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ArcticS
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Discussion Starter #1
I asked this question in another thread, but I think it might get more traffic in the NA forum, so here goes.

Ok, this much I know. Redline is determined from the ability of the valve spring to push the valve into place as the engine spins. This is determined from two things: The strength of the spring, and the mass of the valve, retainer, etc.

It seems that everyone jumps on stronger springs as the solution, but people seem to neglect the importance of the mass of the valve.

I'm considering doing an ITR setup, and one of the valve spring options people talk about on here is the s2k springs. Everyone assumes that since the s2k has a higher redline, the springs must be stronger. But this is not necessarily true, a lighter valve could give the same benefit of higher redline...and more importantly, if the rsx has heavier valves, maybe the s2k springs aren't strong enough to handle high rpms on the rsx.

I know that people have used the s2k springs without any problems. But, people have also used the stock springs, without any problems. I just want to make sure that I have the extra level of protection from the valve springs....

So this is my question:

Does anyone know, as a fact, that the s2k springs have a high enough spring constant to handle the rsx valves???

Or, does anyone know for sure that the rsx and s2k valves are the same weight???
 

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Well, here is what I know.

The S2k and the RSX must share the exact same valve train components. Reason being? I have the Toda valve springs installed in my car and they also are compatible in the F20C. It says on the box F20C/K20A. My understanding is the Toda valve springs can support up to spec c cams on the rsx, and also support all the s2000 cams that Toda sells.

I don't know too much about internal engine dynamics, but I'm willing to say that valve weight isn't a big factor for valve springs. However, I'm fairly confident that the S2000 and the RSX have very similar valves if not the same.

The K20A2 already has s2000 valve springs on the intake side. On the early RSXs the intake side had dual springs and the exhaust side had a single spring. The s2000 springs should be a good upgrade on the early K20A2s, but honestly probably are a waste of money if you already have a 03' with single springs. I went with the Toda valve springs because I was 100% sure they worked properly in the K20A2, and they supported the Spec A cams to 9100rpms which is 500rpms where my current fuelcut off is. I also got them for cheap, and they would work if I ever upgraded to bigger cams (aka Spec A, or N2+). I wanted the extra insurance, only thing I'm potentially worried about now is the connecting rods.
 

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ArcticS
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Discussion Starter #5
swwifty said:
The S2k and the RSX must share the exact same valve train components. Reason being? I have the Toda valve springs installed in my car and they also are compatible in the F20C. It says on the box F20C/K20A. My understanding is the Toda valve springs can support up to spec c cams on the rsx, and also support all the s2000 cams that Toda sells.
I really hope you're right, that the valvetrain is the same for both cars. I know I probably won't run into any problems either way, but I will worry less if I know that they're the same.

You said that the intake side already uses s2k springs. Do you know what the exhaust side uses? I'd hate to replace the springs and find out that the original ones were better or something...

I'm sure that the valvetrain weight would effect max rpm. I don't know exactly how much...maybe I'll try to run the equations tonight, if I get bored enough.

BTW, I agree that toda is a much better alternative...but if I have to pay $400 for valve springs, I probably wouldn't even do the mod. $40 for s2k springs (if I only do the exhaust side) is a little more realistic for me.
 

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ArcticS
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Discussion Starter #6
RSX-CT said:
Springs would be the cheaper alternative to valve replacement. Personally, if I was gonna change anything for new cams (itr/toda) I would just go with the TODA kit.
I wasn't really considering valve replacement...I just wanted to make sure that the s2k springs would work in the rsx.

And as far as the toda kit goes...damn, I have school loans to pay off, man! I have to work on a budget....
 

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just4kinks said:
I really hope you're right, that the valvetrain is the same for both cars. I know I probably won't run into any problems either way, but I will worry less if I know that they're the same.

You said that the intake side already uses s2k springs. Do you know what the exhaust side uses? I'd hate to replace the springs and find out that the original ones were better or something...

I'm sure that the valvetrain weight would effect max rpm. I don't know exactly how much...maybe I'll try to run the equations tonight, if I get bored enough.

BTW, I agree that toda is a much better alternative...but if I have to pay $400 for valve springs, I probably wouldn't even do the mod. $40 for s2k springs (if I only do the exhaust side) is a little more realistic for me.
I believe the exhaust side on the 02' runs the same as the DC5 Type-R.

When I got mine replaced I had dual springs on the intake side and a single spring on the exhaust side.

You do realize your gonna have to pay someone to install your valve springs, unless you DIY. The labor is going to be expensive.

Why are you installing s2k springs? Are you doing cams too? I'd recommend doing both cams and valve springs at the exact same time.
 

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Headlight Guy
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swwifty said:
I believe the exhaust side on the 02' runs the same as the DC5 Type-R.

When I got mine replaced I had dual springs on the intake side and a single spring on the exhaust side.

You do realize your gonna have to pay someone to install your valve springs, unless you DIY. The labor is going to be expensive.

Why are you installing s2k springs? Are you doing cams too? I'd recommend doing both cams and valve springs at the exact same time.
I do have to agree here, I don't think there is any benefit to changing springs unless you do change cams and/or run greater than 8600rpms.
 

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RSX-CT said:
I do have to agree here, I don't think there is any benefit to changing springs unless you do change cams and/or run greater than 8600rpms.
Well I don't agree with that.

I recommend upgrading your valve springs if your going to be reving past the stock redline/fuelcutoff which is 8100rpms on the Type-S.

Like he said though. I wouldn't upgrade my springs alone, I'd do cams at the same time too.
 

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ArcticS
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Discussion Starter #11
Well, I haven't decided anything for sure yet...but I'm thinking about installing the ITR cams, with (obviously) s2k valve springs. And I'll be DIYing the installs.
 

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Headlight Guy
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swwifty said:
Well I don't agree with that.

I recommend upgrading your valve springs if your going to be reving past the stock redline/fuelcutoff which is 8100rpms on the Type-S.

Like he said though. I wouldn't upgrade my springs alone, I'd do cams at the same time too.
I got an early 2002 myself with hondata#4 and I'm good so far. I was concerned myself before ordering but someone over at Hondata e-mailed me stating that they have tested the 8600rpm limit on both spring configurations for thousands of miles without a problem. He stressed that these engines see more 8600rpm than my daily driver.

Think of this too. Single springs are cheaper to manufacture than double springs. Double springs usually are used to capitalize on the their dual resonace. This means they function well at one spring rate for low rpm and another spring rate for high rpm's. The single valve spring could just be a better material to optimize over the entire range but be cheaper to manufacture. But, no one knows for sure.
 

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RSX-CT said:
I got an early 2002 myself with hondata#4 and I'm good so far. I was concerned myself before ordering but someone over at Hondata e-mailed me stating that they have tested the 8600rpm limit on both spring configurations for thousands of miles without a problem. He stressed that these engines see more 8600rpm than my daily driver.

Think of this too. Single springs are cheaper to manufacture than double springs. Double springs usually are used to capitalize on the their dual resonace. This means they function well at one spring rate for low rpm and another spring rate for high rpm's. The single valve spring could just be a better material to optimize over the entire range but be cheaper to manufacture. But, no one knows for sure.
true, but i'd rather be safe than sorry. Investing 400$ for me now, rather than 3,000$ later.
 

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Meow?
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On the original question... you don't have to pull the head to install new valve springs. You do have to pull the head to swap valves. So for someone who is doing a cam swap w/o opening up the bottom end, it's far more practical to swap springs.


Second, there's an issue of quality when it comes to valves that doesn't apply to springs. Nobody makes their own springs because large spring winders are ridiculously expensive. As a result, you just commission them at the rate you want from Eibach or one of the other big names.

Valves are more likely to be produced in-house or locally, so you have to have a lot more faith in the company you're purchasing from.

:)
 

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Tyler
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true, but i'd rather be safe than sorry. Investing 400$ for me now, rather than 3,000$ later.
The install charge was only $400? How well do the TODA springs work with the ITR cams? Did you lose alot of low end power? Is it running too lean or rich? And lastly would you suggest those highly over S2000 or eibach springs?
 

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talyler said:
The install charge was only $400? How well do the TODA springs work with the ITR cams? Did you lose alot of low end power? Is it running too lean or rich? And lastly would you suggest those highly over S2000 or eibach springs?
Yeah the install only cost me around 400$.

The toda springs work just fine with the ITR cams.

I didn't lose any low end power at all.

my a/f ratio is pretty much right on the money you can check out my dyno graphs, etc HERE

I went with the Toda springs because I would guaranted they would support up to 9100rpms safely, and I got a great deal on them.
 

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Everyone here is forgetting to include that there is less possibility for coil bind with a higher spring rate.

Coil bind is more likely to occur with a higher lift/longer duration camshaft (more lift than duration) because the spring itself compresses more/longer than intended from the factory. Coil bind is what causes valve float. When valve float occurs, it is possible bend valves or worse. A higher rate spring will have less ability to bind up under the change in load placed on it.
 

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BigDawg said:
Everyone here is forgetting to include that there is less possibility for coil bind with a higher spring rate.

Coil bind is more likely to occur with a higher lift/longer duration camshaft (more lift than duration) because the spring itself compresses more/longer than intended from the factory. Coil bind is what causes valve float. When valve float occurs, it is possible bend valves or worse. A higher rate spring will have less ability to bind up under the change in load placed on it.
I could have sworn the thread started wanted to use the ITR cams (same lift as stock with a longer duration) setup with S2000 valve springs? So why would coil bind play a part in this setup when the stock valve springs do not coil bind?

In general, what you say is true, but a higher sprung valve spring can also add additional wear to the camshafts. Lets not forget about that.
 

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I understand what the ITR cams are, I am currently running them.

Springs would be the cheaper alternative to valve replacement. Personally, if I was gonna change anything for new cams (itr/toda) I would just go with the TODA kit.
This statement reflects something that should be disregarded. Toda, or any other company for that matter, would not be concerned with changing valve springs to reduce incident if what this man said was true. There would be more interest in changing valves so as to keep factory rates on the valve springs.

My point in including that was to clear the air on some of what had been stated regarding the use of aftermarket valve springs. You can of course rev higher with lighter weight valves, but that is due to the lighter mass having to be pushed downward, which would not reduce the amount of force being placed on the spring itself.

And yes, you are correct about higher spring rates having long term effects on camshafts.
 

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ArcticS
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Discussion Starter #20
BigDawg said:
I understand what the ITR cams are, I am currently running them.



This statement reflects something that should be disregarded. Toda, or any other company for that matter, would not be concerned with changing valve springs to reduce incident if what this man said was true. There would be more interest in changing valves so as to keep factory rates on the valve springs.

My point in including that was to clear the air on some of what had been stated regarding the use of aftermarket valve springs. You can of course rev higher with lighter weight valves, but that is due to the lighter mass having to be pushed downward, which would not reduce the amount of force being placed on the spring itself.

And yes, you are correct about higher spring rates having long term effects on camshafts.
I see your point...but as far as the itr cams go, isn't sjracer correct, that I wouldn't have to worry about coil bind any more than with stock cams? Not to mention, I think the f20c cams have higher lift than itr cams.

I'm learning a lot from this discussion...but let me clear up my original question.

I'm not thinking about swapping valves or anything like that. That would probably be too much work, and the toda springs would be cheaper anyways.

So first off, I'd like to run the ITR cams.

Secondly, I'm not comfortable running them with stock valve springs, so I'd like to upgrade to something. From other posts I've read on here, many people are upgrading to s2k springs. These have a slightly higher spring rate than stock (for exhaust anyways), and they should nicely handle the increased rpms.

The general attitude from these guys is that "if these springs can rev to 9k in the f20c, then they can rev to 9k in the k20a as well". My entire point is that there are more variables in the equation than just the valve springs. It might not be safe to hit 9k in the k20a if, for example, the valves are heavier.

I haven't seen anyone discuss this yet, and I want to make sure that these springs will work for me, without problems, before I blow my motor. And if they don't work, I'll probably do toda springs or something, rather than swapping valves.
 
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