auto plugs on Bendix mags

dennis mangan · #1 04-14-2009, 01:27 AM

Has or is anyone running automotive plugs on mags?
I have just converted my 6A 0320 -160 9 to 1 pistons,to NGK Br8es auto plugs ( 8 plugs)on bendix mags (have not started engine yet) and am wondering if anyone has tried the same, if so what gap and what heat range works the best?

Thanks Dennis

Norman CYYJ · #2 04-14-2009, 08:58 AM

A guy here at CYYJ uses auto plugs on Bendix mags in his RV-7 0-360 for the last 3 years and has no problems.

Ted RV8 · #3 04-14-2009, 10:15 AM

Don't know for sure but I think you would gap them the same as the gap used with massive electrode plugs.

I think the gap is determined by the voltage output of the ignition sysytem.

Just my nickels worth!

Ted

osxuser · #4 04-14-2009, 10:34 AM

Why would you even want to? What are you doing to ground the harness?

Jamie · #5 04-14-2009, 10:38 AM

Quote:

Originally Posted by osxuser

Why would you even want to? What are you doing to ground the harness?

This is my question too. The massive electrode plugs will last a long time if you take care of them.

sonny junell · #6 04-14-2009, 12:42 PM

There is an 8 on our field that is turbo-charged, and he run auto plugs and loves em, Cheap and better spark. You made a good decision.

Norman CYYJ · #7 04-14-2009, 12:50 PM

Regarding the harness, he made his own up using standard automotive ignition cable. No noise in the radio system either.

N208ET · #8 04-14-2009, 12:53 PM

I like the idea of running one set of auto plugs with my bendix mags on my 0-360. I am wondering which would be better, top or bottom, I am guessing bottom. Also, where does one get the harness for that.

Randy

dennis mangan · #9 04-14-2009, 08:25 PM

According to my mag guy he has several aircraft using mags and auto plugs
we have gapped NGK Br8es at .024 and are running these plugs on top and bottom. Bendix mags put a hot spark
Andy Richards my mag guy has worked on everything from p51's
to experimentals built my harness and it looks as good as any factory job.
Will fly on 8 automotive plugs tomorrow. too windy today.

Was hoping to hear that several RV's were doing the same. will keep all informed of progress

osxuser · #10 04-15-2009, 09:44 AM

Yeah, Andy's a good guy... I just don't agree at ALL with the use of auto plugs with mags. I've had the following issues:

1. Harness falls off the plug, typically on the bottom plugs
2. The screw on cap that the harness pops onto comes loose
3. Plug electrode aren't centered sufficiently to create a reliable spark (defective)
4. Heat range incorrect for application (this can be solved with research of course)
5. Radio interference (Seems to depend on a ton of factors)
6. Harness made for the mag comes apart at the mag side (It's a touchy setup at best on that side)

I've got a tad of experience doing this for the Forumla 1's and for RV's, and I'd say LEAVE IT ALONE! You won't save any money, I highly doubt you'll get a 'better' spark (more dependent on ignition system than plug), and you'll add quite a few more failure points to your system.

When I say you won save any money, it's because I've never heard of anyone running an auto plug for 1000+ hours, and the massive electrode Unison or Champions can do that easily if you rotate them every 50 hours.

If you have an EI system that already uses auto style harnesses, I can see justifying it, but converting a mag over isn't a good idea at all.