13B-T compression test adapter?

[RufusTheDufus]

I didn't get a response in the diesel forum so I figured I'd ask here. Anyone know of a source to buy/rent the adapter required to compression test the direct injected 13B (-T) engines?

Thanks.

 

[Malahki]

I had looked for one before unsuccessfully. It was suggested to me to make one out of a used injector

 

[RufusTheDufus]

I'd be happy to make one, but I don't have a spare injector. Maybe I should try to find one.

 

[Malahki]

Yup that was my next problem to

 

[Whistler74]

I don't have a complete answer for you but some time ago I was asking the same question. It was suggested that a cummins adapter could be made to work (sorry - don't remember the details). I did buy the adapter but haven't gotten around to pulling an injector to check.

I will try to do that asap and report back. It will require some fabrication work.

 

[RufusTheDufus]

I'll search for some photos of the Cummins adapter to see if I can make some sense out of it. I know there's a shop here locally that should have a Cummins adapter.

 

[RufusTheDufus]

I have a friend that owns a machine shop locally. He has a multi-head CNC lathe. I dropped off an injector and a sample of a Cummins adapter today. He's going to fabricate an adapter specifically for the 13B-T based on the dimensions of the stock fuel injector.

The adapter will have 1/8" NPT threads on the top of it to be able to hook it up to a compression tester. Might be a couple of weeks before I have a prototype. If there's interest I'll have him run a batch of 10 to 20 of them.

 

[Malahki]

Yup I'd take one if the price is right

 

[cruiserdan]

It would be handy to have one and put it away for a rainy day if the aqusition cost is right.

 

[RufusTheDufus]

The the estimate for the prototype is $200 which is an hour of design time, machine programming and materials (steel). Assuming the protoype works, we'll get an idea how long it will take to run the program to spit out a part I'll know what the manufacturing cost will be. I'd guess I should be able to sell them for $50, possibly less.

At the moment he's not sure if it's going to be a single-piece adapter matching the shape of an injector or if it will be two pieces, the part that inserts into the head and a clamp to hold it down.

 

[Behemoth60]

we'll get an idea how long it will take to run the program to spit out a part I'll know what the manufacturing cost will be. I'd guess I should be able to sell them for $50, possibly less.

I would also sign up for one of these if you are trying to plan a production run... I have two 13B'Ts with mystery compression and a uselss compression tester I cannot connect to the engine...

 

[Whistler74]

adapter I bought a while ago - sorry, I bought it from NAPA but have no part number to share. I think it would be easy enough to fabricate a hold down clamp, as long as the main dimensions are suitable.

I think it was around $20.

 

[dadio13]

I would take one of those as well

 

[RufusTheDufus]

Graeme - what held that adapter in place? Is there another part to it?

 

[Whistler74]

That is the complete adapter as delivered. My thought was to make a collar that would fit into one of the grooves and then drop over the studs that hold the injector. Bolt in place as if it were an injector and test away.

Can you measure the injector you pulled and compare dimensions?

 

[RufusTheDufus]

Sure, I can measure tomorrow.

 

[RufusTheDufus]

Here's the stock injector dimensions.

Diameters listed on the bottom, lengths on the top. The 75mm measurement is from the two surfaces that meet with the cylinder head.

 

[RufusTheDufus]

Have a prototype (finally)

I finally have a prototype in-hand. Tested it today. It works fine but I plan to change the design. There's a quarter inch hole drilled all the way through the center of the adapter. This volume is essentially added to the combustion chamber volume which will lower compression readings. You can see in the one photo that I have plugged the hole and plan to drill/tap it for a Schrader valve. The machinist says this design change will actually be easier to produce because the bit for the 1/8" NPT threads can be used for most of the length of the adapter.

 

[RufusTheDufus]

I have a finished design now.

 

[Malahki]

Nice work RufusTheDufus!!! I already added myself to the list in the merchandise link above but I just wanted to say here that it takes people like Rufus to step forward and invest their time and money to fill these voids in the market and they deserve our support. So don't wait until you need it to buy it or it might not be available. Also if anybody is considering buying a truck with a 13BT this little item is worth every penny and could save you a pile of money in the long run.