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Triumph TR6 - Change plug gap with Pertronix?

Just installed Pertronix EI in my early '74 TR6. I'm confused by previous posts regarding increasing plug gap when a Sport Coil is NOT being used. Should I (and why) increase my plug gap with the Pertronix although I still run my original stock coil? (Also switched to magnecor 8.5's.) Nice even idle with smooth acceleration. NGK BP6ES plugs; change my gap from .025"?
Thanks,
Keith
Keith

Keith,

I went to .040 when I switched to Pertronix. Without points you'll get a stronger spark. The gap increase isn't required, but you will get some benefit from a hotter spark over a greater gap.

... at least that's what they tell me.

Don from Jersey
D Hasara

I also went to about .040. Also added a hotter coil, relativeley cheap upgrade, makes even more sense when already improving your distributor. As I understand it as long as you have the juice you can widen gap as much as it can take before losing proper symetry.
Ian Kinaid

Keith--I think it is important to consider your iginition cables in the decision. If you have 'stock' cables, then the Pertronix isn't buying you much more in terms of increased potential across the plug gaps.

I used to run Bosch platinums, but have since reverted to Champion 9Y's (similar to your NGK's, but cooler) after reading about the plats having a tendency to disintegrate. With the Magnecor cables, gold coil, and the Petronix, I'm gapped at 0.040 with no problems, and will increase to 0.045 at the next plug read to see what a difference there is.

You might be able to pick up a good used Bosch blue coil (equivalent to the Lucas gold) on ebaY.

Rick O.
Rick Orthen

I never heard of Bosch Platinums "disintegrating". I've run them for YEARS in 3 vehicles including the TR without a single problem with them.

Brent

Brent B

Brent--The problem lies with the double plats. It seems the little plat disc on the ground electrode can fall off. This problem doesn't occur with the single plat variety.

Rick O.
Rick Orthen

Guys:
Thanks for the feedback. So...it sounds like even with my stock coil (which I'll probably upgrade at some time anyhow, and resurrect threads re: ballasted vs. non-ballasted) there is an advantage to opening my plug gaps to .040 since I've got the Magnecor 8.5's. After making this change, has anyone noticed if the plugs burn differently and need a mixture adjustment?
Thanks again,
Keith
Keith

Keith,

I haven't noticed any difference nor a need to adjust mixture.

I'd recheck timing, but you'd do that after installing the Pertronix anyway.

Don in Jersey
D Hasara

Hey All,

On the coil choices, I stopped by my local parts store and he had 3 ohm and 1.5 ohm Pertronix coils. I asked him about ballasted vs. non-ballasted coils, and he wasn't sure, so he called Pertronix. They said they didn't make ballasted coils (or maybe it was the NB, yet I see both of these in the Moss catalog), and suggested that I use a 3 ohm coil and bypass the original wires with the inline resistor to my coil. I suppose this would work. But from reading the old ballasted vs. non-ballasted thread, can I simply by the 1.5 ohm pertronix and plug it in as is?

Ig
Ignatius Rigor

I just picked up a Pertronics from lbcar for $72.50 & $30 for the coil. They & some of local people I talked to, said to plug in the 1.5 ohm coil.
ED '76-TR6
ED Edward Dorsch

I have the ballasted Pertronix from Moss. Beware the coil terminals differ from stock. Jim the Goose-Keeper had the correct set of terminals to get me out of the jam. Once you get the terminals figured out, you're all set. BTW, ask a guy a NAPA if he has the terminals and he'll look at you like you have two heads. I wasn't crazy about altering the original leads, so Jim's help was much appreciated!

Don from Jersey
D Hasara

Ballast vs non-ballast..man!!! I thought this subject had gone to bed long ago.

If your year of TR6 has a ballasted ignition ( ballast resister in the wiring harness) system you should use a coil that has an internal resistance of 1.4 OHMS

If your year of TR6 has a non- Ballast ignition system (no resistor in the wiring harness) then use a coil of 2.6 OHMS resistance.

You DO NOT have to remove (or by-pass) the ballast resistor in a ballasted ignition system. NOTE: the Pertronix EI is wired up differently though and this is a problem. The red wire of the EI MUST go to the ballast resistor first then the wire the other side of the resistor goes to the + coil terminal. The problem is,....where is the resistor hidden...under the dash?? next to the coil?? no one has given a definitive answer to this question.

ED, yes use a 1.5 OHM coil if you wish. BUT!!...I suggest you read the statement just above as a 76 TR6 IS a ballast resistor ignition system.

Don from Jersey. The pertronix EI is neither ballasted or non-ballasted. It is the ignition system that is either ballasted or non ballasted. The only choice here is what resistance coil to use (see above). I am not aware of a coil that has different terminals on it. I presume screw on terminals as compared to spade type terminals??? Altering the leads would make no difference. The Pertronix Red and Black leads can be cut to whatever length shorter you want..or lengthened to be sent to the location of the ballast wire. As I have said, this is the problem.

Ignatius (how ya doin man?) Obviously you where talking to a guy that does not know what a ballast vs non balllast ignition system is or even why does he have 2 types of coils. COILS are not ballasted...the ignition system is. That is why there is 2 choices of coils...one for ballasted ignition , one for non-ballasted ignition. Ignatius, if I recall corectly you are 74 TR6. The only thing I can go by is that Dan Masters schematics show the Ballast resistor wire from 73 to 76. So at some time around 73 and on, these years of cars use a coil with internal resistance of 1.4 OHMS. So yes go by the 1.5 OHM coil (assuming your correct age of TR) if you wish..BUT~!!! I suggest you read my statement above and read the pertronix literature where to connect the red wire to. As I stated in my past thread you mentioned, the ballasted ignition system does have advantages over non- ballasted.

1.Pertronix makes a coil called a "Flame-Thrower" (PN H40501) and has an internal resistance of 2.8 OHMS.
2.Pertronix makes a coil called a "Flame-Thrower" (PN 40011) and has an internal resistance of 1.2 OHMS.

CHOOSE THE CORRECT ONE!!!!

Keith, sorry for going off here. It is truly debatable if 40,000 V coils will help our little HP engines out. or even if the Pertronix and 8MM wires makes a difference. The only true determination of improvement is to dyno before and after. One thing is for sure, it makes us feel better with an EI than the old points!

Rick C
Rick Crawford

Rick:
Don't apologize; I appreciate all the detail. Sounds like the PN40011 is the way to go for my '74. LBC CO. currently has it for $30. My EI is installed and working great so far, but is there a specified gap between the two elements? There is at least 1/8 inch of adjustment possible. I just "picked a spot" and it works. (Or am I just looking for something else to 'tweak'?)
Keith
Keith

Keith--Like me, you've lost that little rectangular piece of gapping plastic that came with the Pertronix kit. Although the gap isn't crtitical (as long as the pickup isn't touching the rotor), I used a paper index card top set the gap. Never seen a spec for it.

Go tweak.

Rick O.
Rick Orthen

Hey Rick C, and all,

Thanks again for the clarifications! I guess what confused me (and maybe others) is the fact that Moss lists the coils as ballasted and non-ballasted, when they should probably be listed as "2.8 ohm coil for non-ballasted TR6's", and "1.2 ohm coil for ballasted TR6's." I suppose this is too wordy.

Ignatius
74 TR6
Ignatius Rigor

Rick O.
So THAT'S what that plastic thing was for!!
Keith

Keith
Yup, that is what it is for:). Like Rick O says"(as long as the pickup isn't touching the rotor)".

I beleive the gap to be 8MIL.
Rick C
Rick Crawford

I made the conversion on my 74 TR6 a few years ago. The ballast resistor is actually a wire that is wraped with asbestos (heat shield). It is in the wiring harness that comes off of the alternator and the coil and runs to the ignition switch.
The purpose of the ballast was to reduce the voltage to the coil while the engine was running. When the starter switch is in the start position, 12 V is supplied to the coil for extra voltage to the plugs. When the starter switch is in the run position, approximately 9V is supplied to the coil because of the ballast resistor in the circuit.
I just cut the old wire that attached to the coil at the wiring harness and ran a new wire from a 12 V source at the fuse box. I also put in a Flame Thrower Coil and regapped my plugs to 40 thous. Car runs great.
John

This thread was discussed between 12/04/2004 and 22/04/2004

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