Pertronix Ignition - Gut check

[s2willdo]

I just need someone to think this through with me before I start the car after installing a Pertronix points conversion.

I bought the correct unit for negative ground from Curt and also bought a flamethrower coil from him. So I know I have the right stuff.

1) I removed the ballast resistor from the line that leads to the negative side of coil because the flamethrower doesn't require a ballast resistor
2) That wire is now connected to the negative side of new coil.
3) Also connected to negative side of new coil is the white/black wire from the Pertronix. So two wires on the negative side of coil.
4) Black wire of pertronix is attached to positive side of coil. That's the only wire on positive.

Does all this seem correct? If I'm wired backward and start the car, will I ruin the Pertronix?

 

[Tom H]

I'm puzzled about 2 things. No Red wire? and Why connect the coil with Neg side to the power lead ( +12) ?

What model Pertronix do you have , so I can look up the instructions.

I think because you now have your SII (?) ( I'm guessing from your name) with Neg Gnd, you should wire neg term of the coil to the black wire and the Pos term to the Red (or now wht/ blk) ??) term. Or did you buy a pertronix for an SII and did not tell them it was redone as Neg Earth?

Tom

 

[Tom H]

I looked at some Pertronix instructions, and , as I suspected, the ones with Blk/ Wht wire are for Pos earth cars .

Tom

 

[RootesRacer]

Definitely dont power anything till you are sure on your connections.

When you say you connected the wire that went to the ballast to the negative side of the coil concerns me a lot.
If you have the correct coil and are negative ground, that will destroy your pertronics unit at the first crank.

 

[s2willdo]

Positive ground

Oops I meant to say positive ground. It's a S2 that has never been converted and I bought the positive ground pertronix. Instruction manual is for LU-142AP12, LU-162AP12, LU-166AP12.

My wire to the negative side of the coil which used to have the ballast resistor is white but must have been red before some previous owner spliced in wires and used whatever color they found.

 

[Tom H]

Oh, Positive ground! That makes HUGE difference.

The red wire I referred to is the red wire that is part of the Neg Gnd Pertronix . Good thing we had that little clue, else I might have said you were good to go!

So why not connect it up according to the instructions ??!!

1) Connect the black Pertronix wire to the original wire from the ignition switch
2) Connect the B/W wire to the Coil Neg
3) Connect the coil Pos to the chassis using a 20 AWG insulated wire
4) Their instructions clearly state that only the B/W wire and the 20 AWG wire should be the only wires connected to the coil

Tom

 

[s2willdo]

Wrong kit

Thanks for your help. I had read the directions but read them wrong. I have now hooked it up per the directions but it won't start.

Turns out I have the wrong kit. About 13 years ago I swapped out the 25D distributor for a brand new 45D4 and forgot to order for that distributor. I'll chalk that up as experience and buy another kit.

Thanks for all your help.

 

[RootesRacer]

Thanks for your help. I had read the directions but read them wrong. I have now hooked it up per the directions but it won't start.

Turns out I have the wrong kit. About 13 years ago I swapped out the 25D distributor for a brand new 45D4 and forgot to order for that distributor. I'll chalk that up as experience and buy another kit.

Thanks for all your help.

The only difference in anything between the 25 and 45 is the mounting detail for the module to the breaker plate.
The units are otherwise the same as is the wiring.

You need to make it so the unit sparks the coil with the rotor pointing at any of the 4 wire positions in the dizzy cap.

I'd make a go of using the pertronics even if its for the other dizzy.

 

[s2willdo]

Pertronix Success

I have installed my Pertronix ignition and have been driving the car. It runs fine, but basically the same as it did with points. With the new coil and electronic points I feel like it may be burning fuel more efficiently but it basically runs the same as with points.

I threw a timing light on it quickly at about 1000 rpm, adjusted to 5 degrees before BTDC an it didn't do so well so I'm more at 10 degree which I believe to be the 2nd mark on the harmonic balancer as you move clockwise. I didn't adjust the carbs yet.

It's been about 12 years since I really put an effort into timing this thing and I looked for the old thread we discussed but couldn't find it. I seem to remember getting it down to 700 RPM at idle and it had a reasonable amount of power.

Here's what I'm going to do:
1) Check the timing with a light at 1500 RPM
2) Put my dwell meter on it
3) Put my vacuum gauge on it
4) Use my Colortune to adjust the carbs

Have any of you got advice on the degrees before TDC with a Pertronix? Can you point me to a link that may have good instructions. My shop manual and a couple other books are okay, but I feel like I'm missing something.

 

[RootesRacer]

A Pertronics doesnt change the required timing the engine needs, thats an engine thing.

A pertronics CAN help improve the ignition energy at higher RPMs but beyond that, the primary reason to go with electronic ignition is NOT performance but decreasing the need for periodic distributor maintenance (points adjustment due to wear).


The factory timing procedure assumes the dizzy is in good order, this is often a poor assumption.

I dont adjust timing at idle, there are too many things that can go wrong in a distributor that effect the advance curve. Instead I adjust the timing for max advance (31 or 32 degrees at 4000 or so RPM with the vacuum advance disconnected). After adjusting, if the timing is not 6 to 8 degrees BTDC at 750 RPM idle, then the dizzy internals are messed up and dizzy needs a service/rebuild.
The MOST important timing on the engine is the max advance timing, it should be as I said 31 or 32 degrees on an alpine. Whatever the timing happens to be at all other points is wonderful to know, but should not cause you to readjust the timing.

HTH

 

[s2willdo]

Putting points back in

I have decided to reinstall the points. Before I start the car have I correctly wired this. It is a 3 ohm coil. Positive ground setup. Rubber sleeve insulates coil from being grounded.

1) white wire from ignition key to positive side of coil
2) wire from side of distributor to negative side of coil
3) I eliminated grounding wire from chassis to positive side of coil
4) I eliminated the ballast resistor since this is a 3 ohm coil

I feel like I need to keep #3 above instead of eliminate it.

The reason I'm putting points back in is I was trying to adjust the timing and left the key on too long and am not sure if I ruined the Pertronix. Figure if I go back to points I can static time it and know where I'm starting from.

 

[Tom H]

Very puzzling. I have no idea what wire you speak of in #3. If the white wire from the ignition is connected to the positive on the coil, and you also had a wire from that positive terminal to chassis ground that would be a direct short and the the wires would go up in smoke within seconds of turning the Ignition ON. I don't understand how you had to "remove" that wire. I know of no wire from coil to chassis on any arrangement. So at the very least do indeed leave that wire out.

Of lesser concern, since your car is Positive earth, I think you should connect the white wire from the ignition switch to the Neg term of the coil and connect the distributor wire to the Pos terminal. But I'll defer to others if this is wrong.

Tom

 

[Gene Keller]

new points distributor

You can get a new points distributor from rootesparts.com for 99 Euros, which at $1.13 to the Euro is a reasonable price. I've got one and its a drop in, no modifications needed.
Gene Keller

 

[snamelc]

I'm a real advocate for checking top dead center vs the zero mark on the timing chain cover. There are a number of reasons why this may have become off over 50 years or so, not the least of which can be slippage or distortion of the rubber dampener. I just checked my MGB and it was off 2 1/2 degrees. You can make your own tool from an old spark plug or buy one at your local auto parts store. Just remove the ceramic insulator and tap the resulting hole for an appropriate bolt. Place this tool in No. 1 cylinder, then rotate (by hand) each way, marking the stopping point both times. TDC is then half way between these two marks. It turned out I had been timing the MG 2 1/2 degrees too much advance, causing excessive spark knock.

Bill

 

[s2willdo]

Spark Plug TDC tool

That's a great idea. The link above is to a picture of my tool. I made one after reading your post in about 30 minutes. A piece of advice that I got from a machinist friend is to use Moly Dee Tapping Fluid from Castroil. I watched him tap something else and it made it look like the tap was cutting through butter.

Believe it or not my car is still not timed. I got busy and occupied with winter things. Going to get back on the Sunbeam soon.

 

[s2willdo]

Still not running

I still have not got my car running. After seeing a couple threads about valve timing it made me wonder.

Could my valves need adjusting to get it to start? I really think I've got it statically timed but it just won't start.

Any thoughts on the valves?

 

[Bill Blue]

Before getting involved with valves, lets do the basics. Do you have good spark?

Bill

 

[Tom H]

I agree 100% with Bill. Lots of confusion here about the wiring, so I suspect something is not connected correctly or the points are shorted, or the coil is bad, or , or , or..... Simple to check if there is spark. No sense messing with other stuff if there is no spark.

Tom

 

[Chuck Ingram]

Right on
Spark or the lack of spark would be the first thing to check.
Always look for the simple things first.

 

[s2willdo]

No spark

Sure enough no spark.

Here's what I did to check spark:
1) pulled coil wire and put next to block then cranked in dark garage. No spark.

Here's how I'm wired:
1) white ignition wire from loom by firewall connects to ballast resistor
2) wire leaving ballast resistor goes to positive (+) side of coil
3) negative (-) side of coil connects to wire on side of my 45d distributor
4) distributor was new when I put it in 15 years ago
5) I just replaced distributor cap, rotor, condenser

Here's what I checked:
1) suspected the ballast resistor so put a ohm multimeter directly on both terminals of ballast resistor. I get the same resistance as when I touch the leads together alone. I'll buy a new ballast resistor and try again.

Does it sound as simple as a ballast resistor?