S&S Lifter Failed - Replace with what??
Grand HDF Member
Joined: Jun 2009
Posts: 4,006
Likes: 1,240
From: On the Front Range, CO
I can't recommend which lifter you should go with. I have my preferences, but that's like being a Chevy or Dodge guy.
What I will say is - I wouldn't trust any mechanic/shop that wouldn't immediately suggest pulling the engine to split the cases. These engines are big enough to cannibalize themselves - if there wasn't metal glitter throughout the entire engine, I would be extremely surprised.
Also, flushing the oil cooler? IMHO, that should be replaced. If metal made it to the oil cooler, how did it not make it everywhere else in the engine?
If this repair isn't done correctly, you'll be chasing it for a while to come, both time and money.
It sucks. I can relate with first hand experience, on more than one occasion.
What I will say is - I wouldn't trust any mechanic/shop that wouldn't immediately suggest pulling the engine to split the cases. These engines are big enough to cannibalize themselves - if there wasn't metal glitter throughout the entire engine, I would be extremely surprised.
Also, flushing the oil cooler? IMHO, that should be replaced. If metal made it to the oil cooler, how did it not make it everywhere else in the engine?
If this repair isn't done correctly, you'll be chasing it for a while to come, both time and money.
It sucks. I can relate with first hand experience, on more than one occasion.
Tourer
Joined: May 2020
Posts: 294
Likes: 169
From: California
I can't recommend which lifter you should go with. I have my preferences, but that's like being a Chevy or Dodge guy.
What I will say is - I wouldn't trust any mechanic/shop that wouldn't immediately suggest pulling the engine to split the cases. These engines are big enough to cannibalize themselves - if there wasn't metal glitter throughout the entire engine, I would be extremely surprised.
Also, flushing the oil cooler? IMHO, that should be replaced. If metal made it to the oil cooler, how did it not make it everywhere else in the engine?
If this repair isn't done correctly, you'll be chasing it for a while to come, both time and money.
It sucks. I can relate with first hand experience, on more than one occasion.
What I will say is - I wouldn't trust any mechanic/shop that wouldn't immediately suggest pulling the engine to split the cases. These engines are big enough to cannibalize themselves - if there wasn't metal glitter throughout the entire engine, I would be extremely surprised.
Also, flushing the oil cooler? IMHO, that should be replaced. If metal made it to the oil cooler, how did it not make it everywhere else in the engine?
If this repair isn't done correctly, you'll be chasing it for a while to come, both time and money.
It sucks. I can relate with first hand experience, on more than one occasion.
I would worry more about the installation and repair of your motor. I think most Harley mechanical problems are due more to bad installation than an actual defective unit
Road Warrior
Joined: Nov 2022
Posts: 1,541
Likes: 543
From: MN
I took @$tonecold advice and went with VThunder / CompCam / Chevy LS lifters for my M8 Stage II build. I've owned several LS Chevy engines, put many thousands of miles on them, never had a lifter failure, know of no one that did, and there were lots of these trucks at my workplace where guys talked about their vehicles, so I would have picked up on repeat failures. Also subscribed to automotive trade mags, never read anything about this.
Does a small block Chevy LS V8 engine (with 16 lifters) equate to a Harley V-Twin M8 (4 lifters) with a different cam profile? Of course not. It just speaks to reliability and durability of the brand (whoever makes these) in a high volume automotive application, with millions of engines built. If these fail in an M8 application, then something else is going on - cam too aggressive loading on the lifter, insufficient oiling, etc. RPM isn't an issue either if the M8 in question wasn't modified to overspeed past the ECM limit.
Does a small block Chevy LS V8 engine (with 16 lifters) equate to a Harley V-Twin M8 (4 lifters) with a different cam profile? Of course not. It just speaks to reliability and durability of the brand (whoever makes these) in a high volume automotive application, with millions of engines built. If these fail in an M8 application, then something else is going on - cam too aggressive loading on the lifter, insufficient oiling, etc. RPM isn't an issue either if the M8 in question wasn't modified to overspeed past the ECM limit.
Club Member
Joined: Dec 2014
Posts: 10,734
Likes: 3,755
From: SWFL
I took @$tonecold advice and went with VThunder / CompCam / Chevy LS lifters for my M8 Stage II build. I've owned several LS Chevy engines, put many thousands of miles on them, never had a lifter failure, know of no one that did, and there were lots of these trucks at my workplace where guys talked about their vehicles, so I would have picked up on repeat failures. Also subscribed to automotive trade mags, never read anything about this.
Does a small block Chevy LS V8 engine (with 16 lifters) equate to a Harley V-Twin M8 (4 lifters) with a different cam profile? Of course not. It just speaks to reliability and durability of the brand (whoever makes these) in a high volume automotive application, with millions of engines built. If these fail in an M8 application, then something else is going on - cam too aggressive loading on the lifter, insufficient oiling, etc. RPM isn't an issue either if the M8 in question wasn't modified to overspeed past the ECM limit.
Does a small block Chevy LS V8 engine (with 16 lifters) equate to a Harley V-Twin M8 (4 lifters) with a different cam profile? Of course not. It just speaks to reliability and durability of the brand (whoever makes these) in a high volume automotive application, with millions of engines built. If these fail in an M8 application, then something else is going on - cam too aggressive loading on the lifter, insufficient oiling, etc. RPM isn't an issue either if the M8 in question wasn't modified to overspeed past the ECM limit.
Seasoned HDF Member
Joined: May 2012
Posts: 32,934
Likes: 36,032
From: Carlsbad, CA
Im curious what the failure mechanism was of the S&S lifter.
The reason i ask. My M8 developed cold start lifter rattle around 5,000 miles. Then I had the dealer install the Hd torque cam, latest oil pump, and S&S lifters. After a while the S&S lifter developed cold start rattle. So, Im wondering if there is an oil flow issue. 🤔
The reason i ask. My M8 developed cold start lifter rattle around 5,000 miles. Then I had the dealer install the Hd torque cam, latest oil pump, and S&S lifters. After a while the S&S lifter developed cold start rattle. So, Im wondering if there is an oil flow issue. 🤔
Last edited by TriGeezer; Aug 28, 2023 at 11:20 AM.
Road Warrior
Joined: Nov 2022
Posts: 1,541
Likes: 543
From: MN
Now we're into the meat of the issue - if guys are making race motors, then maybe the best that can be done with such aggressive cams and high spring loads is the dual bushing race lifters and having to replace them every 10k miles? I mean, it doesn't seem like anybody wants to, or can, make lifters for such high load applications in small quantities? IF this is the case, then yer stuck with what the market parts limitations are.
Road Master
Joined: Mar 2013
Posts: 817
Likes: 380
From: Central Ohio
There are plenty of LS guys running stock type lifters (like the Comp #850 / Delphi / GM LS7) with much higher seat pressure than factory, and at a higher RPM than the Harley guys spin. There is also a point where people need to understand that we're forcing a hydraulic lifter to do a job it wasn't intended to
Club Member
Joined: Dec 2014
Posts: 10,734
Likes: 3,755
From: SWFL
What do you mean opening force? No way your springs are 350# on the "seat", which is how most springs are set, then the spring will have a "rate per inch".
There are plenty of LS guys running stock type lifters (like the Comp #850 / Delphi / GM LS7) with much higher seat pressure than factory, and at a higher RPM than the Harley guys spin. There is also a point where people need to understand that we're forcing a hydraulic lifter to do a job it wasn't intended to
There are plenty of LS guys running stock type lifters (like the Comp #850 / Delphi / GM LS7) with much higher seat pressure than factory, and at a higher RPM than the Harley guys spin. There is also a point where people need to understand that we're forcing a hydraulic lifter to do a job it wasn't intended to
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HD EFI Guru
Joined: Jan 2008
Posts: 4,490
Likes: 4,776
My understanding is seat force and open force are two very different values. Think about it. With seat force, the spring is close to its fully extended state. Exerting a minimal amount of force. However when you compress the spring, you need more force as you compress it to max. This explains it pretty well. https://help.summitracing.com/app/an...t%20max%20lift.
Seat pressure and open pressures are very similar between a HD spring and a LS spring. Now when you start talking about aftermarket springs, its a different ball game. The biggest issue is that a LS engine delivers much more oil to the lifter at low RPM's than a HD engine. Hot idle oil pressure in a LS engine is typically 25 - 30 psi with a running pressure of 40 - 60 psi. A HD engine on the other hand is lucky to have 5 psi at hot idle to the lifters, and IMHO that is the route cause of the HD lifter issues. The CVO 110 used heavier valve springs and the combination of low oil pressure and heavy springs killed lifters all the time in city type driving. We were able to track the lifter failures of city ridden bikes versus bikes ridden mainly in the country or open highway and the failure rate over quadrupled in the city ridden bikes. In speaking with a lifter designer who told me that a minimum oil pressure at the lifter for a hydraulic lifter to be 16 psi and running less than that would cause lifter failure. So a HD with lifter failures, does just what he told me would happen to the lifters.
So I do not want any higher spring pressure that you must have to control the valve motion, and work to keep the oil pressure up at lower engine RPM's in HD applications.
Now we're into the meat of the issue - if guys are making race motors, then maybe the best that can be done with such aggressive cams and high spring loads is the dual bushing race lifters and having to replace them every 10k miles? I mean, it doesn't seem like anybody wants to, or can, make lifters for such high load applications in small quantities? IF this is the case, then yer stuck with what the market parts limitations are.
This is why Steve Cole designed springs that allow higher lift cams with the stock spring pressures. With four valve heads the pressure required for each valve is much less. Even though each lifter is opening two valves, if you keep the spring pressures at the stock level, you shouldn't experience a problem with lifters caused by being overloaded by the springs.