Adjustable pushrod advantages
Seasoned HDF Member
Joined: Mar 2009
Posts: 24,712
Likes: 9,219
From: Snow Hill, NC
An adjustable pushrod allows the PROPER lifter pre-load, in spite of factory pre-load specs, to help insure quiet engine operation, at full thermal expansion.
Base circle, re-surfaced heads, longer/shorter cylinders are all other large reasons for their use.
Scott
Base circle, re-surfaced heads, longer/shorter cylinders are all other large reasons for their use.
Scott
Advanced
Joined: Oct 2015
Posts: 68
Likes: 1
From: ct
How is adding weight to the valve train good for perfomance?What is the difference in weight between stock and adjustables?Why does Harley put collapsable pushrod tubes on and solid pushrods on stock?Is adding reciprocating mass good?
Road Captain
Joined: May 2008
Posts: 718
Likes: 152
From: Ozarks
If my heads would just clear the frame and pop off I might go solids. I have to disassemble the rockers first and then remove the heads so adjustable rods are so much more convenient. The front cylinder isn't too bad at all but the rear is a total bitch.
Road Warrior
Joined: Sep 2015
Posts: 1,447
Likes: 463
From: USA
The collapsable push rod tubes has been a functional part of the vtwin valve train for years. It's been a easy access to pushrod adjustment when the adjustable pushrod length was the primary means of valve adjustment.
Last edited by Taggs; Apr 8, 2017 at 04:53 PM.
Seasoned HDF Member
Joined: Aug 2011
Posts: 11,814
Likes: 5,120
From: SW Ohio
Good point... I don't have the specs in front of me on the weight differences but I am sure it's measurable.
The collapsable push rod tubes has been a functional part of the vtwin valve train for years. It's been a easy access to pushrod adjustment when the adjustable pushrod length was the primary means of valve adjustment.
The collapsable push rod tubes has been a functional part of the vtwin valve train for years. It's been a easy access to pushrod adjustment when the adjustable pushrod length was the primary means of valve adjustment.
Like I said, adjustables aren't the devil and most people think it's a lot more work than it is to remove the top rocker cover and loosen/lift the rocker plate. Shops like adjustables because it's quicker for them and they get to sell a set of push rods and tubes. Granted there are some builds that will require them but doing maintenance like changing lifters, tensioners and the like on a stock engine it isn't necessary. Also, rocker box gaskets are good for a couple of times and don't need to be replaced every time.
Not to mention the breather umbrella valve and filter pad are wear items and having the rocker plate out is a fine time to drill the return hole out for less oil carry over to the intake. Earlier Twin Cams have a plastic (less efficient) breather assembly and you can replace them with the newer stamped steel models at this time for very little money. If you're not deaf like I am you might be concerned with top end noise and want to install Rockouts as well. In general, a short cut always short cuts something.
Last edited by Campy Roadie; Apr 9, 2017 at 04:50 AM.
Road Warrior
Joined: Sep 2015
Posts: 1,447
Likes: 463
From: USA
The 2 piece push rod tubes also provide a way to put your fingers on the solid push rod and turn it to insure there isn't any binding before starting the engine after re-assembly.
Like I said, adjustables aren't the devil and most people think it's a lot more work than it is to remove the top rocker cover and loosen/lift the rocker plate. Shops like adjustables because it's quicker for them and they get to sell a set of push rods and tubes. Granted there are some builds that will require them but doing maintenance like changing lifters, tensioners and the like on a stock engine it isn't necessary. Also, rocker box gaskets are good for a couple of times and don't need to be replaced every time.
Not to mention the breather umbrella valve and filter pad are wear items and having the rocker plate out is a fine time to drill the return hole out for less oil carry over to the intake. Earlier Twin Cams have a plastic (less efficient) breather assembly and you can replace them with the newer stamped steel models at this time for very little money. If you're not deaf like I am you might be concerned with top end noise and want to install Rockouts as well. In general, a short cut always short cuts something.
Like I said, adjustables aren't the devil and most people think it's a lot more work than it is to remove the top rocker cover and loosen/lift the rocker plate. Shops like adjustables because it's quicker for them and they get to sell a set of push rods and tubes. Granted there are some builds that will require them but doing maintenance like changing lifters, tensioners and the like on a stock engine it isn't necessary. Also, rocker box gaskets are good for a couple of times and don't need to be replaced every time.
Not to mention the breather umbrella valve and filter pad are wear items and having the rocker plate out is a fine time to drill the return hole out for less oil carry over to the intake. Earlier Twin Cams have a plastic (less efficient) breather assembly and you can replace them with the newer stamped steel models at this time for very little money. If you're not deaf like I am you might be concerned with top end noise and want to install Rockouts as well. In general, a short cut always short cuts something.
Road Captain
Joined: Dec 2015
Posts: 650
Likes: 355
From: connecticut
I thought I took the easy route until today when the front intake push rod (s&s adjustable decided to loosen up, and a $235 tow later and 30 minutes in my garage I locktited the lock nuts down. My fault, but that wont happen with non adjustables. This winter i installed the upgraded cam plate with hydraulic tensioner's oil pump s&s lifters lifters and andrews 21n cams. Not sure if I even needed adjustable s but it is such a pain in the *** to remove the tank, rocker covers and everything else.
Road Captain
Joined: Oct 2012
Posts: 520
Likes: 37
From: houston, tx
Just ordered some S&S adjustable push rods, though I wanted to use fixed custom length pushrods for my build. Chose the S&S because i didn't want to order a pushrod length checker and then possibly order 3 or 4 different pushrod lengths. (Not to mention time involved for shipping of the orders to get here.)
It was a tossup between the S&S and Smith Bothers, went with the cheaper option. Between the two i haven't read of any catastrophic failures or extra wear other than the occasional loctite experience.... Ability to swap lifters out without pulling the tank and rockers sold me as well.
It was a tossup between the S&S and Smith Bothers, went with the cheaper option. Between the two i haven't read of any catastrophic failures or extra wear other than the occasional loctite experience.... Ability to swap lifters out without pulling the tank and rockers sold me as well.
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The adjustability, quiet engine operation, and positive lifter load, trumps any negligible weight differences, every time.
Scott
Cruiser
Joined: Jan 2016
Posts: 101
Likes: 9
From: Massachusetts
Interesting thread. I had used S&S adjustables when installing an S&S 510G geared cam set in my 05 Softail Deluxe FLSTN.
Sure, I found the bolt cutting easy, and short cutting the extra disassembly at the top pretty neat. But I did later have an adjustable rod collapse and temporarily cause a dead valve and cylinder + awful clicking (rod was lashing up and down at this point). No problem, re-extend the rod, do the lifter pre-load and retighten. Probably, I had not done the jam-nut on the rod correctly. WATCH THIS.
I might, if I had to do it again, use my solid rods, and go through the extra disassembly, reassembly. Curious how one adds the right preload to existing lifters in this case- with reinstalling the solid rods and oem lifters.
Sure, I found the bolt cutting easy, and short cutting the extra disassembly at the top pretty neat. But I did later have an adjustable rod collapse and temporarily cause a dead valve and cylinder + awful clicking (rod was lashing up and down at this point). No problem, re-extend the rod, do the lifter pre-load and retighten. Probably, I had not done the jam-nut on the rod correctly. WATCH THIS.
I might, if I had to do it again, use my solid rods, and go through the extra disassembly, reassembly. Curious how one adds the right preload to existing lifters in this case- with reinstalling the solid rods and oem lifters.
Last edited by Brian Kelley; Apr 12, 2017 at 12:54 PM.