so i built up my "street" VTR engine a while bike with STD bore JE high compression pistons. now i am doing the same with my "track" VTR engine and 2 things have come to light that i wanna run past you fine folk.
the 2 problems i have uncovered
1. Honing Cylinders is POINTLESS and actually HARMS your engine; the only exception being on damaged/rebore to OverSize cylinders.
Article to support this :
Careful with That Hone, Eugene!
2. "Easy" break-in on the new rings is bad and results in burning of oil and loss of power leading to overall damage. For example "taking it easy" for the first 600 miles, as per the manufacturers recommended break in procedure results in improper ring seal leading to problems and poor performance. the theory is that to properly seal new rings, which do not rely on spring tension to seal as they have minimal spring tension, but rather the gases getting underneath the rings and forcing them out against the wall helping them to seal properly. the only way to achieve this is through running the engine hard on acceleration and deceleration, loading the engine both ways. during decel, the vaccum created sucks out any particles rather than them getting get between your rings and piston and eventually causing damage to the cylinder wall.
Article to support this:
Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power
Now neither of these articles are where i learned of these so called automotive "myths". Rather i learned of them on a recent trip to the Monterrey Rolex Historic's AKA Vintage car racing. I am close with a few of the drivers and there mechanics which build and rebuild these motors all the time. so this is coming from knowledgeable people who do this professionally. Now the premise of these practices being refuted is that engine's are made to a much better quality, with much finer tolerances, and higher quality parts than motors of decades past and these "ancient ways" are not only unnecessary, but down right bad.
ahhh but again you say if these old techniques dont apply to new engines, wouldnt the teams racing vintage cars, still abide by the laws of the past? NO because even though the car is old, the motor is new. i recant what i said, most of the cars really arnt even the cars they are suppose to be. they usually are the body of the car, and by that i mean a fibreglass replica with flared wheel wells and all, but underneath is usually a tube chassis with purpose built race engines. usually the tail lights are about the only thing these cars share with the car they are replicating.
so my "street" engine build, i did the traditional "easy" break in, as well as a simple hone on the cylinders. but on my "track" engine, i will do just the opposite. NO hone at all, and a hard break in. i will then compare results via 1.leakdown test 2.compression test 3.Dyno runs to measure power and torque.
now i have before and after dyno runs (thanks to my mates over at ducati) of the "street" engine pre and post piston install with NO other changes.
i will do the same with the "track" engine, the only difference being no hone, and a hard break in. then i will compare the % of either increase(hopefully) or loss of power due to the changes in the build and break in procedure. the compression and leakdown should tell alot of the story as well.
should be interesting, but ive come to find out that my ducati dealer uses the "hard" break in procedure and all freshly out of the crate bikes INCLUDING the $70,000 1199 Superleggera AND in their shop, purely on Re-Ring jobs that have no damage to cylinder walls, they DO NOT hone the cylinder. they simply check for tolerance specs, and if all is well, re-ring and button it up. a number of the bikes that come through the shop have been upgraded with low friction 2 ring pistons which require changing more often. so this info is consistent with what i learned in Monterrey. hence why i am trying it all out.
i know some of you will call me stupid, and that i will destroy my engine, but i wanna know for myself what the truth is in these matters and its a risk i am willing to take. from the research ive done, and the people ive talked to, id be stupid to hone the bores, as well as loosing on power if i run the engine in easy. so we shall see! would love to know what you guys make of all this!