Marine Coils VS Automotive Coils

[Grayhorse]

Anybody know the technical difference between automotive ignition coils and the marine type? Both of my engines have automotive type, wonder how big of a deal not to have the "correct" ones.

 

[Olds Eddie]

Re: Marine Coils VS Automotive Coils

If there not epoxy filled high vibration coils they won't last long. Some ignitions like different internal resistance than others and will not produce as good a spark if not correct.

 

[rodbolt]

Re: Marine Coils VS Automotive Coils

depends on the system and what design coils were OEM. a few were identical and still are, others were vastly different. then you have systems that cannot cross to the auto market cause they were never offered in an auto version. so its all rather relative.

 

[KaGee]

Re: Marine Coils VS Automotive Coils

Take your coil to NAPA. Like Rod said, if they can't come up with a replacement, then it's OEM.<br /><br />If it's a standard points/condenser ignition chances are excellent for a replacement.

 

[rbezdon]

Re: Marine Coils VS Automotive Coils

I did some research on this when I converted to the Pretronix system and found that the main difference is what Olds Eddie said, marine are heavy duty epoxy filled for high vibration and auto are mostly oil filled (and cheaper). The epoxy ones run a bit cooler too I think. If you change, becareful to get the right one for your ignition setup. Different resistence coils are for points/no points (some type of module, ballast resistor/no resistor, higher energy voltage levels/standard levels. Some even require better wires to go with them.

 

[ron7000]

Re: Marine Coils VS Automotive Coils

Originally posted by Grayhorse:<br /> Both of my engines have automotive type

how do you know or what makes you think they are automotive?<br /><br />

 

[Grayhorse]

Re: Marine Coils VS Automotive Coils

One of them has a Chrysler symbol and part number on it, the other has a IHC tractor part number on it. As I've been refurbishing the boat, I've learned the previous owner was rather frugal, and cut a quite a few corners, so I've been following up on some of the minor items like parts compatability.

 

[Scaaty]

Re: Marine Coils VS Automotive Coils

Originally posted by vatter41:<br /> difference is what Olds Eddie said, marine are heavy duty epoxy filled for high vibration and auto are mostly oil filled (

Better duck, monkey wrench coming at ya...I have both an Evinrude and Volvo coil, both oil filled, both OEM (Evinrude stamped on the one). Shoots that theory down

 

[Scaaty]

Re: Marine Coils VS Automotive Coils

Originally posted by Robby6950:<br />

Originally posted by vatter41:<br /> difference is what Olds Eddie said, marine are heavy duty epoxy filled for high vibration and auto are mostly oil filled (

Better duck, monkey wrench coming at ya...I have both an Evinrude and Volvo coil, both for point ING with need for external ballast resistor, both oil filled, both OEM (Evinrude stamped on the one). Shoots that theory down

 

[Grayhorse]

Re: Marine Coils VS Automotive Coils

This gets more interesting. Contacted a friend of mine with Echlin, a major manufacturer of Ignition replacement parts. As he's a salesman, dunno if he's completely up to speed on everything technical, but he tells me that any coil rated for a standard points/condensor ignition system of the proper (3 ohm) rating, with a 20,000 volt rating should run just fine. Most Mercruiser's supposedly ran oil filled, external resisted coils for points systems, but when they came out with the HEI ignition systems, epoxy filling was necessary because of the higher voltage (40,000 volts), and cooling requirements. Epoxy filling was also recommended for any application involving high vibration. Draw what conclusions you may from all of this, but I think with what's been stated in these posts, plus this new info, would indicate it's OK to run a NAPA Echlin IC12 coil (thats the number the local NAPA store determined using the Mercruiser application) for Mercruisers with points type ignitions. Loads of thanks for all your help!

 

[KaGee]

Re: Marine Coils VS Automotive Coils

Hmmmm.... for all the worry about vibration... checked out the city streets lately?? Rattles your cage every time you go to the store or an errand.<br /><br />Grayhorse, your friends explanation makes perfect sense to me. The epoxy is more for electrical insulation.<br /><br />I believe the IC-12 is the same coil in my boat.

 

[doczenith1]

Re: Marine Coils VS Automotive Coils

On the vibration issue...I definitely think that the coil attached to my boat engine vibrates way more than the coil that was attached to the inner fender of my '78 Fairmont.

 

[Uncle Dave]

Re: Marine Coils VS Automotive Coils

Now now lets not get too high on this marine enviroment thing.<br />My truck motor run in dust (dirt road).<br />My boat motor run is water filtered air. (lake)<br /><br />My truck motor run in muddy splashes<br />Boat motor has no mud unless shallow water<br /><br />My truck motor get wet (throughly) when driving in the rain.<br />Boat motor stay dry for the most part.<br /><br />My truck realy vibs on the washboard dirt road.<br />Boat slides along on a cushion of water<br /><br />I believe this marine vs truck thing need a bit more investigation.<br /><br />Actually I think I will swap the boat and truck motors.<br /><br />Uncle Dave

 

[Olds Eddie]

Re: Marine Coils VS Automotive Coils

The vibrations that kill components are high frequency. If you mount the coil to the transom as opposed to engine mounting it would not be subjected to as much H/F vibes. Ask any Harley rider with solid mounted motor about this and you will hear about short bulb life and constant failures of electrical components. Are the factory installed oil filled coils mounted to the engine?

 

[fordworker]

Re: Marine Coils VS Automotive Coils

Really, a coil is a coil. as long as the rating is the same. Vibration not an issue. people have been comparing cars and trucks and talking about hf vibes. Coils come in regular and high performance versions. perhaps a high performance coil will work better and last longer, if you feel it is worth the extra dollars. consider lawn tractors. that would be a better comparison. the coil is mounted right to the engine. the engines run near full throttle all or the time, just like a boat. they pick up extra vibration from the mower deck also. <br />Most "car type" boat engines can use auto parts with no problem. points, dist. cap, starters, alternators, even water pumps on many models.

 

[Uncle Dave]

Re: Marine Coils VS Automotive Coils

OE<br />Good point. My coil on my 140 is clamped directly to the engine block. Lots of vibes and HEAT there. Perhaps an insulating type mount could be fabricated.<br />The coil probably needs to be electricaly grounded to the block. So in addition use a grounding strap that can take the constant flexing. Braided copper straps are obtainable at most part stores.<br />Uncle Dave

 

[DJ]

Re: Marine Coils VS Automotive Coils

Many marine coils have ballast resistors built in. The ballastic resistor reduces the voltage (to the coil) down to about 9.5.<br /><br />Running 12 volts, to many coils, will overheat them in a hurry.

 

[KaGee]

Re: Marine Coils VS Automotive Coils

OK guys, this is going nowhere fast. In the scheme of things, it's all about nothing. Coils are not a big source of failure. Read the threads here. If you need a coil, an "automotive" replacement from NAPA is a safe and acceptable substitute.<br /><br />And FordWorker... automotive alternators???? I don't think so!

 

[rbezdon]

Re: Marine Coils VS Automotive Coils

If fordworker going to use the auto alternator, starter etc, he is going to be SORRY one of these days. The problem is they will work, (perform the function of starting, charging etc) BUT they will void the boat insurence if something happened and the owner would be liable for all damages because it is not SAFE to use them.

 

[prockvoan]

Re: Marine Coils VS Automotive Coils

Most "car type" boat engines can use auto parts with no problem. points, dist. cap, starters, alternators, even water pumps on many models. [/QB][/quote]<br /><br /><br />If you start using auto parts in a boat,I don't want to be around when you blow up your boat!