Loss of engine performance fundamentals

Hi all,

Can anyone help me out to understand one thing.

I feel like I don't fully understand how does engine bottom end wearing affects the overall performance. I've heard that piston rings wearing causes less compression. If so, then where exactly that compression disappear, through oil rings into the engine?

Thank you in advance!

Hi Niko,

Yes it is true that worn piston rings will cause a lower compression. This happens as the seal the compression rings on your pistons provide is substandard and therefore allows compression to get down passed them and into the crankcase, it's also known as blow by. A sign of excess crankcase pressure would be an unusual amount of oil coming from your breather or your oil catch can filling up quickly.

Thank you very much Brandon!

I had never heard of such a term before but thanks to this information some things became clearer again.