Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Fact or Fiction

[rockhopper]

Thing is though, race bikes are rebuilt every couple of races, youd really like a road bike to go on producing good power for 20,000 miles plus.

[JPM]

Originally posted by rockhopper
Thing is though, race bikes are rebuilt every couple of races, youd really like a road bike to go on producing good power for 20,000 miles plus.

Tis true, but I don't think they run the road bikes anywhere near as hard etc on the dyno as they might a race bike. Saying that though the small rebuild on a 998RS02 (500 Miles) is something like valves, collets, valve seals, and a few other bits, then the big service (1000 mile increments) is all of the top end as above and bottom end also.... I don't know if pistons/rings come into this.

Where's Nelly, Skids, Shazaam etc?

[Mr_S]

Corse race schedule shows pistons to be replaced every 250Km after the first 500!!!

http://www.sigmaperformance.com/2000...hedule-big.jpg

On the flip side, I had an R1 run in using the mototune method that lost no RWP well beyond 10K miles with no other mods and would still have been going strong until an organisation that shall remain nameless wrote it off by dropping a trailer on top of it.

The engine went off to go racing.

[Edited on 15-3-2005 by Mr_S]

[Shazaam!]

The answer to how to break-in an engine, and whether to use a synthetic oil during break-in, is different for new engines and rebuilt engines. What the engine manufacturers do and recommend for a new engine break-in should not be construed as the best solution for a rebuilt engine. Here’s why.

The manufacturer controls the complete quality assurance and quality control process: design, fabrication, build, inspection and testing. The overall result is not necessarily better than can be achieved by a custom engine builder, just more consistent.

So when a manufacturer first fires-up a new engine on a test stand, they know from experience (and monitoring each engine’s exhaust oil combustion products) that the piston rings will seat properly before the engine leaves the factory. Every Ducati is run-in for ten minutes or more on the dyno using a prescribed rpm and temperature sequence. Many manufacturers including Ducati, Porsche, Mercedes-Benz, Corvette, Viper and Aston Martin do their initial fill with a synthetic oil, and piston wall glazing is simply not a problem for them.

The piston rings seal is mostly complete after this initial test run. The follow-up part of the break-in (that you read in your Owners Manual) has little to do with piston ring sealing. It’s meant to accommodate the time it takes for normal wear to occur to thousands of mating parts like bearings and gears, that will happen regardless of the type lubricant used. It’s particularly important to change any lubricant early, and often, to remove the resultant wear debris.

However, when you rebuild an engine you can introduce a number of variables (that affect glazing) that are different from a new engine such as piston ring material, clearances (that affects ring pressure on the wall) and cylinder wall surface finish. Also, not all engine rebuilders have complete, accurate control over their cylinder-wall finish and ring type like the manufacturers.

Cylinder wall glazing occurs when the engine is run at power levels too low to produce temperatures high enough to expand the piston rings sufficiently to prevent a film of oil being left on the cylinder walls. The high temperatures in the combustion chamber will oxidize this oil film so that it creates a condition commonly called glazing. When this happens, the ring break-in process stops, and excessive oil consumption can occur. Excessive glazing can only be corrected by removing the cylinders and re-honing the walls.

The build quality of engines 25 years ago probably contributed to the controversy that somehow synthetic oils are too slippery for break-in and that conventional oils should be used.

So what do the oil manufacturers say?

According to a Road & Track article a few years ago regarding the use of synthetic oil during break-in, Mobil’s position was that engines break-in just fine on synthetics, and that any wear point in the engine significant enough to be an interference, and thus susceptible to rapid wear, would be a wear point no matter what lubricant is used. Redline on the other hand, recommended a mineral oil for break-in. They say that in their experience, occasionally a rebuilt engine will glaze its cylinder walls when initially run on Redline synthetic, so by using a mineral oil for 2,000 miles, verifying there is no oil consumption, and then switching to the synthetic, glazing is eliminated.

In any event, your break-in period has long expired, both from a cylinder glazing prevention and a wear point-of-view. As they say, ride it like you stole it.

[Edited on 3-15-2005 by Shazaam!]

[jobr]

Originally posted by psychlist
....Don't forget Slick5o

Always used to put Slick in my own car and haven't bothered for years as its the companies.

My bike is hopefully nearly run in and due its first service in a few weeks - is it worth adding Slick in to the bike???????????

[Monty]

"When this happens, the ring break-in process stops, and excessive oil consumption can occur."
Shazaam, is that the reason that my TZ smokes??-I always wondered......................:P

Sorry, couldn't resist, I'll get me coat.................

John