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.
- fits Big Twin Flathead 1937-1948
- cast aluminum
- with cams and gear cover
- replaces OEM 402-37, 584-37, 24515-37, and 25208-37
Quality information re. Cannonball Crankcases.
The W&W Cycles AG selection of Cannonball engine cases are not related in any way in terms of manufacture or distribution to the products of Motortechnic/Motortechnic-mfg (distributed in the USA by V-Twin MFG/Tedd Cycle, Inc., among others).
We have been working for years with three German companies selected by us, who carry out the casting and machining, including the fitting and honing of the bearing races for the crankshaft.For this reason we grant our own manufacturer's warranty for Cannonball products.
Tappet Guides for Flatheads
Tappets for Flathead
James Gasket Kits for Engines: Big Twin Flathead U 1936-1948
VT-Cycle ULR Cylinder Heads
Dyno tests showed 18% more power and 13% torque increase over a stock 1946 UL with medium compression heads, just by swapping over to ULR heads! Check out the dyno diagram! These are true rear wheel numbers, power was up big time and torque curve is impressive! Remember, torque is the most important figure with flatheads!
Cannonball Cylinders for Big Twin Flathead
Manufactured from gray cast iron GJL 300 according to state-of-the-art foundry procedures. After all, metallurgy has made one or two advances since the 1930s, which improved stability and durability significantly. To ensure everything fits as it should the blanks are machined on CNC-equipment. All dimensions, gasket surfaces and threads are perfectly true to size. Another improvement are hardened and replaceable valve seats (unmachined) which allow safe operation with today’s unleaded fuels. Valve guides are not included in the scope of delivery and must be ordered separately.
Have any questions?
Our service team will be glad to help out: Mondays - Thursdays 08:00-17:00 CET, Fridays 08:00-16:00 CET, Phone: +49 / 931 250 61 16, eMail: email@example.com