Flathead Parts

Sidevalve engines determined the factory’s model policy for many decades and it wasn’t before 1973 that the last Servi-car with Flathead powerplant rolled off the production line. To make sure that these legends will continue to eat miles, miles and more miles, Cannonball crankcases and cylinders provide that any tired sidevalve Big Twin can be put back into service.

Cannonball Big Twin Flathead Crankcases Kits with Cams and Gear Cover
Cannonball Big Twin Flathead Crankcases Kits with Cams and Gear Cover
The main challenge during restoration and assembly of Flathead engines is the exchange and alignment of the bushings in the right crankcase and the gear cover. Nine bronze bushings need to be installed and line reamed to ensure that four cams and the pinion shaft with its gears turn smoothly. This is a major task and requires several special reamers, which your average workshop does not have. The problem increases when case and cover were not factory matched.
These Cannonball cases for 1937-1948 Big Twin Flatheads feature a pre-fitted gear cover with all bushings and pins installed and are line bored for a set of Andrews cam gears, which are also included. This work is performed in Germany on a coordinate line boring machine, which is superior to reaming. The cover also has its flutter valve and spring-loaded oil separator seal ring installed. All this will cut the working time for the complete engine assembly at least in half and guarantees a quietly running motor, just as if assembled in Milwaukee, provided that the remaining valve train is in good order, too.
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Cannonball Big Twin Flathead Crankcases
Cannonball Big Twin Flathead Crankcases
Reproduction crankcases which meet or exceed highest restoration demands. Cast from state-of-the-art materials and machined on CNC equipment for strength and precise fitment. Intended to work with stock or identically constructed engine components. Finished and detailed like the original counterparts so these cases will smoothly blend into your old mill to give it a new life. For ease of installation both case halves are carefully matched and feature pre-installed case bushings, which are line bored and lapped for standard rollers. Cam bushings are already in place and reamed. (For exact measures pls see facts).
All cases feature laser-engraved CB production numbers, which are registered and filed.
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Cannonball 2-Bolt Manifolds for Flatheads
Cannonball 2-Bolt Manifolds for Flatheads
Direct bolt-on manifold for Linkert to Bendix carburetor conversions on all U and WLDR Flatheads. Also accepts Keihin (butterfly) carburetors.
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Cannonball 4-Bolt Manifolds for Flatheads
Cannonball 4-Bolt Manifolds for Flatheads
These manifolds allow the trouble-free installation of 4-bolt, 1-1/2” Linkert carburetors, like M35, M74 or MR, on sidevalves. The selection includes a version for W-series 45 cui. models and U-models 1937-1948. Just the right part for the sports oriented Flathead rider. Cylinder stubs require to be shortened to match the respective situation.
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Cannonball 8 mm Belt Drive Kits for 45
Cannonball 8 mm Belt Drive Kits for 45" (750cc) Flatheads
For a conventional 750cc side-valve, the original primary drive or something of equal value is usually sufficient.
However if you consider to increase the power of your 750cc engine and might even takle a spin on the race track, your 3-disc clutch will probably not be the appropriate companion.
In any case, this Cannonball primary drive offers traction to the very end of a 750cc Flatty's tuneability. CNC – machined steel and aluminium components, 5 friction discs and a sturdy aluminium pressure plate with spring-loaded steelballs assure a smooth frictional connection. The high quality of all components, perfect function and durability are the main aspects that have been taken care of while creating this product. Clean disengagement, engagement such as easy adjustment are nice side effects of this.
Anyone who rides it knows what we are talking about. But surely people will also enjoy this drive if they don't have a start number on their springer fork.
By the way, this primary drive is perfectly suited for hand clutch conversion, as the spring forces are comparatibly low. The result is a smooth, easy and precise clutch operation at the hand lever.
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