Does a ""hot" coil make a difference with points?
- Thread starter leroyd92
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Why not convert to HEI?
No. The amount of voltage is the minimum required to jump the gap. If your old coil can do 30k, your new one 60 k but it only needs 15k to jump the gap thats all it's going to produce.
..........also - some "hot" coils can suck way more current than normal coils - had a 350 here where the owner could manage only about 20miles on a set of new points ............ thought I was clever and suggested hes got dud points supplier. New quality points soon had me seeing smoke pouring from the distributor cap when I lifted the cover to set dwell - knew then too much current going through - new "old" style coil and haven't seen the guy again - happy chappy
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Your '85 still has points? What boat? Our '84 Century Resorter w/ the 350 has the Thunderbolt HEI. Interesting.
As stated, a 'hot' coil wont give you much with a stock setup. You may see some improvement from converting to an HEI w/ a hot coil and wider plug gaps, but if you are happy with the way its has run, probably best to leave well enough alone.
As stated, a 'hot' coil wont give you much with a stock setup. You may see some improvement from converting to an HEI w/ a hot coil and wider plug gaps, but if you are happy with the way its has run, probably best to leave well enough alone.
Most carbureted small block Ford/Chevy powered boats I've ever seen have Points.....Right up 'til they switched to EFI, Though I'm not a boat/marine mechanic & try to avoid them!!
You ask if you will gain anything I presume you are asking about gaining reliability and not performance given your "coil went out" statement. The issue you are facing is poor quality coils made today. The epoxy filled coils simply aren't as good as the oil filled coils. If you are buying generic coils from Autozone etc. shake the coil and if you hear fluid sloshing around that will be a better choice. Coils I have used with success in stock GM point systems are:
Accel 8140 - They were still oil filled up to a few years ago. I have 2 brand new ones in my inventory and 2 used ones but I bought them years ago I cannot guarantee you that they are still oil filled today so you will have to shake them before you buy. I hate the color (bright yellow) on my stock appearing muscle cars so I paint them black with no harmful effects. In a boat it doesn't matter probably so leave it yellow. Don't get the chrome model (8140C) that has poor heat dissipation characteristics.
Master Pro 2-5195 - Budget oil filled coil (made in China, but remarkably reliable, where oil filled coils can still be made) available at O'Reilly's for $24. I have a couple in inventory.
Junkyard Old School (GM V8 non-transistorized ignition cars up to 1972) Delcos - These are getting old now and scarce but if I see a low mile original car in a junk yard I grab these coils. These 50 year old coils (if they are low mileage) are better than many of the new ones you buy now. These generally get scavenged by the restoration car guys though doing factory restorations.
Are you running the correct ballast system to drop running voltage? Usually points will burn out before the coil if you are running full 12v (other than starting) but I still have to ask. Are you using any aftermarket ignition boxes (multispark etc.)? Those boxes kill substandard coils as well, you would need to upgrade the coil if you are running a multispark box. If your system is plain old points, a stock coil is fine. Heat kills coils too, is there decent airflow around your coil? Mounting angle is critical as well, should be near vertical (coil wire output tower up), never horizontal.
Accel 8140 - They were still oil filled up to a few years ago. I have 2 brand new ones in my inventory and 2 used ones but I bought them years ago I cannot guarantee you that they are still oil filled today so you will have to shake them before you buy. I hate the color (bright yellow) on my stock appearing muscle cars so I paint them black with no harmful effects. In a boat it doesn't matter probably so leave it yellow. Don't get the chrome model (8140C) that has poor heat dissipation characteristics.
Master Pro 2-5195 - Budget oil filled coil (made in China, but remarkably reliable, where oil filled coils can still be made) available at O'Reilly's for $24. I have a couple in inventory.
Junkyard Old School (GM V8 non-transistorized ignition cars up to 1972) Delcos - These are getting old now and scarce but if I see a low mile original car in a junk yard I grab these coils. These 50 year old coils (if they are low mileage) are better than many of the new ones you buy now. These generally get scavenged by the restoration car guys though doing factory restorations.
Are you running the correct ballast system to drop running voltage? Usually points will burn out before the coil if you are running full 12v (other than starting) but I still have to ask. Are you using any aftermarket ignition boxes (multispark etc.)? Those boxes kill substandard coils as well, you would need to upgrade the coil if you are running a multispark box. If your system is plain old points, a stock coil is fine. Heat kills coils too, is there decent airflow around your coil? Mounting angle is critical as well, should be near vertical (coil wire output tower up), never horizontal.
Get rid of those points, convert to electronic with PerTronix. Inexpensive, super easy to install, and in my experience bullet proof, never seen one fail. No more dwell to set, timing to correct, set it up and it's done for good.
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Leroy are you running ballast resistance when Key in RUN position? OTW you will be eating points and coils.
Factory coil is fine. Accel and Mallory junk is for teenagers with money and no experience.
Make sure your dwell matches with the specified point gap (30deg /0.016") If it doesn't agree, you have a worn distributor cam. Most tuneups neglect cleaning and lubing the cam lightly .
Want more spark? HEI and have a spare ignition module and heatspreader compound. 1mm gap on plugs
Points? have a spare points and condenser set and some 16 ga. wire .
Factory coil is fine. Accel and Mallory junk is for teenagers with money and no experience.
Make sure your dwell matches with the specified point gap (30deg /0.016") If it doesn't agree, you have a worn distributor cam. Most tuneups neglect cleaning and lubing the cam lightly .
Want more spark? HEI and have a spare ignition module and heatspreader compound. 1mm gap on plugs
Points? have a spare points and condenser set and some 16 ga. wire .
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The stock coil is high quality.
I've used aftermarket stuff on my 60's cars.
On the Vette, I ripped out the MSD spark box, coil, etc and put the original coil and points back in.
IMO, Pertronix points conversion ain't a bad way to go, but you will gain nothing in power, unless you are running like 7,000 RPM.
Aftermarket coils seem to fail more than OEM in my experience.
I've used aftermarket stuff on my 60's cars.
On the Vette, I ripped out the MSD spark box, coil, etc and put the original coil and points back in.
IMO, Pertronix points conversion ain't a bad way to go, but you will gain nothing in power, unless you are running like 7,000 RPM.
Aftermarket coils seem to fail more than OEM in my experience.
Same with " High performance" plug wires Stock parts are fine until you start boosting intake pressure
I've tried a few different coils on the market just because. At least on my vehicles with points, I need a 3Ω coil. The generic Duralast branded 3Ω coil I bought from Autozone when I had one die within walking distance of a store has worked as well as any Bosch, Mallory, or Pertronix branded coil I've tried. The Pertronix "flamethrowers" SEEM the highest quality, but at the same as said the coil will only fire as much as is required to jump the spark plug gap(as a side note, the gap does affect this voltage a lot, but the pressure inside the cylinder, A/F ratio, and even humidity-to a small degree-affect it also). As a hedge against failure, I just carry a spare in the trunk-also a tested and known good Duralast one.
Also, this may be even more controversial than points replacements like Pertronix, but I run a Winterburn CDI module on my MG. It's triggered by the points, but there's essentially no electrical wear on them because the contacts only make/break ~12V with a small amount of current(typical Kettering type ignition will see ~300V on the points). That system lets me open my plug gap up to .035 for a much "hotter" spark, and fewer misfires. A year and a half after installing it, the jury is still out as to whether it improves power and MPG perceptibly
, but at least I don't have to worry about the points anymore.
One last thing-I ran Pertronix for a while, although I used a complete Pertronix brand drop-in distributor(in a Lucas 25D4 casting in my case). In retrospect, I'd have been better off with the original/rebuilt distributor with a Pertronix module fitted, as the quality of the new production complete distributor was not great. Although the car always started and ran fine with it, I was always afraid of things like the fact that you can fry the Pertronix module if you leave the ignition hot without the engine running. The newer Ignitor II and III are supposed to cure that(plus add some other more advanced features) although at the time those weren't available for my car.
Also, this may be even more controversial than points replacements like Pertronix, but I run a Winterburn CDI module on my MG. It's triggered by the points, but there's essentially no electrical wear on them because the contacts only make/break ~12V with a small amount of current(typical Kettering type ignition will see ~300V on the points). That system lets me open my plug gap up to .035 for a much "hotter" spark, and fewer misfires. A year and a half after installing it, the jury is still out as to whether it improves power and MPG perceptibly
One last thing-I ran Pertronix for a while, although I used a complete Pertronix brand drop-in distributor(in a Lucas 25D4 casting in my case). In retrospect, I'd have been better off with the original/rebuilt distributor with a Pertronix module fitted, as the quality of the new production complete distributor was not great. Although the car always started and ran fine with it, I was always afraid of things like the fact that you can fry the Pertronix module if you leave the ignition hot without the engine running. The newer Ignitor II and III are supposed to cure that(plus add some other more advanced features) although at the time those weren't available for my car.
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So basically, this thread was started because our boat had some random power loss issues.
After a minute at 3k rpm. It would act like it's running out of fuel. But no matter how far off you'd back of the throttle, it would still end up dieing, it couldn't ever catch up. We verified fuel was not the issue.
We got home one day after a trial test, and I noticed the positive lead to the coil was loose, like, no nut on the post loose.
So I bought a new coil to replace the original 1985 coil.
Took the boat out yesterday, it ran for 15 minutes straight before dieing the way it normally would. And the coil was hot, really really hot.
Got home, and checked the ballast resistor, it was crunchy and wiggling in the holder. The ohms reading was 1/3 the resistance of the new one I bought today.
So I suspect that it's what was heating up the coil.
I also bought a capacitor." Jus cuz "
I'm hoping the resistor was the issue
After a minute at 3k rpm. It would act like it's running out of fuel. But no matter how far off you'd back of the throttle, it would still end up dieing, it couldn't ever catch up. We verified fuel was not the issue.
We got home one day after a trial test, and I noticed the positive lead to the coil was loose, like, no nut on the post loose.
So I bought a new coil to replace the original 1985 coil.
Took the boat out yesterday, it ran for 15 minutes straight before dieing the way it normally would. And the coil was hot, really really hot.
Got home, and checked the ballast resistor, it was crunchy and wiggling in the holder. The ohms reading was 1/3 the resistance of the new one I bought today.
So I suspect that it's what was heating up the coil.
I also bought a capacitor." Jus cuz "
I'm hoping the resistor was the issue
At least in my little corner of the car world, most of the ignition condensers(capacitors) on the market are fundamentally flawed. I've had new ones fail within a few hundred miles. I don't know if this is true across the board, or just true for the current supplier of most of the condensers that fit Lucas distributors.
In any case, based on recent experience, I would NOT replace a good old condenser. In fact, I've done a few point swaps for other people where they handed me a new set of points and condenser in the box, and I pulled out the new points and left their old condenser in place with the advice of keeping the replacement in the glovebox.
In any case, based on recent experience, I would NOT replace a good old condenser. In fact, I've done a few point swaps for other people where they handed me a new set of points and condenser in the box, and I pulled out the new points and left their old condenser in place with the advice of keeping the replacement in the glovebox.
Interesting fact......Many Domestic automobiles with Points didn't use a Ballast Resistor, They had a Tungsten Resistive Wire to power the Coil. I have never seen one fail. Many were cut/butchered though.
Funny coil story... Long time ago, like 1984 or 5 I had a 69 Charger that I had swapped the 383 for a hot 440. I had an MSD coil in it and one Saturday afternoon when I went to leave work, the car didn't start. No spark. I rummaged around the shop and found a coil from a Ford truck but one or both of the studs on it was stripped. I couldn't thread a nut onto it so I cleaned it up and soldered the wires directly to the coil. Later that night, I went to Hot Rod Burger King, a long Island hot spot. A couple of guys asked to see my engine so I opened the hood. A short while later I had people asking me about that "mod" and did I notice any increase in power.
Being the constant prankster back then I replied yeah, huge gains. Mileage too. Go for it.
Being the constant prankster back then I replied yeah, huge gains. Mileage too. Go for it.
Didn't the GM HEI ignition system come out about 1975? We had a 72 Malibu that had points and the 76 had the HEI.
I was a marine mechanic in 84-85. Lots of the boats had points except the new Mercruiser Thunderbolt stuff. I can't remember a lot of electronic stuff, honestly. Even the Cigarettes had either dual points or magnetos.
Shortly after I made the switch from boats to generators, everything went EFI.
Shortly after I made the switch from boats to generators, everything went EFI.
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