Suggested Break-in - New Rings

[Manfred]

As noted on this thread: http://boxerworks.com/forum/viewtopic.php?f=1&t=7886 I put new rings on my '87 R80RT and had new valve guides and new exhaust valves installed.

Any recommendations from the all-wise airheads as to how I should ride for break-in and for how long?

[melville]

I did this with my Airhead, and similar with all the VWs I build. Ride it in a low traffic environment, where you can run it from 2K rpm to 6K rpm in 2nd and 3rd (maybe 4th?) gear, up and down, 50 to 80% throttle accelerating and fully closed decelerating. Do this for 200 miles or so. Change the oil and filter (open up the filter to see what's in the oil) and proceed normally from there. Maybe another oil change in 1000 miles.

[Manfred]

Thanks! That matches what I found on Dan's page: http://www.dansmc.com/engine_breakin.htm

[Kurt in S.A.]

IMO, the most critical time is the first 60 seconds of engine start. Start engine and hold around 3K RPM for 45-60 seconds, then jump on for a ride of 20-30 miles. Varying the speeds (I'd only go to 80% of your normal speeds), up in gears, down in gears, shut the throttle on downhill runs, avoid a lot idling. If new valves, check head torque and clearances after a few heat cycles and then again in 200 to maybe 500 miles.

Kurt in S.A.

[ME 109]

IMO, the most critical time is the first 60 seconds of engine start.

Seems to be the thought of the more experienced airhead mechanics. Using no oil on the rings or bore at rebuild is an important part. Just a drop smeared on the skirts.
This needs to be done with a fully primed oil circuit so the engine can be taken to 3000 rpm immediately on start-up without molly coddling the rpm until the oil light goes out.

Sounds harsh but that's that's the best way, apparently.

[Kurt in S.A.]

This needs to be done with a fully primed oil circuit so the engine can be taken to 3000 rpm immediately on start-up without molly coddling the rpm until the oil light goes out.

Certainly after a rebuild along these lines, it would be good to crank the engine with float bowls off so it doesn't start but circulates the oil. I did that to be sure I was getting oil to the rockers, then I buttoned it up.

I think the issue is the cylinder walls can get glazed pretty quickly...they heat up and oil is splashing on them. So, a lot of ring shaping happens before the walls get glazed in that first minute.

Kurt in S.A.

[ME 109]

This needs to be done with a fully primed oil circuit so the engine can be taken to 3000 rpm immediately on start-up without molly coddling the rpm until the oil light goes out.

Certainly after a rebuild along these lines, it would be good to crank the engine with float bowls off so it doesn't start but circulates the oil. I did that to be sure I was getting oil to the rockers, then I buttoned it up.

I think the issue is the cylinder walls can get glazed pretty quickly...they heat up and oil is splashing on them. So, a lot of ring shaping happens before the walls get glazed in that first minute.

Kurt in S.A.

Cranking to get an empty oil circuit fully charged is the problem with going the 'installing rings dry'. The cranking splashes oil into the bores and negates any benefit from installing rings dry. This is at least for nikasil barrels.

[Major Softie]

Cranking to get an empty oil circuit fully charged is the problem with going the 'installing rings dry'. The cranking splashes oil into the bores and negates any benefit from installing rings dry. This is at least for nikasil barrels.

I am very curious about this.

if just a couple slow turns of the crank to charge the oil channels is going to splash oil into the cylinders and destroy any ring seating advantage of dry ring installation, then, how will the first couple revolutions upon startup (including however many revolutions it takes to start) be any different at all in regards to the rings?

[Major Softie]

As noted on this thread: http://boxerworks.com/forum/viewtopic.php?f=1&t=7886 I put new rings on my '87 R80RT and had new valve guides and new exhaust valves installed.

Any recommendations from the all-wise-ass airheads as to how I should ride for break-in and for how long?

There, Manfred, I fixed your post for you.

[Manfred]

Thanks for the laugh!