ring seating

[nicolas]

i have heard and read debates about how to run in your piston rings.

here is a interesting view about it. it is the break-in and tune up part of the Tom Wilson book How to rebuild your volkswagen air-cooled engine.

in short he says to run the car with the new engine not at a steady speed, but to accelerate and to coast the car a few time so the rings can be set at both sides (oil/combustion). no need to use full trottle, but at 3/4 is Ok. this way the pressure needed to make the sealing of the rings actually work, is applied and used to 'lap' the rings and the cylinders into the same shape.

thought i would share this.





and of course open the debate   

[BeetleBug]

Here you go: http://www.mototuneusa.com/break_in_secrets.htm

-BRBB-

[modnrod]

Most of my stuff, I do an initial fire up routine (5 on, 5 off, 15 on, 15 off, etc) to bed in the cam a bit and get the tune close, then go for a ride/drive/ambulate away.
Vary throttle, speed and gears to try to maintain something close to surrounding traffic if any, but always on and off the throttle, I don't stay steady for longer than 2 or 3 mins for the first 200km.
The on/off throttle apparently beds in rings by taking into account ring flutter, etc, but also cools the bore with excess fuel on overrun, and changes load on the engine.

Having said that, every drag engine I've ever built gets run in while turning the tyres for the first time in the waterbox..........
 

[andy198712]

Rings vs cam break in though?

Luckerly I plan on using tool steel lifters so will just drive off.

Before I've found a nice hill and drive up and down that for a while to break in rings

[nicolas]

Rings vs cam break in though?

Luckerly I plan on using tool steel lifters so will just drive off.

Before I've found a nice hill and drive up and down that for a while to break in rings

well still following the articles suggestions, the cam should be broken in on the first startup of the engine. when you start it for the first time and want it warmed up and set up so it will idle and do a first checkup on leaks and so. then rev it up! or better put put some loading and unloading on that engine.