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Pertronix one more question

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shorn

Jedi Knight
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To: Dave Russell, OK, I hooked the pertronix up as you indicated. The Healey started right up and seems to idle better than with points. One problem: although the tach seems to read ok at idle up to 1000 rpms, it doesn't work when the rpms get over about a 1000. It actually drops back to zero. The tach seemed to work ok with the points although I suspect the guage always read a little high.
I've only owned my Healey about a year, but there seems to be a rule of thumb that states when you fix one problem, another will develop. Oh well, I love it, scraped knucles and all. Scraped knucles are from rebuilding brake calipers.
 
Hi Shorn, some times adding an additional loop to the tach pickup cures this problem,also are you using a hot coil??-FWIW___Keoke This assumes you have an electronic tach.
 
Sorry you are having problems.

Not sure which model you have. I think it is a BJ8. Again, not sure if the BJ8 tach is the same as the earlier ones. If it is, Keoke is correct.

The tach signal pick up is from a single turn of the white coil supply wire (insulated) that loops through & around a "plastic holder thing" on the back of the tach. To get more signal coupled to the tach, loop this wire around two or three times. You may have to substitute a short piece of smaller diameter wire to get enough room for multiple loops, but keep this piece as short as possible.
D
 
Two things I noticed: 1. the white wire that loops through that little plastic thing had a small burn hole on it, which I replaced, and 2. probably more important, the ground wire connected to the tach bracket seemed a little loose when I took the tach out. Tightened it down and now the tach works fine.
One other thing on the Pertronix: when I installed the unit under the distributor cap and started the car, I noticed the cap moving a little. Apparently the rotor would not fit down far enough on the dist cam because of the magnetic piece that fits over the cam. I had an extra rotor, which fit better allowing the dist cap to fit on the dist tightly.
Anyway the BJ8 starts fine and idles smoother when cold, and the tach works again. Of course in the same amount of time that this took to get right, I could have changed the points and condensor about a dozen times, and adjusted the points another dozen. Let see, and the ignitor costs 10 times what the points cost. Oh well, on to the next project.
 
Shorn, glad the igmition is working ok now.However I suggest you remove the rotor and the Magnetic cam, look at the adapterplate that came with the kit, if you see rubbing marks on it from the magnet.Take the plate out and increase its cut out radius until you remove the rubbing marks. Reassemble and make sure the magnet goes all the way down on the Dist cam and the rotor now seats correctly.---Keoke /ubbthreads/images/graemlins/yesnod.gif Next project: add a Lucas Sport Coil /ubbthreads/images/graemlins/yesnod.gif NOW! open the spark plug gap up to about 0.35" and have fun---Keoke /ubbthreads/images/graemlins/cool.gif
 
Glad that it is working,

Originally, the rotor was designed to seat (its vertical height) by its bottom surface contacting the top of the distributor cam surface.

With the Pert., the trigger ring seats (for height) on the top of the distributor cam surface. The rotor in turn seats on the top of the Pert. ring instead of on the cam end as originally. This raises the rotor height about .060" above stock.

Some rotors are taller than others. A new "Moss replacement Lucas" rotor raises the top of the rotor another .030" to .050", depending on which rotor is randomly selected.

The net result can be that for the Pert. with replacement lucas rotor, the rotor could sit .100" higher than originally designed. Some distributor caps have the internal brass contacts located further down (closer to the rotor) than others. A typical stock setup with "original Lucas" parts would have the top of the rotor .095" below the cap contacts. (vertical clearance) The combination of the Pert. ring raising the rotor by .060" & a taller rotor could result in reducing this clearance to zero or less. A really bad parts mismatch could cause rotor contact with the cap.

A combination of the wrong parts dimensions could cause the rotor to contact the cap terminals. This will cause a lot of trouble in a hurry. You just never know what size the replacement parts are going to be.

It is possible that the Pert. ring & or the rotor was not fully seated.

If in any doubt about the dimension stack up, you can flat sand the bottom surface of the rotor to let the rotor sit down a bit lower & give some additional cap contact clearance.
D
 
typical, I spoke or wrote too soon on the tach. I thought it was working when I tightened the ground, but alas it is not. Seems to work ok to about 1500 rpms and then as rpms go up the tach drops to zero. I will try adding another loop in back of the tach. Don't know if the adjustment screws (seems to be 4 screws on the back) might help too.
 
I added another loop from the ignition--coil wire and the tach is working perfectly. Actually I had to substitute a piece to 18 guage speaker wire to get the additional loop, but it did the job.
Next project. I had the tranny tunnel off today and decided to clean 50K miles of caked oil and grease off the transmission. A spray bottle of Simply Green and a spray bottle of warm water did the trick. The tranny now matches the engine. Oh, oh, I'm in trouble again. My wife is looking for her tooth brush. Wonder where that could have /ubbthreads/images/graemlins/angel.gif /ubbthreads/images/graemlins/angel.gifdisappeared to??
 
Quick, just put it back in the rack and she'll never know!! /ubbthreads/images/graemlins/nonono.gif /ubbthreads/images/graemlins/laugh.gif
Jeff
 
One thing I forgot to mention. The Pertronix still requires a ground connection through it's mounting surface. If the flexible grounding pigtail on the point mounting plate is broken or missing, you can get erratic ignition or strange tach readings.
D
 
pigtail is still grounded. Pertronix works great now as does the tach with the 2nd loop. I am amazed at how easy starting the Healey is even when cold with the Pertronix. It wasn't difficult before but it's better now and it idles very smooth. I guess I am sold.
 
Hi,
Saw your post on the Pertronix. I have one installed in my '59 100-6 along with a Pertronix coil. I have not changed the gap on my plugs though. What would this do for me? Are any changes required in timing, etc. needed?
Thanks,
Chuck
 
I have not changed the plug gap, and at this point haven't messed with the timing either. The Healey seems to be running so well that I don't want to jinx it by changing anything.
 
HI Chuck, Installation of the pertronics unit simpy due to minor mechanical position changes of its components relative to those of the points can shift the engine timing a bit. I would always recheck it upon initial installation.Having a higher secondary voltage allows the plugs to fire efficiently at a wider gap which hopefully creates a better flame spread in the clyn.---Keoke
 
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