Lifter pre-load

Reply Subscribe

Thread Tools

Search this Thread

Jun 4, 2020 | 07:18 AM

#11

Racepres

Seasoned HDF Member

Joined: Jul 2014

Posts: 8,590

Likes: 3,361

From: Cental, MI

^^ I go with Schex...and the EV-27 is noisy... no preload is going to Change that... Adjustable is For Out of Normal Cam Specs...and there are still One Piece pushrods available, in custom Lengths... I use a set of adjustables to get the appropriate length...
Oh...and if you run Solid Lifters.... ya Need adjustable pushrods... Think Ironhead Sportster, and converted Shovelheads... Gots 'Em

Jun 4, 2020 | 05:39 PM

#12

Adam76

Road Master

Joined: Apr 2017

Posts: 1,050

Likes: 92

From: out there

Quote:

Originally Posted by Racepres

^^ I go with Schex...and the EV-27 is noisy... no preload is going to Change that... Adjustable is For Out of Normal Cam Specs...and there are still One Piece pushrods available, in custom Lengths... I use a set of adjustables to get the appropriate length...
Oh...and if you run Solid Lifters.... ya Need adjustable pushrods... Think Ironhead Sportster, and converted Shovelheads... Gots 'Em

ok thanks , I was told that a bit more preload makes the ev27 a little quieter? If not then the stock pushrods will be the easiest for me. I'm just running Johnson hylift hydraulic tappets.
cheers

Jun 4, 2020 | 09:51 PM

#13

1997bagger

Seasoned HDF Member

Joined: Aug 2008

Posts: 5,079

Likes: 2,151

From: Ohio

Quote:

Originally Posted by Schex

If your not going to machine any surfaces, and If the engine is stock, it should have about .100" preload.
Then going from stock head gaskets to .030" Cometics will gain about .015", if your pistons are in the hole enough to use Cometic .010" base gaskets, you gain another .005" or .010", so your at or near .125"., which should be OK.

.125 should calm down a EV-27 or Woods cam, ran a Wood W6H for roughly 8 years, setting the lifter depth to .140 does quiet them down but depends on oil pressure, lifter condition and valve spring pressure. It's my understanding the clack comes from the steep ramp of the cam lobe shock hit and recovery of the lifter not really designed for a street engine. The .140 has already lost roughly .020 from thermal expansion making it .120, a .100 setting will be roughly at .080 now, seems the tighter compressed oil area of a lifter takes the shock better than longer travel possibly due more like a solid lifter not collapsing and recovers easier from the cam step lobe shock. Trying to use a 3rd grade education the best as possible and ran the most aggressive street cam design being quiet as a church mouse, the 640 in the current engine is quiet setting lifters deep.

Last edited by 1997bagger; Jun 4, 2020 at 09:55 PM.

Jun 6, 2020 | 08:04 AM

#14

Racepres

Seasoned HDF Member

Joined: Jul 2014

Posts: 8,590

Likes: 3,361

From: Cental, MI

Quote:

Originally Posted by Adam76

ok thanks , I was told that a bit more preload makes the ev27 a little quieter? If not then the stock pushrods will be the easiest for me. I'm just running Johnson hylift hydraulic tappets.
cheers

Running an EV27 right now...with O.E. Pushrods... I would do it that way again... In fact next is an EV13...again I will use O.E. Pushrods