Stock replacement tappets by JIMS which accept the standard Panhead/Shovelhead hydraulic units.
- for hydraulic units or solid lifter adaptor
- fits Panhead and Shovelhead
Big Axle TappetsA design which spells reliability and longevity. By omitting the inner race of stock tappet rollers it is possible to increase the diameter of the bearing rollers by 27% and that of the axle by 36%. The result is a failure safe bearing which is particularly important in performance engines with high lift cams and strong valve springs.
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
S&S Hydraulic Unit for Tappets
Have any questions?
Our service team will be glad to help out: Mondays - Thursdays 09:00-16:00 CET, Fridays 08:00-16:00 CET, Phone: +49 / 931 250 61 16, eMail: firstname.lastname@example.org