Hugh, you may find this interesting, the Taipan plugs I have come with aluminum washers. I do not know the reason but they work great.

I would just use the plugs as they are, as long as there are no burrs on, and they go in easily or even snugly.  If there is binding, then a  cleanup with a die carefully adjusted may be in order.  Slop in the threads is definately not good.   I didn't know that Taipan even made plugs.  Are they any good?  I have one of their motors and it is great.  Aluminum washers should be fine, they may not last as long as copper, but are disposable anyway.  I suppose the expansion would be more even or more similar than copper or????  It wouldn't be any worse anyway, and would be less expensive to make.

Micro fasterners sells the tap,die and drill bit. Costs are $9.55,$5.05 and $1.45. These guys are my priority go to place for all stuff with screws. Not an add but an endorsement (non Compensated)

www.microfasteners.com



Dennis

The TAIPAN plugs are very good and are color coded so you don't lose track of which is which after removing from the package. The one at the 10:00 position is the 4c, it's very good.

hobbsy - where do you get the Taipan plugs?

http://www.hobbycentre.com.au/TAIPAN07.html
http://www.hobbycentre.com.au/index.html Here is Dave's whole site

Clarence Lee. You are kidding, right?

>>> My point was that "cleaning up" the threads on a conventional glowplug is going to lose rpm >>>

Oh my, they have medicine for people like that! ha, just kidding.

Not to worry, the die doesn't pull "substantial" material off of the rolled threads. The rolled threads are not that bad. It just takes a few imperfections or high spots off that would become the troublesome spots that could weld to the aluminum in the head under heat and pressure.

Thanks,

Ernie Misner

Yes, others have used the aluminum washers, can't remember who. Maybe K&B.

Enya makes a nice 4C plug now as well as their 3,4,5,6.