Bedding in Piston Rings

What type of oil are people using to bed in rings after a rebuild?....

manx850 said:

What type of oil are people using to bed in rings after a rebuild?....

Click to expand...

I used the old-school 30W non-detergent, combined with short blips of the throttle for the first half hour the moment the engine fired. 500 miles, then back to synthetic 15W-50. No smoke; no consumption. This is with Hastings rings.

Nathan

I have genuine old stock AE pistons and ring supplied by Mick Hemmings he told me to assemble them with normal good quality engine oil then just ride the bike. Don't over rev it or let it bog down and slog in to high a gear just ride it sensibly for first few hundred miles. It worked and all is well with no fuss.

However the best advice I would say if fitting so other make of piston is follow manufacturers instructions.

toppy said:

I have genuine old stock AE pistons and ring supplied by Mick Hemmings he told me to assemble them with normal good quality engine oil then just ride the bike. Don't over rev it or let it bog down and slog in to high a gear just ride it sensibly for first few hundred miles. It worked and all is well with no fuss.

However the best advice I would say if fitting so other make of piston is follow manufacturers instructions.

Click to expand...

When I did the top end in 2012 mick got the barrels honed ,supplied Pistons , did the valve guides and seats. His advice at the time was very similar to Toppys and I have to say, after I don't know how many miles it does not smoke or use any oil, not the fastest bike in the world but I am happy with how the work turned out. However others may have different methodology that could do the job every bit as successfully .

Jg

First off let me say this is not my recommendation -so following me is at your own risk.

It always bothered me that when building a new engine I would use anything less than the best oil during break-in, when the engine runs hottest and needs the best oil it can get.

Last time I did pistons and a new bore, I used a fine [AN500] finish hone on the cylinders.

I filled it with Royal Purple's best synthetic and after a trip around the block, I headed for Texas. After the first 500 mile day just riding normally, I changed the oil and filter out behind the motel. More Royal Purple.

Royal Purple is still in the bike with ~7000 miles since the last change. It uses very little oil and the oil is not black- It still looks clear on the stick. The bypass filter I added when I did the pistons seems to be doing it's job very well. Jim

During my OCD phase of racing I would bed pistons and rings in manually with Solvol Autosol. My logic was that I could the skip the running in oil and bedding in phase and just race. I did a few OCD things like this, but started to think that despite adding hours and hours of prep time... it did bugger all else!

So I started to tire of it after a while and, basically, just put the good oil in and caned it from the outset!

These days, with new build road engines (like the Trident Hunter) I used good oil but added a bedding in additive.

All methods seem to work just fine!

Like Jim, the idea of using sub standard oil to aid bedding in doesn't feel right to me. "Bedding in" is after all just a nice phrase for "wearing out" so whilst it might help bed the rings in, what's it doing to cam, followers, etc?!?

And to the argument that good oil stops the rings bedding in at all, I'd simply say "ride it harder" get it good n' hot with a nice long spanking and I'm pretty sure the rings will bed in!

Personally and FWIW "good oil" in my shed is Red Line 20/60 motorcycle oil. If you buy Red Line you must buy their specific motorcycle oil as it has MUCH more zinc which our cams n' followers require.

And yes, before anyone 'helpfully' points out that Red Line (and any 'good' oil) is expensive... so are engine rebuilds...!