Thank you Jones, I will do new testing g as mentioned.
As an update, I did compression tests today both wet and dry using the injector ports doing each port 2x for both tests. I plugged in the block heater for about 2 hours prior to testing with the shop temp around 50. I also verified all electrical connections were good and clean. Additionally, I verified that the glow plugs were working, watching them through the injector ports. The #2 port seemed to always have some smoke coming from it throughout the tests while the others had none. For the WET test I put about 1tsp of engine oil in the port taking both tests without inducing additional oil. I also took pics of the ports with the glow plugs energized and off, pics of the injectors and a quick video trying to start the tractor.
When turning over after the glow plugs had been energized for 30 sec I noticed a clunking noise that wasn't there before. On the second attempt to start and to identify the location of the knocking noise, the starter went out. I have since ordered a new one that will arrive on Thursday. After installation I will post the response from the tractor.
Here were my results for the compression tests ....
#1: DRY 250psi & 250psi
WET 300psi & 295psi
Glow Plug 10.8 volts
#2: DRY 210 psi & 240psi
WET 260psi & 270psi
Glow Plug 10.8 volts
#3: DRY 340psi & 345psi
WET 350psi & 350psi
Glow Plug 10.11 volts
I appreciate your information and advice, I will post an update after the new starter is in.
What is your nominal compression ratio? What altitude are you located at because barometric pressure (p1) plays a role in the final answer. The equation I use for determining compression pressure is:
Compression pressure calculation:
Engine compression ratio is actually a volume ratio not a pressure ratio. The equation I use to calculate the compression pressure is based on the isentropic equation pV^gamma=Constant (
eqn 1) where p is the pressure, V is the volume and gamma is the ratio of specific heats of air.
Sparing you all the gory details, the equation for what you see on a compression gauge;
delta p = p1 x [(compression ratio)^gamma -1],
(eqn 2)
where p1 is atmospheric pressure, gamma is 1.4 and delta p is the compression gauge pressure
Now the isentropic equation assumes constant mass in the cylinder but because of valve timing the mass in the real engine is not constant. And gamma isn't a constant either so K is a constant that adjusts the theoretical value of compression gauge pressure to account for this.
Eqn 2 then becomes delta p = K x p1 x [(compression ratio)^gamma -1]
(eqn 3)
Assuminsg gamma =1.4. From experience K is between 0.70 and 0.75.
So a compression ratio 6.0 engine would have compression gauge pressure at an atmospheric pressure of 14.7 psia would be 124.6 psig (K=0.75). This is what you could expect as a maximum for a engine in good mechanical condition.
In your case your engine has much higher CR than the gas engine data show above. The CR could be anywhere from 17 to 23. At CR =17 and p1 =14.7 psia, K=0.70, delta
p = 533 psig. At CR=23, delta p=814 psig. You need compression pressures in the range of 400 +/- 25 psig and you only have one cylinder close to that.
Based on these numbers and your measurements i would conclude that your rings are severely worn and quite possibly your valves might also be leaking. I would remove the cylinder head and have it checked for burned and/or leaking valves, flatness,etc and re-ring the pistons or replace the pistons and liners as the case may be. Since the pressures between adjacent cylinders are also down, I'd also suspect a blown head gasket.
