Tonight I did a compression test on my 54 235. This was the first compression test on this engine, and my first compression test ever. I've read a lot about this, so I understand what the readings mean, but what I want to know is are my findings acceptable for a 235, or should I be saving for an engine rebuild in the near future?
The dry test showed:
#1 = 115, #2 = 115, #3 = 125, #4 = 119. #5 = 95, and #6 = 115.
A wet test showed #5 = 132, so at least for #5 I can say that the ring is worn to some degree. I didn't do a wet test on the rest since they all had relatively even readings, but their low readings (should be 130 or better) could be rings or valves or both.
The book says they should all be 130 or better and +/- 5-10 pounds for "satisfactory engine performance". The engine seems to have worn evenly across the board, with #5 being the only exception.
The truck seems to run pretty well right now. Maybe it could run more smoothly (it rumbles a bit maybe), but at least now I can attribute the slight rumble to #5. Or can I?
So all this leads to my main question: how bad are my readings. Is 115 (15 down from the perscribed 130) ok, so-so, bad, or really bad? Am I missing gobs of power and fuel economy, or am I not that bad off? As I said, the truck runs pretty well, and I realize I might not be getting optimal gas mileage/power, but I don't want to rebuild the engine right now.
If you had an engine like this, what would you do? My truck is being rebuilt to a safe and mechanically sound state -- I'm not doing a full restoration. So I have tolerance for it not being perfect, but I don't want to overlook a big issue. And I don't have the experience with this 235 to know how big an issue I have on my hands. My instinct tells me just to forget about it and drive the truck...
