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911pcars 911pcars is offline
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Join Date: Jul 2000
Location: So. Calif.
Posts: 19,910
I'm sure some Bimmer engine rebuilder has gone through this before and may have suggestion for strategically removing metal from the factory con rods, pistons and piston pins w/o sacrificing strength.

Not sure you gain much by polishing the piston crowns. Removing sharp edges would be good insurance against localized hot spots and resultant pre-igntion. Some builders apply a ceramic coating to the piston tops to reduce heat transfer; add low-friction coating to the skirts to reduce friction, but make sure the vendor has a track record. Swain Tech is one such company.

In general, removing casting flash minimizes stress risers and should increase fatique life. If the rods were shot-peened previously, have them treated again after grinding, smoothing, polishing and balancing.

In general, anything you can do to blue-print an automotive engine is fully applicable to a motorcycle engine. the overall cost is less too since you're only counting two cylinders.

Hope this helps,
Sherwood
Old 08-29-2006, 10:58 PM
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