Question on hydraulic lifters
06-02-2005, 12:57 PM
#3
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Originally Posted by 777
It's the springs that cause valve float. I don't know what you are talking about. You'd have to give us a LOT more information on what your setup is to help you out.
Excuse me for my ignorance. I am relatively new to LS1 motors. I am just trying to determine the rpm range of my motor.
I've had some experience in the past with the first generation small block chevy. The problem on those motors was that the hydraulic lifter would 'float' at about 6500 rpm. In other words, at high rpm, the orifices within the lifter that allowed the oil to circulate back and forth (hence, hydraulic lifter) were not large enough to allow the fluid too pass under high rpm (6500+). The lifter would then 'float'. This was one of the main drivers for going to a solid cam since it allowed you to extend your rpm range.
The only reason why I am asking is because I may want to go to a solid roller cam someday, but not sure if I can justify it just now.
I've already have the heavy duty springs and retainers.
06-02-2005, 01:10 PM
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Originally Posted by 10SECDWS6
Excuse me for my ignorance. I am relatively new to LS1 motors. I am just trying to determine the rpm range of my motor.
I've had some experience in the past with the first generation small block chevy. The problem on those motors was that the hydraulic lifter would 'float' at about 6500 rpm. In other words, at high rpm, the orifices within the lifter that allowed the oil to circulate back and forth (hence, hydraulic lifter) were not large enough to allow the fluid too pass under high rpm (6500+). The lifter would then 'float'. This was one of the main drivers for going to a solid cam since it allowed you to extend your rpm range.
The only reason why I am asking is because I may want to go to a solid roller cam someday, but not sure if I can justify it just now.
I've already have the heavy duty springs and retainers.
I've had some experience in the past with the first generation small block chevy. The problem on those motors was that the hydraulic lifter would 'float' at about 6500 rpm. In other words, at high rpm, the orifices within the lifter that allowed the oil to circulate back and forth (hence, hydraulic lifter) were not large enough to allow the fluid too pass under high rpm (6500+). The lifter would then 'float'. This was one of the main drivers for going to a solid cam since it allowed you to extend your rpm range.
The only reason why I am asking is because I may want to go to a solid roller cam someday, but not sure if I can justify it just now.
I've already have the heavy duty springs and retainers.
06-02-2005, 01:22 PM
#5
TECH Senior Member
Valves float not lifters.
Incorrect valvetrain geometry / spring weakness will cause that.
A lifter pump up is when you have incorrect preload on the lifters, then they pump up at higher rpm, which will cause their failure.
Incorrect valvetrain geometry / spring weakness will cause that.
A lifter pump up is when you have incorrect preload on the lifters, then they pump up at higher rpm, which will cause their failure.
06-02-2005, 01:24 PM
#6
Originally Posted by 10SECDWS6
Excuse me for my ignorance. I am relatively new to LS1 motors. I am just trying to determine the rpm range of my motor.
I've had some experience in the past with the first generation small block chevy. The problem on those motors was that the hydraulic lifter would 'float' at about 6500 rpm. In other words, at high rpm, the orifices within the lifter that allowed the oil to circulate back and forth (hence, hydraulic lifter) were not large enough to allow the fluid too pass under high rpm (6500+). The lifter would then 'float'. This was one of the main drivers for going to a solid cam since it allowed you to extend your rpm range.
The only reason why I am asking is because I may want to go to a solid roller cam someday, but not sure if I can justify it just now.
I've already have the heavy duty springs and retainers.
I've had some experience in the past with the first generation small block chevy. The problem on those motors was that the hydraulic lifter would 'float' at about 6500 rpm. In other words, at high rpm, the orifices within the lifter that allowed the oil to circulate back and forth (hence, hydraulic lifter) were not large enough to allow the fluid too pass under high rpm (6500+). The lifter would then 'float'. This was one of the main drivers for going to a solid cam since it allowed you to extend your rpm range.
The only reason why I am asking is because I may want to go to a solid roller cam someday, but not sure if I can justify it just now.
I've already have the heavy duty springs and retainers.
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06-02-2005, 01:48 PM
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Originally Posted by 777
I didn't mean to be rude if that is how you took it. You can run the stock lifters (with everything else being setup correctly; springs, retainers etc.) to 7000+ Thing is does your cam make power up there. If it doesn't there is no need to rev that high.
Cam is a G5 cam: http://www.lmperformance.com/4934/1.html
Springs are the comp cam valve springs.
I might change out the cam later for a soild roller w/ alittle more lift/duration.
No offense taken
06-02-2005, 01:51 PM
#9
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Originally Posted by 10SECDWS6
Cam is a G5 cam: http://www.lmperformance.com/4934/1.html
Springs are the comp cam valve springs.
I might change out the cam later for a soild roller w/ alittle more lift/duration.
No offense taken
Springs are the comp cam valve springs.
I might change out the cam later for a soild roller w/ alittle more lift/duration.
No offense taken
06-02-2005, 02:05 PM
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Originally Posted by PREDATOR-Z
Dude no offense, but I do not think you understand what it means to go solid roller.
Trust me, I know exactly what it means to go solid roller
06-02-2005, 02:10 PM
#12
There's more to a solid roller setup than just changing cams to a "solid roller" cam. You have to do a lot of work to the valvetrain.
There is more than one type of spring that comp makes. Some are strong, some aren't. Which ones do you have?
EDIT: Just to let you know, I am running quite a bit bigger cam than that and I don't have any valve float even at 6800
There is more than one type of spring that comp makes. Some are strong, some aren't. Which ones do you have?
EDIT: Just to let you know, I am running quite a bit bigger cam than that and I don't have any valve float even at 6800
Last edited by 777; 06-02-2005 at 02:16 PM.
06-02-2005, 02:13 PM
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Originally Posted by 777
There's more to a solid roller setup than just changing cams to a "solid roller" cam. You have to do a lot of work to the valvetrain.
There is more than one type of spring that comp makes. Some are strong, some aren't. Which ones do you have?
There is more than one type of spring that comp makes. Some are strong, some aren't. Which ones do you have?
Agreed....
06-02-2005, 02:14 PM
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Source: http://www.amotion.com/tech/camtalk.html
HYDRAULIC lifters use the engine's oiling system to automatially adjust the valve lash (clearance) to zero. They are the most common type of flat tappet cams and lifters for street use. Hydraulic cams can use any one of the three types of these oil filled lifters.
Stock type hydraulic lifters are quiet running and require little or no adjustment after installation but are limited in performance to about 5500 rpm. The ANTI-PUMPUP lifter is a type of hydraulic lifter that will rev higher but requires adjustable valve train components. VARIABLE (also known as Vari-Duration) hydraulic lifters are the next step up from anti-pumpup lifters. They improve low-end power and permit higher rpm use without the requirement of valve adjustment. RHOADS is the original manufacturer of variable hydraulic lifters and still makes the most effective ones.
MECHANICAL or SOLID cams use a solid or oil control flat tappet (lifter) which requires regular valve adjustment. Some performance shops prefer solid lifters, even for street use, because they can adjust the way a cam will perform to a limited extent by changing the amount of lash (clearance) in the valve train. Decreasing the lash increases the duration and lift, increasing the lash decreases the duration and lift. For race use solid lifters will perform up to about 8500 rpm.
MUSHROOM lifter cams use solid lifters that look similar to an upside-down mushroom. The base of the lifter (where it contacts the cam lobe) is wider than the body of the lifter. These are used mostly on oval tracks when roller lifters aren't allowed. Block machining at the bottom of the lifter bores is required.
ROLLER cams, as the name implies, use a lifter with a roller as the surface that follows the cam lobe. The roller surface allows very precise valve movement, as well as reduced friction, permitting a much wider operating range than is available with a flat tappet cam. Hydraulic roller lifters are common in late model engines and a variety of performance cams are available. They are as quiet and maintainance free as flat hydraulic lifters. Solid roller lifters are used mostly in highly modified race engines although there are a couple available for "pro street" applications. For maximum rpm use a solid roller design is definitely the best choice.
HYDRAULIC lifters use the engine's oiling system to automatially adjust the valve lash (clearance) to zero. They are the most common type of flat tappet cams and lifters for street use. Hydraulic cams can use any one of the three types of these oil filled lifters.
Stock type hydraulic lifters are quiet running and require little or no adjustment after installation but are limited in performance to about 5500 rpm. The ANTI-PUMPUP lifter is a type of hydraulic lifter that will rev higher but requires adjustable valve train components. VARIABLE (also known as Vari-Duration) hydraulic lifters are the next step up from anti-pumpup lifters. They improve low-end power and permit higher rpm use without the requirement of valve adjustment. RHOADS is the original manufacturer of variable hydraulic lifters and still makes the most effective ones.
MECHANICAL or SOLID cams use a solid or oil control flat tappet (lifter) which requires regular valve adjustment. Some performance shops prefer solid lifters, even for street use, because they can adjust the way a cam will perform to a limited extent by changing the amount of lash (clearance) in the valve train. Decreasing the lash increases the duration and lift, increasing the lash decreases the duration and lift. For race use solid lifters will perform up to about 8500 rpm.
MUSHROOM lifter cams use solid lifters that look similar to an upside-down mushroom. The base of the lifter (where it contacts the cam lobe) is wider than the body of the lifter. These are used mostly on oval tracks when roller lifters aren't allowed. Block machining at the bottom of the lifter bores is required.
ROLLER cams, as the name implies, use a lifter with a roller as the surface that follows the cam lobe. The roller surface allows very precise valve movement, as well as reduced friction, permitting a much wider operating range than is available with a flat tappet cam. Hydraulic roller lifters are common in late model engines and a variety of performance cams are available. They are as quiet and maintainance free as flat hydraulic lifters. Solid roller lifters are used mostly in highly modified race engines although there are a couple available for "pro street" applications. For maximum rpm use a solid roller design is definitely the best choice.
06-02-2005, 02:24 PM
#15
TECH Senior Member
I meant understand the implications on your LS1.
G5-112 G5 224/230 Duration & 581/572 Lift at 112 Lsa
G5-114 G5 224/230 Duration & 581/572 Lift at 114 Lsa.
G5-X1-112 G5X1 228/232 Duration & 588/574 Lift at 112 Lsa
G5-X1-114 G5X1 228/232 Duration & 588/574 Lift at 114 Lsa
G5-X2-112 G5X2 232/240 Duration & 595/608 Lift at 112 Lsa
G5-X2-114 G5X2 232/240 Duration & 595/608 Lift at 114 Lsa
G5-X3-112 G5X3 2??/2?? Duration & 600/610 Lift at 112 Lsa
G5-X3-114 G5X3 2??/2?? Duration & 600/610 Lift at 114 Lsa
as you can see, your cam is "small" compared to the bigger 3 other hydraulic ones the also carry, and now they even have an G5X4
You just do not go solid roller for just a "little more lift"
G5-112 G5 224/230 Duration & 581/572 Lift at 112 Lsa
G5-114 G5 224/230 Duration & 581/572 Lift at 114 Lsa.
G5-X1-112 G5X1 228/232 Duration & 588/574 Lift at 112 Lsa
G5-X1-114 G5X1 228/232 Duration & 588/574 Lift at 114 Lsa
G5-X2-112 G5X2 232/240 Duration & 595/608 Lift at 112 Lsa
G5-X2-114 G5X2 232/240 Duration & 595/608 Lift at 114 Lsa
G5-X3-112 G5X3 2??/2?? Duration & 600/610 Lift at 112 Lsa
G5-X3-114 G5X3 2??/2?? Duration & 600/610 Lift at 114 Lsa
as you can see, your cam is "small" compared to the bigger 3 other hydraulic ones the also carry, and now they even have an G5X4
You just do not go solid roller for just a "little more lift"
06-02-2005, 05:03 PM
#18
TECH Senior Member
Originally Posted by Unaffiliated Racing
Well valves do float..but it's caused by many things. Mainly the ability of the lifter not being able to keep up. You can only out so much sping on it before the hydraulics in the lifter fails. And as we have discussed before weight is a huge issue. You and I both love the 918 springs...why?...because of the weight. Lifters are made to pump up. Pumping up will not cause any failure. It's when they won't pump up is when you run into adjustment problems.
I meant incorrect high preload (too long p-rod or too tight adjustables) will put too much stress on the lifter internals and when they pump up, they fail. sorry about that.
06-03-2005, 07:49 AM
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Wait a minute, valve float is basically when the valve has too much inertia and loses contact with the lifter. As stated before, the causes can be several things (springs, cam geometry, valve size, etc.)
06-03-2005, 07:58 AM
#20
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Originally Posted by bowtieman81
Wait a minute, valve float is basically when the valve has too much inertia and loses contact with the lifter. As stated before, the causes can be several things (springs, cam geometry, valve size, etc.)
Originally Posted by PREDATOR-Z
A lifter pump up is when you have incorrect preload on the lifters, then they pump up at higher rpm, which will cause their failure
Originally Posted by PREDATOR-Z
incorrect high preload (too long p-rod or too tight adjustables) will put too much stress on the lifter internals and when they pump up, they fail.
