Jims Tappets for Hydraulic Units Panhead and Shovelhead



Stock replacement tappets by JIMS which accept the standard Panhead/Shovelhead hydraulic units.
- Tappet by Jims
- for hydraulic units or solid lifter adaptor
- fits Panhead and Shovelhead
- steel
- Over-/Undersize: +0.000 ”
- replaces Harley-Davidson part number HD 18522-53A
- gross weight: 100 g
Solid vs. Hydraulic Lifters
Harley engines 1953-up generally work with both hydraulic and solid lifters but swapping solids for hydraulics and vice versa most often results in a change of cam performance. If cams which are designed to be installed with solid lifters are combined with hydraulics the following happens: good hydraulic lifters follow the cam lobe with zero lash and you suddenly end up with a longer duration, or in other words, the valves are opening earlier and closing later wih the same cam. This is because hydraulics compensate for the heat expansion of the cylinders where solids loose lift and duration through lash. For this reason we recommend to choose tappets/lifters according to the respective cam description in the W&W catalog.
If you plan to buy a new cam and new lifters, we feel that some comparison might help because each design has some specific advantages. In general it should be considered that Evolution type tappets (OEM & JIMS) are of a much sturdier design than the earlier Panhead/Shovelhead series.
Hydraulic Lifters
+ quiet operation
+ no valve adjusting service
+ no loss of lift and duration from heat expansion
– higher rpm applications (racing) not recommended
– affected by low oil pressure
– affected by contaminated oil
Solid Lifters
+ safely work in 6000+ rpm (race) applications
+ unaffected by low oil pressure
+ unaffected by contaminated oil
+ long service life
– require regular adjustment
– noisy valve train
See also:

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: service@wwag.com