Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties valve to cylinder angle

valve to cylinder angle

Moderators: Curt!, Pa

Post Sun Jan 26, 2014 8:25 am

Posts: 103
Location: Switzerland

Does anyone know the angle that the valves are tilted compared to the cylinder axes (in the front cylinder the valves are tilted backwards and in the rear cylinder thy are tilted forward. I tried to measure the angle on a factory blueprint and came up with roughly 4.35 deg. when I try to measure on a real cylinder I get something around 3.5 deg. Is this angle the same for WL, UL and WR cylinders (I know that the valves on WR cylinders are tilted towards the piston perpendicular to the longitudinal axis of the bike as well)?

Post Mon Feb 10, 2014 10:04 am

Posts: 19
The UL valves are at 4.5 degrees.
S&S Cycle, Vintage Lead (formerly Flathead Power)

Post Mon Feb 10, 2014 11:41 am

Posts: 103
Location: Switzerland

Thanks Eric,
From the drawings I have, it seems that the WL are the same. WR cylinders might be different. I measured the front and rear intake valve on my WR cylinders and found 3.5° and 3.7° respectively. Since I only had to fix the hole of the intake valve guide, I did not measure the exhaust valve angles but looking at the two valves it might be even different. Maybe exhausts are 4,5° and intakes 3.5°?? They look weird anyway because the angles toward the cylinders are different for intake and exhaust as well (1.033° and 3.533°).

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