Tumbler/Vibratory Polishing valve springs

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Dan Timberlake
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Re: Tumbler/Vibratory Polishing valve springs

Post by Dan Timberlake »

https://performancetechnician.com/pdf/2 ... prings.pdf

At the tire pump or carb fuel inlet and in most technical disciplines "pressure" is used when considering the area to which a force is applied.

In most of our literature "pressure" is also used when talking about the force exerted by a spring when compressed.
That misuse is kind of unfortunate, and probably causes either a chuckle or some heartburn when read or heard by folks with more formal technical backgrounds or training.

But usually in the cam catalogs the "error" stops at the word pressure, and the spring's force is correctly described as just pounds.

The article in the original post is a little loose with its use of "terms and definitions," adding the per-square-inch where it really does not belong.

Seat or open pressure
The pressure in pounds per square inch of
the installed spring with the valve on the seat.

Nose or open pressure
The pressure in pounds per square inch with
the valve in the fully open position.

Spring rate
The amount of weight needed to compress a
spring one inch, rated in pounds per square inch.

Spring rating
Spring load in pounds per square inch at
both the open and closed position. Usually
displayed as a range, for example “125#-425#.”
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Re: Tumbler/Vibratory Polishing valve springs

Post by modok »

travis wrote: Fri Feb 15, 2019 12:25 am
modok wrote: Thu Feb 14, 2019 10:11 pm I would estimate.... about 75% of valve springs that currently exist are shot peened.
I’d bet it is at least that. In the piston engine aircraft world, at least back when I was in it, 100% of valve springs was shot peened to very specific specs of shot size and peening duration. Granted, a spring failure at 20,000 feet is a bit more of an issue than one at ground level :lol:

I know Howards Cams is a big pusher of vibratory polished springs, quoting 2-3x life expectancy over non polished springs.
Yes, and I should also say and the % is increasing.

Also, as far as i know, there is no real definition of where "peening" ends and "rem polishing" begins.
Polishing? by countless tiny hammer blows. Like the difference between wet blasting and dry blasting. The addition of water changes the nature of the impact to create more of a polished surface, instead of bouncing off the media hits then goes sideways and adds a polishing action, no sharp peaks like dry blasting, but the action IS still an impact also.
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Re: Tumbler/Vibratory Polishing valve springs

Post by modok »

Dan, I call it spring pressure because that's what the squares say is the right word.
Get too picky I'll revert to calling it valve tension. The stem is in tension. Ha ha

As far as material removal, IF the action is "wet micro peening" making up the terms as I go., then the material removal will be almost none.
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Re: Tumbler/Vibratory Polishing valve springs

Post by digger »

How about preload
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Re: Tumbler/Vibratory Polishing valve springs

Post by modok »

poundage
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Re: Tumbler/Vibratory Polishing valve springs

Post by Warp Speed »

It's actually Force but..........
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Re: Tumbler/Vibratory Polishing valve springs

Post by Krooser »

Why not simply call one of the spring manufacturers and ask them???
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Re: Tumbler/Vibratory Polishing valve springs

Post by rickseeman »

BOOT wrote: Mon Feb 11, 2019 7:30 pm I don't plan to go overboard, I'll experiment with tumble time. I'd like to see how long it takes to remove the paint from gm ls springs and I have some used comp springs I'll try as well. I think the media would have to be pretty abrasive to damage them.
Vibratory finishing is about all I've done for the last 40 years. Can your machine handle steel media? If I was going to do valve springs that's what I would try first. Probably steel pins. If the media didn't strip the paint off I would remove the paint first. Pins are expensive by the way. I would expect them to come out beautiful. If you want you can send me a spring I will do some testing. www.vibratoryfinishing.com
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Re: Tumbler/Vibratory Polishing valve springs

Post by BOOT »

rickseeman wrote: Mon Feb 18, 2019 12:20 pmVibratory finishing is about all I've done for the last 40 years. Can your machine handle steel media? If I was going to do valve springs that's what I would try first. Probably steel pins. If the media didn't strip the paint off I would remove the paint first. Pins are expensive by the way. I would expect them to come out beautiful. If you want you can send me a spring I will do some testing. www.vibratoryfinishing.com
I don't have a tumbler yet and only planned to try a cheap HF one(actually was gonna go get one here maybe today) and if I like polishing then I'll invest in a better brand later. The smaller HF one only does dry and from what I've researched steel needles/balls is more of a wet media. From the limited info(about springs) I've found other than the article I linked(that used walnut), it appears a place that does performance auto parts(including valve springs) uses a combination of ceramic sizes wet. Goodson has steel & ceramic media on their webstie but as I said those are wet and I want to try cheaper dry for just now.

Thanks for the offer I'll consider it but only if I plan to at least purchase something from you and as a hobbyist I don't want to waste a businesses time. I actually came across your site when comparing media and contemplating if I wanted to try a dry mix of walnut with some ceramic. I already ordered some compound from another place to try but planned to test plain walnut to see if that'll work at least with the paint(idk how good of paint it is really and I don't want to do them by hand as someone else suggested), as I don't really want to use paint stripper unless I absolutely have to or. I know the plastic triangle media is suppose to be good for paint removal but read they leave a messy residue. Thanks also for the suggestions.
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Re: Tumbler/Vibratory Polishing valve springs

Post by BOOT »

Keep forgetting to share my results here. Not long ago I started making youtube vids and figured this experiment would be good to practice on. Per suggestion I made a shorter version as well LOL

Full version https://youtu.be/rhworepybBo

Short version https://youtu.be/K2I6uFp-Zoo

During the shots I was working on other stuff so it kinda stretch out longer than I wanted. I may revisit it next winter but for now I tried what I wanted and am happy enough with the results. FYI with the paint removed you can see the shot peen surface and the media I used didn't seem to be aggressive enough to damaged it. I still want to try a media combo later like maybe some ceramic but I'm in no rush.

If anyone has a suggestion feel free to comment, especially if it involves the insides LOL Pretty sure they are just getting packed somewhat, maybe something larger mixed in would help with that?
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Re: Tumbler/Vibratory Polishing valve springs

Post by BlitzA64 »

OK, first of all the insides..... My opinion is the outside is riding on the plastic bowl, the weight of the spring is pushing on the media and the bowl as you would on a piece of sandpaper. Obviously that can not happen on the insides so much less if any removal would happen.

My question would be why not just use lacquer thinner or paint remover to remove the paint? I have soaked items in lacquer thinner overnight to remove paint with success. Once the paint is off you could play with polishing if you wish.

I would try a polishing powder/rouge mixed in not the liquid stuff. You will still likely have a disparity between the inside and outside unless the springs are suspended in some manner.

Just my thoughts, good luck
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Re: Tumbler/Vibratory Polishing valve springs

Post by BOOT »

I've soaked them in mineral spirits, can't rem how long but I know it was a day at least but that's how I clean them always and then right into oil. I don't want to use a paint stripper, try to avoid that nasty stuff. My research showed rouge is used alot for brass(ammo) casing polishing and I may try it at some point, after I remove the paint. Still the batch of unpainted springs wasn't too promising, I've always read/herd all springs are coated somewhat just assumed it was more a oil type layer. I wonder if it they were maybe soaked in phosphoric acid, that would give them a dull color.

Suspending them from the lid I suppose would be possible, I'll have to try that when I revisit it next time. Might try loose(string/wire) or ridged(rod). Nice part bout using a cheap tumbler is oh-well if I mess it up.
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Re: Tumbler/Vibratory Polishing valve springs

Post by digger »

I've cleaned springs in a ultrasound cleaner with mixture water, kero and detergent. Works pretty good actually and shouldn't affect the mechanical properties

Data I've seen suggest the WPC induces more residual compressive stress than normal shot blasting and offers a better fatigue life improvement. Anyone doing that ?
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Re: Tumbler/Vibratory Polishing valve springs

Post by j-c-c »

I would think any time dependent mechanical process that is "wet" (water) with the alloys at play with high performance springs, would suggest a possible hydrogen embitterment concern, the last thing a spring should endure, unless timely baking is part of the process.

Also surprised no one has mentioned cryo, no downside I am aware of other then cost.
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Re: Tumbler/Vibratory Polishing valve springs

Post by BOOT »

digger wrote: Wed May 29, 2019 7:02 pm I've cleaned springs in a ultrasound cleaner with mixture water, kero and detergent. Works pretty good actually and shouldn't affect the mechanical properties

Data I've seen suggest the WPC induces more residual compressive stress than normal shot blasting and offers a better fatigue life improvement. Anyone doing that ?
WPC?

I was actually thinking bout getting one for some other junk but now that I look into it, seems they can be used to strip paint from difficult parts. So I may try that next! Still think i'd run the springs in the tumbler to get the majority of paint off and finish up in the ultra sonic cleaner might be the fastest, then back into the tumbler to try n polish and clean residue or w/e with ultra sonic.
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