Why not put a Petronix conversion on a 3.7 Mercruiser??

[bowhuntrrl]

I'd like to put one of these electronic ignition kits on my 190 hp 3.7 liter. However, most places that sell these seem to have a mention of "not reccomended for 3.7 engines". Does anyone know why you shouldn't use one of these on a 3.7??? Thanks<br /><br />Rich

 

[denniz]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

I have a petronix conversion in a 68 amx 390. I have no idea why they would not recommend it for that engine. Have you tried emailing them to find out?

 

[Bondo]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

Most of the kits I see are for the Chevy Dist....<br />Do they make 1 to fit the 470 dist. ????<br />My Guess is, If they Don't make it, You Can't use it....

 

[MrBill]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

I have been told from a somewhat reliable source, but have not been able to confirm, that the reason is related to the difference in charging system (stator, etc.). I will attempt to confirm, if others know the answer I'd also be interested.

 

[bowhuntrrl]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

I called Pertronix this morning and spoke with their tech support. According to them, there is no reason that it can't be used with a 3.7 !!! The application is purely a matter of physically fitting in the distributor. He also said that they work with Mercruiser's shift interuptor. If you are running these on an old OMC Stringer drive, then some extra wiring(resistors) need to be added, but Mercruiser is ok. He also said that if anyone has any specific reasons, he would love to discuss them. Sounds like it should be ok from what I can determine. The Pertronix application number is 1146A.Here is a disributor for their products that they reccomended to me since I'm in Massachusetts. http://www.vintageperformance.com/retrorockets/mercruis.htm This listing on their site includes 3.7 (470) engines. I guess this should dispell any rumours or myths about this.<br /><br />Rich

 

[philtheskipper]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

I bought my petronix module from that distributor and I was very pleased. They answer any questions you may have and ship very fast. Get it!

 

[Magnum P.I.]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

I put a Pertronix in my 59 Ford Skyliner, Totally changed it's personality, no more pinging, lights right off and on cheap pump gas. I'll try it on my 3.7 when I get it.

 

[beckerdg]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

If you find a reason let me know. But I doubt I will take it out. I have a pertronix ignition in a 86 mcm170 with the standard stator charging system. I also swapped the coil with a 3ohm higher energy model and removed the resistor wire. Runs great. I would caution against buying the Ignitor I model. It will self destruct if you leave the ignition on without running the engine. (personal experience) Get the Ignitor II model.

 

[cobra 3.0]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

How much does the Pertronix Igniter II go for?

 

[merc 140 pontoon]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

Make sure you follow the installation directions carefully. A mechanic installed my Pertronix Ignitor incorrectly. If you have a ballast resistor, or a resistance cable in the harness, the positive lead that feeds the Ignitor needs to tap in before the external resistor, not just be put on the coil positive post. When my harness resistance cable began deteriorating (increased resistance with heat), this caused huge problems--the voltage at the coil positive post would drop below 7.5V, and the Ignitor would shut down, killing the engine. The whole thing became difficult for me to troubleshoot, but I eventually got it straightened out. Other than the bad installation job by the mechanic, I've been very happy with the Ignitor. With the Ignitor II, I believe you don't have to worry about burning out the unit if the key is left in the "run" position with the engine not running.<br /><br />Steve

 

[MrBill]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

The conversion kit that I was considering was offered by marinenegineparts.com. Their Electronic Ignition Conversion Kit - 18-5297 indicates that it is not recommended for the 3.7, but it is suppose to be ok for GM Delco ignitions. I inquiried why the kit bears the warning "Not Recommended for Mercruiser 3.7L-470/485". The company responded with the following message...<br />"Good question. It might be overly conservative on our part becasuse a couple kits that we sold for that applicaction did not work well, it could have been other problems that the customer had or it could be something unrelated. So we put that warning in there, I have sold others to people with that same application and they said they had no problem, so it ia a little bit o a gamble, but it might be worth it to buy one."<br /><br />This statement came directly from marinenegine parts.com.<br /><br />My question now is...is the above kit the same Petronix one referenced by others?

 

[JasonB]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

I also installed an Ignitor II on my 302 Ford Mercruiser with a prestolite disto. Along with it, I tossed in a new Pertronix coil and a set of MagStar marine wires. What a difference. Idle is smoother, starting is better, and throttle response seems better. Granted, the coil and wires I replaced wee original 1976 issue.<br /><br />I bought from Vintage Performance and was very pleased with their service. The ignitors run about $70, the Ignitor II is about $100 and the marine grade coil was ~$35.<br /><br />As mentioned above, I also recommend the Ignitor II for the auto protection circuit that protects the unit if the key is left on.<br /><br />MrBill, I have suspected for a while on whether the kits offered by some companies were rebadged Pertronix boxes.

 

[Boomyal]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

JasonB<br />Do you have a url for 'vintage performance'? I did a google on it but did not come up with one. $70 seems a good price for the pertronix.<br />thanks

 

[JasonB]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

It's listed above, but here's a link to their Pertronix page: http://www.vintageperformance.com/retrorockets/

 

[Boomyal]

Re: Why not put a Petronix conversion on a 3.7 Mercruiser??

oops! Thanx