Solid Roller Lifters with Hydraulic Roller Cam
Teching In
Joined: Mar 2018
Posts: 11
Likes: 4
From: Montgomery IL
I run a hybrid (ie solid rollers on a hydraulic roller cam) in my traditional Pontiac based 433ci motor. The primary reason for doing this is to use an off the shelf cam (typically hydraulic roller profiles are more popular thus their performance characteristics are "known" and established) with a light weight lifter that delivers consistent performance.
While it works perfectly in my car, there are three considerations:
1) Valve lash may need to be set as low as .004. Getting that kind of accuracy by nailing the pushrod length on a non-adjustable rocker set up like most LSs have would be a nightmare. So in my view, adjustable rockers would be mandatory.
2) Due to take up and closing ramps, the lobes used need to be somewhat conservative. That would rule out most of the high lift stuff which are the profiles most likely sought after.
3) Valve Spring pressure will be essentially the same as a solid roller.
These three considerations beg the question, "what am I gaining here?" For an LS.........Not much, as there are lifters out there known to be reliable compared to retrofit hydraulic roller Pontiac lifters and the valve train is generally, not adjustable. Further, you can do plenty of RPM with LS off the shelf rollers. You might get a bit better stability at higher RPM if everything is set up perfectly, but none of it is probably worth the hassle or added cost on an LS application. Gen 1-2 motors, completely different story.
While it works perfectly in my car, there are three considerations:
1) Valve lash may need to be set as low as .004. Getting that kind of accuracy by nailing the pushrod length on a non-adjustable rocker set up like most LSs have would be a nightmare. So in my view, adjustable rockers would be mandatory.
2) Due to take up and closing ramps, the lobes used need to be somewhat conservative. That would rule out most of the high lift stuff which are the profiles most likely sought after.
3) Valve Spring pressure will be essentially the same as a solid roller.
These three considerations beg the question, "what am I gaining here?" For an LS.........Not much, as there are lifters out there known to be reliable compared to retrofit hydraulic roller Pontiac lifters and the valve train is generally, not adjustable. Further, you can do plenty of RPM with LS off the shelf rollers. You might get a bit better stability at higher RPM if everything is set up perfectly, but none of it is probably worth the hassle or added cost on an LS application. Gen 1-2 motors, completely different story.
TECH Resident
Joined: Sep 2019
Posts: 822
Likes: 262
From: Melbourne, Australia
you would run the spring pressures the same unless your using adjustable rockers.
Better to go llsr cam and use stsndard rockers then use shims and pushrod length to set lash tht way you can run lighter spring pressures if weight is your reason for using solids(i think darth has a thread here on tht)
You achieve nothing by using solid lifters , the weight saving is no where near important on the lifter side as it is on the valve side
Better to go llsr cam and use stsndard rockers then use shims and pushrod length to set lash tht way you can run lighter spring pressures if weight is your reason for using solids(i think darth has a thread here on tht)
You achieve nothing by using solid lifters , the weight saving is no where near important on the lifter side as it is on the valve side
Teching In
Joined: Mar 2018
Posts: 11
Likes: 4
From: Montgomery IL
you would run the spring pressures the same unless your using adjustable rockers.
Better to go llsr cam and use stsndard rockers then use shims and pushrod length to set lash tht way you can run lighter spring pressures if weight is your reason for using solids(i think darth has a thread here on tht)
You achieve nothing by using solid lifters , the weight saving is no where near important on the lifter side as it is on the valve side
Better to go llsr cam and use stsndard rockers then use shims and pushrod length to set lash tht way you can run lighter spring pressures if weight is your reason for using solids(i think darth has a thread here on tht)
You achieve nothing by using solid lifters , the weight saving is no where near important on the lifter side as it is on the valve side
I get there is not much to be had by decreasing lifter weight but clearly that is not the sole or even primary reason anyone is considering running a hybrid.
Joined: May 2004
Posts: 1,593
Likes: 267
From: Halfway back on the Highway to Hell...again!
Like Jimbo said, Call Cam motion. You'll talk to Bobby or Steve. Both are good friends of mine and they will explain the low lash setup. One of the ladies at Cam motion has a C6 Vette that uses a LLSR and dailys it. She has umpteen thousand miles on it and has yet to do an adjustment. The motor I'm building, a 416 for an Optima streetcar challenge car, is getting a Bumpstick Bobby special LLSR.
BTW, you will always see a nice hp gain through the entire band going Solid.
The only real downside is cost. It is definitely not cheap. Typical initial cost is about $2500-3k
BTW, you will always see a nice hp gain through the entire band going Solid.
The only real downside is cost. It is definitely not cheap. Typical initial cost is about $2500-3k
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TECH Addict
Joined: Dec 2017
Posts: 2,190
Likes: 976
Works fine. Set the lash REAL close, like, .006" - .010". Won't be "as good as" a properly spec'ed solid, but will "work" "OK". Sometimes surprisingly well. Other times ... not so much. The weenier the hyd cam, the less likely it is to be a disaster.
Rarely as well as a purpose-built setup. But, sometimes you can get the benefits of solid lifters, with a cam you already have.
A solid tends to need more spring than a hyd, esp seat pressure. Best to choose an "optional" "hi-perf" spring as spec'ed for the cam, not the " minimum acceptable".
Rarely as well as a purpose-built setup. But, sometimes you can get the benefits of solid lifters, with a cam you already have.
A solid tends to need more spring than a hyd, esp seat pressure. Best to choose an "optional" "hi-perf" spring as spec'ed for the cam, not the " minimum acceptable".
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Verdad Gallardo Joined: May 2004
Posts: 1,593
Likes: 267
From: Halfway back on the Highway to Hell...again!
The cons are: noisy valvetrain, $800 for lifters, $12-1500 for rockers plus gaskets an other misc stuff.
Noisy valvetrain yes if it’s an old school solid that waned .010-012 lash. The LLSR stuff is quiet as a mouse. No lash = no noise.
Joined: May 2004
Posts: 1,593
Likes: 267
From: Halfway back on the Highway to Hell...again!