Hydraulic roller lifter preload for more RPM's [Archive] - Chevelle Tech

: Hydraulic roller lifter preload for more RPM's


Badrat496
Aug 15th, 09, 2:25 AM
My combo
BBC 454
stroker crank 4.25
10.2 compression
ultradyne hydraulic roller 245/253 @ .050 650/650 lift 110 lc
850 holley DP
Team G single plain
MSD Ign.
I am wondering if anyone knows what would be the best preload for my Morel lifters for more RPM and to help prevent valve float?

Wolfplace
Aug 15th, 09, 2:48 AM
My combo
BBC 454
stroker crank 4.25
10.2 compression
ultradyne hydraulic roller 245/253 @ .050 650/650 lift 110 lc
850 holley DP
Team G single plain
MSD Ign.
I am wondering if anyone knows what would be the best preload for my Morel lifters for more RPM and to help prevent valve float?

Preload does not cause valve float
Loss of valve train control does

trmnatr
Aug 15th, 09, 2:59 AM
My combo
BBC 454
stroker crank 4.25
10.2 compression
ultradyne hydraulic roller 245/253 @ .050 650/650 lift 110 lc
850 holley DP
Team G single plain
MSD Ign.
I am wondering if anyone knows what would be the best preload for my Morel lifters for more RPM and to help prevent valve float?

I like to adjust them with it running, Some engines want 1/8, 1/4, 1/2 and 1 turn

Depends on the engine

My 327 wanted less than a 1/8 turn

Now they way i get them to zero is back it up until you feel it in your hand (hand on rocker, cant explain the feel, its just a feel you learn over time) then take it until at zero lash (you can feel it) then start to preload it listening to the engine - The engine will tell you what it wants

Mike is correct that preload doesnt cause valve float

Badrat496
Aug 15th, 09, 3:06 AM
Thanks for the replys!

GRN69CHV
Aug 15th, 09, 8:39 AM
What springs are you running? Springs really make the difference.

69-CHVL
Aug 15th, 09, 8:46 AM
One of the designers at Comp mentioned that hyd lifters are more sensitive to preload than what they would like. They are working on another hi-perf. hyd lifter that will be better.

GRUMPYVETTE
Aug 15th, 09, 1:39 PM
Preload does not cause valve float
Loss of valve train control does

I was wondering how long it would take for facts to enter this discussion, while its true that badly adjusted valves won,t help its the lifters loss of controlled contact with the cam lobes surface most of all that causes valve float,the more you pre-load the hydraulic lifter seat the more time it takes for the lifter to return its adjusted seat once its lost lobe contact and fully expanded its seat, to full length, you can add a rev kit and add a few hundred rpm by adding additional spring loads on the lifters but hydraulic lifters are fairly heavy compared to some of the better solid roller designs, and hydraulic lifters can,t use the same high spring loads and still work correctly and the cam lobe ramp designs are different between the two cam lobes

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=910&start=20

heres the frequent result of 6500rpm PLUS on a stock hydraulic roller lifter valve train
a few pics:

http://i29.tinypic.com/34sozyr.jpg

http://i29.tinypic.com/143gv2d.jpg

INTMD8
Aug 15th, 09, 2:15 PM
I usually aim for .080 preload on the lifter though I have not seen more or less effect rpm potential.

I run up to 200lbs seat pressure with a hyd roller on a turbo application that sees 7800rpm.

I would probably aim for around 180lbs on the seat with a hyd roller big block and try to keep it as light as possible at the valve. (use the smallest diameter spring with no damper to achieve the proper pressure, ti retainers, etc). You can run high seat pressure on a hyd roller if you use a spring that doesn't have a very high rate (say 390-425lbs/in). You do not want to run high seat pressure with a high rate spring as it will get crazy over the nose.

Run a stiff pushrod even at the expense of weight. A heavy pushrod will not effect rpm potential but a pushrod that is too weak certainly will.

Also, run a good quality rocker arm that lets you achieve proper valvetrain geometry. (pushrod length will need to be correct) but some cheapy rockers make it impossible to get the geometry correct regardless of pushrod length.

Wolfplace
Aug 15th, 09, 2:20 PM
Let me expand
Lifter preload does not cause "valve float"
But
More preload will cause more problems if you lose control of the valvetrain for a couple of reasons
Pretty simple if you stop & give it some thought
The more preload you have the longer it will take for the lifter to recover if you lose control simply because it takes longer for the lifter to stabilize
The more preload the further the valve is going to be off the seat when the piston comes up to greet it
Hence the pictures above

Some examples
Solid lifter cam
You have say 50 thou of clearance at the valve on the intake (yes you can run it this close & closer on the intake)
It is in fact very close to 50 thou under all conditions not considering rod stretch et al
The exhaust is a whole nuther can of worms,,, :D

Hyd lifters
You have the same static 50 thou with say 50 thou of preload
You lose control of the valvetrain for whatever reason (usually not enough spring or the wrong spring for the parts & RPM involved)

Ok, you now just lost that 50 thou of clearance times the rocker ratio
The math says you have negative 25 thou with a 1.5 rocker & negative 85 thou with a 1.7
You now get to take your own pictures just like Paul's :D

So,,
Although preload doesn't cause the problem it certainly compounds it & is one of the reasons for hyd lifters with "zero lash" or running less than "recommended" preload can in some cases help
It is not that you didn't "float" the valves,,, it is just that you did not notice it as much because it may recover quicker

Or in the words of Mr. Joe Sherman,,,
Hyd lifters are for girls :D
No disrespect for all the ladies out there that row gears & go fast, just a "politically incorrect" comment on squishy lifters,,,, so don't shoot the messenger

Badrat496
Aug 15th, 09, 4:33 PM
The springs were an upgrade when I purched the Dart heads to handle .650 lift they are supposed to be 150 seat 400 open. I will try and set the preload less to see if this helps. I may try the beehives cause a solid roller on the street idling worries me and flat tappets seem to go flat. Thanks for all the information so far keep it coming.

INTMD8
Aug 15th, 09, 5:45 PM
they are supposed to be 150 seat 400 open.

Seems a bit on the light side, especially if you have steel retainers. I would pull one off and have it checked (make sure to measure the installed height), if it's a cheaper spring they can sometimes lose 20+lbs of seat pressure very quickly.

Wolfplace
Aug 15th, 09, 6:32 PM
Seems a bit on the light side, especially if you have steel retainers. I would pull one off and have it checked (make sure to measure the installed height), if it's a cheaper spring they can sometimes lose 20+lbs of seat pressure very quickly.
=
Agreed, 150 is less than I would even consider with that cam.

Originally Posted by Badrat496 http://www.chevelles.com/forums/olp/images/buttons/viewpost.gif (http://www.chevelles.com/forums/showthread.php?p=2480051#post2480051)
they are supposed to be 150 seat 400 open


No offense but,,,
"supposed to be" does not really cut it, you need to check this stuff ;)

GRN69CHV
Aug 15th, 09, 7:46 PM
Since I went to Beehives, valve train stability is significantly improved. I run 1/2 turn preload. Couple advantages to a Beehive. Spring and retainer wetight are one. Harmonics are much better. Inherent design of dual springs is friction from inner/outer rubbing together. This completely goes away.

victtor
Aug 15th, 09, 8:04 PM
HI yes the behivee fixs alot probs in bbc hyd rollers i have had em in my zz454 6200rpm no probs
victtor

Badrat496
Aug 15th, 09, 8:13 PM
Does anyone know which beehive spring would work with my cam? I know call the manufacturer but is anyone useing ones that would work and do you trust them?

Wolfplace
Aug 15th, 09, 8:53 PM
Does anyone know which beehive spring would work with my cam? I know call the manufacturer but is anyone useing ones that would work and do you trust them?
=

Lunati 74855
These are some of the best Beehives around, they are a PAC spiring

Tokyo Torquer
Aug 15th, 09, 10:32 PM
I found the less pre-load, the better.. my Comp roller lifters were great at 1/4 turn pre-load, but my Morel roller lifters were quite noisey at start up with only 1/4 turn preload.. they wanted at least a 1/2 turn to stay quiet.

I have since given up on mushy lifters and their valve float issues.

how69ss
Aug 16th, 09, 6:41 PM
I found the less pre-load, the better.. my Comp roller lifters were great at 1/4 turn pre-load, but my Morel roller lifters were quite noisey at start up with only 1/4 turn preload.. they wanted at least a 1/2 turn to stay quiet.

I have since given up on mushy lifters and their valve float issues.

I have morels, 1/4 preload, which is what straub suggested for my setup for max hp. They are loud, too, when the engine starts up, until it's warmed up good.

steelcomp
Aug 16th, 09, 7:20 PM
I ran Morel HR's with 200/500# on a .640"/.620" Straub BB Chev blower cam that rev'd 6700 with no signs of slowing down. Vlves never floated, .025 (1/4 turn) preload.
Valve train geometry is essential to wanting to push a HR to it's limits. If you have a good, quality HR lifter like the Morel, you can get away with a little higher perssure on the nose. Seat pressure is your friend in preventing valve bounce.
It's an old hyd. lifter trick to zero lash them so they can't pump up. It's worth a few hp up top. You have to be careful though...if you're dealing with a stock lifter with a wire retainer and you really float the valves, the lifter plunger can pop the retainer and that's not considered a good thing.:sad:
I keep a very nice HR spring on the shelf if anyone is interested. It's a reverse rotation pac spring that works very well, annd is very reaosnable.

Wolfplace
Aug 16th, 09, 9:19 PM
I ran Morel HR's with 200/500# on a .640"/.620" Straub BB Chev blower cam that rev'd 6700 with no signs of slowing down. Vlves never floated, .025 (1/4 turn) preload.
Valve train geometry is essential to wanting to push a HR to it's limits. If you have a good, quality HR lifter like the Morel, you can get away with a little higher perssure on the nose. Seat pressure is your friend in preventing valve bounce.
It's an old hyd. lifter trick to zero lash them so they can't pump up. It's worth a few hp up top. You have to be careful though...if you're dealing with a stock lifter with a wire retainer and you really float the valves, the lifter plunger can pop the retainer and that's not considered a good thing.:sad:
I keep a very nice HR spring on the shelf if anyone is interested. It's a reverse rotation pac spring that works very well, annd is very reaosnable.

This is true, Morel now has a killer lifter that will easily handle well over 200 seat & 500 open
They recommend 15/40 oil & specifically recommend against using 20/50
I don't see a problem using something less than 15/40 if your clearances are set up for it but if you have an issue with these lifters assuming they are set up properly I would first try the recommended oil to see what happens.

But I feel if you are going to run squishy lifters in a performance application you should look at the Beehive springs
Set up properly Beehives appear excellent most of the time & there are some good ones out there now.
As noted earlier,run good pushrods & do not get real excited about weight on this side of the rocker
Stiffness is way more important,, you have enough crap acting like a spring ;)

steelcomp
Aug 16th, 09, 10:32 PM
These were just standard Morel HR's. Ran straight 30wt for the break in on the dyno, will recommend 10-40 M1 to the customer. If there's a problem, I'll up it to the 15-40, but this is a street deal so I don't really anticipate any issues.
+1 on the P/R's. The weight trade off for rigidity is definitely worth while.
I have zero experience with beehives, but I'm paying attention.;) This is true, Morel now has a killer lifter that will easily handle well over 200 seat & 500 open
They recommend 15/40 oil & specifically recommend against using 20/50
I don't see a problem using something less than 15/40 if your clearances are set up for it but if you have an issue with these lifters assuming they are set up properly I would first try the recommended oil to see what happens.

But I feel if you are going to run squishy lifters in a performance application you should look at the Beehive springs
Set up properly Beehives appear excellent most of the time & there are some good ones out there now.
As noted earlier,run good pushrods & do not get real excited about weight on this side of the rocker
Stiffness is way more important,, you have enough crap acting like a spring ;)

GRN69CHV
Aug 16th, 09, 10:35 PM
I've pulled the valve covers with the motor at full op temp with both dual springs and Beehives. A 425 rate Beehive will be noticeabpy cooler than the dual springs.

Badrat496
Aug 17th, 09, 12:52 AM
Im going to check with the guy who set up the heads to see if he thinks the springs are the problem. I took it out tonight and it seemed like it was cutting out around 5800 rpm and I have checked everthing else. Thanks for all the information and now I guess either more spring pressure or Beehives it is.

ss396boy
Aug 17th, 09, 2:24 AM
I ran Morel HR's with 200/500# on a .640"/.620" Straub BB Chev blower cam that rev'd 6700 with no signs of slowing down. Vlves never floated, .025 (1/4 turn) preload.


Good to know...i have the same combo of Morel's and Straub cam. Was only planning on spinning to 6k

69-CHVL
Aug 17th, 09, 8:29 AM
In regards to pump-up and holding the valves open - do you think that the lifter actually does have the time to pump-up and hold the valve open? When valve bounce happens, the valve will bounce off the seat once or twice and settle down. This happens so fast that they have to use cameras in slow motion to capture the action. I dont think I lifter will pump up that fast to take up the slack...were talking milliseconds here.

GRN69CHV
Aug 17th, 09, 9:28 AM
This is an interesting point. When first ran the 26120 Beehives on Vince's original 454HO motor with the iron rec port heads, the springs had to be set about .060-.080 shorther than installed , the factory lifters absolutely did not like the added seat pressure and had a valve tap at idle, even with 1 full turn preload. I take this as a true indication that the lifters were bleeding down due to higher seat pressures.

69-CHVL
Aug 17th, 09, 9:55 AM
The beehives seem to do OK with the GM lifters at the spec height/seat pressure of 155. Once I installed -.050 locks though to get a little more valve tip exposed (valve tips were flush with the retainer at the 1.88 height), that's when the lifters started ticking. Figure the pressure was around 170 at that point. Lifters probably didnt like the 155 either, just couldnt hear anything.

steelcomp
Aug 17th, 09, 12:22 PM
In regards to pump-up and holding the valves open - do you think that the lifter actually does have the time to pump-up and hold the valve open? When valve bounce happens, the valve will bounce off the seat once or twice and settle down. This happens so fast that they have to use cameras in slow motion to capture the action. I dont think I lifter will pump up that fast to take up the slack...were talking milliseconds here.
Valve bounce and lifter pumping are two totally different things. Yes valve bounce happens fast, but it's a power killer and can be destructive if too excessive. If the valve is bouncing it's not sealing or transferring heat. A lot of people think when they tighten their lash (on a solid lifter) and the engine runs better it means they need a different cam, when in many cases they're just settling down the rocker harmonics and reducing valve bounce. The lifter pump most guys are talking about is off the nose of the cam when the valves float. Then the valves won't bounce at all...they never close because yes, the lifter will pump up and take up the slack and hold the valve open.

Wolfplace
Aug 17th, 09, 1:58 PM
Valve bounce and lifter pumping are two totally different things. Yes valve bounce happens fast, but it's a power killer and can be destructive if too excessive. If the valve is bouncing it's not sealing or transferring heat. A lot of people think when they tighten their lash (on a solid lifter) and the engine runs better it means they need a different cam, when in many cases they're just settling down the rocker harmonics and reducing valve bounce. The lifter pump most guys are talking about is off the nose of the cam when the valves float. Then the valves won't bounce at all...they never close because yes, the lifter will pump up and take up the slack and hold the valve open.
=
Exactly :thumbsup:

Vince,
It is called negative acceleration where the pressure on the lifter can go to zero or near zero.
And if severe enough the lifter leaves the cam completely & comes crashing down uncontrollably somewhere on the closing side,,, this is very hard on parts
Ever ride a roller coaster or come off the edge of a steep hill?
Ever notice what happens when an elevator starts down?

If the internal oil & spring pressures in the lifter are more than the applied load which is what may happen off the nose,,,
guess which one wins ;)
Once "pumped up" it can take a fair amount of time for the lifter to stabilize again & the further it has to travel (the more oil it has to get rid of) the worse the problem can be

Anyway, what goes on at seating is only part of the problem

69-CHVL
Aug 17th, 09, 2:13 PM
=
Exactly :thumbsup:

Vince,
It is called negative acceleration where the pressure on the lifter can go to zero or near zero.
And if severe enough the lifter leaves the cam completely & comes crashing down uncontrollably somewhere on the closing side,,, this is very hard on parts
Ever ride a roller coaster or come off the edge of a steep hill?
Ever notice what happens when an elevator starts down?

If the internal oil & spring pressures in the lifter are more than the applied load which is what may happen off the nose,,,
guess which one wins ;)
Once "pumped up" it can take a fair amount of time for the lifter to stabilize again & the further it has to travel (the more oil it has to get rid of) the worse the problem can be

Anyway, what goes on at seating is only part of the problem

Did I mention I like solids for all of the above reasons :D

But seriously, if you valvetrain goes into this severe of separation, you got major issues regardless of preload, p/v clearance etc. Thing with hydraulics though, is that the more spring you add to prevent this, the more performance is typlically lost due to "bleed" off as I so elequantly documented.

Viscious, viscious, cylce. I'll stick with beehives and a ~6100 rpm ceiling on my next HR setup. Till then, I'm liking this XR286/EZ Roll combo...d#mn thing is making great power, w/o spreading needles throughout the motor :D, or oillite-type bushings yet :eek:

Wolfplace
Aug 17th, 09, 4:26 PM
Did I mention I like solids for all of the above reasons :D

But seriously, if you valvetrain goes into this severe of separation, you got major issues regardless of preload, p/v clearance etc. Thing with hydraulics though, is that the more spring you add to prevent this, the more performance is typlically lost due to "bleed" off as I so elequantly documented.

Viscious, viscious, cylce. I'll stick with beehives and a ~6100 rpm ceiling on my next HR setup. Till then, I'm liking this XR286/EZ Roll combo...d#mn thing is making great power, w/o spreading needles throughout the motor :D, or oillite-type bushings yet :eek:
=
Works for me :D

It does not have to be severe to "pump up" the lifter, that is just an example of the bad things that can happen,
We see signs of these kind of problems on the closing side with solids when not enough spring & or not enough pushrod is used
Or I suppose it could just be the design of the lobe but I am not a cam designer, just know that if you do not keep the acceleration down off the nose or you lose the ability to control it it can seperate & beat the crap out of things.
It is very hard to lose control when opening the valve but from full open on I think it gets interesting,,,

The "bleed" deal is not the issue with the Morel lifter it is with the stock type lifter or some other lifters as noted above by both Scott & I
They are designed to handle more spring
Good lifters to run if you feel the need to run squishy lifter stuff with aggresive lobes & or 5lb valves, :D

69-CHVL
Aug 17th, 09, 10:21 PM
Just for the record, my bleed down happened with Crane lifters, 175/440 springs, Ti retainers, and RPM-friendly lobes. I'm not sold on HR lifters till I see some real-world testing, as in make a couple of passes with the HR lifters, pull out and replace with solids, and no change in ET/MPH. Then I'll be sold on the $$$ HR lifters.

Tokyo Torquer
Aug 17th, 09, 10:55 PM
My last adventure with HR lifters was interesting. I installed a set of Morel hydraulic roller lifters and Pacaloy beehives with the seat pressure set at 175-180# and 380# open on my other blower motor. I knew the motor really well and was perplexed when I first drove it. Up to about 2500rpm, the exhaust note was very different and it picked up a bunch of low end torque. Nothing else had changed. At higher rpm, I noticed no change.

I can only think of one explanation for the above. At lower rpm/ oil pressure (and this motor had very healthy oil pressure), the morel lifter was bleeding down with the high seat pressure and creating a "smaller" cam. Once the revs/ rpm were up, she was able to keep the plunger up in the lifter bore.

GRN69CHV
Aug 18th, 09, 6:52 AM
Mike, that's exactly what we found, difference was I was running a higher over the nose pressure also, That's the beauty of a Beehive in this appication. You run less spring and get better valve train control at the same time.