Any interest in Compression tester adapters for the MEP-802A and 803A?

[Ray70]

Hello guys, I was wondering if I could your feedback as to if any of you working on the DN2M DN4M LPW2 LPW4 motors would have any interest in a compression gage adapter for these motors?
I made 2 for myself and they helped out a lot on several machines, so I was wondering if anyone else might want one?
They are machined from solid steel bar stock and fit in place of the injector, using the original injector hold down clamp.
It has an o-ring built into tip to seal it against the head ( rather than the copper washer ) and ( the next one I make will have ) a schrader valve in the tip for more accurate readings with no pressure loss in the gage / hose system.
I can make them with either a 1/4 NPT ( to accept a quick connect fitting ) or 14mm spark plug thread ( your choice depending on your gage ) to attach your existing compression gage to it.
Considering the time it takes me to hand machine one, I'd anticipate needing to sell them for about $40-50, but if there is enough interest, maybe I could have a local shop machine them for me and probably cut the price in half?
I haven't seen an adapter for these motors available commercially, but if one already exists, please let me know and I'll just keep mine and turn off the lathe!

 

[Chainbreaker]

I wish someone would make a similar one for the MEP-002a/-003a. I would buy one for sure!

 

[Light in the Dark]

I don't need one, but thanks for offering up to the forum.

 

[Ray70]

Hey Chainbreaker, Its been a while since I worked on an 002 /003 but I know I have some new glow plugs left. I can take a look and see what would be involved in making an adapter to put in place of a glow plug and adapt it to a standard 14mm compression gage hose. I'll take a look at it and see what I can do...

 

[Chainbreaker]

There is a thread somewhere here where that has been done as a one-off item for a SS member by a machinist friend of his as I recall. I think there was even a dwg attached to the post showing how it was machined. I'll do some searching and see if I can resurrect it and link here.

 

[Chainbreaker]

Here is the post: https://www.steelsoldiers.com/showthread.php?83566-Compression-Testing-on-MEP-002A-003A

After re-reading that thread...the issues with using the GP hole is that you have to remove the intake manifold to take a reading from #2 cylinder (at least on the MEP-002a, not sure about -003a). The other issue is that often the copper washer gets stuck in the hole after removing the GP and is difficult to replace. I was hoping there was a way to use the Injector hole instead, because the injectors are easier to reach and less difficult to remove and probably easier to make an adapter for.

 

[Ray70]

Well, there's a couple ideas that come to mind. If the adapter was as short as possible and it had a right angle or 45 fitting on the end with an 1/8" grease gun hose leading out to the gage, do you think that would fit? I can't say myself because I don't have a machine to look at. Otherwise, if someone can measure an injector and show me what the business end and mounting would need to look like I can surely make something. Unfortunately without a machine to look at I can't do much to help design it....
As far as the copper washer, the glow plug looks like it seals with a tapered seat, is there supposed to be a copper washer in there too or are you confusing that with the injector?

 

[Chainbreaker]

Well, there's a couple ideas that come to mind. If the adapter was as short as possible and it had a right angle or 45 fitting on the end with an 1/8" grease gun hose leading out to the gage, do you think that would fit? I can't say myself because I don't have a machine to look at. Otherwise, if someone can measure an injector and show me what the business end and mounting would need to look like I can surely make something. Unfortunately without a machine to look at I can't do much to help design it....
As far as the copper washer, the glow plug looks like it seals with a tapered seat, is there supposed to be a copper washer in there too or are you confusing that with the injector?

Yes, the glow plug definitely uses a copper washer. The copper washer is sold flat and is deformed to fit the tapered seat of the GP when it is torqued down. That is what makes the copper GP washer so difficult to remove since it conforms to the taper and thus often gets stuck in place. I had to modify one of those paint can openers (J hook type) to be able to reach in to the GP hole and try to snag the deformed GP washer to get them out. Even with my Jerry rigged tool it was a bit difficult. So, that's I really don't want to remove good glow plugs to test compression.

I do have a new injector in my spares that I can measure (micrometer) and photograph as well. There may be some dimensional dwgs out there so I may try Googling around to see what pops up.

 

[Ray70]

Sounds good. if you can't find any dimensional drawings, just send me pics and dimensions of the injector you have. Also, let me know the approximate diameter of the center hole in the retainer plate that secures the injector into the head.