Homebrew pop test fixture

[3500GMC]

Decided to fab a cool little (and very effective) pop tester. 0-3000 psi. Good for the 6.2/6.5 IDI diesels. I suppose all other IDI mechanical diesels would apply. Had a bottle jack just setting not used. Whatthehell.... The only money I spent was on the huge guage. I have a lathe and a mill... that helps.:reddevil:

I have some very cruddy injectors that need a good cleaning. Maybe new nozzles. I was surprised how much ULSD would fog from the business end of the injector. Some good, some bad. Some would leak until pop was reached then just squirt a stream.... not good.

Shims are the next thing. I bought a roll of .003" shim stock. I am in the process of making a stamping die for custom shims. (11mm dia.) Rebuilding injectors is not that complicated if you are resourceful.

The gauge is the absolute heart of the fixture. An actual test instrument from a nuclear plant in Oregon that was decommissioned. (yes really) It was a surplus NIB piece that was auctioned on Ebay. The retail on this beast is rather spendy. But one can still find deals on ebay.

 

[ak diesel driver]

got any pics that show how it's all attached?

 

[3500GMC]

Better pics should help. Click on pic.
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..
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[ak diesel driver]

thanks

 

[3500GMC]

Made pretty much everything, including the injector fitting. The feed line is just 3/16" brake line cut to the EXACT length as OEM. The other end is just the standard 3/16 inverted flare to a 1/8 NPT brass fitting. This is so I can fab another line easily if I want to do a different mechanical IDI injector. OR if I F up the line somehow.

The custom fitting was brazed to the 3/16" line after the custom injector nut (14mm x 1.5) was made.

 

[Matt Bachand]

Very nice! LOL what a huge gauge is right!

ITs so damn big I didn't even recognize the bottle jack! Looked like all little parts!

 

[3500GMC]

Thank you sir. Yeah I wanted a gauge I could see the increments clearly. The gauge I feel is the heart of the whole pressure matching operation.

I just finished up making some .003" shims from a roll of shim steel for matching the injectors. Used a shim punch. 11mm or 7/16" thereabouts.

 

[bk95td]

Is the resevoir from a hydraulic clutch ?

 

[davo727]

Looks to me like its from a gravity feed touch up spray gun

Is the resevoir from a hydraulic clutch ?

 

[3500GMC]

Ding ding ding. Correct. I was in need of a better cup for my little HVLP gun so this is where the old one ended up. I tapped it 1/8 NPT on up inside past the original threads.

 

[TurboTahoe]

The gauge is the absolute heart of the fixture. An actual test instrument from a nuclear plant in Oregon that was decommissioned. (yes really) It was a surplus NIB piece that was auctioned on Ebay. The retail on this beast is rather spendy. But one can still find deals on ebay.

Pray tell, how much for the gauge?

-Rob

 

[3500GMC]

Ebay buy it now, $40. $54.49 to my door.

 

[EchoEagle]

Brilliant!

 

[JiFaire]

Very nice!

 

[Samyguy]

how are the .003 shims working out???

 

[3500GMC]

Thanks for the nice comments gentlemen.

The shims are the same dia. as OEM, so when I finally get to use them, it will be interesting how much pop pressure will vary when adding, subtracting .003" at a time. My supplier has .0015" in stock also.

I am wanting to do tests with the injector at elevated temperatures. Say 150 to 200 degrees F.

I've some other 'projects' in the way right now, but I will get there.

Oh and a tip: Don't use #1 permatex as thread sealant... When diesel comes in contact at 2000psi, it turns to brown liquid and will leak like a sieve...:rolleyes5::mad2: I ended up using good ol' teflon tape and cranked the shit out of the connections.

 

[ak diesel driver]

got any pics of the shim punch you made?

 

[3500GMC]

I actually used a shim punch die set.. Initailly I wasn't sure if a 7/16" dia would work- which my die set is for std. sizes.. There are metric shim punches available too, just don't have one. There is room in the injector for using a slightly larger or smaller dia shim. (by a few thousandths)

If you are worried about the hardness of the shim you could use blue-tempered or stainless..

It would be easier to source a ready-made shim assortment though...

 

[bison]

Nice job on the tester.
But you should put a needle valve between the jack and the T so you can hold the pumped up pressure just to the gauge and injector to be able to do a leak down test( just under pop pressure)

 

[3500GMC]

I can do that, yeah...

I am using a liquid filled guage, so it's a little easier on the eyes now.