lifter question, also may have found an easy way to verify pushrod length
01-11-2018, 06:50 PM
#1
lifter question, also may have found an easy way to verify pushrod length so before i ask u guys to **** all over my pushrod verification method i may have found, i need a question answered.
if u fully compress a new hydraulic lifter, will it stay fully bottomed out upon releasing. so if u were to rotate the crank by hand with the pushrods in the motor, after u do a few rotations will the plungers in the lifters be all bottomed out?
if u fully compress a new hydraulic lifter, will it stay fully bottomed out upon releasing. so if u were to rotate the crank by hand with the pushrods in the motor, after u do a few rotations will the plungers in the lifters be all bottomed out?
01-11-2018, 08:42 PM
#5
You wouldn't want to measure length with the lifters bottomed out anyway. Remember the lifters stay pumped up when the motor is running.
You shouldn't have an issue with lifter compression as you're checking length anyway. Since you want the cam on the base circle you don't have to worry about the valve springs compressing the lifter.
You shouldn't have an issue with lifter compression as you're checking length anyway. Since you want the cam on the base circle you don't have to worry about the valve springs compressing the lifter.
01-11-2018, 09:00 PM
#6
so i was thinking, everyone is afraid of slightly compressing a lifter during pushrod measuring and messing with the measurements right? well what if we bottomed them out on purpose. let me start over....
so u measure the int and exh on a 1 cylinder. say after preload u come up with needing a 7.375 rod. well the experts say u should check 3 or 4 cylinders if not all, but thats a pain in the ***, especially with the motor in the car. so u find some used 7.375 rods on ls1tech, and when they arrive, you pop them all in, and torque down ur rockers. then u rotate the motor by hand a few times bottoming out the lifters. now its time to check (or so my theory).
with the lifters bottomed out, and with cyl 1 at tdc, the int and exh valves are roughly on the base circles. and now ur rods would be loose, because the lifters are bottomed out. (as happy salesman said, this doesn't happen with the motor running) if you know the total travel of ur lifter is .15, and the desired preload is say .05, then u could use a feeler gauge under the rocker tip between the valve and if it comes to around .1 then u know you are correct (that space ur measuring between the valve and rocker won't exist because when running the lifter will pump back up each time until the rod won't let it AKA lifter preload).
but the real beauty if this method would work is that u could use the feeler gauge on all the other cylinders to check the lengths on them, all without using the pushrod length checker and loosening the rocker multiple times. does that make sense what i was thinking?
so u measure the int and exh on a 1 cylinder. say after preload u come up with needing a 7.375 rod. well the experts say u should check 3 or 4 cylinders if not all, but thats a pain in the ***, especially with the motor in the car. so u find some used 7.375 rods on ls1tech, and when they arrive, you pop them all in, and torque down ur rockers. then u rotate the motor by hand a few times bottoming out the lifters. now its time to check (or so my theory).
with the lifters bottomed out, and with cyl 1 at tdc, the int and exh valves are roughly on the base circles. and now ur rods would be loose, because the lifters are bottomed out. (as happy salesman said, this doesn't happen with the motor running) if you know the total travel of ur lifter is .15, and the desired preload is say .05, then u could use a feeler gauge under the rocker tip between the valve and if it comes to around .1 then u know you are correct (that space ur measuring between the valve and rocker won't exist because when running the lifter will pump back up each time until the rod won't let it AKA lifter preload).
but the real beauty if this method would work is that u could use the feeler gauge on all the other cylinders to check the lengths on them, all without using the pushrod length checker and loosening the rocker multiple times. does that make sense what i was thinking?
Last edited by Floorman279; 01-11-2018 at 09:03 PM. Reason: .....
01-12-2018, 12:27 AM
#7
I... sort of get it? However I don't think it would work well in practice. You'd have to take in the thickness of the spring at full bind that's inside the lifter during measurement. I feel like it's a too imprecise method (too much to mis-measure or give inaccurate readings) to work well. Not to mention you'd have to fully torque the heads on, make your measurements, remove the heads, reassemble the lifters, and torque the heads back on.
Seems like more work than the standard method tbh.
Seems like more work than the standard method tbh.
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01-12-2018, 06:45 AM
#8
I... sort of get it? However I don't think it would work well in practice. You'd have to take in the thickness of the spring at full bind that's inside the lifter during measurement. I feel like it's a too imprecise method (too much to mis-measure or give inaccurate readings) to work well. Not to mention you'd have to fully torque the heads on, make your measurements, remove the heads, reassemble the lifters, and torque the heads back on.
Seems like more work than the standard method tbh.
Seems like more work than the standard method tbh.
01-12-2018, 06:56 AM
#9
I have actually seen this type of measurement discussed in the past and it was by some pretty knowledgeable folks that use a method that bottoms the lifter. I think one issue is that you need to get the oil out of the lifter in a reliable manner so it will bottom and that might be tough.
01-13-2018, 05:44 PM
#10
I have actually seen this type of measurement discussed in the past and it was by some pretty knowledgeable folks that use a method that bottoms the lifter. I think one issue is that you need to get the oil out of the lifter in a reliable manner so it will bottom and that might be tough.
vettenuts, the guys you remember talking about this, were they speaking of lifters that don't have springs in them? maybe high end? i don't know anything about lifter anatomy
01-13-2018, 06:21 PM
#11
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Most guys use a solid lifter to do it.
01-13-2018, 11:37 PM
#13
TECH Senior Member
01-14-2018, 07:20 AM
#14
correct thats why i figured u could only use new lifters to do it. so the guys who responded to this thread say that theres a spring that prevents the lifter from staying bottomed out when pressure is released.
vettenuts, the guys you remember talking about this, were they speaking of lifters that don't have springs in them? maybe high end? i don't know anything about lifter anatomy
vettenuts, the guys you remember talking about this, were they speaking of lifters that don't have springs in them? maybe high end? i don't know anything about lifter anatomy
01-14-2018, 08:32 AM
#15
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Lifters are very difficult to compress. You dont need to make a solid lifter. The issue is, a regular valve spring is stronger. So that WILL compress it. Use a checker spring from COMP or use the rocker bolt turn method with everything setup with normal parts. Spring pressure does NOT come into play using that method. People way overthink this crap.
01-14-2018, 09:50 AM
#17
what i don't understand is many people say that u have to try to collapse the lifter at all when its new and dry, but now many people also say that u can easily collapse it and you should make a lifter a solid to measure. its not that we overthink it, its just who the hell do we believe? a ton of people say apples and a ton say oranges.
as far as checker springs, for the average garage guy setting up hydraulic rollers, not llsr or similar, we just need to be close not exact. why would i wanna pull the springs off my new heads to swap on the checkers? not to mention many people say checking one cylinder isn't enough. people aren't overthinking this, the internet is. no one can be right lol. thats why if my thought would work u get the "happy medium". ur doing the right thing by checking all cylinders, no need to remove the heads again which is a pain, and also saves u from swapping springs.
as far as checker springs, for the average garage guy setting up hydraulic rollers, not llsr or similar, we just need to be close not exact. why would i wanna pull the springs off my new heads to swap on the checkers? not to mention many people say checking one cylinder isn't enough. people aren't overthinking this, the internet is. no one can be right lol. thats why if my thought would work u get the "happy medium". ur doing the right thing by checking all cylinders, no need to remove the heads again which is a pain, and also saves u from swapping springs.
01-14-2018, 11:02 AM
#19
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what i don't understand is many people say that u have to try to collapse the lifter at all when its new and dry, but now many people also say that u can easily collapse it and you should make a lifter a solid to measure. its not that we overthink it, its just who the hell do we believe? a ton of people say apples and a ton say oranges.
as far as checker springs, for the average garage guy setting up hydraulic rollers, not llsr or similar, we just need to be close not exact. why would i wanna pull the springs off my new heads to swap on the checkers? not to mention many people say checking one cylinder isn't enough. people aren't overthinking this, the internet is. no one can be right lol. thats why if my thought would work u get the "happy medium". ur doing the right thing by checking all cylinders, no need to remove the heads again which is a pain, and also saves u from swapping springs.
as far as checker springs, for the average garage guy setting up hydraulic rollers, not llsr or similar, we just need to be close not exact. why would i wanna pull the springs off my new heads to swap on the checkers? not to mention many people say checking one cylinder isn't enough. people aren't overthinking this, the internet is. no one can be right lol. thats why if my thought would work u get the "happy medium". ur doing the right thing by checking all cylinders, no need to remove the heads again which is a pain, and also saves u from swapping springs.
01-14-2018, 11:25 AM
#20
And that where youre dead wrong. You have to literally LEAN on the pushrod to get the plunger in the lifter to go down. The rocker bolt can collapse it, the valve spring can collapse it (if you try hard enough). The rocker turn method requires NO solid lifter and NO checker spring. Its really very easy and simple and is something thats way over-thought. Right up there with pulling a harmonic balancer off.
anyway i think im just gonna go with the rocker turn method even tho many ppl **** on that method, and many like that method. thats the internet for u. anyway i just went and set my pushrod length checker to 7.333 (i did that because im measuring with a caliper and my 7.4s measured 7.409, so i added .008 to 7.325 assuming the ones i will be receiving will measure a little over 7.325) any who, i ended up getting 1.5 rocker bolt turns until the 22 lb click. i made sure the opposite valve on that cylinder was just beginning to open to make sure im on the base of the lobe. so that puts me roughly .072 preload which is a hair high but after reading threads on here and other forums many reported dead silent morels when u do .060 to .070 preload so actually i think im set. hopefully the rods i get mic a hair lower, than im perfect, if the bolt turn method doesn't leave me astray.
o and i did this on 2 cylinders and got the same result. and now those 2 lifters can easily be compressed and i can feel the spring pushing them back up. i guess once u break them free they move easy, or they just pumped up a minimal amount of oil from the oil soak