points and condensor to CDI ignition on 3.0 OMC Cobra

Hey again

So while I was at my local boat shop getting my engine a tune up, fluids changed, etc..he told me I should really upgrade from the points and condensor setup to a new electronic CDI for my boat. He said that it's inexpensive, and improves engine performance. Does anyone know anything about this "swap out" he said it was very easy, basically taking the distributor cap off, and installing a "U" shaped CDI unit down into it.

Anyone know what I should be looking for for a 1990 OMC Cobra 3.0L ( 4 cyl) engine?

"He" was very likely talking about a Pertronix conversion kit.
Here's the deal, IMO.

#1....... your 1990 OMC 3.0L ignition distributor is 25 years old.
That's 25 years of wear on the distributor shaft, bushings, etc...... and perhaps more importantly, wear on/at the advancing mechanism.

#2.... the Pertronix kit is Hall Effect.
Pertronix uses a very small diameter magnet embedded plastic triggering wheel.
The triggering wheel and sensor are rather cheesy, IMO.

#3... the conversion kit (as he wants to install it without removing the distributor) does ZERO to correct any wear.


Do they work???? Yes, but I will not use them.



.

I do believe in Pertronix!! yet for my 5 Cents -after 38 years in marine repair- stay with the points !!easy to find. replace & you wont be dead on the water =should something go bad!! All the 3,0 is = is a 1962 up chev 2 engine & dizzy!! Bullitt proff!

Thanks for your guys advice. The shop guy at the place that does all my boat work swears on this upgrade, and he recommends to anyone coming in with old OMC Cobra's to do the upgrade.

So you guys are saying this is NO real performance improvement by switching to CDI? And actually my engine is fairly new..I replaced the original engine back about 5 years ago.

Dan

twinpilot001 said:

I do believe in Pertronix!! yet for my 5 Cents -after 38 years in marine repair- stay with the points !!easy to find. replace & you wont be dead on the water =should something go bad!! All the 3,0 is = is a 1962 up chev 2 engine & dizzy!! Bullitt proff!

Click to expand...

Points, in this case, are not a bad thing. Not worth the couple hundred bux that dood wants to charge for it.

Stay with the points. Any one can make them work in a pinch, Pertronics, not so much.

switching to electronic distributor makes for a number of changes. You will have to buy a different shift assist module.
You will not achieve any performance improvement.
Also if boat guy is calling an electronic distributor conversion "CDI", then you need a new boat mech, as clearly he has no idea what he is talking about. CDI stand for capacitive discharge ignition, or more commonly, "wasted spark". This requires the addition of a (black box) capacitor, usually one made by MSD, that fires all the plugs every time any piston gets to the top of the compression stroke. 4 pistons, 16 spark events per 2 turns of the crank instead of 4.

.....................

o2batsea said:

1.... switching to electronic distributor makes for a number of changes. You will have to buy a different shift assist module.
You will not achieve any performance improvement.

2... Also if boat guy is calling an electronic distributor conversion "CDI", then you need a new boat mech, as clearly he has no idea what he is talking about. CDI stand for capacitive discharge ignition, or more commonly, "wasted spark".

3.... This requires the addition of a (black box) capacitor, usually one made by MSD,
that fires all the plugs every time any piston gets to the top of the compression stroke. 4 pistons, 16 spark events per 2 turns of the crank instead of 4.

Click to expand...

1.... I agree!

2.... Yes, perhaps find a new mechanic.

3.... Not sure that this is correct!

Dan Heerts said:

Thanks for your guys advice.
The shop guy at the place that does all my boat work swears on this upgrade, and he recommends to anyone coming in with old OMC Cobra's to do the upgrade.
Understood.... but I think that he's not really giving this complete thought.

As said, the Pertronix kit does ZERO for any correction to older and possibly worn shaft bushing and/or for a worn advancing system.

Now.... if he were to test your distributor on a Sun, Allen or King distributor machine, and find it to be OK... or to make any necessary corrections, then I would agree.... it will work OK for you.
However, most people don't even give that a thought.... they just install the kit, they set BASE advance, and then they send you out the door and on your way.

So you guys are saying this is NO real performance improvement by switching to CDI?
Correct..... No real performance increase, but many times it will improve start ups!

And actually my engine is fairly new..I replaced the original engine back about 5 years ago.
OK.... but did you also replace the ignition distributor at the same time.... or did you re-use the existing?

A new complete engine would very likely be equipped with a modern day electronic ignition system.


Lastly.... the Pertronix is Hall Effect!
Hall Effect intrinsically is OK.... but the way in which Pertronix does it is rather Cheesy.
Their triggering wheel is nothing more than a small diameter magnet embeded plastic ring.
In my opinion, this is very Cheesy at best!

You'd do much better with a VR or photo-eye system.

Click to expand...

.

Unless someone is doing something different nowadays, the Cobras all ran with points and as said earlier, the breaker less system won't work with the shift assist modules. Don't ask how I know this.

3.... Not sure that this is correct!

Click to expand...

yeh, check it out. Pretty much all modern engines made since about 2000 use coil packs or coil on plug that fire all the plugs every time there's a spark event.