Marine HEI Distributor

[michael hunter]

As most of you know I am not an advocate of using automotive parts on a marine engine. However after recent talk about HEI conversions it got me doing some research.
What I found is the automotive distributors sell far below 100.00 some as low as 40.00 as for the marine version more like 300-400. So I ask the question exactly what is the difference between automotive and marine distributors. This is almost impossible to find out, lots of info on fuel pumps,carbs,alts and starters but almost nothing about distributors. So besides vacuum advance and venting I see no difference between the two . If anyone has any facts about marinizing a automotive dist let me know.

[MRoberts]

My understanding is that a Marine distributor is sealed to protect the spark from getting to possible gasoline fumes in the engine/doghouse area. This is not necessary on a automobiles due to the fact that the fumes will vacate the engine compartment on their own. On a boat they have nowhere to go unless your blower is activated...

[michael hunter]

That is somewhat true however there are 3/8 holes covered by fine brass screen in the bottom of the stock dist. Gas fumes are heaver than air so im pretty sure they are there to vent the cap.

[Wulphie]

A reverse rotation engine will have a different gear.

[michael hunter]

Yes it will they are available too my 89 is standard rotation.

[wotan2525]

AFAIK the difference is in the venting. That fine mesh screen on the ventilation holes is to prevent spark from escaping the unit, hitting the fuel vapors in the bilge and causing an explosion. The marine dizzys have those screens in place but other than that use the same caps, rotors and assembly.

I've got a friend that has big dollars into his drag cars. When he showed me the $50 ebay distributors that he runs, I was a convert. I've run them in everything since then and have never had a problem.

Now, why don't they add the screens and market them as "marine?" Demand. They can crank out a container load of automobile dizzys and sell through them relatively quickly. The market for the marine unit is much, much smaller.

[lively]

I'm really interested In your findings , and how did you fit the distributor in next to thermostat housing ? I wanna use a HEI on my engine build to clean up the wires and ballast resistor . Did you just pick one up of eBay ?


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[michael hunter]

its a tight fit but doable . I got it on ebay. I set the advance weights to 30 degrees max advance . It runs great time will tell how it will all work out.

[Sdc77]

Hello Michael,
I just receive my HEI + 8.5mm ACCEL wires, and will do the swap soon.

What spark plug do you use behind of your HEI ?

Thanks

[michael hunter]

Same plugs just open the gap to 45.