Switching to HEI

[502 JET]

I have a 79 Mercruiser Alpha 260 (350) sbc.It is still running points.I would like to switch it over to a Hei distributor. :confused:
Has anyone successfully done this?
Here is where the problem lies.There is a momentary stutter switch that shorts out the ignition so you can shift from forward to reverse.With out the ignition cutting out it would be very difficult or impossible to shift (and also damage to the drive could occur).I believe this switch is connected to the negative side of the coil.
If I install the Hei how would I connect the stutter/cut out wiring?
If I connect it to the tach terminal of the Hei would it give the same affect?

[GofastRacer]

Well I'm not familiar with that setup, but I would think that it's connected to the tach, sounds like it's a safety deal so you can't throw it in reverse at high RPM's??, I'd give it a try and see what it does, can't hurt anything!.. BTW, make sure you have a "direct" 12 volt feed to the HEI, use 12 guage wire minimum and if you have to have a long wire use 10 guage!....

[tbanzer]

If I am correct HEI is not a marine distributor ( explosion proof). But to answer your question you would interupt the main power wire on the side of the cap I believe it is marked BAT with the TACH terminal next to it.

[GofastRacer]

They do come in a marine application!..
D.U.I.! (http://www.performancedistributors.com/)

[jtmarten]

I have a 79 Mercruiser Alpha 260 (350) sbc.It is still running points.I would like to switch it over to a Hei distributor. :confused:
Has anyone successfully done this?
Here is where the problem lies.There is a momentary stutter switch that shorts out the ignition so you can shift from forward to reverse.With out the ignition cutting out it would be very difficult or impossible to shift (and also damage to the drive could occur).I believe this switch is connected to the negative side of the coil.
If I install the Hei how would I connect the stutter/cut out wiring?
If I connect it to the tach terminal of the Hei would it give the same affect?
No. You'd just momentarily disable the tach. The switch should be connected to the BAT terminal of the HEI as long as it's an inline connection. If you hook it to the BAT side make sure the switch isn't grounded when closed. I'm pretty sure it's an inline switch, but it's been a long time.

[502 JET]

No. You'd just momentarily disable the tach. The switch should be connected to the BAT terminal of the HEI as long as it's an inline connection. If you hook it to the BAT side make sure the switch isn't grounded when closed. I'm pretty sure it's an inline switch, but it's been a long time.
The interrupt switch grounds the negative side of the coil now.So it would not work grounding the positive terminal.

[jkh04200]

What kind of igniton is on it now?

[502 JET]

What kind of igniton is on it now?
It its either a Mallory or Prestolite distributor with points.

[DelawareDave]

It may be easier to switch to a Thunderbolt ignition. Everything would hook up the same.
Oh- it's called the "shift interrupter switch".
502- I believe I have the Merc service manuals for that motor in my storage boxes someplace. Try Marine Power Service in Brick (I think) for new/used parts, if you can't find someone closer.

[502 JET]

It may be easier to switch to a Thunderbolt ignition. Everything would hook up the same.
Oh- it's called the "shift interrupter switch".
502- I believe I have the Merc service manuals for that motor in my storage boxes someplace. Try Marine Power Service in Brick (I think) for new/used parts, if you can't find someone closer.
Thanks Dave
I have a manual.I know about the the thunderbolt system.I can get a new complete system for about $250. wich is cheap.I may just go this route.

[jkh04200]

502,
I have a thunderbolt in mine and I was considering going to an HEI. I actually bought an accell from Jegs. Anybody need a distributor? Never been out of the box. I wanted to go to the HEI because the thunderbolt is a full electronic distributor and advances 24 degrees electronically and cannot be adjusted. At the time I was wanting to run about 18 initial which ofcourse would give me to much total. I had a marine mechanic beg me not to make the switch. I have since found that you can get a module for these distributors that will allow you to adjust the amt. of advance to your needs. I'm glad I didn't change.

[DelawareDave]

502,
I have a thunderbolt in mine and I was considering going to an HEI. I actually bought an accell from Jegs. Anybody need a distributor? Never been out of the box. I wanted to go to the HEI because the thunderbolt is a full electronic distributor and advances 24 degrees electronically and cannot be adjusted. At the time I was wanting to run about 18 initial which ofcourse would give me to much total. I had a marine mechanic beg me not to make the switch. I have since found that you can get a module for these distributors that will allow you to adjust the amt. of advance to your needs. I'm glad I didn't change.
Some people switch to the V-6 module which has the lesser advance.

[jkh04200]

Some body makes a module specifically for these dist. that will allow you to dial in any degree you want. If anybody is interested I can dig around and find the mfg and part#.

[502 JET]

As long as I have enough clearance around the distributor.
I tested an hei distributor in a pick-up today.As I originally suspected grounding the tach terminal of an hei distributor will stall the engine.So I will be able to connect the shift interrupter switch to the tach terminal of the hei and have it work.
As for the hei not being explosion proof the only difference I see with the DUI distributor is that has screens installed in it.The hei being a self contained unit (no external coil or coil wire) it seems to me that there is less of a chance of sparks.I am going to install screens in the hei before I install it in the boat.

[tbanzer]

If the stock distributor and advance components are in good shape I would consider an electronic conversion to your existing distributor. Pertronix make drop in electronic conversion for most all distributors for around $100, I have installed many of them and Only had one failure and it lasted for about 6 years b4 it started acting up.