Pertronix EI

Just an update that was discussed under ballast resistor. I finally got the right rotor for the Pertronix kit 1582 which is for the screw down rotor cap on a prestolite distributor. With alot of comm. with Carl @ vintageperformance.com(retrorockets.net)it was finally determined that an after market rotor was installed on my 88' that was not OEM. The following are OEM rotr equivalent.

    ECHLIN       AL-169   ( NAPA)
    BORG-WARNER D-195
    PRESTOLITE   4-94

I hope this helps anybody out there looking to do the same Conversion. After all was said and done it took me about 45 mins to do the convert. Price was $72.00 and included shipping. Rotor from NAPA was $13.00

AMEN JIM!!!!!   Ain't no machine gonna outsmart me.

Is this kit for converting from old style distributor to the electronic ignition. If so, where did you get the kit for. Mine is an '83 and it has the clip down prestolite.

Thanks

Okay,here we go. Dropped the boat in the water this past weekend and after settling in a cove after a 15 min ride for about a 30-40 min lunch break the boat failed to start. Ran the battery down to almost nothing. Checked for a spark and got nothing. Put the points back in and got nothing. Should I go after the coil or something else. Can't believe the coil would just quit like that but it is 15 years old. Any thoughts???? Ideas?? Thanks in Advance..

Tim

I recently found a copy of a 98 performance mag, with an interesting article called "GET TO THE POINT" It is a comparison between breaker point & electronic ignition. It states: Horsepower comparison of a single point ign. versus an HEI verses an MSD electronic distributor on a 5.7L GM crate engine equipped with a 9.5:1 compression, Corvette alum. heads, a Crane HMV 272 cam, an Edelbrock Performer manifold, a Holley 750 cfm carb., and 1 3/4 " headers with turbo mufflers.

RPM                      2500 3000   3500   4000   4500
New single point       346   355   364     370    363
New HEI                  343   354   360     369    359
New MSD electronic 345   357   363     367    360
Dist. W/ 6AL box
& blaster coil
                   5000 5500
                   334   298
                   335   303
                   335   303
Peak H.P. is at 4000 RPM.
Seems simple and cheaper, is better?

My simple electronic conversion greatly improved my boating experience. (How do you chart that?) Maybe I am just not good at setting points. I found myself spending way too much time pulling my dist. cap. Although I do find the chart very interesting and I don't doubt the results. Thanks! (I still recommend the conversion.)

I admit I'm suspicious of thos numbers, Hard to believe a magazine would go through the trouble to precisly match the two distributer's advance curves, so thats a variable.

Thanks for sharing the numbers, its good discussion.

My seat-o-the-pantsometer said the MSD difference was dramatic; when I left the base timing and advance mechanisms alone and only changed the electrics.

The points-igniter jump was insignificant except the settings didn't drift and could count on it starting and the contacts not deteriorating.

However, the Igniter-MSD combination was truly dramatic.

All I can say is that I think HP/rpm numbers don't tell the entire story.

As skiers and drivers you understand we are more sensitive to throttle responce than the typical boater; as the carb transitions through its circuits from idle, accel pump (cam, shooter and clearance), primary mains, Power valve vacuum setting, PVCR diameter, then finally secondary jetting (often a metering plate on the 4160 and its chosen spring.

Our carbs are most often a compromise of 'close enough'.

Some people can really dial them in but they are rare (browse some Pantera sites and prepare to be in awe of how much there is to tweak and the methods involved)

Well, you can't have Pantera performance from an 'out of the box' "'73-89' 351/350" carb unless your prepared to open it up 20-40 times and a serious investment in time and analysis.

We are more sensitive to perfomance than the average wally boater, but you can't have Pantera perfomance on a one-size fits all carb.

but I digress...

My point is, there are periods in these transitional areas where the carb is switching circuits, where the extra energy spark becomes benificial; and an extra-strong spark can make a carb in good working condition feel and work great.

Naturally, an MSD won't repair vacuum leaks on the throttle bushings, clean cruddy needle valves, clogged idle circuits, or blown power valves, or magically fix corroded advance mechanisms.

Now, is 500V primary overkill? probably.

Would 24V primary provide 80% of the benifits? likely.

But its a simple add on that really shines when everything else is in good order.

So, an MSD could become less significant if our carburation was absolutly spot-on , for all ranges, loads and inputs. It also follows that an MSD is less significant when WOT on a dyno.

Please excuse me sounding so mater-of-fact on this; just attempting to make my thoughts on this as clear as I could, and hope that answers your question Jim.

Heh, I see there's no convincing you, polyhead, and thats OK with me. Least we can have some fun.

I suspect we're more similar than first appears; I detest EFI as much as you do EI, for your similar reasons. The day I bring my boat to a dealer for service is the day I sell it.

However, contrary to your scenario I won't loose a day skiing due to ignition..with a flathead screwdriver I can move a few terminals and run straight off the Pertronix instead of the MSD, and if the pertronix fails, I can use the same screwdriver to throw in the breaker plate left the glovebox. If I could do it fast enough it would be FAA certified.

Now you do have one of them 'radar ranges' in your kitchen, right? just jesting!

I mean, we all got the same bug, right, thats why we're dinkin with old boats.

Perhaps you'll get a chuckle..., I got a elder customer (80's) that insists on running 87 octane in his '70 Century Mk II 340 v-drive. Looks at me like like I'm a martian when I explain what he's doing to that engine. Guess it doesn't really ping if he can't hear it ...poor engine. Took me 10 years to convince him its not splash-lubricated so don't buy non-detergent oil.. same disease as me, just 'advanced stages'

jim thats alot of rpms! is the 289 have a way shorter stroke? do you drive a white avalanche? saw one at the boatramp with a brand new techsun trailer set up for an inboard and thought to myself i know that guy{not really}. we need to meet up sometime. you goin to the san antonio reunion?

Yes, the 289 is a short-stroke engine, only 2.87" and a 4" bore. The stock bottom end can take about 7300 rpm max when in good condition.

Jim,

I wouldn't reprop based soley on your rpm's being higher than 351 guys. A 351 has the torque to chug the big props and lower rpms because it has a 3.5" stroke.
You already fixed the heads, got the cam, the only way a short-stroke engine is going to make the power you crave is if you spin it.

It the same reason a 302 is fun in a mustang but an absolute dog in a truck.

Also, if you're simply after top end alone, you might be nearing the upper CFM limits of that smaller carb. However, if may be optimal for the way you use the boat. Check manifold vacuum to see it begins to creeps back at WFO above 5krpms, thats the best way to check.


Perhaps your timing was indeed optimal at 10 degrees initial already. Adding the 93 octane could have added more percentage of ethanol to the mix, which has less BTU/vol, affected the burn, knocked your jetting off too because the A/f ratio will need to be slightly different. An EFI engine like a Black Scorpion will compensate and make more power with 93 beacuse it can tweak the timing and mix, but your carb can't.


It might be better to record your final timing instead of initial, and compare to standards for that engine.

You might get somewhere with 89 octane, but sounds like you were right-on to start with.