Hi folks,
i nead a little advice, i'm having new pistons & rings fitted to my UK spec 91 CRX VTEC B16A1 soon, i'm using a new set of JDM Civic Type R 0.25mm oversized high comp pistons & rings , what's the best way to bed em in, how many miles/km roughly will it take, also i've been told to use mineral oil for a few 100 miles/km then to flush & use f/synth oil, any ideas??
Craig

 

I would go for 1000 miles not reving above 3,500rpm (you want the engine to vary in rpm too so you don't just want to get on the freeway and cruz at 3,500rpm for 1000 miles, try to let the motor run up to that point then run back down). Really also you don't have to stay below 3,500 for the whole break in, for every 200 miles you go you can probably rev another 1,000rpm once you are past 500. I just like to make sure the the rings and bearing have seated perfectly before I go romping on the brand new motor. Change the oil at 500 miles. For oil I would just go with non/synthetic until break in is complete. But it's up to you! Have fun

 

On top of what's been said, my auto engines instructor indicated that this would be the only time an operator (i.e.: the driver) would be justified in lugging the motor. It helps to seat the rings apparently. Why, I know not!

 

As long as the cylinder walls are honed properly, and the pistons/rings are installed
correctly, the rings should bed in fine. My break ins last 10-50 miles.
All my blocks run well, dont smoke, and make excellent compression and leak
down numbers.

 

Yeah, about 10 minutes of idle for us and off to the dyno for power runs...