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Discussion Starter #1
My tach worked fine when I pulled the engine out a week or so ago then installed the new motor with an HEI Pertronix Flame Thrower and now the tach doesn't work, it's plugged into the dist. good and has a good ground, think it's the distributor ? TIA rick
 

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Well Rick I think you remember my long debacle trying to get my reproduction OER roller tach to work with my Pertronix. I sent it in to Redline and they changed the guts to digital. Looks the same except when you turn on the key it does a RPM cycle like new cars. My old tach that needed refacing initially didn't work either but it ended up just being corrosion on the connector and then it worked, ugly but it worked. So today I am running a Pertronix 2 LS series (Lobe sensing, no stupid mag collar) and the updated OER roller Redline changed tach guts. Some tachs will work and some will not. There are some resistors and diode mods that you can try and even filters but none worked for me. It's worth a call to Pertronix but ........BTW in my case Jegs bought me a new OER tach and sent it to Redline for modification all on their dime. About $600 worth, now that's what I call excellent Customer Service
 

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Discussion Starter #4
I'll give Pertronix a call tomorrow, it has a digital rev limiter inside maybe that has something to do with it
 

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I'll give Pertronix a call tomorrow, it has a digital rev limiter inside maybe that has something to do with it
Nope that is just the Pertronix 3 module. That was the one I bought for multifire but later decided to go back to the Pertronix 2 and corresponding coil. Only going to a new tach guts ie the latest tach internals fixed my problem. If support is no help I would suggest buying a new modern tach and just move on. Don't take out the distributor or coil to keep an old tach, SUN or not SUN
 

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Discussion Starter #6
Well I guess the Sun tach will go on a shelf, Bill from your experiance with Pertronix do you know if any modern tach works ? maybe I can find one that looks similar to the Sun Super II, I don't care for the big tachs with lights
 

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Discussion Starter #7
Summit has a house brand digital tach for $85 made in U.S.A. so guess I'm ordering that with blue readout, not much mounting info though
 

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Well I guess the Sun tach will go on a shelf, Bill from your experiance with Pertronix do you know if any modern tach works ? maybe I can find one that looks similar to the Sun Super II, I don't care for the big tachs with lights
Rick I believe my internals are from AutoMeter. I would call Pertronix support and get a list from them or better yet call Home - Redline Gauge Works and see if they have something to make your SUN work. They are easy to talk to and will help. They may also have a tach to sell that will work. These guys know their stuff.
 

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1967 Chevelle SS 396 L78 (Sold in 1970)
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This may be a dumb question but what’s wrong with going ‘old school’ with a good distributor containing points & condenser?

I never bothered to change points & condenser on my new ‘67 L78 up to 3 years of constant use! Never failed me and my 10,000 rpm Sun SuperTach always worked swell! ;-)

If your Sun Tach is a 10,000 rpm model & you pull it I may be interested in it.
 

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There are modern tachs out there that look very similar to the Sun Super Tach... I put one in my Chevelle that is made by Bosch this spring (similar looking, but has no Sun logo, got this at Summit)... and I also put an actual new Sun Super Tach in my '38 Chevy gasser that is an all modern tach with the old housing (I bought this online somewhere but was pricey).
 

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Discussion Starter #11
I called Pertronix today and the tech said I needed a $5 resistor and was going to email me the part#, well I haven't got the email, I'm calling them again tomorrow, the problem is something about the multi spark dist. that the tach can't sense, what the tech said anyway, so the need for a resistor, I think Bill went through that whole Chinese fire drill ?
 

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Discussion Starter #12
The reason I went with Pertronix is the built in rev limiter, I've heard too many bad things about the newer MSD stuff and it was less cost than buying a dist. & box, nothing wrong with points & condensor, I carried an extra set, match book, pc. of fine sand paper and a screwdriver in the glove box of whatever car or truck I had when I was younger but when I bought a new engine wiring harness for my 68 I upgraded to HEI
 

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Rick, points have many downfalls. Spark Energy is # one, Short dwell is # 2, SIngle fire not multifire #3, no rev limiter #4 and drastically less accurate as wear occurs #5. No point bounce #6 and much higher spark and on and on. He is a link to what they will probably send you. I tried 3 different resisters, diodes and capacitors and bought a 30 dollar filter and nothing fixed it. As I already said I believe my conversion was Autometer but I was dealing with a factory Roller tach and had to keep it that way. You don't! Please call Redline, tell them I sent you not that they will remember me but who knows and get their take. The owner usually answers and always helpful. Give him a call. Here is a link to Pertronix's link that is probably where the email was going to send you to. Do not go back to points, there time has come and gone........otherwise go to an HEI and install Pertronix rev limiter but even then you should run with a filter to protect the tach and make it function. Remember you are going to full 12 volt ignition and that tach was not designed for continuous 12 volt source.
 

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Discussion Starter #14
The tach worked fine with the other 454 and an HEI dist. before, I've never had a points dist. in this car, I feel the same way about a points dist. and this isn't a matching #'s show car by far, I guess restomod would discribe it best, I spoke with Pertronix again yesterday and ordered the part the tech said would fix it, 10K ohm resistor 0.5 watt from Amazon for $5.99 should be here friday so I'll know more when I put it in, hope I didn't already damage the sun tach
 

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Rick you would think they could throw in a couple resistors and diodes in the box. i paid 2 bucks at U Do It for 3 boxes of 5 resistors including a couple diodes and you pay 6 bucks for one. Big sports. They should have sent you and me the resistors for free considering the likelihood it it probably will not fix your problem. I hope I am wrong and it works. BTW the filter I mentioned was used on cars back in the 70's with factory HEI. It's the tach that can't handle the 12 volts. The later tachs in the 80's were designed for the higher voltage. Not sure about the SUN ll. However the resister will drop the voltage to the tach as well it just will not smooth out the signal.
 

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Discussion Starter #17
Yeah Bill you'd think for the price and them knowing about the problem they'd send the cheap needed part and let the customer either use it or toss it, JMHO
 

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Discussion Starter #18
Well for $5.99 I bought 100 resistors, I can't stop laughing, I should have enough spares to last the rest of my life and give away 90 LOL 🤣now to go there in a bit to see if it works
 

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Well for $5.99 I bought 100 resistors, I can't stop laughing, I should have enough spares to last the rest of my life and give away 90 LOL 🤣now to go there in a bit to see if it works
Don't cut your harness until you know it works. Just tac it to the harness and bend the resistor end and wrap it around the coil stud. If it works then go permanent. You should donate the 99 resisters to Pertronix and say ship these with your modules and distributors. Just a little dig
 

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Discussion Starter #20
I didnt get a chance to try one today but I will asap, Fl and busted air conditioners keep me hopping lol
 
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