Model Spark Plugs

[Cheshire Steve]

I have a couple of IC models - (Westbury designs) that are part completed. They say to drill and tap 1/4" by 32tpi for spark plugs. Are these available ? One of them is already tapped with this thread but the previous owner didn't make a very good job of it - so I am wondering if there is a next size up spark plug.

So any info on what is available would be appreciated. Also any ideas on 'make you own' if this is an alternative.

Thanks, Steve

 

[joe d]

Steve

NGK ME 8 is threaded 1/4 -32, rimfire brand is as well. I got some from MJN, but I've heard that recently he's hard to get ahold of. I've seen instructions here and there on how to make them, doesn't seem all that complicated but I've not tried it yet. Of course, I can't recall where I saw this, but I'm sure somebody here will direct you (and me!)

Cheers, Joe

 

[stevehuckss396]

Yes they are out there.

First, there us Dale Detrich who makes them from scratch for 12 bucks a pop. They last for many years and perform very well. He will be at the NAMES show next week.

http://www.daledetrich.com/spark_plugs.htm

Second, there is a plug out there called a "Rimfire" for 17 bucks if you buy 4. I have no personal experiance with them so I cant comment on those.

http://www.jerry-howell.com/RF-Plugs.html

Third, you can make plugs your self. Many people do it. I made one with a 6-56 thread. I would post a picture but I cant find it.

 

[chuck foster]

you can go here for my write up on how i make plugs.

http://www.homemodelenginemachinist.com/index.php?topic=2054.0

chuck

 

[RobWilson]

Hi you could try NGK CM6 its the smallest plug they do.
Spark Plug Thread: M10
Thread Length: 6.5mm (bottom of washer to thread end)
Spark plug overall Hight:35.6mm
There about £4 each on Ebay

 

[Stan]

The NKG CM-6 is an off the shelf spark plug at a Honda dealer. Small engines, not motorcycles. They use it in one of their small engines.

 

[Cheshire Steve]

Wow, thanks guys.

Really impressed that Howell has long reach 1/4" by 32, Hemingway Models in the UK have short reach 1/4" by 32 at about $20. So it looks like we have a standard, and they are out there somewhere. They are so tiny that at least air freight won't cost much !

As for the M10 NGKs, that seems to be the next size up. Though it is quite a big step - and that seems to be it. Well at least that keeps it simple !

So if I have a 1/4 by 32 with a dodgy thread, then I am guessing a helicoil is not on, so a threaded insert would be the answer if needed - or a step up to M10.

And as for Chuck's help with making your own plugs - well that is probably not something I would go for as a first option as I already have a lot on my plate - but it is great to know, and would be the right way to go for true-to-scale models. Thanks.

Steve

 

[mu38&Bg#]

Recoil has 1/4"-32 helicoil kits. Helicoil does not, not that I found anyway.

 

[Cheshire Steve]

Helicoil at that size - I am amazed, thanks for the info.

Steve