Harley-Davidson Club Finland

GM makes Harley lifters now. They are, in fact, small block Chevy lifters..however, the plungers have been reworked to accomodate Harley oil needs.

Questions about using a Chevy lifter in a Harley prompted me to do some research. Please let me share some of what I already knew, plus what I recently learned from Charles Hicks, HMIC at Topline's Johnson-Hylift:
As you may know, there are only a few hydraulic lifter manufacturers in the US: TRW, Delphi, and Johnson-Hylift being among them. All domestic engine manufacturers, including Harley, contract with them for lifters.

From 1998 thru mid 2002, Johnson-Hylift supplied lifters to HD, as did TRW. Hylift designed and produced a special piston and valve body to work across the temp ranges and varying oil psi typically encountered on an air-cooled engine such as the Harley. TRW on the otherhand supplied a Chevy lifter with a modified pushrod seat. IMHO, this explains why some '99-'02 Harleys were noisier than others - those with the Hylift supplied lifters run quieter.

Unfortunately, Hylift ran into financial problems and found themselves on the auction block in 2002-2003. All production came to a stop. Chuck Hicks met with Harley and agreed to sell Hylift's lifter specs to Delphi. Delphi declined and tried to purchase Hylift at auction, but was beaten out by my friend, Chet Starron of Topline Engineering. Hylift is now a fully owned subsidiary of Topline Engr., Chicago.

Since mid 2002 HD has used Delphi for their hydraulic lifters. That's why there was a Harley p/n change from 18538-99A to 18538-99B. However Delphi could not use the hi-volume / hi-pressure lifter piston & valve body specially designed for Harley engines because Hylift owns the patent. So Delphi followed TRW's route and modified a Chevy lifter. The main difference is the Delphi lifter tries to boost the hydraulic psi by decreasing the piston diameter, but this leads to a smaller high pressure oil reservoir. The volume is too small and allows the lifter to clatter. IMHO, that is why so many of the late model bikes are noisy.

For a while, after Topline brought Hylift back on-line, they supplied the valve bodies for Screamin' Eagle lifters...until all of the HD 18538-99A lifter bodies were used up. Now they are supplied by Delphi and are the exact same lifter as what originally comes in the bike's engine. And Hylift supplies the lifters/valve/pistons for JIMS.

Just some "inside info" I thought folks would find interesting.

BTW, AMS is currently working with Hylift to make a complete HD lifter that has the improved A900 "guts". Since Harley lifter sales represent less than 1% of Hylift's sales, our project with Hylift isn't exactly a hot priority. However, I spent a half hour on the phone with Chuck Hicks, and he assured me he would personally follow this project thru. He is sending me a set of 4 complete lifters, specially made to our specs with the A900 "guts", for us to test. We should get them by the end of next week. We will disassemble and measure them, document everything, and reassemble them.