Norton Commando 850 Valve Guides - Exhaust

A Proprietary Alloy as Designed for and used exclusively for NASCAR team is now available for your beloved British bike.  Under exclusive arrangement with the manufacturer,  MAP Cycle is proud to offer this material to our custmers.  NASCAR '45'^TM is a proprietary Manganese bronze based alloy that (unlike its Ampco 45/C630 nickel loaded brothers) forms a long linear vertical grain structure for superior wear with an expansion rate similar to aluminum.  This similar expansion and highest amount hof heat dissapation allows for a tighter valve to guide clearance for not only longer life but also a more stable and accurate valve seating.

• Helps eliminate pitting on seats and/or valve faces


• Superior durability


• CNC machined to exact specifications


• Better heat dissipation compared to the popular AMCO 45/C630 materials


• Expansion rate similar to aluminum (perfect for aluminum cylinder heads)


• Honed internal finish for best oil retiention


• Proven in Racing and on the street by enthusiasts across the globe

Exclusive Ringed Margins

No longer require different guides for sealed/unsealed applications. Remove a small bit of material and add our high temp viton oil metering seal (MAP9240). A true cost saver as No additional guides are needed if you happen to decide on using seals.

Constant research and development

M.A.P. NASCAR '45'^TM valves guides are the absolute best guides available for street or track.  Etched with type and size for ease in identification.  Insist your dealer carry the very best British valve guide.  To be sure of the highest quailty possible remember to ask for them by name - Nascar '45'^TM