WE ALWAYS AMS-HYLIFT...NEVER A PROBLEM!
Below is from the AMS site. We agree 100% with these statements!
From 1999 - 2001, Johnson-Hylift supplied lifters to Harley-Davidson...
Johnson-Hylift designed and produced a special piston and valve body
to work across the temp ranges and varying oil psi typically encountered
on a Harley engine. Since 2001, in a cost-savings move, HD has used
Delphi hydraulic lifters, which explains Harley's p/n change from
18538-99 to 18538-99A, and after some problems, a second Delphi lifter
was used, p/n 18538-99B. However, Delphi still did not use a 0.655"
hi-volume / hi-pressure plunger and valve body like those specifically
designed for Harley by Johnson-Hylift. After some research AMS learned
Delphi 18538-99B lifters bleed down rather quickly due to the
higher engine temps and heavy valve spring pressure found on most
Harley Twin Cam's. The oil reservoir inside the lifter is too small,
allowing the lifter to clatter, and likely causes many Twin-Cam bikes
to be noisy. Note: ALL lifters bleed off during operation and even
more-so when the bikes sits, engine off.
Tom at AMS has known Chet Starron, who owns Johnson-Hylift, for many
years. Chet put Tom in touch with the original engineer of the earlier HD
18538-99 lifters, which don't seem to be as noisy as those made by Delphi.
Working with Hylift' engineering staff, AMS modified a Johnson-Hylift lifter,
to accept a very precise check valve, a larger plunger that allows more oil
reservoir volume, and a ball seat that fits much tighter, yet has an oil feed
groove to allow more upper rocker box oiling. The result was a significantly
improved lifter, with a much bigger internal oil reservoir that will keep the
lifter/pushrod from bleeding too much and bottoming out. The bigger
reservoir maintains a cushion of oil inside. The improved ball seat ensures
better top-end rocker oiling and better pushrod tip fit.... all of which makes
for a quieter lifter.
AMS and Hylift have continued to develop this lifter, and today, we offer
3 versions of the AMS-Hylift lifter for Harley Twin Cam applications:
AMS A2313S for stock and performance street bikes. $29.95 each
AMS A2313R for all out, hi-rev racing applications. $39.95
AMS A2313-002 this is a 0.002" oversized version of the AMS2313, for use
in cases with worn lifter bores. $39.95
We recommend using Andrews adjust pushrods, or stock non-adjustable
pushrods with them... however other brand adjustable pushrods will work
too. These lifters have a wide preload range, which makes for easy
installation if adjustable push rods are used.
There are many other things that can cause "lifter" noise - it can be coil
bind, rocker to spring cap interference, spring cap to stems / guide length
interference, poor oiling, high lift cam profile causing loft, overheating motor,
wrong oil viscosity for ambient temperatures, aerated oil, low oil pressure,
gear drive backlash, worn drive chains, etc. However if you're convinced
you've eliminate all of these things, and the lifters still rattle, then the next
step is to a set AMS-Hylift Lifters. With their larger oil reservoirs, they will
usually lessen or eliminate the noise.
HOLESHOT CHOPPERS and PERFORMANCE
2421 Mercantile Dr Suite F
Rancho Cordova CA
916-852-8352 ext 101