45 Flathead tuning and top speed

[TriNortchopz]

"Your “obsolete” Harley-Davidson OHV & flathead V-twin... engine is capable of surprising speed & power, without loss of original appearance or reliability. Over 50 years of research and experience has gone into these booklets. They are the original, best, and most complete technical literature you can buy to get the most from your classic vehicle.
Before making any decisions about modifying (or even rebuilding) your motor, get the best help available, and do it right the first time. In some cases, more details or a complete list of contents is available; click the booklet cover..."

“45 Performance”;
is the complete edition of 45 power & speed booklets, subject titles including strokers, relieving, porting, factory hot parts, big valves, motor data, bore & stroke chart, sprocket ratio chart, transmission ratio charts, racing specs, service tips, more.

“The Illustrated Guide to Improve the Flathead V-Twin Oil Feed System”;
is Jim Casey’s extensive instructions on how to modify your Harley-Davidson flathead oil system. This includes: 1937-48 74 & 80” U-Series twins (U, UL, UH, & ULH) and 1937-73 45” solo, military & Servi-Car twins (G, GA, GE, W, WL, WLA, WLD, WLDR, & WR).

“45 Stroker Flywheel Instructions”

http://victorylibrary.com/books1.htm

This may be of interest:

45 Flathead racers

https://cyclesource.com/tag/45-flathead/

[oneuptom]

I think another reason my built KK was such a good runner was because it didn't have any blow by or oil scavenging issues. Most likely because I fit the pistons so tight. When I got the motor the bores weren't round or straight and there was excessive piston clearance. I honed the bores straight and round then knurled the pistons to fit with a 0.002" clearance. Broke it in nice and easy and never had any sticking or galling problems.

[docmel]

All this work and costs to hop up a 45 is worthless unless you can or are willing to change out the tranny. Or the tranny spocket/rear sprocket ratio (I dont recommend it, especially owth a 3 speed). You are stuck with a top speed of like 45-50 mph keeping both, period