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 Post subject: Valvespring suspension
PostPosted: October 16, 2016, 11:52 am 
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I have applied for a patent for this, so i may as well share it.
Once i realized that valvesprings have rates similar to suspension sorings, last far longer, and are far lighter, i got to wondering about trying them instead. Thd first problem was the lack of travel, about 12 mm per spring. But stack 8 of them, you get nearly 4" of avaliable compression, some of which will be used up in carrying the static weight of the vehicle. Also, 16 valvesprings is still lighter than one coilover soring, let alone a Camaro production front coil.
So the next issue was how to keep them stacked during dynamic movement. Well, a bar up through the middle proved practical when i tried it on a Camaro. The bar had to either be curved if run in the stock location, which had several problems, or have a pivoting mount when moved out toward the balljoint. The bar had to go up through a hole in the frame, then i had to remove the springs to see what the bar would hit under full compression of the springs.
I didn't try driving it that way, but it seemed to me, and still does, that such localized loading would require making the frame thicker at the spring seat, to spread the load out a little.
I hope to try this on a running car next summer, but the lighter the car, the less springs you would need, but then you lose travel. Or softer- rate springs, but you can go down only do far, so there must be a minimum practical load, and a LoCost may prove too light, but thinking about a rocker-arm arrangement may be the best of both worlds.
I will sell licenses to use valvesprings in suspension for just $10 per car, and because you LoCost guys are kind to me, each of you can get one license for $5.
I didn't start this thread to turn a profit, just to inspire new thinking.


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PostPosted: October 16, 2016, 12:30 pm 
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Dave1976 wrote:
I have applied for a patent for this, so i may as well share it.
Once i realized that valvesprings have rates similar to suspension sorings, last far longer, and are far lighter, i got to wondering about trying them instead. Thd first problem was the lack of travel, about 12 mm per spring. But stack 8 of them, you get nearly 4" of avaliable compression, (And get 1/8 the spring rate) some of which will be used up in carrying the static weight of the vehicle. Also, 16 valvesprings (Where did the 16 come from? To get 4" of travel you would need 8x8=64 to get 4 inches at the same total spring rate) is still lighter than one coilover soring, let alone a Camaro production front coil.
So the next issue was how to keep them stacked during dynamic movement. Well, a bar up through the middle proved practical when i tried it on a Camaro. The bar had to either be curved if run in the stock location, which had several problems, or have a pivoting mount when moved out toward the balljoint. The bar had to go up through a hole in the frame, then i had to remove the springs to see what the bar would hit under full compression of the springs.
I didn't try driving it that way, but it seemed to me, and still does, that such localized loading would require making the frame thicker at the spring seat, to spread the load out a little.
I hope to try this on a running car next summer, but the lighter the car, the less springs you would need, but then you lose travel. Or softer- rate springs, but you can go down only do far, so there must be a minimum practical load, and a LoCost may prove too light, but thinking about a rocker-arm arrangement may be the best of both worlds.
I will sell licenses to use valvesprings in suspension for just $10 per car, and because you LoCost guys are kind to me, each of you can get one license for $5.
I didn't start this thread to turn a profit, just to inspire new thinking.


See my 1st "thinking" in red above. Then I think: So how does the weight of 64 valve springs and 8 steel bars compare to the Camaro coil spring? And how would you get 8 stacks to equally share the load? In order to fairly compare weights, the performance (spring weight + mounting system vs travel) And how to compare the cost of 64 coil springs and hardware vs one coil spring? And are you compressing each spring within it's normal travel when used in a valve train? more compression "may" mean shorter life.

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PostPosted: October 16, 2016, 12:59 pm 
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Agree with the above. The spring constant of a given alloy is just that, constant, so no matter how it's sliced, it's all the same. I'll be amazed if a patent is issued because you're just rearranging an existing concept.

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Last edited by KB58 on October 16, 2016, 1:15 pm, edited 1 time in total.

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PostPosted: October 16, 2016, 1:08 pm 
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Noone has ever before produced any car that used valvesorings for the suspension. That is the patent i applied for, don't have yet.
If each valvesping has a rate of 300 piunds per inch, then the stack stays at 300 pounds per inch. I saw that from how the Camaro settled.
Each spring having nearly 1/2" of range, means that unloaded, 8 springs gives 4".
I'm a Chevy v8 guy, so valvesprings come in boxes of 16.
4" of unloaded range is obviously not enough, so a stack of 8 isn't enough. 2 stacks of 8 doubles the effective rate, a single long stack does not. Again, proven on the test mockup.
I'm not enjoying typing enough to detail everything i tried, just sharing the parts that matter. If they don't make sense, i can try explaining it differently. If it still makes no sense, then you can try it yourself or accept my word, or live with confusion. Your choice.


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PostPosted: October 16, 2016, 1:13 pm 
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I think car springs look the way they do because its the most economical solution. There is no reason why smaller springs won't work, they just cost more - it's a much higher grade and more expensive steel alloy.

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PostPosted: October 16, 2016, 1:22 pm 
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Dave1976 wrote:
If each valvesping has a rate of 300 piunds per inch, then the stack stays at 300 pounds per inch

If you're stacking springs in series, then that is not the case. Springs stacked in series apply equal force to each other, also equal to the force you apply at the ends. So if you have a 300lb/in spring, apply 150 lbs, you see 1/2" of deflection. If you stack eight of them in series and apply 150 lbs to the ends then each spring will deflect 1/2" for a total deflection of 4" and a spring rate of 150/4 = 37.5 lb/in.

If you stacked 8 x 300lb/in springs in series and saw a resulting 300lb/in spring in your test, then I posit that there is a flaw in your test somewhere.


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PostPosted: October 16, 2016, 1:25 pm 
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Dave1976 wrote:
If they don't make sense... you can try it yourself or accept my word, or live with confusion. Your choice.

Or, knowing physics and mechanical properties and realizing that nothing's new here. You're on the verge of sounding arrogant so proceed with caution when navigating facts - see post above. All you're doing is overly-complicating spring design with one that's heavier, more expensive, and larger than a single spring.

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PostPosted: October 16, 2016, 4:45 pm 
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horizenjob wrote:
I think car springs look the way they do because its the most economical solution. There is no reason why smaller springs won't work, they just cost more - it's a much higher grade and more expensive steel alloy.

Marcus, Correct me please, I thought most steels have essentially the same spring constant (give or take 10% or so). any given size wire dia, number of turns, and coil diameter will have close to the same deflection with a given weight. What changes with the more expensive alloys is the yield strength or how much you can stress it before fails.

Maybe I'm misunderstanding......I do want to know.....

Dave, Let's make it simple. When stacked together, all valve springs in that stack see the same load. So if 50# is applied to a stack of six 300#/ inch springs. Each spring in the stack will compress 50/300 or 1/6". So if 6 springs are in the stack, the stack will compress 1 ". Right? therefore the "stack" assembly becomes a 50#/inch coil. If you stack more springs, the "assembly" becomes a lower rate.

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PostPosted: October 16, 2016, 5:43 pm 
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Marcus, Correct me please, I thought most steels have essentially the same spring constant (give or take 10% or so). any given size wire dia, number of turns, and coil diameter will have close to the same deflection with a given weight.


That's right. So they use an expensive alloy when they want a spring to take a high stress, like in a cylinder head where there is not so much space. Maybe it's just the really high performance after market stuff that is really fancy. I think some motors run more than an inch of lift these days. I think the suspension springs are not so fancy though. Aftermarket coilovers might be better than a OEM suspension spring too. Mind you, sort of guessing here...

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PostPosted: October 16, 2016, 7:08 pm 
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rx7locost wrote:
I thought most steels have essentially the same spring constant (give or take 10% or so).


I recall seeing everything fall within a few (as in around 2 or 3%). Its close enough that you can treat them as the same stiffness.

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PostPosted: October 16, 2016, 8:59 pm 
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Look, if the theory doesn't match my observations, then the theory is in error.
The valvesprings I had on hand were for a Chevy 350, which spec at 76 pounds at a 1.7" installed height. If you add up 8 of them, that would be 616 pounds. About the same as IROC-Z / WS6 coils.


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PostPosted: October 16, 2016, 9:32 pm 
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If you add up 8 of them in parallel... Think about how big that becomes, and that combination still only had a fraction of an inch for travel. Add a mechanical rocker to increase travel and the effective rate drops off. There is no magic solution - one single spring of appropriate size is in practice, impossible to beat. CAN what you're doing work - absolutely, but it'll be heavier, more complicated, more expensive, and larger than a single-acting spring solution. Can't get around physics and mechanical properties of materials.

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PostPosted: October 16, 2016, 10:25 pm 
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Here is another way to look at the springs.
Attachment:
Springs.jpg
Springs.jpg [ 95.35 KiB | Viewed 2830 times ]

I currently run a 300lbs spring and a 150lbs spring in series. To get my actual spring rate it is
A x B
A + B

300 x 150
300 + 150

45000
450

= 100

My effective spring rate is 100 lbs.

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PostPosted: October 16, 2016, 11:32 pm 
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Dave1976 wrote:
Look, if the theory doesn't match my observations, then the theory is in error.
The valvesprings I had on hand were for a Chevy 350, which spec at 76 pounds at a 1.7" installed height. If you add up 8 of them, that would be 616 pounds. About the same as IROC-Z / WS6 coils.



Or possibly you are not observing right...... there is that possibility.

To start with, your referenced chevy valve spring rating is not the same method of rating. It says to compress the spring to 1.7" it takes 76 lbs of force. It is not the same as lbs/inch rating. To know what the coil spring rating is, you would also need to know the free height of the spring.

2nd: if you add up 8 of 76 lbs you do get 616 lbs (actually you get 608 but I will not belabor that point). Just because you can mathematically add 8 numbers doesn't mean that is the way springs react when stacked. If I put 1 spring valve spring on a scale and place a 76 lbs weight on it, it will compress x amount and the scale will show 76 lbs. Now I stack 8 of them up and put them on the same scale and place the same 76 lbs weight on it, each valve spring will compress the same "x" amount and the scale will still show 76 lbs. But now the stack will have compressed 8x. Because each spring compressed the same x as when you tested 1 spring. If you are right and I am wrong, when you place a 76 lb weight on the top, the scale would read 608 lbs. Now that wouldn't really happen would it?

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PostPosted: October 17, 2016, 12:08 am 
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wrightcomputing wrote:
Here is another way to look at the springs.
Attachment:
Springs.jpg

I currently run a 300lbs spring and a 150lbs spring in series. To get my actual spring rate it is
A x B
A + B

300 x 150
300 + 150

45000
450

= 100

My effective spring rate is 100 lbs.


UNTIL one of the springs is totally compressed and you begin running on the other spring. This is the theory behind (almost) 0 value helper springs and also using helper springs with a larger value to give you a bit of variable spring rate.

I ran helper springs with a value along with a much stiffer spring than I could normally run on the street to give me the softness of spring rate for the first X" of travel to allow for a smoother street ride, BUT to give me the stiffness I needed for the track when the car was run harder.

In a bump or pothole I got shook to death as we quickly exceeded the short soft travel, but in every other situation the transition was all but seamless so it worked as I wanted. When I was on the track I got a small amount of lean and then the car was totally on the stiffer spring and yet the car handled rough tracks or the street with aplomb.

The hassle is you need more suspension travel than you get in the typical Locost.

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