Compression too low?

[6 Nebraska IDIs]

Ok this is not really a serious question, more of a venting of depression. My dad bought a motor for his 94 CC project last year and we finally got around to working on it. The motor looked great from what we could tell looked like it had been serviced very well. But I guess I was wrong. I did a compression test on it before installing it into the truck and here's what I got.
1. 115
2. 220
3. 275
4. 90
5. 75
6. 65
7. 45
8. 40

In your opinion, is that too low of compression to fire diesel properly?

 

[Shadetreemechanic]

Squirt some pb blaster down the glowplug holes (alot), and try it again in a couple of days.
It will be better.

 

[fx4wannabe]

How are you checking the compression if its not in a truck? If you aren't spinning it fast enough it won't have a true reading.

 

[GOOSE]

How in the H E double hockey sticks can compression numbers get that low. Look at the pics in my attached thread. I still had 240 or so psi's on that cracked cyllinder. It would leak antifreeze and hydrolock the motor. Amazingly enough it was still in specs for compression. Are you sure the gauge is correct? I am sorry to hear this if they are accurate numbers.

http://www.oilburners.net/forums/showthread.php?t=39283

 

[RLDSL]

If it was bought last year, the rings may be stuck from sitting. If you can get a closed loop for the cooling system ( a large bicycle or small motorcycle inner tube works for this across the rad fittings and a bike tube across the heater fittings , fill with water ) plug in the block heater and jump the glow plugs and try to fire the thing and run it for a few minutes at a time to loosen it up, then try taking those reading again with the engine warm after oil has circulated and see what happens.

 

[david85]

How are you checking the compression if its not in a truck? If you aren't spinning it fast enough it won't have a true reading.

The adaptor plate (some times also called a "starter ring") bolts directly to the engine with 2 bolts at the top of the block and this is what the starter bolts to. Hot wire power to the starter and it will spin the engine over.

I assume the standard way is to use the starter....

 

[fx4wannabe]

The adaptor plate (some times also called a "starter ring") bolts directly to the engine with 2 bolts at the top of the block and this is what the starter bolts to. Hot wire power to the starter and it will spin the engine over.

I assume the standard way is to use the starter....

Never though of doing it that way. I got one I want to check before I tear into it.

 

[icanfixall]

Numbers 3 & 4 cylinders may create enough heat for combustion but the rest of the cylinders wont. Those numbers are terrible even for a gasser. Somehow the rings are stuck and not sealing. Theres no way a motor like that could have been a runner before you bought it. If you squirt anything into the cylinders be careful. Whatever goes in will act like fuel so it will burn and start the motor. Also you could hydrolock the motor if more than about 1 oz in poured in thru a glow plug hole. When you try to turn over the motor after the "fluid" is in leave out the plugs and just crank till you feel the starter is getting warm. Stop and let it cool down and do it again. Watch for fluids to be pumping out of the glow plug holes and very high volosity.