75' mercruiser 302 distributor

[BrockR]

i was thinking about switching to hei ignition from the old points system and was wondering if i had to buy a marine distributor or would a aftermarket one for a similar auto engine work?

 

[ziggy]

Re: 75' mercruiser 302 distributor

generally speaking, ya shouldn't use any peripheral auto parts on your marine engine. ya need a marine rated distributor that's uscg approved so your safe from inadvertently exploding.

 

[BrockR]

Re: 75' mercruiser 302 distributor

even though you "shouldn't" use auto parts will it affect anything , basically will it run with it in there.

 

[gene8084]

Re: 75' mercruiser 302 distributor

In case you missed it, the operative word in Ziggy's post was "exploding". Don't substitute auto for marine (period), especially with electronic parts (starter, altenator, distributor). Sparking and fumes on a boat = explosion/fire.

It's just not worth saving $100-150.​

Play safe.

 

[BrockR]

Re: 75' mercruiser 302 distributor

where are all of these alledged sparks and fumes coming from if everything is in good working condition then what is sparking and where are gas fumes leaking from?

 

[BrockR]

Re: 75' mercruiser 302 distributor

1. im not arguing with anyone im trying to get to the bottom of why an auto distrib and marine distrib are different, you cant just tell someone its gonna explode that doesnt help! why dont cars explode?

2. you have no idea how my boat is set up, i do not run with an engine cover so there would be no fume build up.

 

[QC]

Re: 75' mercruiser 302 distributor

1. im not arguing with anyone im trying to get to the bottom of why an auto distrib and marine distrib are different, you cant just tell someone its gonna explode that doesnt help! why dont cars explode?

2. you have no idea how my boat is set up, i do not run with an engine cover so there would be no fume build up.

Please chill a little . . .

The reason that this is an issue with Marine and not Automotive is that gasoline fumes are heavier than air. Take a look at your car, it has lots of holes between fuel and the ground . . . In the case of a boat, holes in the bottom are usually bad. Soooooo, the heavier than air fumes build up in the bilge, sit there waiting for the correct air to fuel ratio. Yes, open air is better, buuuuut, the issue is not while underway usually. It is sitting still after a leak has developed and then starting. Happens often. It is why there is a Blower (none on your car) and regulations that contain any ignition source on a boat, Starter, Distributor, Alternator, et.c etc. and it is why there are different Carbs and other fuel system components too. They are designed to leak into themselves instead of simply drip as am example. There are fuel line specs, anti-syphon valves too, all due to Boom and none of the same on cars

Oh, last thing. If you can predict when fuel leaks will develop, would you please call me just before any of my stuff leaks and I'll stop worrying about these things. All sarcasm intended, but only to make a point

 

[gene8084]

Re: 75' mercruiser 302 distributor

1. ... Why dont cars explode?
2. you have no idea how my boat is set up, i do not run with an engine cover so there would be no fume build up.

As you?ve extrapolated, cars don't explode because their engine compartments are well ventilated naturally. The bottom is open, fumes settle and dissipate, the grill is open and cars have substantial air flow even while idling due to the fan which cools the radiator.

Boat engines are "typically" enclosed below deck or under an engine cover. Carburetor engines by nature have gas in the throat and emit fumes which grow worse when sitting in a confined space in or out of the sun. Thus the reason we run our blowers for 4-5 minutes before starting at the ramp.

As an additional precaution, because we can't ventilate enough to eliminate all ills, we use flame arresters on the carburetor and marine designed ?spark free? distributors, starters and alternators since these are other likely culprits to emit sparks.

There?s a lot more to it, but I sense you get the gist of it.

Obviously, none of us can speak to your setup?we neither know what it is nor can override sound advice and regulations established by the Coast Guard.

Technically, your engine will start and run on the blocks. We?re just not recommending it for application in a typical marine setup.

Welcome to the forum.​

 

[Don S]

Re: 75' mercruiser 302 distributor

One thing that most people seem to forget about distributors in marine engines, is that the advance characteristics are completely different from automotive.
So if the advance is wrong and can damage your engine, and cost you power, plus they aren't spark shielded for sparks proplerly, what good is an automotive distributor?