ninjette.org - View Single Post

DannoXYZ · December 27th, 2019, 02:39 PM

Compression-height is different between 250 and 300 pistons. That's distance between centre of pin and top of piston.

In either case, if you're going overbore, you'll want to sleeve either type of cylinder. Bruce has some great build threads with using ZX6 pistons, rods and sleeves. There's absolutely nothing that will go into 300's alloy cylinders. Until you Nikasil* coat it or install sleeves. Types of rings used will also depend upon type of cylinder-wall, either Nikasil or iron sleeves.

* Nikasil is patented process by Mahle. So called something else in U.S. Check out U.S. Chrome for one supplier that can do that plating process, called something else...

There are hypereutetic alloys used for blocks by Porsche, BMW and Mercedes (alusil) that has high percentage of silicon. At end of boring and honing process, an additional etching/lapping step is used to remove aluminium from cylinder walls, leaving hard silicon crystals. These are extremely durable bores, easily lasting 200k-miles with practically zero wear. Iron-coated pistons are used in these bores. I'm not sure if 300's cylinders is made of this material or if pistons have some special coating. Certainly rings are different than what's needed for iron bores.

December 27th, 2019, 02:39 PM	#10
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Compression-height is different between 250 and 300 pistons. That's distance between centre of pin and top of piston. In either case, if you're going overbore, you'll want to sleeve either type of cylinder. Bruce has some great build threads with using ZX6 pistons, rods and sleeves. There's absolutely nothing that will go into 300's alloy cylinders. Until you Nikasil* coat it or install sleeves. Types of rings used will also depend upon type of cylinder-wall, either Nikasil or iron sleeves. * Nikasil is patented process by Mahle. So called something else in U.S. Check out U.S. Chrome for one supplier that can do that plating process, called something else... There are hypereutetic alloys used for blocks by Porsche, BMW and Mercedes (alusil) that has high percentage of silicon. At end of boring and honing process, an additional etching/lapping step is used to remove aluminium from cylinder walls, leaving hard silicon crystals. These are extremely durable bores, easily lasting 200k-miles with practically zero wear. Iron-coated pistons are used in these bores. I'm not sure if 300's cylinders is made of this material or if pistons have some special coating. Certainly rings are different than what's needed for iron bores.