Ring Tension

[SWOLN]

I'm thinking about building a motor, or having on built, that's tighter than the usual built motor. Specifically, in the ring area. I want to know more about ring tension, and how I would go about increasing it. Would I just have a smaller ring gap? Do I need to have the rings made so that the overall tension is greater ? Can one do that ? I'm kind of trying to figure out how to decrease blow-by. I was talking to a friend about running synthetic oils in their drag car. He says they run good old Valvoline because they lose horsepower with the synthetics because the rings unseat themselves. Can sonmeone offer insight? Thanks

[KJ8003]

Ring tension is decided by the material used in manufacturing and the unsprung diameter (free) versus the installed diameter (bore size, compressed). The difference in ring tension going from a gap of .020" to .012" or something like that is negligible. As far as building a motor with tighter clearances in order to eliminate blow-by is not really a good idea. You do your ring clearances based on the ultimate horsepower goal of the engine. Very bad things happen if the rings touch when the motor heats up at max output. My advice is run on the loose side of the clearance and run a better crankcase ventilation system so the blow-by causes less problems. Generally .006" per inch of bore is a good gap for the top ring and .0065" to .007" per bore inch is good for the second ring.

Increasing ring tension can have plus and minus's. The more ring tension the more parasitic loss.

[SWOLN]

Originally Posted by KJ8003

Ring tension is decided by the material used in manufacturing and the unsprung diameter (free) versus the installed diameter (bore size, compressed). The difference in ring tension going from a gap of .020" to .012" or something like that is negligible.

This I can uderstand and deal with through the manufacturer of the pistons and rings.

Originally Posted by KJ8003

As far as building a motor with tighter clearances in order to eliminate blow-by is not really a good idea. You do your ring clearances based on the ultimate horsepower goal of the engine. Very bad things happen if the rings touch when the motor heats up at max output.

I appreciate you knowledge here, specifically about when the rings touch, but I am trying something a little different than the status que.

Originally Posted by KJ8003

My advice is run on the loose side of the clearance and run a better crankcase ventilation system so the blow-by causes less problems. Generally .006" per inch of bore is a good gap for the top ring and .0065" to .007" per bore inch is good for the second ring.

Please don't take this the wrong way, but I am not looking to run on the loose side, thanks for your suggestions.

Originally Posted by KJ8003

Increasing ring tension can have plus and minus's. The more ring tension the more parasitic loss.

I'm not too worried about the parasitic loss.

Can someone please take a look at my original post and offer outside the box solutions ? I am trying to further expand some ideas I have. Some of the ideas stem from oil/lubrication conversations I've had in the past and recent observations. Specifically, light weight oils, where the lubrication is so good that it unseats the rings and causes a loss of horsepower. Horsepower loss seems to be about 100 hp with synthetic, on a 2500hp+ motor. I'd hate to think that nothing could be done, and to just deal with the hp loss along with the oil loss as the rings unseat themselves. Could one add an additional ring to combat the losses?