how do i tell what piston is at TDC???

[tankwilson]

Need a little help on installing my new HEI distributor. I have a few questions.

What cylinder is number 1,2,3... etc.

How do i tell if it is at TDC?

I installed the new HEI and the vacum hits the block.

Can someone give me some pointers on installing one of theses?

Thanks

matt

[greg g]

Number 1 is closest to the radiator. Pull the plug s and with an assistant bump the starter with your thumb over the plug hole of #1, till you feel pressure building. Then you can turn the engine over by hand with the fan until the O mark on the crank pully aligns witht he pointer and Number 1 will be at top dead center. If all is right the diz should drop in withthe rotor pointing at about 7 oclock. There is another fastener on the bottom of the diz that will allow some further rotation to allow you get it lined up better, Then make sure you start your wires with number 1 going from tha 7 oclock tower of the cap going to number 1. then follow around as per the firing order.

[mackster]

I'm stealing a little bit this thread, does anyone know how much will you gain with this conversion from stock? is it a lot? how expensive is a HEI? d you recommend it? Your thoughts please....

[greg g]

The only real gain is in not having to replace points or have any performance degredatio due to point wear or having the gapchange over time. Usually folks thing the HEI mean High energy Ignition. It actually stands for Hall effect induction. It basically replaces the points as the switch that fires the coil with a magnetic field and sensor switch instead. Kind of like the sensor for ABS or for some speed controls. It does not give you a hoter spark but rather a more precise and dependable one. You do usually retain the same coil.

It has been said that you can adapt the MOPAR electronic ignition if you are running 12 volts. Basically you source the stuff from a mid 80's slant 6 system and adapt the distributor by switching the drive tang from the flathead

dizzy. then use the module and coil fromt he late model to complete the system.

[mackster]

The only real gain is in not having to replace points or have any performance degredatio due to point wear or having the gapchange over time. Usually folks thing the HEI mean High energy Ignition. It actually stands for Hall effect induction. It basically replaces the points as the switch that fires the coil with a magnetic field and sensor switch instead. Kind of like the sensor for ABS or for some speed controls. It does not give you a hoter spark but rather a more precise and dependable one. You do usually retain the same coil.

It has been said that you can adapt the MOPAR electronic ignition if you are running 12 volts. Basically you source the stuff from a mid 80's slant 6 system and adapt the distributor by switching the drive tang from the flathead

dizzy. then use the module and coil fromt he late model to complete the system.

Thanks Greg, nice to know. I thought that it will give you a hotter spark and more horsies... Thanks for the info. Mack G.

[Plymouthy Adams]

Greg...thank you..I thought for a time I was the only one who called HEI by its real name...as associated with GM they have to remoniker everything as if they are the leader in auto technology when in fact they have not introduced any new technologies in years..their research department is too busy reverse engerneering so their HEI is by their own description High Energy Ignition..the all in one package under the distributor cap is part in part that system and I will gladly give them full credit for creating a nighmare and the most awful looking montrsity to ever sit in a distributor hole...

[tankwilson]

Thanks greg. That is exactly what i needed to know.

[hkestes41]

If you really want to get into the technicals of both a point style & HEI ignition system along with the benefits / problems associated with each here is a good link.

http://www.jetav8r.com/Vision/Ignition/CDI.html

[martybose]

Thanks Greg, nice to know. I thought that it will give you a hotter spark and more horsies... Thanks for the info. Mack G.

Actually you do get a much hotter spark. When I first put in my Langdon HEI it didn't run real well. Then I opened up the plug gap to .060" and it now starts and runs much better than original.

I am having somewhat of an issue with the advance curves on my unit. I'm running 5 degrees initial, and finding that the centrifugal advance is too much too soon for my flathead. I looked into advance curve kits for this unit, but they are all about bring the curve in faster, which isn't what I need. I'm now considering just locking the centrifugal advance down so that it doesn't work at all, then running 5-10 degrees initial and leaving the vaccuum advance working. Time will tell, as I'm pulling the head off for some other changes right now.

Marty

[tankwilson]

So what plugs and plug gaps is everyone running on Langdons HEI??

[martybose]

So what plugs and plug gaps is everyone running on Langdons HEI??

With my Edmunds aluminum head, which requires 1/2" reach plugs (unlike the OEM head, which uses 3/8" reach plugs), I'm currently running Autolite AP425 plugs, which is a platinum plug. They aren't ideal, however, because they were designed for a .032" gap, and are bent out of shape to get to a .060" gap.

Since my head was damaged by running 3/8" plugs previously, I was researching how to fix the sparkplug threads. My mechanic recommended timeserts as the best fix, and stated that as part of the repair he could change it to a 3/4" reach plug, since there is a much greater choice of plugs in 3/4" reach. When he does this, I will contact Autolite to find a plug that has the same heatrange and tip style as the AP425, but has a 3/4" reach AND is designed for 0.060"-0.080" plug gaps.

Marty