[CtG]

So checked compression on the front 3 cylinders on the left side of the engine (drivers side)
I used a home-made adapter built out of a grease-gun's 12" whip with 1/8" NPT adapters into my fitting for the gauge.

300, 298, 302.

Any thoughts on if my cobbled adapter might be giving me these low readings, or if I need a short block :doh:

 

[Arisley]

I would not trust the connector. Put a teaspoon of oil or so in the cylinder. Put your connector on there. Bar the motor over, check for a leaky connector.

 

[icanski2]

Get one of these. Star Products TU-15-22A Compression Tester - Compression / Press Test

 

[vapstroke]

Use a good compression gauge make sure your battery's are fully charged hook up a charger while your doing the test. Remove all 8 glow plugs prior to testing. Allow each cylinder to go through 4 compression strokes. You should build the majority of your compression on the first stroke and it will level off through the other 3 strokes.

 

[Jeremy]

That may not be that bad, the compression numbers very alot depending on your elevation.

So checked compression on the front 3 cylinders on the left side of the engine (drivers side)
I used a home-made adapter built out of a grease-gun's 12" whip with 1/8" NPT adapters into my fitting for the gauge.

300, 298, 302.

Any thoughts on if my cobbled adapter might be giving me these low readings, or if I need a short block :doh:

 

[CtG]

6000 feet.

 

[Jeremy]

your fine....Thats a pretty good number for 6000ft, how many miles? You may have another cyl thats low, have you tested the rest yet?

 

[oldwood]

Thats a good price on that adapter as I just paid 46.34 for the same adapter, that included shipping from Network Tool Warehouse. It looks like the got to me for 6.00-7.00. It hooks right into my Ford Rotunda CT.

 

[CtG]

No, I have to move it again. Every time I start the thing in the last few days I get nervous... Don't want tens of thousands of RPM's to turn into pieces flying.
Sigh....
Guess I need to take off the pass valve cover too.

148,457.

I may go to Parker Store and see if they have an adapter that'll fit. Or what they'd charge to make me a 6" whip with the glow plug fitting on one side and 1/8" NPT female on the other.

 

[Tom S]

No, I have to move it again. Every time I start the thing in the last few days I get nervous... Don't want tens of thousands of RPM's to turn into pieces flying.
Sigh....
Guess I need to take off the pass valve cover too.

148,457.

I may go to Parker Store and see if they have an adapter that'll fit. Or what they'd charge to make me a 6" whip with the glow plug fitting on one side and 1/8" NPT female on the other.

If you figure out that one post it up.

 

[CtG]

Still done with my cheater adapter, however....
With the engine warm, definitely not hot.

1-298, 2-302, 3-298, 4-298, 5-300, 6-300, 7-302, 8-298

So unless my fitting is hitting ~300 and bleeding down, masking a lower cylinder thats "lower" figure is still above 300, then I'd say they are all pretty stinkin even.
After I get the right threaded fitting, be that make, borrow, or buy, I'll check them again.

 

[Arisley]

Still done with my cheater adapter, however....
With the engine warm, definitely not hot.

1-298, 2-302, 3-298, 4-298, 5-300, 6-300, 7-302, 8-298

So unless my fitting is hitting ~300 and bleeding down, masking a lower cylinder thats "lower" figure is still above 300, then I'd say they are all pretty stinkin even.
After I get the right threaded fitting, be that make, borrow, or buy, I'll check them again.

Those numbers look low. But like you say, they are all consistant.

 

[Jeremy]

I found this on the diesel stop from Tom S. in Colorado....

----------------------------------

There are some variables that affect the readings obtained from compression testing. They are cranking speed, altitude, temperature, worn camshaft lobes and high-performance, long-duration profile camshafts. The cranking speed needs to be maintained the same for each cylinder. This may mean jumping your battery to maintain the speed. There are factors to compensate for the different altitudes and the corresponding temperature differences. These are as follows: 1,000 feet = .9711, 2,000 feet = .9428, 3,000 feet = .9151, 4,000 feet = .8881, 5,000 feet = .8617, 6,000 feet = .8359, 7,000 feet = .8106, 8,000 feet = .7860. The equivalent compression reading for a cylinder that should be 135 psi by the data at 5,000 feet would be 135 x .8617 = 116.33.

----------------------------------


So your 302 psi is actually 361 psi, and the 298 psi is 356 psi.

 

[icanski2]

I found this on the diesel stop from Tom S. in Colorado....

----------------------------------

There are some variables that affect the readings obtained from compression testing. They are cranking speed, altitude, temperature, worn camshaft lobes and high-performance, long-duration profile camshafts. The cranking speed needs to be maintained the same for each cylinder. This may mean jumping your battery to maintain the speed. There are factors to compensate for the different altitudes and the corresponding temperature differences. These are as follows: 1,000 feet = .9711, 2,000 feet = .9428, 3,000 feet = .9151, 4,000 feet = .8881, 5,000 feet = .8617, 6,000 feet = .8359, 7,000 feet = .8106, 8,000 feet = .7860. The equivalent compression reading for a cylinder that should be 135 psi by the data at 5,000 feet would be 135 x .8617 = 116.33.

----------------------------------


So your 302 psi is actually 361 psi, and the 298 psi is 356 psi.

:whs:
I was trying to find those correction factors myself but ended up having to do some actual work instead.

 

[Tom S]

I think I found that information doing a internet seach. Good work finding that old post.

 

[CtG]

Couldn't get a whip made, but I picked up an M10x1.0 O-Ring boss male to 1/8"NPT female adapter.... Will be checking to see if it clears here soon.
$12 for that. About $5 for the grease whip (I had a spare, so no money spent this round) and a few bucks for the 1/8"NPT barrel connector. So a bit cheaper than the MityVac one, moreso considering the about $7 shipping they wanted.
If it works, I'll toss the adapters part number up (Bought at Parker Store)

 

[CSIPSD]

let us know! I have the cheap Harbor freight kit that has every adapter but the powerstroke one???

 

[CtG]

Use a 12" grease fitting whip. 1/8" NPT both ends.
A 1/8" NPT barrel connector (female both sides)
The Harbor Freight diesel compression tester kit (it has a short 1/8" NPT fitting)
And Parker Store part No. M10-1/8F8OHGS

Works pretty derned well.
M10x1.0 is the pitch, you can take the washer off the o-ring or leave it. Either way.

Same 302PSI.

So I guess I'm right around 350 at sea level...

 

[icanski2]

Use a 12" grease fitting whip. 1/8" NPT both ends.
A 1/8" NPT barrel connector (female both sides)
The Harbor Freight diesel compression tester kit (it has a short 1/8" NPT fitting)
And Parker Store part No. M10-1/8F8OHGS

Works pretty derned well.
M10x1.0 is the pitch, you can take the washer off the o-ring or leave it. Either way.

Same 302PSI.

So I guess I'm right around 350 at sea level...

I tested mine last year with around 190k miles on it and the cylinder compression readings ranged from 380 - 430 psi. The cylinder leakdown test readings ranged from 16-24%. (That test is a pain in the rear to do by yourself) There was no correlation between compression reading and leak down reading on each cylinder.