Differences in lifters
Road Captain
Joined: Jan 2008
Posts: 667
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From: Lufkin, Tx.
I'm running the V-Thunder 875-1 lifters in my build with Wood tw68g's and they are very quiet. I asked Wolfgang if he thought they would be ok and he said yes. Spoke with someone in the tech dept. at Comp Cams and they told me the 875-1 wasn't the short travel lifter, that it has .160 travel. So far they are working fine.
HDF Community Team
Joined: Jun 2006
Posts: 12,776
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From: san antonio
I'm running the V-Thunder 875-1 lifters in my build with Wood tw68g's and they are very quiet. I asked Wolfgang if he thought they would be ok and he said yes. Spoke with someone in the tech dept. at Comp Cams and they told me the 875-1 wasn't the short travel lifter, that it has .160 travel. So far they are working fine.
Seasoned HDF Member
Joined: Nov 2010
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From: Oxford, Nc
Good time for this question perhaps:
If you start at say .010" and adjust from there, ( my Black Ops run about .014,) what in the lifter gives an advantage to one adjustment vs the other?
In other words, if it is an 'adjustable' lifter, wouldn't the proper tension be achieved simply because the lifter is going to expand until it has no place to go, whether you start at .010 or end up with .014 as I did?
And it would follow, what advantage to a short travel lifter, higher rev capability perhaps?
If you start at say .010" and adjust from there, ( my Black Ops run about .014,) what in the lifter gives an advantage to one adjustment vs the other?
In other words, if it is an 'adjustable' lifter, wouldn't the proper tension be achieved simply because the lifter is going to expand until it has no place to go, whether you start at .010 or end up with .014 as I did?
And it would follow, what advantage to a short travel lifter, higher rev capability perhaps?
Road Captain
Joined: Jan 2008
Posts: 667
Likes: 59
From: Lufkin, Tx.
.160" is short travel; typical is .200" and the 875-1 is probably the better choice over the 850-1 for those cams. The 850-1 is, IMHO, a better choice for a big bore build with "bolt in" cams. Both the 850 and 875 are good hardware but you should be sure and talk to the parts guy at CompCams and make sure you get Delphi lifters, not brand X.
HDF Community Team
Joined: Jun 2006
Posts: 12,776
Likes: 2,607
From: san antonio
Originally Posted by Stiggy
If you start at say .010" and adjust from there, ( my Black Ops run about .014,) what in the lifter gives an advantage to one adjustment vs the other?
In other words, if it is an 'adjustable' lifter, wouldn't the proper tension be achieved simply because the lifter is going to expand until it has no place to go, whether you start at .010 or end up with .014 as I did?
And it would follow, what advantage to a short travel lifter, higher rev capability perhaps?
In other words, if it is an 'adjustable' lifter, wouldn't the proper tension be achieved simply because the lifter is going to expand until it has no place to go, whether you start at .010 or end up with .014 as I did?
And it would follow, what advantage to a short travel lifter, higher rev capability perhaps?
You have neglected to include the bleed down as part of your logic; every lifter has a bleed down rate. If hydraulic lifters didn't bleed down, they would be solid lifters. The cylinders grow taller as they heat up and increase the valve train stack up dimension. As the cylinder grows, the hydraulic lifter pumps up to maintain zero lash. Some lifters bleed down faster than others and the internals of the lifter, the viscosity of the oil, the oil termperature, machining tolerances and engine rpms affect the bleed down rate. When a lifter goes bad and bleeds down faster than it should, the bleed down introduces lash into the valve train and results in the noise some find so annoying.
When a lifter bleeds down it alters the valve timing as the lash has changed. On a hot start, the change in valve timing raises the CCP and this makes hot starts more susceptible to kickback. A limited travel lifter has less less room to bleed down and thus the valve timing is more consistant hot or cold. The other benefit is should valve float occur the limited travel will/should not allow the valve to come into contact with the piston as the lifter pumps up in it's attempt to maintain zero lash.
Last edited by djl; Sep 13, 2011 at 09:14 AM.
How are they better than the HQ lifters? Not wanting to start an argument, I'm just wonding what you base the statement on.
Last edited by Mike; Sep 15, 2011 at 01:31 PM.
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