Marinized HEI Distributor

[thumper723]

My 1968 Intl 23' w/ Elec Shift 225 OMC has point ignition, as is expected of something this old. <br /><br />My question is, I have done some searching, and it seems that boats used points well into the 80's, long after the auto industry went electronic. <br /><br />Is there a self contained a'la HEI system for Small Block chevy's available? <br /><br />I have owned enough cars with points, and I would prefer to deal with HEI, or it's marine equivalent.

 

[rodbolt]

Re: Marinized HEI Distributor

the HEI was never marinized. however the delco EST was or you can shift to the prestolite BID both work well. I like the EST due to no mechanical advance problems.

 

[prockvoan]

Re: Marinized HEI Distributor

Mercruiser TB systems are HEI.

 

[rodbolt]

Re: Marinized HEI Distributor

no they are not<br />merc uses thunder bolt, their own design or the delco EST. on some of the antique stuff they ran a BID for a year or two. but the HEI label was something GM coined for ign systems used on the auto from 74 to about 85. most everything since about 85 was EST. merc tried a distributorless system as did OMC. neither was popular. but the HEI was never marinized, heck we could not keep the advance weights from rusting on cars much less boats with that system. the HEI also had a vacum advance set up that very very few modern boats ever used. as most marine engines are operated in a range where engine vacum is rather low most all relied strictly on mechanical advance to match timing with engine RPM regardless of load. with modern computer controled systems the timing can vary widley depending on engine RPM and load as well as a few other factors here and there. but the GM electronic of the 74-85 period were the only systems labeled and traded as HEI. even though it stands for High Energy Ignition. by that strict definition any electronic system can be labeled HEI. that being said I can show you all kinds of boats that are running the GM HEI system taken from a car. I wont repair them but I still see a lot of them.

 

[Duramax]

Re: Marinized HEI Distributor

It seems that the "HEI" name is used frequently to reference the Delco EST system. I have Indmar marine engine manuals and that always call it the HEI distributor system. What is different?

 

[rodbolt]

Re: Marinized HEI Distributor

the delco EST has a seperate coil and an ignition module that electronically advances the ign timing based on dist rpm(engine speed) the theory of operation is very similar to the older HEI delco system but can accept a wider range of computer controls or ,with the correct module, can operate as aa stand alone system. makes a wonderful system to replace a point type distributor. the only problem I see with them is, on some commercial applications, the pickup coil has a tendancy to corrode and fail. but its still a good system. you can think of the EST as a second generation of the delco HEI. so far we dont see the rotor burn through problems thaat were associated with the first generation.