that's why I allways add a cup of MMO or better yet some high grade 2 cycle oil every time I fuel up

[28]

Great read guys, lots of very interesting things in this thread. Thanks to Corley too for sharing this info as I’ve jumped on the band wagon as well and was able to get one for cheap cheap. I’ll fire up my lathe when I dig myself out from under the mountain of projects I seemed to have buried myself in and see how it goes.

[bettlesr]

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I bought a rebuilt distributor and modified it as Corley said. Put it in and hooked it up only to find I got NO spark. So, now I am waiting for a new module. And, yes I did wire it up correctly. Depending where you go, the new module can cost more than the rebuilt distributor did in the first place. Got a new out of the box module coming.

[Corley]

Originally Posted by bettlesr

I bought a rebuilt distributor and modified it as Corley said. Put it in and hooked it up only to find I got NO spark. So, now I am waiting for a new module. And, yes I did wire it up correctly. Depending where you go, the new module can cost more than the rebuilt distributor did in the first place. Got a new out of the box module coming.

It's always possible to get a defective part I suppose, but before you plant the new part in there, a couple of things to check. First, are you running a 6volt car, if so, this is not going to work. You need to have 12v, negative ground. Next, check your coils primary resistance. That is from one of the small terminals to the other. You should have something in the 3 ohm to 4.5 ohm range. If it is less than 3ohms, get a different coil, preferably one that is for 12volts, with internal resistor. Next, triple check your wiring. The farthest terminal (on the modual) from the wires exit hole should be connected to the plus side of the coil. The closer terminal connects to the negative side of the coil. Nothing else connects to the negative side of the coil. Switched 12volts connects to the plus side of the coil, along with that farthest distributor wire. Connect a ground wire to the base of the distributor.

When you assembled the distributor, you need to make sure the rotor piece is installed in the correct side up orientation, it can be put on upside down. Also, the two verticle pole pieces should be aligned so the rotory part intersects these at the same time, and with fairly equal gap. Be sure you didn't forget the rotor. Ha!

Sure sorry to hear go got a dud, but stuff happens I guess. I now these work very well, but with a rebuilt dizzy you are never sure why it got turned in in the first place. I've seen those modules on fleabay for $10, and I've seen them for over $100. If you are not in a hurry, they pop up from time to time. If I can help further, let me know.

By the way, just for fun, I converted an HEI Olds distributor for the model A, and it also works great. It is big and ugly though, and harder to convert as the case is smaller and must be sleeved.

[tinkirk]

Corley

i have installed this and after 3-4 try's i was finally able to get the advance part dialed in to where i can say good enough right around the 28 mark at 3000 rpm no load and it will go to about 32 if i spin it a little higher but i figure that, that is something that i will not do to much or maybe not at all

Thank You for all the info that you have offered up
Tinkirk/Terry

[Corley]

Terry,. Good on you!

[bettlesr]

Corley:

OK
I put the new module in and connected it up. Fired right up and ran great. I then shut it off and shortened the plug wires. The honda wires were way too long. Tried to start it again and nothing. Seems like the module went out again. Switched back to my "B" distributor and it ran OK. The coil is a Pertronix with about 5 ohms on the primary.
Where did you connect the ground wire from the distributor body? Would the coil mounting bracket be good?
Hope I can get this to run more than 5 minutes per module :>)
Thanks
Dick

[Corley]

Originally Posted by bettlesr

Corley:

OK
I put the new module in and connected it up. Fired right up and ran great. I then shut it off and shortened the plug wires. The honda wires were way too long. Tried to start it again and nothing. Seems like the module went out again. Switched back to my "B" distributor and it ran OK. The coil is a Pertronix with about 5 ohms on the primary.
Where did you connect the ground wire from the distributor body? Would the coil mounting bracket be good?
Hope I can get this to run more than 5 minutes per module :>)
Thanks
Dick

Dick,

Apparently you are living wrong, as the gods seem to hate you. Perhaps you will need to change your religion or something. OR, it could be Kara, getting back at you for something awful you did in the past! Whatever it is, that really stinks. By the way, no one has put any curses on you lately have they?

The ground should not really cause this problem, but there is a screw hole right next to the place the other wires exit the distributor. Two of the rebuilt units I converted had a spade tab terminal attached there. Just run a wire from that to a good ground point on the car.

So far, I've not seen any failures on this module, so I'm baffled as to why you would have two failures in such short order. I'm sure that you could also use a ballast resistor in serries with the coil feed line, as it won't degrade the spark enough to cause any trouble, but would drop the voltage enough to offer some protection for the module. The original ckt in the Honda fed 12volts directly to the coil/module, so I didn't feel you should need that. One more thing, I hope that you used some thermal grease under the module to conduct the heat away.

I wish you good luck,
Corley

[bettlesr]

I am running 12V Neg ground. The coil primary is a little over 5Ω. I am wondering if the fuel shutoff solenoid valve and / or the fuel pump is sending a spike back to the ignition when the key switch is shut off. These will get moved to the accessory relay I use for all my accessories. As far as the heat conducting grease, the module mounts on a little piece of aluminum the is solid around the mounting screws but only has a small rib between the ends. Maybe I should machine up a more solid piece to help remove the heat. The "good" module seemed to die right after I shut the engine down.

[bettlesr]

Corley:
I finally found out why my '80 Honda distributor quit after shortening the wires. I eventually got a '79 honda distributor with points and modified that. It works great.
When I was cutting the tang on the bottom of the shaft I found the problem. When I first put in the '80 unit I had to turn the distributor around 180° to get it to work. When I replaced the wires after shortening them I put them in where it looked like they should go WRONG it was now 180° out again. As the '79 distributor is working fine I have not tried the '80 unit again yet. DUH???

[Corley]

You might also try a capacitor from the coil 12v side to ground. This would be for noise suppresion. I also have an electric fuel shutoff valve, and no issues with module damage. I suspect you just got a bad one, but who knows???

[denniskliesen]

My past experience with pertronix was in a different application. Others who had them in the same vehicle as I that had experienced failures realized straight up that it was a must to have resistor plug wires and resistor spark plugs along with the correct coil. I had considered going with a FSI setup when getting my Model A running but decided to keep it more original in appearance with the distributor and plugs and wires.

[Corley]

Originally Posted by denniskliesen

My past experience with pertronix was in a different application. Others who had them in the same vehicle as I that had experienced failures realized straight up that it was a must to have resistor plug wires and resistor spark plugs along with the correct coil. I had considered going with a FSI setup when getting my Model A running but decided to keep it more original in appearance with the distributor and plugs and wires.

I run resister wires, don't know if they are required, but I figured they would be used with the original Honda application. Still can pull better than an inch of spark at the plug. This is basically just lifting the entire ignition system from the Honda, so should be super reliable. But, like I said, I'm not the expert, I just did what some other guys in the SF Bay area started doing 25 years ago, and the one who got me on to it has never had a failure using this setup.

The Pertronics, on the other hand, seems to have quite a few failures, so probably needs the high resistance coil, a ballast resister, resistance wires, resistor plugs, or etc. to live.

[katy]

I am wondering if the fuel shutoff solenoid valve and / or the fuel pump is sending a spike back to the ignition when the key switch is shut off.

Putting a diode backwards across each devise would cancel any spikes generated.

[bettlesr]

I am going to switch my Pertronix coil for a Standard replacement Honda coil as well.

[emf]

OK Corely, time for an update on my efforts. My roadster has some slight modifications on it, such as B engine with two Stromberg 81's and a Stipe Cam. I wanted to try this because I think I can... I bought a points version to avoid the 6/12 volt problems with electronics (I'm still 6 volt). To cut to the chase, I set the advance at idle around 5* and locked the set screw on the side of the head. After a run of about 4 miles, I stopped and while smiling to myself, noticed the idle was high. I checked the timing and it had jumped to 15*. The lock screw seemed to back off a bit, allowing the distributor to turn slightly. I might have to change the lock screw to a hex head to allow me to torque it a bit... How did you succeed in locking the distributor in place???

Frank

[Corley]

This is no different than an FSI distributor or a model B distributor in this regard. The original lock screw works fine on mine. Do you by any chance have a binding shaft? It would seem to take a lot of force to cause the distributor to turn and loose it's timing setting.