I know its not a vett and I'm sure someone will be offended I posted this but you guys/gals are the masters at chevy motors and modifications soo....
91 chev 5.7 in a ski supreme ski boat. has a points/patronix distibutor. can I yard that one out and just drop a HEI in it? If so, are there any tricks I should know about? (Wiring it)
I'm having issues with cap and rotor set up and think it's better to just update it.
Thanks again

 

In a word - Yes.
As I recall, there is only one wire going to the HEI - I did it on my Vette a couple years ago...BUT...I could be wrong about the "one wire"...

I'm sure some of the guys here will detail it for you....

 

Yup, just drop in the HEI and put 12 volts on the "battery" terminal. (make sure it's switched battery so the engine shuts off with the key)

If you have a Tack in your boat, the tach lead (usually green in color) goes on the "tach" terminal. Viole, DONE. No sweat.

 

Yes you can, but do you really want a non-marine distributor in a ski boat? I would look around for a different marine distributor, you don't want stray sparks finding any stray fuel. The results could be, well, explosive.

 

True, but the only typical difference is in the base/cap gasket and in this case, maybe the wires around the boot under the cap....
to the cap and coil.....that's about it....

they can be added on, maybe need a new dizzy cap...

 

So I talked to the boat guys and they say "NO"... they say that it will not have enough advance.and the only way to do it is to install a marine distro with points/ patronix and that means $$$$$$$$
So why can't I just run a vacume advace line? He said that boat motors don't create enough vacume and that it will only run about 2500 RPM WTF

 

Ummm, are you kidding??!! It's a 350. Plain and simple. I can twist that distributor to run 80 degrees advance. Let's look at this objectively. What's the difference between finding a stray spark along with stray fuel in a boat engine compartment, rather than a car engine compartment. It seems to me the laws of physics and engine design don't change all that much depending on location.

A boat engine has SOOOO much cam overlap that it doesn't make ANY vacuum for a vacuum advance??? Says who?? Put lighter advance springs in it! I don't EVER remember a boat rumpity rumping down a water way. They all sound rather timid to me. I think the boat guys are trying to sell an expensive distributor. Somehow points are LESS susceptible to corrosion than electronic ignition?? Who comes up with this stuff?

Put the HEI in it, put new wires on it, use dielectric grease in all the boots and around the base, set the timing to 40 degrees total advance and call it a day!

I just got done helping my brother in law on his boat. He has a 302 Ford in his. He goes to O'reily's for his tune up parts. The distributor looks just like a car unit. We ran it hard for two days straight without an issue. Why would a Chevy engine be any different? There's no magic here.

 

Thays what I'm saying...

 

Marine distrubuters don't run the vacuum advance and Gene is correct about the base gasket. If you will have Coast Guard safety inspections that may become an issue. But I would use an hei, many did.

If seeing salt water, it won't hurt to run a ground wire to the dist case.

Boat engine compartments are considered closed, whereas an auto isn't. They do blow just from fumes. That's why blowers are mandatory.

 

That's all I was trying to say. Yes, physically the swap is no big deal. But to do things in a boat the same as a car without considering the whole thing could be disasterous. Will it work-yes; should it be done-I don't know, depends on you and the boat and other factors. I wouldn't in that boat. The hood on an inboard ski boat is like a turtle shell. Fumes can build up with no place to go and a stray spark can ignite them. An inboard/outboard or a jet boat has more ventilation up high on the engine and I would be more willing to put an HEI on one of those. If you do this, use good plug wires. My .02

 

I'll admit that my boat experience is limited, but the "hood" on my brother-in-laws boat is FAR from sealed. And as noonie said, if blowers are mandatory on these boats, why is everyone worried about fumes? If there's an exhaust fan running to evacuate fumes, there should be NO fumes to ignite. Right? What's the difference between silicone wires for a boat and silicone wires for a car? It's chemically the same material. If you use dielectric grease on the boots, it WILL NOT arc from the boots. You would have to cut a wire to get an arc. Seems to me, you would have the same problem with the ANY wire that you used. A bead of silicone or dielectric grease around the base and it'll be sealed. So again I ask, what's the problem?


How's that saying go? "The people that say it can't be done are usually being left behind by the people doing it."

 

Boats with automotive derived engines are in several categories:
1)Jet boats-engine is exposed in most cases
2)Inboard/outboard-has an outdrive like an outboard but the engine is at the back. Engine is high up and vents well until you get to the larger boats of this type, then they are below deck in an enclosed space.
3)V-drive-similar to inboard/outboard but has a fixed prop out the bottom instead of an outdrive off the back. Engine high and back and fairly well vented.
4) True Inboard-which is what a Ski Supreme is- The engine is under a turtle shell hood in the middle of the boat. Prop shaft comes through the hull and back. Yes, there is ventilation, but at low speeds and when stopped there is less ventilation than any other style boat. Fumes can be trapped under the shell. You have to be religious about running the blower and the blower is disconnected in distance from the engine(engine middle of boat, blower back of boat).

Also, an HEI (High Energy Ignition)is a much higher voltage spark than a conventional coil with points and condensor. If your wires are bad and crack or don't seal around the boots or if the resistance is too high, an HEI is much more likely to "leak" sparks than a conventional ignition system.

Finally, I never said it COULDN'T be done-I questioned whether it SHOULD be done. And now I am done. This is not even a Corvette or a car question. This is better asked on a boat site. Do what you want, I wouldn't do it. I'll add to your quote "The people that say it can't be done are usually being left behind by the people doing it."-either that or those that are hurt trying to do something unwise.......