Cannonball Tappet Guide Kits for Big Twin Flatheads Standard

Valve spring cover by Colony; fits U models 74 cui and 80 cui 1939-1948; steel, CAD (zinc nickel galvanized); replaces OEM HD 18236-39; gross weight: 723 g

Screw; for Tappet guides; steel, parkerized; oval countersunk head with slot; thread: 1/4”-24; length: 13/16 ” (21 mm); replaces OEM HD 2329; gross weight: 10 g

Adjusting screws by Colony; for Valve; fits Flathead models 1929-1973, K models 1952-1953; steel, parkerized; wrench size: 7/16 ”; thread: 9/32”-32; with self-lock nut; replaces OEM HD 221-15A, and 18556-40; USA; gross weight: 59 g

Gasket by James Gaskets; for Tappet guide; fits 45 cui/750cc 1937-1973, Big Twin Flathead 1937-1948; paper; replaces OEM HD 18631-30; gross weight: 10 g

These stock replacement cams for Big Twin Flatheads of the U series are similar to original parts but the lobes have been redsigned using modern computer cam design and smoothing techniques.

Great tool to remove reluctant tappet guides from the gear case. Just screw it on, turn in the bolt and off she goes.

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. ...

If you plan to build a real Hot Rod out of your U series Big Twin Flathead, we have the cams for you. These 4 bad babies feature cam lobes profiled after those legendary KHK models from 1956 and spell horsepower. However, all lobes have been redsigned using modern computer cam design and smoothing techniques. Of course, these are no easy drop-in parts, but do require an experienced mechanic. The gear case has to be machined for the higher intake lobes and all components involved need to be checked for necessary clearance and tolerances, i.e. lifter to guide clearance, cam shaft side play and valve to head clearance. The set comprises 4 cams.

Aluminum cylinder heads for side-valve engines. In air-cooled engines, material with good heat dissipation is of great importance. When heat builds up, it results in power loss. Higher compression is meant to produce more power, but higher-compression engines run hotter. That’s why, starting in 1940, Harley-Davidson equipped the higher-compression side-valve engines (5:1 and above, with the standard being 3.6:1–4.5:1) with aluminum cylinder heads. Aluminum dissipates heat better than cast iron. The heads offered are supplied in pairs.