should valves rotate ?

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tubtar

tubtar

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Solid roller , good rockers , 240 seat and 590 over the nose.......I have about 500 miles on the motor and don't think it's seen 8000 r.p.m.
I am putting it back together after removing the rockers over the winter , and noticed scrub marks that tend to indicate that the valves have not rotated as it has been running.
This is my first go round with a solid roller , so I don't know if I have a problem or not.
15 of the 16 valves appear to be fairly stationary and the one on the right in this pic shows that it has spun around some.
Thanks for your help.
 

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They should to keep from getting hot spots built up, especially the exhaust valves. Theres nothing there to Keep em from rotating.
 
To my understanding the difference between a multi groove valve/keeper and a single groove is that the multi groove is designed to allow the valve to rotate. But a single groove set up does not. I'm pretty sure that you're running single groove parts. With that said and seeing that only one valve is showing signs of movement I would be suspicious of what is going on there.

Ted
 
I think the same way.......that one is different tells me that I have a problem.
They are single groove , so that would mean I have 1 problem as opposed to 15.
Now to try and figure out what the issue is.
I have to assume it is valve train harmonics.......I'll check to see if the one spring is softer maybe for starters.
Any other ideas ?
 
You should have no rotation. The one showing multiple rocker tip scrub patterns is experiencing some kind of valve train control issue. Verify the valve lash first, then check spring pressure. Might have excessive clearance in that valve guide. Poor valve, lock, retainer fitment.
 
In many engines the rocker is offset slighty to one side to rotate the valve. Studebaker V8 truck engines had ball bearings in the retainer. I have observed circular wear patterns on valve tips. I think rotation may be desirable, but on aluminum head engines, shims are often used at spring seat, to avoid spring seat wear.

I am no expert, but I observe.
 
I know when building for a performance application, the exhaust valve rotators are one of the first things that gets crapcanned. I don't think the valves are designed to rotate unless they have rotator retainers and or offset rockers like what Kit is talkin about. The rotators are much thicker than a standard retainer and would bring spring pressure way up on the exhaust side on a performance engine. Not the type thing you want.
 
For any sort of long term survival, the valves MUST rotate. This is not governed by the keeper type, that's simply a function of the valve material and the manufacturer/application.

The rotator seen commonly on Chevy motors are there to GUARANTEE rotation, that's why they show up in industrial motors. Without rotation, the valve is not able to wear concentrically. If you've ever wondered about why valves aren't square, this is part of it. Put dykem aka layout dye on the valve tips, run it for a bit, and check. They may not spin round and round but if they were supposed to run in a fixed axis with no freedom of rotation, they'd be keyed. They WILL rotate back and forth and over time make full rotations.

Rotators get tossed for weight, they maintain the same installed height on the spring. The valves rotary motion occurs simply because they aren't constrained.
 
jos51700 said:
For any sort of long term survival, the valves MUST rotate. This is not governed by the keeper type, that's simply a function of the valve material and the manufacturer/application.

The rotator seen commonly on Chevy motors are there to GUARANTEE rotation, that's why they show up in industrial motors. Without rotation, the valve is not able to wear concentrically. If you've ever wondered about why valves aren't square, this is part of it. Put dykem aka layout dye on the valve tips, run it for a bit, and check. They may not spin round and round but if they were supposed to run in a fixed axis with no freedom of rotation, they'd be keyed. They WILL rotate back and forth and over time make full rotations.

Rotators get tossed for weight, they maintain the same installed height on the spring. The valves rotary motion occurs simply because they aren't constrained.
Click to expand...

^^what he said. Don't worry about it. When it does rev, they'll move around more.
 
YouTube "spintron, valve rotation". Neat stuff.
 
Thank you gentlemen.
I have the LSM on head spring tester on the way so I can check that.
For now , I will pay attention to the adjuster and double check the lash.
it just seems odd that one cylinder was so different from the rest.
 
Pay careful attention to whats being stated in the video. Note that valve rotation is a sign of valvetrain instability.

[ame="https://www.youtube.com/watch?v=_REQ1PUM0rY"]Valve Float - YouTube[/ame]
 
jos51700 said:
For any sort of long term survival, the valves MUST rotate. This is not governed by the keeper type, that's simply a function of the valve material and the manufacturer/application.

The rotator seen commonly on Chevy motors are there to GUARANTEE rotation, that's why they show up in industrial motors. Without rotation, the valve is not able to wear concentrically. If you've ever wondered about why valves aren't square, this is part of it. Put dykem aka layout dye on the valve tips, run it for a bit, and check. They may not spin round and round but if they were supposed to run in a fixed axis with no freedom of rotation, they'd be keyed. They WILL rotate back and forth and over time make full rotations.

Rotators get tossed for weight, they maintain the same installed height on the spring. The valves rotary motion occurs simply because they aren't constrained.
Click to expand...


I have seen more exhaust valve rotators on Chrysler and Ford engines than any GM.
 
magnumdart said:
The difference may lurk in the valve stem or guide.
Click to expand...

skrews said:
Click to expand...

skrews said:
Click to expand...


I have gotten this from a couple other guys I respect , so I will definitely pay some attention to the keeper too.
I am curious if I have a bad spring and that led to floating the one valve too.
If I am lucky , I will be able to fix it without pulling the head.
But if not , I guess that is the price of having fun.
I really appreciate the help a lot Guys.
 
If you have a weak spring you might see if you can shim it up enough to get it in line with the rest. Double check for coil bind. Might have been an installed height issue from the word go too.
 
I had a couple 454 Chevys in tool trucks that had valve rotators on the exhaust valves. Must be a heavy duty thing. I don't remember seeing them on car engines. tmm
 
skrews said:
Click to expand...

How about a source? I don't generally consider it wise to take technical advice from someone with something to sell. Especially when they hint that normal operation might require more and more expensive race engine parts rather that a simple pin, as suggested in the first link below.

Link makes it look like a Manley valve brochure.

I maintain my position: http://www.cdxetextbook.com/engines/comp/vlves/valverotation.html
https://books.google.com/books?id=D...onepage&q=valve rotation in an engine&f=false
 
I get where you are coming from jos51700.
That was my understanding of how things worked in an engine..........but this is my first trip down solid roller lane and I thinks things are different here.
I have no expectation of getting 100,000 miles out of my set up.
Not without several freshen ups anyway.
As far as trying to sell me more and more expensive race parts , I have a Bullet cam , Crane Ultra Pro roller lifters , Manton pushrods that I speced for the engine as far as length and oil restriction. ( push rod oiling ) , T&D rocker arms, Manley titanium retainers , Comp 10 degree keepers , Victory stainless valves in aluminum W-9 heads. I think I beat them to that particular punch.
They were set up by a local shop that has a reputation for quality , so I am leaning towards something not being right with the one pattern that is different from the rest , and that it is a physical difference in hardware.
I'll let you know what I figure out , but I have way too much wrapped up in this deal to let this go unchecked.
 
....and I'm still curious. Are you running lash caps on the exhaust valves? I know a lot of people do on these builds including both of mine. Not sure what or if any difference it makes, but it might....
 
jos51700 said:
How about a source? I don't generally consider it wise to take technical advice from someone with something to sell. Especially when they hint that normal operation might require more and more expensive race engine parts rather that a simple pin, as suggested in the first link below.

Link makes it look like a Manley valve brochure.

I maintain my position: http://www.cdxetextbook.com/engines/comp/vlves/valverotation.html
https://books.google.com/books?id=D...onepage&q=valve rotation in an engine&f=false
Click to expand...


Both of your provided links clearly show and talk about using valve rotators. Valve rotators are not used in performance builds, so valve rotation is not supposed to occur. If it does, something is wrong.
 
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