Static Compression PSI for 18:1 Piston Engines?

[robscarab]

Just curious about the readings other members are getting on thier rebuilt 18:1 engines? I did all 8 cylinders and got 360 to 365 cold and prior to putting any miles on it. The readings were taken on the 6th puff and it wasnt climbing after 5 puffs anyway. The first puff was about 250 psi on all cylinders. I plan on taking readings after the first 100 miles cold and warm just for reference purposes. (to see if I am getting better readings after the rings start to seat)

So is 360psi normal for a fresh 18:1 rebuild ?

[TAG]

I have been wondering about this also. I have about 30,000 miles on mine now and i have no way of knowing if i do in fact have an 18:1 motor. You pretty much have to take the sellers word for it & i did have a hassle when i bought mine. I had to return the first one i got because the navistar logo had been hand ground off the valley of the block. Never got any kind of an xplanation why. I just took the next one in line on the shipping container & never thought to ask if that one was marine. I could easily see the seller just saying take that one just to get rid of me. He totally could not understand why i wanted the navistar logo intact on the motor. If anyone can post some numbers it would be very helpful. I fully intend to check mine but it may be mid winter before time allows.

[john8662]

340-350psi is what mine was making.

J

[More Power]

I have about 30,000 miles on mine now and i have no way of knowing if i do in fact have an 18:1 motor.

How's it start cold (say 25 degrees F), and what are the glow cycle times?

If your 6.5 starts more or less like a typical 6.5 at 25 degrees with 6-8 second glow cycles, you have a stock CR (21.x:1). If it needs 12-14 seconds of glow time at those temps to start normally, you may have an 18:1. :)

Jim

[TAG]

Its hard to say because it has started poorly since the day the dealer installed an injection pump at 92,000 miles. It has 231,000 miles on it now. It always starts, just not immediately when it gets colder outside, so its hard to tell a difference between the motors. I will compression check in the fall when i replace the glowplugs.

[robscarab]

Anyone else have a psi reading for their 18:1 build?