HarleyTechTalk

Technical Forums => Evo Sportster => Topic started by: xlfan on December 01, 2018, 04:16:13 AM

Title: Solid pushrod end mating hydraulic tappet
Post by: xlfan on December 01, 2018, 04:16:13 AM
Would a solid pushrod end mating to a stock hydraulic tappet cause the tappet to pump up, resulting inn too high lift on a -93 1200?
Title: Re: Solid pushrod end mating hydraulic tappet
Post by: rigidthumper on December 02, 2018, 06:25:05 AM
Are you having valve to piston issues?  All stock evo sportsters have solid pushrods and hydraulic tappets, so, no. There is a possibility of valve float, but vary rare with stock cams.
Title: Re: Solid pushrod end mating hydraulic tappet
Post by: xlfan on December 03, 2018, 03:00:18 PM
Sorry, I meant solid pushrod end as in blocked oil hole inn pushrod.

It will be a hybrid topend without rocker arm lubrication through tappet and pushrod.
Title: Re: Solid pushrod end mating hydraulic tappet
Post by: rigidthumper on December 04, 2018, 07:39:00 AM
OK. Standard hydraulic tappets use the oil to fill the gap, and the pushrod funnels the extra pressure to the top end. Maybe add a groove or two in the top of the cup so the oil has somewhere to go after filling the lifter?

Title: Re: Solid pushrod end mating hydraulic tappet
Post by: xlfan on January 20, 2019, 08:38:02 AM
Thanks alot 😊 we're gonna try a tiny v-groove in pushrod ball. I'm actually a little embarresed that I didn't think of that myself. Thanks again.
Title: Re: Solid pushrod end mating hydraulic tappet
Post by: xlfan on February 16, 2019, 01:25:53 PM
Kind of odd looking Sportster 😊
Title: Re: Solid pushrod end mating hydraulic tappet
Post by: rigidthumper on February 17, 2019, 06:05:35 PM
Way cool! Are the carbs/runners anywhere big enough to feed those cylinders?
Title: Re: Solid pushrod end mating hydraulic tappet
Post by: xlfan on February 18, 2019, 12:31:25 AM
It will be exciting to find out, it hasn't been started yet  :smile: but it is stock carb for the 500cc BSA M33 cylinder. A tad smaller bore than the 1200 EVO, and a tad longer stroke than the 500 BSA, it will end up around 1100 cc, the build never had high performance as a goal, just a cool custom v-twin BSA, the world haven't seen too many of.  :smile: