Hey fellas, how do you check the compression on a 3 cyl diesel? Special tool? Leak down procedure? Rent or make tooling? Thanks Tim
Ok, experts, here's my plan. Obtain an old injector body from local injector shop. Weld a threaded weld o let fitting on it. Use a 1ooo psi guage and crank engine and see how much she has and how long it takes to bleed back to zero. Sounds ok in therory and is doable. Any thoughts? Hoping for 350psi. Thanks Tim
Yes Tim, my Gramps and I did the same thing to check the compression of my old 67 Benz once. It should work fine. If you could incorporate a check valve, the gauge would hold the pressure long enough to read after the test.
Blake
Well, I got the old injector for a shop and modified it for a gauge, now the bad part, #1 120 psi #2 115psi #3 140psi . Motor needs a complete rebuild I would guess. Looking for a running motor. Tim
Tim, did you put any oil in the cylinders before you checked the compression?
What the oil because it may just land in the bowl of the piston and the compression will be more because the volume in the cylinder is less. I would make the leakdown test and see if the air blows in the pan, through the intake or out the muffler. By the way I used to have a home made tester for the pencil nozzles. It read lower than the regular adapter.
I didn't use any oil in the cylinders, just dry. I opened up[ the injector tip so as to get enough compression in the hose for the test. The first stroke on all the cyl netted 75 psi and built from there. I can pressurize the cyls and see where the air is going. Located a 3 cyl gas eng for 1200.00 exchange that is supposed to run good.Will look at it on Sunday.Still in crawler so I can operate it. Thanks for the replys fellows. Tim
Well, I went and looked at the gas engine and a diesel he had. The gas engine leaked oil out rear main seal like a sieve, but ran good for 1250.00. The diesel has a burnt valve, kinda has a sucking noise just off idle for 1850.00. I would have to pull either engine and then work on them. So, it's back to square one. I could probably rebuild mine for 1500.00 maybe. Tim