Norton Commando 850cc Long-Rod Billet Piston Set

Get the very best pistons available for your vintage Norton! Manufactured from 4032 aluminum alloy, they’re the ultimate piston for air-cooled engines!

Fits:

• Norton Commando 850cc with long-rod conversion (see MAP7063 stroker rods)

Features:

• Race proven and tested under the harshest conditions
• Made with 4032 billet aluminum, high-silicone content for super strength! This alloy's low-expansion properties allows for tighter running clearances, which reduces needless engine noise and extends piston life
• Each billet piston is fully CNC machined using the latest SolidWorks software resulting in the lightest possible weight and even heat distribution
• One of the lightest, commercially available, vintage, British bike, piston kit on the market
• Micro-grooved piston skirt for longest life and resistance to scuffing
• Second ring-land accumulator groove helps prevent the unloading of the top ring from trapped blow-by gases
• Updated wrist-pin oiling with four pressure-fed location holes. This increases oil volume to the pin and limits heat buildup in the small end of the rod and wrist pin
• Dual clocked pin bore grooves effeciently hold and disperse increased levels of oil around the wrist pin
• Race-proven ring pack built by the highest quality, performance ring manufacturer (see ring specs below). Modern metric sizing for the least amount of friction with the best heat transfer. This results in a cooler running piston and longer piston life
• Tapered wrist pin inner diameter for rigidity and light weight
• Race-type SpiroLoc wrist pin clips for added reliability. They will never come out unexpectedly!
• Fully compatible with Nikasil-plated bores
• Our piston kits are race-tested world wide!

Includes:

• Two race-proven, billet alloy pistons
• Two sets of high-performance piston rings
• Two lightweight wrist pins
• Four SpiroLoc wrist pin clips
• Full installation instructions

Piston Rings:

• 1.0mm Nitrided stainless steel barrel-face top ring
• 1.2mm Ferrox iron “Napier-style” second ring
• 2.8mm Nitrided stainless steel rails with expanded (three-piece design) oil ring

Component weights:

• piston (based on standard size piston)

MAP9037       850cc  Long Rod      8.5:1 compression  (stock head)      9:1 (.040 decked head)                                                188 grams

MAP9038       850cc  Long Rod     10.5:1 compression  (stock head)     Check clearance with modified or decked heads       220 grams

• Pin with clips:  60 grams
• Rings:  17 grams

Compression height:

• 8:5:1 piston set is 1.006 inches
• 10.5:1 piston set is 1.128 inches

Note:

• The 8.5:1 pistons work best with premium pump gas
• The 10.5:1 pistons require racing fuel