Panhead facts & figures
Model overview
 
E: 61" cubic inches engine (e.g. EL)
F: 74" cubic inches engine (e.g. FL)
L: high compression (7 : 1) (e.g. FL)
H: Super Sport, higher compression than FL model
S: sidecar gearing (e.g. FLS)
F (not first character): footshift (e.g. FLF)
P: springer forks (e.g. EP), stamped at end of serial number
E: (third character): 61" cam & M61 carburator (e.g. FLE)
B: electric start (e.g. FLB)
 
E 61" c.i., 6.5 : 1 compression
EL 61" c.i., high compression
EP 61" c.i., springer fork
ES 61" c.i., 6.5 : 1 compression, sidecar gearing
ELF 61" c.i., high compression, footshift
ELP 61" c.i., high compression, springer fork
ELS 61" c.i., high compression , sidecar gearing
EPS 61" c.i., springer fork, sidecar gearing, springer fork
ELPS 61" c.i., springer fork, sidecar gearing, springer fork
F 74" c.i., 6.6 : 1 compression
FL 74" c.i., high compression
FP 74" c.i., springer fork
FS 74" c.i., 6.6 : 1 compression, sidecar gearing
FLB 74" c.i., high compression, electric start
FLE 74" c.i., 61" cam & M61 carburator
FLF 74" c.i., high compression, footshift
FLH 74" c.i., high compression Super Sport
FLP 74" c.i., springer fork
FLS 74" c.i., sidecar gearing
FLEF 74" c.i., high compression, 61" cam & M61 carburator, footshift
FLFB 74" c.i., high compression, footshift, electric start
FLHB 74" c.i., high compression, electric start, Super Sport
FLHF 74" c.i., high compression, footshift, Super Sport
FLPS 74" c.i., high compression, springer fork, sidecar gearing
FLHFB 74" c.i., high compression, footshift, electric start, Super Sport
   
S (sidecar gearing) and F (footshift) not shown in serial number
 
General specifications 1948 - 1954
  E & EL F & FL
Type of engine 61 C.I. OHV Twin 74 C.I. OHV Twin
Cylinder bore 3 5/16" 3 7/16" (87.3 mm)
Stroke 3 1/2" 3 31/32" (100.8 mm)
Piston displacement 60.32 cubic inch 73.66 cubic inch
Compression ratio
(low compression model)
E: 6.5 to 1 F: 6.6 to 1
Compression ratio
(high compression model)
EL: 7.0 to 1 FL: 7.0 to 1
Horsepower (N.A.C.C. rating) 8.77 9.44
Wheelbase 59 1/2" 59 1/2"
 
General specifications 1955 - 1957
  FL FLH
Type of engine
74 C.I. OHV Twin
Cylinder bore
3 7/16" (87.3 mm)
Stroke
3 31/32" (100.8 mm)
Piston displacement
73.66 cubic inch (1207 cc)
Compression ratio 7.25 to 1 8.0 to 1
Horsepower 55.0 @ 5400 RPM 60 .0 @ 5500 RPM
Torque 62 lb-ft @ 3200 RPM 65 lb-ft @ 3200 RPM
Wheelbase 60" 60"
Sprockets and gear ratios
1949 - 1954
Sprocket teeth:


4-speed
3-speed
Solo
Sidecar
Solo
Sidecar
Engine sprocket E & EL 61
22
20
22
18
Engine sprocket F & FL 74
23
21
23
20
Clutch sprocket
37
37
37
37
Countershaft sprocket
22
22
22
22
Rear sprocket
51
51
51
51
 
Tire data
 
Front
Rear
Sidecar
Solo, rider only

- 4.00 x 18 tire

14 lbs.
16 lbs.

- 5.00 x 16 tire

12 lbs.
14 lbs.
Solo, rider and 1 passenger

- 4.00 x 18 tire

18 lbs.
26 lbs.

- 5.00 x 16 tire

12 lbs.
16 lbs.
Sidecar, rider and 1 passenger
passenger or 150 lb. sidecar load

- 4.00 x 18 tire

20 lbs.
24 lbs.
14 lbs.

- 5.00 x 16 tire

14 lbs.
16 lbs.
14 lbs.
Torque specs  
Sources: see also Books
Bruce Palmer: How to restore your Harley-Davidson
Greg Field: Original Harley-Davidson Panhead
Peter Henshaw: The legend of Harley-Davidson
Harley-Davidson Panhead Service Manual - 1948 - 1957
and various other sources
 
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