Help distributer conversion

[andy032612]

I just recieved my new HEI distributer it has two wire hook ups one for power and one for the tach, my coill has 2 or 3 wires on each side. and where do I pull the vacume from for the new distributer???
any help would be great or should I just take it to the shop???
It is a 1981 260 mercruiser with a new long block with about 50 hours on it.

 

[Fun Times]

I just recieved my new HEI distributer it has two wire hook ups one for power and one for the tach, my coill has 2 or 3 wires on each side. and where do I pull the vacume from for the new distributer???
any help would be great or should I just take it to the shop???
It is a 1981 260 mercruiser with a new long block with about 50 hours on it.

I'm Not 100% sure, But I'm going to suggest you give these guys a try also, There pretty good with the older engines.
Good luck.

Look in the I/O area.:thumbsup:
http://forums.iboats.com/

 

[BonBini]

An HEI unit uses 12v key on continuous voltage supply to run. Your old points set up used 12v during cranking (to provide a hot spark for starting) and then dropped back to 6-8 volts via ballast or resister wire (so the points wouldn’t burn)… You’ll have to be sure to supply the correct voltage to this HEI unit. And also you'll need the correct spark plugs with the correct gap!

That pesky little vacuum hose. That would be for the vacuum advance. The hose would typically connect to either a "live vacuum" source via intake manifold or a "ported vacuum" source at carb.

This HEI distributor sounds to me to be of an automotive type. Your boat engines timing advance curve is quite different from a car or truck engine.

Are you planning on tuning this distributor to fit your engine or were just going to plug and play?

 

[andy032612]

I was hoping to plug and play any recommedations or did I waste my money on this distributer.???? should I order a new one?and thanks for the reply

 

[BonBini]

This is what I’m thinking…

1)… if the advance curve comes in too quick, you could get some spark knock. A spark knocking engine raises hel on the rod bearings.

2)… I don’t believe the HEI dist cap has the little moisture absorbent paper built with in.

3)… HEI’s don’t do well with heat. I’m thinking that’s why Merc didn’t seem to use them.

I think a better choice may have been one of Merc’s “Thunderbolt” systems. They seem to be pretty reliable and are calibrated to work with a boat engines load demands. and would definatly be plug and play.

 

[andy032612]

Thanks I will order a new one thats what happens when you think ya found a cheaper short cut.

 

[1956olds]

so thunderbolts are electronic ,do they have points?

 

[BonBini]

so thunderbolts are electronic ,do they have points?

I don't know the history of how they started out, but they are pretty much of the electronic type from mid 80's on....

Different modules are used to bring in the timing. ie: hp and engine size.

 

[1956olds]

Thanks,i was considering pertronics myself for my 260 mercs,i run pertronics in my 56 olds with flame thrower coil and had to have the advance curve changed by machine shop when it was installed.

 

[SCORPIO]

Also be careful with non marine distributors, they aren't spark proof. I have Thunderbolt IV distributors in my '89 and they are electronic units. They look fairly basic with a pickup and black box for timing. Keep it simple.

 

[1956olds]

With the pertronix they just change the top parts the distributor is still the same part it just had to be changed because it was originally vacume advance and now it is electronically advanced ,or thats how it was explained to me anyway.

 

[SCORPIO]

The Pertronix just replaces the breaker plate in a points set up with an electronic pickup. I had one on my old boat, worked fine and eliminated the tuning drift that goes with points.

 

[stevea661]

I did the pertronix on mine. I also had the distributer checked and the advance adjusted. It seems to work fine. I also regapped the plugs. I did have one question that has yet to be answered reguarding the balist wire, I am still running it at about 8vdc and have thought it would probably be ok to run at 12vdc. Anyone know for sure?