Spark Plug Questions

[srf471]

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I did a forum search looking for these answers, but to no avail.
I have a C85-12 in my L2M. I am looking to replace the spark plugs, which are currently Champion REM40E's. I have a friend with the same motor in a Champ and he switched to REM37E's a while back and recommends them because he feels they don't foul as much as the 40E's. What is the feeling of the group here???? What plugs are you guys using??? Also, what gap do you recommend? Thanks in advance.

Nick Preble
N58075
N471F

[dewhitaker]

Re: Spark Plug Questions

The following link will take you to TCM website. Look for Service Letter SIL03-2B. It is a listing of approved spark plugs.

http://www.tcmlink.com/serviceBulletins/index.cfm

I am leaning towards changing over to shielded mags by Slick, and I will probably use UREM37BY. They are about 3/8 inch shorter than standard plugs. In addition, according to Autolite Unison website, they were designed to have less problems with lead fouling.

Hope this helps. If anyone else has any thoughts on this, or has experience with this set up, please let me know how it worked out.

[Jim Herpst]

Re: Spark Plug Questions

You Say these plugs for the Slich shielded are shorter than "standard". Do they require the "cups" on top of the cowling ? Can one get shielded plugs now for a C-85 that do not require the "cups"

[dewhitaker]

Re: Spark Plug Questions

Hi Jim, thats the big question I am trying to determine. Here is the link to the Unison press release where I got my information.

http://www.unisonindustries.com/news/press_releases2001/press_shorter_autolite0405.html

The wording of this release talks about Lycoming engines, but as noted in the TCM Service letter, this plug is approved also for the Continental.

I do not want to use the cowl bumps on my 1941 with the A-65 engine. I believe some of the Aeronca people have been able to do this according to some of their postings on their forum.

I am going to try to get some accurate measurements of the space under the cowl on mine to determine if this is feasable. Sure hope so!

[mhorowit]

Re: Spark Plug Questions

I tried the standard shielded plugs on the bottom and short shielded plugs on top. The short shielded plugs were not short enough to allow a smooth bend of the shielded harness. I had a sharp bend and the insulation rubbed off from rubbing against the cowling. Forrest said there was sufficient variation between a/c that you won't know for sure if short plugs will work until you try them. - Mike

[dewhitaker]

Re: Spark Plug Questions

Thanks Mike, thats the "hands on" information I was looking for. I suspected that might be the case. Harry Fenton put a posting on the Aeronca mail forum describing that very issue. His fix is to use plastic spiral wrap from the auto parts store and wrap the wire where it touches the cowling, for extra protection. It would really be great if Unison or someone could manufacture a 90 degree connection to use on those front two plug wires. Then again there is always the Ercoupe shielded cup method.

[mhorowit]

Re: Spark Plug Questions

There is always the DIY cans that were published in the Newsletter. - Mike

[M Towsley]

Re: Spark Plug Questions

Mine has the shorter plugs on the front with the plastic spiral wrap. However, there is still a need for two very small bumps on the cowl, which someone did a nice job of handmaking on my airplane. There is no way you could use the shorter plug without some type of space underneath as it would crush the lead over with resulting damage, at least on my airplane. The plastic spiral wrap has a tendency to back itself off as there is not enough length there to make the bend at the top of the plug and stay put.

[Forrest Barber]

Re: Spark Plug Questions

In my opinion the 37 plug is too cold and will foul more; however maybe someone has experience that I do not know about! The 11AC guy here switched to the 37 shorter plug and it was shorting out to the cowl pluss missing at times from the colder plug range. I just do what the engine manufacturer says........

[mulwyk]

Re: Spark Plug Questions

DIY Cans? in the newsletter? Guess I missed that. I'd sure like to get away from those cowl bumps and keep the nice smooth original look. Is there a newsletter archive?

Bob Gustafson

[Hank Jarrett]

Re: Spark Plug Questions

We NEED a newsletter archive! I have a pretty complete set for the National and Virginia Carolinas clubs but don't have a scanner. There is a real wealth of information in them, especially the really OLD ones. Anyone in south east Virginia with a scanner want to spend a cold wet Saturday or Sunday together converting a bunch of old paper into electron streams?
Hank J

[mhorowit]

Re: Spark Plug Questions

We NEED a newsletter archive! I have a pretty complete set for the National and Virginia Carolinas clubs but don't have a scanner. There is a real wealth of information in them, especially the really OLD ones. Anyone in south east Virginia with a scanner want to spend a cold wet Saturday or Sunday together converting a bunch of old paper into electron streams?
Hank J

Hank - I have a flatbed scanner here. I'll scan anything you send up here - Mike (near DC)
PS- figure out if there are any copyright concerns.

[Jim Herpst]

Re: Spark Plug Questions

I have said it before and I will say it again. Check with Bruce Bixler before you do this with his stuff . I have the club newsletters since I joined in 1995 I really cherrish each one. Would I like to have the earlier ones? You BET. Would I pay for em YOU BET!!!! Bruce ???

[Hank Jarrett]

Re: Spark Plug Questions

Having talked to Bruce in the past I can't imagine there would be a problem but you are right. We SHOULD ask, and offer to make a donation for his (and his predicessors) work. Forrest... don't you see him fairly regular? I actually thought he read this list but haven't heard from him in a while.
If all concerned don't have a problem, I know Mike well enough to trust him with my precious (and going WAAAAAAY back) collection. When we get the "go" Mike H and I will work out the details. There are a few issues missing but SOMEBODY on the list should have some to fill the holes. I would LOVE to have them in PDF on a CD or DVD!

[AlvinMcIver]

Re: Spark Plug Questions

Hank and Mike,
I have a high speed scanner which can scan double sided documents turning them into pdf format. Take the staple out, load it, and push the button and before you can get the staple out of the next one, the first one is on its way via email as a pdf file. I'd be happy to scan and send via email to the two of you (once permission is obtained) for placement on cds if that would be of assistance. I have a cd burner, but I don't know how to use it with any certainty.
Alan