How do you compression test a multifuel engine?

[houdel]

How can I do a compression test on a deuce multifuel engine? I realize of course the first step is to pull out all the injectors. But what then?

I've done this many times in gas engines with a compression tester with a rubber tip that you jam in the spark plug opening while cranking the engine, but I doubt this would work on a diesel.

Is there a specific guage that will clamp in the injector port? If so, where can they be found?

Also, what is the acceptable compression pressure for a good running, used multifuel engine?

 

[red devils dude]

the gauge adapter for the engine is the tricky part the injector is sort of a one off design
first you would need the injector's spec's then a OTC(or similar) dealer could match it to the right adapter.

 

[Gatnom]

I have not done the MF, but I've always been able to get old injectors from a test shop, modify as needed, tig on a pipe nipple, etc. to get connected to the pressure gauge. Not sure where to come by a junk injector for these engines on short notice, but I'll bet there are plenty out there somewhere........ Dave

 

[SixBuy]

I'm in the process of doing that right now and here's what I've found:

You can buy new diesel compression gauges direct from tool companies cheaper than the 'deals' on ebay and a whole lot less hassle!

I just got a TU-15P compression gauge only (no case) and a TU-15-11A adapter (American Bosch) from Tooldiscounters.com for 30.95 and 33.82 respectively, plus about $10 shipping. New with guarantee, Made in USA by Star/Hoffmann.
The adapter comes with a screw on boltpate to span the holes that bolt the injector in. You'll need to pick up a couple of 1 1/2" 5/16-18 bolts and washers to use with it. Get grade 8 to avoid disappointment!
Use the longer of the two adapters that screw on the body. If you're checking compression with the valve cover on, you'll need something on the bottom end to make the seal and raise the adapter ehough to clear the valve cover. I used a 3/8" long piece of fuel hose the fit snugly on the tip and was slightly less od than the body of the adapter (about 21 mm). Worked well.
The adapter can also be used for cylinder leakdown testing by removing the scrader valve in the quick connect plug. I got a cyl leakdown set and adapter hose but haven't been able to manually turn the engine to TDC for the test. If anybody has a simple solution I'd like to know.
The book says 525 psi on compression. I got everywhere from 490 to 520. It usually took 4 to 8 cycles to max out the gauge. Anybody had similar results?

 

[houdel]

Harley - can you come up with a good web site address for tooldiscounters? I tried www.tooldiscounters.com and all I got was "Page not Found"! Thanks, Lee

 

[SixBuy]

Lee,
Sorry 'bout that - It's "www.tooldiscounter.com" (No 's'). Just checked it, works fine. Of course you can also google on discount tools and maybe find a better deal...
I was hoping some others would chime in with their experiences but apparently there's not much interest here.

Let me know how it works for you.

 

[red devils dude]

most of the members just find take out engine's and put them in I think there been like 5 guys that
rebuilt there engine's so there's not much testing going on either.

 

[SixBuy]

Heard that! I've got what appears to be a good engine, just needs a 'tune-up'. Figured compression was the place to start. With good oil pressure and good compression you've got something to work with....

 

[Recovry4x4]

Hey gang, heed this warning. Get a spare engine and sit on it. There are tons of folks just swapping out engines and scrapping the old ones. One would do good to acquire one or two extra engines for possible future rebuilds. One day the engine supply will dry up. My goal is to have 2 enignes in cans to rebuild or just keep.

 

[red devils dude]

kenny
I'm looking but I got a bunch of spare for the engine(crank,rod's etc) so as long as my block's good I'm all set.