I'm doing some distributor work

[Michael Mayben]

I can send a pic, but it's going to have to be until I get back to my place. We put the points back in it and it fired right up! After wards, I got thinking, we didn't use the little jumper wire inside the distributor when we used the p-tron unit. Could this be our problem.

We put a different set of head on this 345. I have more questions on this topic later.

By all means!!! The braided jumper is the ground connection that bonds the upper and lower breaker plate assemblies together and then bonds to the distributor body back to the engine to the battery negative terminal. The upper breaker plate is mounted on three plastic bearing points and will not ground through the vacuum advance diaphragm. There is a rudimentary ground through the pivot post and spring connector clip underneath the breaker plate assembly, but that is no where near sufficient ground for a p-tron (or even breaker points and condenser) to be able to operate as that will be a "high resistance" ground and electronics can't cope with that! And that three-legged spring clip serves to add preload to the upper breaker plate so it can't flop aroiund and is held snugly onto the bearing points. Otherwise, the timing goes to hell from vibration and the distributor guts moving around.

This pic shows a p-tron installed in a 1510 Holley distributor for a four cylinder app. This is the newest one which is non-adjustable so the mounting plate is a bit different than yours. But notice the braided ground cable. This is a distributor I rebuilt and sent out a few weeks ago.

 

[JetSnake]

Yeah, that's my problem. Is the .030 black spacer suppose to stay on the magnet wheel?

 

[JetSnake]

Man, I feel dumb, but that's only because the p-tron instrucktions stink!!!. I put the p-tron unit back it along with the black spacer and the grounding strap.

I never known of this truck to run better then it does now with the p-tron unit it.

 

[Michael Mayben]

Great!

I finally gave up on trying to "help" the pertronix folks with their bullshit instructions! No telling how much time I've wasted on that subject since 1977 or so (the old "per-lux" stuff)!

And now since they have revised many of the applications with design changes, it's even worse! They make no mention at all of the change in the mag wheel install!

Some manufacturers are very receptive to informed customer/end-user technical feedback,...many could care less! And this does not involve some obsolete crap that hasn't been in production for years, this is new stuff that is being phased-in right now into the distribution chain that is very much rocketscience for most enthusiasts who depend upon instructions for complete, successful conversions. And this p-tron stuff is not inexpensive...the slightest "wrong" install can lead to immediate meltdown of the part and the warranty decision will be: "customer installation issue". See that "white" shiny sticker on the module? That is a heat-sensitive material that shrinks at a pre-determined threshold and indicates either the primary ignition system was left "hot" without the engine running (key left on), or the p-tron was used with the totally wrong ignition coil primary resistance factor. Either case leads to module meltdown and a warranty claim with that condition will be denied!

But fortunately because of folks like yourself who ask these questions here on the forum, at least ihon members can hopefully end up with solutions for their issues and we all learn new stuff here everyday!

One last tip...you must "re-time" the engine after installing the p-tron! Try the "power timing" trick you find posted as a sticky at the top of this sub-forum.

Thanks for playing with us and we really hope the crop pays off for ya this year!

 

[Michael Mayben]

these are the heads we took off, 359489-c3. These are the heads we put on, 432089-c1. The heads we put on don't look like they have as much compression, and we used a thicker head gasket. When we pulled the new heads of the donor engine, we noticed the thinner steel head gasket. How much is this going to hurt our compression ratio?

Sorry I overlooked this one!

The compression ratio difference in the case of your grainhauler ain't gonna make any difference! You ain't dealin' with a performance engine build!

But if you can get the compression ratio down around 5:1 or so, ya May be able to run it on kerosene (or "drip gas") but you will have to start it on gasoline and then switch over after it gets up to temp!

 

[Glennrockford]

I made the mistake of not doing my homework to check for the right p-tron unit and after a return and breaking my breaker plate, calling pertronix and getting the right unit(1481)...it was finally installed along with a new coil.....what a difference! Best $120 I have spent in awhile!

 

[Michael Mayben]

So glenn...did ya "advise" the p-tron folks that their instructions suk???

And their application guide can be real ambiguous also as to proper application. Especially in the case of the IH engine apps, it's imperative that you know exactly which distributor you are attempting to source the p-tron for...it's not enough to year model, engine type, etc., since so many of these vehicles have had the various distributors swapped around over the years!

 

[Glennrockford]

so glenn...did ya "advise" the p-tron folks that their instructions suk???

And their application guide can be real ambiguous also as to proper application. Especially in the case of the IH engine apps, it's imperative that you know exactly which distributor you are attempting to source the p-tron for...it's not enough to year model, engine type, etc., since so many of these vehicles have had the various distributors swapped around over the years!

Naw....I figured it was kind of my fault and the parts guy for assuming my distributor was a prestolite. I am chalking it up as a learning experience...do your homework yourself and don't trust the parts guy!! The bummer was I removed the breaker plate and snapped a pin holding the plates together. The original ignitor had a plate and I assumed that my old plate needed to be removed...so I did and found out that the new plate did not fit in my distributor! Arghhh... I just read another thread about running extra quarts of oil....I was running only 5 quarts and my 304 was knockin' a bit....added another quart and seems to have gone away....this forum kicks ass!