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Jims Big Axle Tappets for Hydraulic Units Panhead and Shovelhead

Stock replacement tappets by JIMS which accept the standard Panhead/Shovelhead hydraulic units.

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Big Axle Tappets

A 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 significant 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 much 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
Tappet »Big Axle hydraulic« by Jims; for hydraulic units or solid lifter adaptor; fits Panhead and Shovelhead
W&W# Picture net price* Available from warehouse Germany?
64-363 Jims Big Axle Tappets for Hydraulic Units Panhead and Shovelhead Over-/Undersize: +0.000 ”; replaces OEM 18522-53A $93.73 each
in stock
64-365 Jims Big Axle Tappets for Hydraulic Units Panhead and Shovelhead Over-/Undersize: +0.005 ” $101.35 each
in stock
* United States of America: Tax free shipping. Please check your local import fees.

See also:

  • S&S Hydraulic Unit for Tappets

    S&S Hydraulic Unit for Tappets The stock replacement hydraulic unit for all Big Twins from 1953–1984.

  • Solid Lifter Adaptor

    Solid Lifter Adaptor For all Big Twins from 1953–84. These adaptors replace the hydraulic units and work with all OEM type adjustable pushrods. A simple, low cost possibility for ...

Have any questions?

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    eMail: sales@wwag.com