Valve spring questions
 

I was looking around trying to find information on valve springs since it's the last part I need for my build. It doesn't seem there's any real information here about them other than some people think they're worth it and some people don't. It depends on the situation.

My motor will have stock cams (at least for now) and I was planning on just getting a little higher rev limit going with stiffer springs so I could spend less time changing gears. I see there's different rates, single or dual springs (I guess dual is better and supposed to reduce harmonics?). I only want to go over by maybe 500-1000RPM. I'm installing a billet oil pump, is there anything else I should get for longevity of the motor? I'd love to get an ATI damper, but that's too rich for my blood, at least for now.

So what's a good spring rate for a 1.6 for what I'm looking for? Is there anything else I should know about choosing springs? Is the RPM increase even worth it, or do I need cams to be useful?

I really do not think you will need to go with a bigger valve spring to get 500 rpm. What you may want to do instead of getting a stiffer spring is to go with the shim under solid lifters. This will lighten up the valvetrain significantly, which will keep your valves from floating at a higher rpm than what the hydraulics will allow. It will give you just a bit more power too, but not because you can spin it faster, but because there is a lighter rotating assembly. It is a popular modification for us n/a guys.

The power gains will be small, and you really should have a cam to go with the lifters to see any significant gains, but it is a good start on upgrading your valvetrain, and your stock cam will work despite what some people say. Again, do not expect any power gains by going a higher rpm with a stock cam. It is a chore to set it up, but can be done by the do it yourselfer.

As I said, not really looking for power gains, just don't want power loss at the higher RPM so I can stay in gear longer. I'll have to look into the shimming, do you happen to have a link or a recommendation of where to look?

I got mine from Mazdaspeed Motorsports, but you need to be a member. You can try Webcam or Integral Cam as well. They should be able to help you out.

He doesn't mean shim your springs. You have to change your hydraulic lifters for the shim under bucket type. Similar to the 99+ 1.8 lifters but the shims are under the bucket so that they don't fly out at high revs or cam lift. The only draw back to these is that you have to remove the cams to get at the shims which is a ball ache when setting the lash initially.

Yeah, I just started reading up on it, so I understand now. I'll have to look around since the solid lifters I've found are $650. I'm hoping I'm not going to have to spend that much. There's a question as to whether running the HLA cams with solid lifters is bad. Do the people who go solid always go with solid lifter cams? I would think as long as it's shimmed properly that it would run fine.

I think if you are spending the money on lifters you may as well get a package of lifters and cams from integral so that you can really make some power up there as well as not having to shift.

Wouldn't I lose low end with cams, though? This is still a DD. I'm trying to get as much fun juice out of the motor as possible without impacting normal driving or longevity of the motor too much.

Depends how wild you go. Talk with the guys at integral and they can tell you which cam will produce the results that you want. But do tell them what your final goals are, if you tell them your current setup and they specify a cam you may find that when you wind the boost up or change CR or port the head that the cam is no longer optimal.

Not many people here claim to be cam experts least of all me! So talk to the pros.

So I talked to Integral Cams finally and they say springs and HLA are good. They noticed no real difference with their testing between HLA and solid. Solid with more aggressive cam profile would probably be better, but HLA is still good for at least 8k RPM.

Also, for boosted 1.6L miata he recommended stage 2 intake and stage 1 exhaust cams to have a good street car with an increase at the top end.

So I guess I'm back to figuring out which spring rate and type I want to get.

If you wanted cheapness then you could always go the Volvo route.