Originally Posted by
motoclay
You guys talking about pinch crack me up....you realize that if it's still metal to metal it's not 100% broken in right? A well done motor will last forever as long as you keep the dirt out of it and don't run it lean. Compression is a good thing....if you are only getting 3 gallons out of a motor you are failing somewhere in your process or judgement of what is a word out motor.
To an extent, I agree with you. People get too wrapped up in "low compression".
BUT, it's still an ABC engine, therefore zero interference when cold means there's going to be a gap at operating temperature between the piston and sleeve due to expansion.
With that said, I have plenty of old engines that have no "pinch" at all. With a lot of fuel ran through them.
They run good and I could probably use them if I needed to.
However, the first sign (in my experience) of lower compression is lack of a solid low idle. Which is when I rebuild or replace my engines.
So are they worn out?
They run.. just don't idle well.