MEP-002a / 003a glow plug compression adapter?

[Isaac-1]

Does anyone know of a source for a glow plug compression test adapter for the MEP-002a / 003a generators? These glow plugs are threaded 7/16x20 unlike most glow plugs which have metric threads. I have seen mention that one of the members here was making these, but I don't know who or if they still are.

thanks Ike

 

[Jimc]

it was njtoolnut but i dont think he is here anymore. your prob better off getting a 7/16 bolt and drilling the center out and making something up yourself. if you do find a source let us know. that thread size seems to be very uncommon.

 

[Jimc]

isaac, im not sure what your compression tester is like but i went on the big auction site and typed in "7/16 20 adapter" and tons of fittings popped up. mostly going from 7/16-20 to a flare. maybe your hose on your tester could have a 3 or 4an fitting put on it.....might be easier than making something. just a thought.

 

[Isaac-1]

I thought of that too, but it looks like the threads on all of those are too short

See



p.s. my other thought is to possible remachine a 12mm glow plug adapter to 7/16x20

 

[Jimc]

Yes they are deep on the glow plug but the threads in the head go all the way to the outer edge

 

[johnray13]

I am not sure a drilled out bolt would work as I think the compression would leak out the threads. The 'seal' is made at the copper gasket, mid way up the plug.

I tried making an adapter out of a ORB 7/16x20 x 1/4 NPT hydraulic fitting and it sort of worked. By that I mean, the problem was the o ring was too distorted to reuse on the next cylinder so I had to put a new o ring on for each one.

The picture of your glow plug got me thinking that I might try drilling out a glow plug next time. Maybe cut of the element, drill a 1/8" hole through the body, cut the spade connector off and tap a 1/8" NPTF into the head.

When/if I have a plug go bad I will definitely try to convert the old plug into an adapter.

 

[johnray13]

Also, make sure your set up has a check valve. When I first made mine, I put the check valve at the gauge end. My compression was way low. I soon figured out to get a correct reading, your check valve needs to be just behind the GP adapter or the cubic inches of volume in the hose will give you faulty readings.