Morel roller lifter

[ek02]

Dave, what preload do you recommend on the 885's? I have tried "0" and a slight preload, and they are noisy no matter what. I know my lobe profile has a lot to do with the noise.

 

[David Husek]

They are the same as the 885's
Rite?
Check out this item I found on eBay: http://pages.ebay.com/motors/link/?nav=item.view&id=400301084761

If you order these, jegs or summit will drop ship from comp. Comp has superseded the 885 to 15853 which is an open wheel lifter(not shielded) and will not work.

 

[David Husek]

Dave, what preload do you recommend on the 885's? I have tried "0" and a slight preload, and they are noisy no matter what. I know my lobe profile has a lot to do with the noise.

The comp 885's preload should be .025" cold for an iron block iron head. You can take them up to .030".

 

[Ttype6]

I have tried "0" and a slight preload, and they are noisy no matter what.

As the motor heats up everything expands. This means that the clearances increase. If you don't preload enough,the lifters can't pump up/adjust to keep the clearance at zero as the rockers move farther away from the cam when the head grows.

 

[robzombie]

As the motor heats up everything expands. This means that the clearances increase. If you don't preload enough,the lifters can't pump up/adjust to keep the clearance at zero as the rockers move farther away from the cam when the head grows.

You have it backwards. Clearances decrease as everything heats up and EXPANDS.

That's why observed clearances are so important and you have to take into account machining [what has been taken away] and thermal expansion from normal operating temps.

They call it cold lash for a reason and it's always more clearance than hot lash.

You started the sentence off right and then took a 180* turn and I just wanted to point that out so as not to confuse people that read your post.

 

[bison]

You have it backwards. Clearances decrease as everything heats up and EXPANDS.

That's why observed clearances are so important and you have to take into account machining [what has been taken away] and thermal expansion from normal operating temps.

They call it cold lash for a reason and it's always more clearance than hot lash.

You started the sentence off right and then took a 180* turn and I just wanted to point that out so as not to confuse people that read your post.

You are incorrect. The cold lash with an aluminum headed engine will be greater once its up to operating temp. Aluminum alloys expand at nearly twice the rate of ferrous metals. Therefore preload decreases and lash will increase. Ive ran these lifters in various engines and when run with zero preload cold on an aluminum headed engine you can hear lash after making a pass.

 

[robzombie]

You are incorrect. The cold lash with an aluminum headed engine will be greater once its up to operating temp. Aluminum alloys expand at nearly twice the rate of ferrous metals. Therefore preload decreases and lash will increase. Ive ran these lifters in various engines and when run with zero preload cold on an aluminum headed engine you can hear lash after making a pass.

Where in this thread is aluminum even mentioned by the OP.

You are right,aluminum does expand at higher rates than steel for a given temperature. They also dissipate heat faster and allow more compression/boost and timing than a steel headed motor, which means they actually run cooler than steel heads because they retain less heat.

If you want to get into aluminum VS. steel heads we can start another thread, but there are already many threads on here that support many differing opinions on each.

I wasn't wrong in what I said, as the engine comes up to temp the clearances will decrease due to thermal expansion, that's why intake and exhaust lash/preload are different. The exhaust side will expand more due to
the increased amount of heat than what the intake side sees, whether it's steel or aluminum, it only changes what the lash/preload is set at, and I will leave it at that.

 

[bison]

Where in this thread is aluminum even mentioned by the OP.

You are right,aluminum does expand at higher rates than steel for a given temperature. They also dissipate heat faster and allow more compression/boost and timing than a steel headed motor, which means they actually run cooler than steel heads because they retain less heat.

If you want to get into aluminum VS. steel heads we can start another thread, but there are already many threads on here that support many differing opinions on each.

I wasn't wrong in what I said, as the engine comes up to temp the clearances will decrease due to thermal expansion, that's why intake and exhaust lash/preload are different. The exhaust side will expand more due to
the increased amount of heat than what the intake side sees, whether it's steel or aluminum, it only changes what the lash/preload is set at, and I will leave it at that.

Have you ever checked cold and hot lash on any engine? Also just because aluminum dissipates heat better than iron doesn't mean they will simply allow more compression or boost and definitely not more timing if the aluminum cylinder head uses a modern combustion chamber.


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[Lil Truck]

You are incorrect. The cold lash with an aluminum headed engine will be greater once its up to operating temp. Aluminum alloys expand at nearly twice the rate of ferrous metals. Therefore preload decreases and lash will increase. Ive ran these lifters in various engines and when run with zero preload cold on an aluminum headed engine you can hear lash after making a pass.

I have read that some builders recommend preload on Aluminum heads and morel lifters to be .050 vs .030? Any comments ?

 

[kidglok]

I wasn't wrong in what I said, as the engine comes up to temp the clearances will decrease due to thermal expansion

Yes you were. When the head expands it moves the rockers away from the pushrods, effectively increasing the distance between the rocker tip and the pushrod, hence more clearance.


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[earlbrown]

The valves elongate as they heat as well. That's why you usually see a larger lash on the ex side even on a symmetrical cam.

 

[we4Mateo]

The valves elongate as they heat as well. That's why you usually see a larger lash on the ex side even on a symmetrical cam.

Wouldn't the valves getting longer just counteract what kidglok mentioned about the hot heads pushing the pedestals up and away from the cam/pushrods and thus picking up clearance?

 

[earlbrown]

Assuming everything is the same... but it's really not. The different materials have different thermal expansion rates, and then you couple that with different temps of the various components of different materials.

Then you have the geometry of the various thermal expansion... If you have a 1.5:1 rocker. It would take 1.5 thou to make up for moving the rocker shaft 1thou away from the cam.

So 1 thou of pushrod expansion will close the gap 1.5 by itself, if the block/head expands at the same rate there will be no change... that will allow a hot valve to close the gap.

It's much easier to just measure the lash/preload hot and cold than to even attempt to measure everything and do the math.

 

[bison]

I have read that some builders recommend preload on Aluminum heads and morel lifters to be .050 vs .030? Any comments ?

The preload won't matter too much unless you are running it so that the plunger bottoms out early. It's not something that most should try but there are lifters available for it. It could be a bad situation if the lifter was preloaded too much though. The hyd cam profiles out there assume a big hyd cushion (lifter plunger) that acts as a big shock absorber. If you look at the opening on some of the hyd lobes you will see that they are as aggressive as the most aggressive solids. The lifter absorbs the ramp. By running the preload down to force bottoming of the plunger you are taking the full hit of the ramp as soon as it's bottomed. Also when running a solid with lash it's wise to analyze the cam so you know where the lash ramp ends. Once that lash ramp ends the opening becomes extremely aggressive. Failure to do so and running excessive lash will result in valve train failure and a possible catastrophe. Yes with aluminum blocks and heads you may need to run zero cold lash on certain applications. Otherwise with all the expansion you will be off the lash ramp and it will get ugly fast.


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[robzombie]

Have you ever checked cold and hot lash on any engine? Also just because aluminum dissipates heat better than iron doesn't mean they will simply allow more compression or boost and definitely not more timing if the aluminum cylinder head uses a modern combustion chamber.


Posted from the TurboBuick.Com mobile app

As far as my quote on the aluminum heads that was a generalized statement which is true, but not all of the examples in that quote may or may not apply at the same time.

I've done more than my fair share of lash/preload, setting/adjusting in my days. When setting lash it is usually referred to setting solid lifters like when I was young and did it all the time on race motors and JAP crap as well as euro trash.

Preload is used on hydraulic lifters and I've run them to spec as well as loose when at the track to get a few more rpm out of the motor. Yes I have run them with a slight clickety clack at the track and when the rpms were up there they would stop because they would pump up due to not being able to bleed off at the higher rpms and that also kept the lifters from bending push rods among other things like collapsing a lifter or two.

I've run them tight on low rpm motors also to get a little more lift off the valve on certain combos.

You may know more than me about turbos but you are wrong when it comes to this discussion.

I was an ASE wrench for more than twenty years Brian and I know what I posted is right and won't back down when I'm right, sorry if you disagree but the facts are the facts.

 

[bison]

Preload is used on hydraulic lifters and I've run them to spec as well as loose when at the track to get a few more rpm out of the motor. Yes I have run them with a slight clickety clack at the track and when the rpms were up there they would stop because they would pump up due to not being able to bleed off at the higher rpms and that also kept the lifters from bending push rods among other things like collapsing a lifter or two.

I've run them tight on low rpm motors also to get a little more lift off the valve on certain combos.

What was i running here?

 

[robzombie]

I didn't and won't listen to your video, you know as well as I do videos and the sound on them are not going to reproduce what You would hear in person and I refuse to get sucked into this game you're trying to play.

If clearances becomes looser/greater when a motor comes up to temp like you say, please explain why on solid lifter motors that there are gaps of lets say .025 on the exhaust and .012 on the intake?
And as the motor warms up it gets quieter. I'll tell you, it's because the thermal expansion is closing up the tolerances.

Hydraulic lifters usually require some preload like you said and the plunger acts like a cushion, but at higher rpms, depending on the lifter design it can't bleed off the oil as quickly, or like a rhoads style that bleeds off more at low rpms to effectively make high lift long duration cams seem smaller until they reach a certain rpm for better low rpm drivability and bleed off oil slower at higher rpm and pump up the lifter achieving full lift of said cam.

What I said about lash and preload is correct and I'll leave it at that.

 

[Ttype6]

as the engine comes up to temp the clearances will decrease

Metal,and most anything on the Earth expands as its temperature rises. While your valve train parts are expanding,so are the block and heads that they are housed in or fastened to. The block grows outwardly in all directions like an explosion or like all of the bodies in the universe where every body is moving farther away from every other body. In this case it's molecules. The head is also growing in this way which makes it taller which moves the rocker arms farther away from the camshaft. The aluminum head grows even more.

 

[turbobitt]

I was an ASE wrench for more than twenty years Brian and I know what I posted is right and won't back down when I'm right, sorry if you disagree but the facts are the facts.

Well I guess the lesson learned here are some peoples "facts" are worth more than others.
AG

 

[bison]

Your mouth?

Wrong. Mouth was shut the entire time.