HEI Delco Distributor/OMC ESA Module

[DavidWhite61]

I have a 1988 OMC with a new 5.7 engine that has a HEI Delco distributor in it. I need a diagram that shows how to wire the interrupter switch to by pass the ESA module(no points anymore). I can easily disable the overstroke switch which is the other thing that is needed. Any links to a wedsite that has this info?? Thanks.

 

[rodbolt]

Re: HEI Delco Distributor/OMC ESA Module

you will still need the shift interupter(ESA) in the circuit or a shift cut out switch like a mercruiser if this is a cobra drive. How did you marinize the HEI? The HEI was never used in a marine application that I am aware of.<br /> good luck and keep posting

 

[olbuddyjack]

Re: HEI Delco Distributor/OMC ESA Module

I'm in the middle of the same conversion right now. Rods right, you shouldn't bypass the ESA. I used the pentronics diode fix to hook mine up but it quit working. The HEI uses full 12v to run instead of 7-9v like the Mallory and I'm thinking the ESA is having trouble with the extra voltage, maybe. Idaknow, I'm still checking. I've heard of someone using a remote button on the shifter kinda like the land lubbers use on their drag cars for the line locks. Wire it between the tach post and ground, then push the button for a second to stumble the motor when you shift.

 

[TwoBallScrewBall]

Re: HEI Delco Distributor/OMC ESA Module

If it's a delco EST distributor, I can help you out. If it's an automotive HEI I can't. Let me know what it is, if it's the EST ignition I just did the conversion from points on my boat to EST and it's working perfectly. <br /><br />Let me know.

 

[DavidWhite61]

Re: HEI Delco Distributor/OMC ESA Module

The way I was told to do it was to hook the interrupter switch to 12V(key on) and then to the 12V distributor wire. Effectively making the interrupter switch a cutoff for the distributor. I believe that this is the way mercruiser does theirs. The down side is that the shift mechanics all have to be in just about perfect working order so there is no stall either going to forward or reverse. That to me is easy enough. I've talked to a few marine engine distributors and that is what they do. There is also an aftermarket ESA module being made, not ready yet, which I will most likely go to but in the mean time using the interrupter to temporarily stall the engine I think is the way to go. As far as I know my distributor is a HEI Delco, that's whats on my paper work.

 

[TwoBallScrewBall]

Re: HEI Delco Distributor/OMC ESA Module

Basically you got it. You don't go to the 12v lead on the dist though, you send the lead from the switch to the timing shunt lead on the distributor. The ESA uses ground, to the switch, then to the ESA and out to the dist. With the HEI (EST) you need to instead run +12 to the interrupt switch, then directly to the timing shunt lead of the dist. This will cause the engine to lose some RPM when the switch is tripped because it will be removing all electronic advance from the system and setting your spark back to exactly 0 degrees for a moment. Works perfect for me. Good luck!

 

[DavidWhite61]

Re: HEI Delco Distributor/OMC ESA Module

Steve - thanks for all the info. I hooked up the interrupter switch today to 12V with a 2amp fuse and the other side to the 12V timing shunt and it worked like a charm. Easy shifting once again. Thanks!

 

[seahorse5]

Re: HEI Delco Distributor/OMC ESA Module

If you have an automotive HEI distributor in your boat, it is not marine approved by the Coast Guard. Not only are you breaking a Federal Law (Title 33-Part 183) but you are putting yourself and your loved ones in danger, not to mention any innocent bystanders, with the chance of a gasoline explosion. Check with a legal advisor about your liability for operating a boat in an unsafe condition.<br /><br />If you have the EST marine conversion, then the later model OMC interupter module works fine.

 

[Lou C]

Re: HEI Delco Distributor/OMC ESA Module

I guess no one likes setting points anymore--when I started driving it was an annual ritual, points n condenser, rotor n cap. I remember having to sit on top of a Chevy small block to get to the points. Electronic ignitions were just coming on the scene in the early 70s, ChryCo had it first, GM and Ford followed. <br />For now I will just stick with that, not so hard to pop in set of points with the spring tune-up. Does the electronic dist work better with the ESA, or is it more or less the same performance, just no yearly maintenance?

 

[cobra 3.0]

Re: HEI Delco Distributor/OMC ESA Module

If you are going electronic ignition, why not be safe and just get a Pertronix II module for your existing distributor?<br /><br /> http://www.pertronix.com/ <br /><br />I put it on mine and it runs super SMOOOOOTH!

 

[DJ]

Re: HEI Delco Distributor/OMC ESA Module

I have no idea why one needs to teplace points and condenser every season. They were good for at least 12-15,000, or more, miles in automotive applications. Duty cycles have nothing to do with wear on these items.<br /><br />Most boat owners never come close to that amount of time (hours) in a season.<br /><br />A GM HEI unit is NOT a good idea in a boat. Not approved, not spark proof.<br /><br />The Petronix is the simplest conversion.

 

[DavidWhite61]

Re: HEI Delco Distributor/OMC ESA Module

What I was told by the engine distributor is that this is a HEI Delco marine distributor. They've used them for 12 years. This is one of the largest marine engine distributors so I got to believe they have their bases covered. The HEI Delcos are even referenced in the OMC manuals. It's not like I went down to Advance Auto and purchased an automotive distributor off the shelf. I can only assume like everyone else who purchases a "Marine" product that they have taken the appropriate steps to make it true "Marine" in spec with Coast Guard regulations.

 

[TwoBallScrewBall]

Re: HEI Delco Distributor/OMC ESA Module

A lot of people confuse "HEI" with "EST". Similar, but not the same. I'm sure you're fine, and glad you got it working. <br /><br />EST is basically an HEI with Electonic Spark Timing, meaning the advance is controlled by a module instead of by centrigugal weights. Much more consistent. True HIE like in a car is for the most part still mechanically advanced, it just uses a high energy coil and no points. It's a little more complicated but that's the general idea.