Springing for efficiency?

[shocker_monkey]

I'm looking for some advice regarding efficiency, I tried to search but it wasn't very effective. I have a pair of full body pre-2k cockers. Playing a scenario game yesterday the field was having compressor issues during the entire day and wasn't filling more than 2500. And I was consistently running out of air before I was running out of paint, to the tune of a hopper and maybe 2 pods.

So I'd like some advice on re-springing my cockers for best efficiency. Both of them have the high flow valve from ID and the springs that came with it. While I've built and timed a bunch of cockers over the years, I've never really spent time tuning them for efficiency.

What should I be looking for in springs? Stiffer valve spring and softer hammer spring? Has anyone used the "matched" spring sets from the likes of FreeFlow or AutocockerParts.com? Is it a result of the ID valve?

[Jonnydread]

I know when tuning a cocker for 12g efficiency you generally want high pressure and low volume. For constant air I would imagine you would want to sweet-spot it as "tightly" as possible, but the ideal operating pressure is going to be different for different guns. If you have high flow lowers/internals I would imagine you could probably get away with a stiffer valve spring and a lighter main spring. In your case I wouldn't be afraid to turn your HPR up a bit and spring it to coincide with that as low pressure does not always translate to efficiency.

[Shaftski]

The inception spring kit should give you the right spring combo, if you are willing to experiment and have access to a chrono.

I would leave the valve spring alone for now. Then turn reg pressure up, start with the lightest hammer spring in the inception kit and see what you get for FPS. If you can set the IVG for FPS range you need, look at shot to shot FPS and look for consistency.

Usually the spring included with aftermarket valves is the best one to use with it. Palmer does make a HP valve for snipers if you want to try running at line pressure, then all tuning would be done by re-springing.

You may also find the answers you need over on the inception forum. Best place on advice on how to tune that valve.

[shocker_monkey]

Thanks guys. I do have access to a chrono, but no good place to get air around here. So it will likely be something I take a special trip to the field for.

I don't have the full inception spring kit, just the ones that came with the valve. But I'm planning on picking up a couple sets.

[Shaftski]

You probably have a gas supplier near you, where you can lease filled HPA or CO2 bulk tanks. Most places have fairly reasonable rates. Or find a dive shop that can fill a scuba for you.

Hydroponic grow shops and home brewing suppliers also carry bulk CO2. Usually you buy a tank and swap it for a filled one, like with a lot of propane cylinders for grills.

[iamthelazerviking]

Or Scuba/diving shop! I am lucky enough to live near one who fill my tank for $5 (or $3 if the right person is working)

[Mr. Hick]

A hopper and 2 pods on what sized tank? That's near a quarter case. If you're running a 50ci or less thats a good shot count on 2500psi.

[shocker_monkey]

77CI. On a full take I get maybe 5 pods? I want to be able to hit the field at scenario games with 7 or 8 pods and not have to worry about running out of air in the middle.

[Mr. Hick]

Oh, ya. My old 99 STO gets about 3/4 case on a 68/45. So, you got some issues. Being that you are running 99 style bodies you should be running a bit higher operating pressure for shorter dwell times. You probably are letting a damn good bit of air through with a long dwell time and the lower operating pressure.

[gabe]

That's not great. I can usually run at least 5-7 pods on a 45/4500 with a CCM lower tube kit sweetspotted. You should be getting over half a case and even up to a full case if tuned well on a 77ci.

Just get a decently balanced spring set with a good valve and work from there. Even just a WGP stock lower tube should net you more than what you are getting now.

[shocker_monkey]

Yeah that's why I'm thinking something is messed up with my spring combinations. I think I'll snag a set from AutocockerParts and see how it does and just start there.

[Grendel]

You may have the valve dwell too long so your valve is still open or not fully close when the ball is gone too far down the barrel. This will cause use of Gas for no gain in velocity (inefficient). Is you setup farting? I expect both of your springs are too soft but balanced so you get desired velocity. What pressure are you running behind the valve?

[shocker_monkey]

Grendel I don't currently know what my pressure is set to. I did the sweetspotting via the normal velocity method, but don't have a gauge to test output from my regs. I suppose that's something I need to figure out as well.

And no, I've heard guns that fart and mine don't do that.

[Alexndl]

You can make a quick tool to check tank and reg pressure by using a remote tank adaptor or ASA a long as you have two port. Use a gauge on one side and a slide check on the other to purge once you got your measurement

[shocker_monkey]

I have no idea what hammers or main springs I'm running. The only thing I know for sure is the ID valve with the spring it came with. I'm beginning to think that maybe I need to just do a full lower tube replacement. There may just be too many variables in play at once without knowing exactly what is in the gun.

[Magmoormaster]

The issue you're facing is that you're using 2k+ springs in a pre-2k body. Pre-2k valve chambers a shorter, and thus require a shorter spring.

[shocker_monkey]

Well I must admit this might be the first time I've ever heard that. Can you point me in the direction of where to find some?

[gabe]

That's not entirely true. 97 and older valve springs are shorter but 98 and up uses a normal autococker valve spring.

A way that I came up with to tell if the springs are fairly balanced for low pressure is to see how the hammer sits at rest and degassed. The hammer should have enough hammer spring tension to slightly open the valve when it's forward. Not like a hard hammer resting against the valve but definitely the hammer spring slightly stronger than the valve spring. You can feel the valve spring giving an assist when you pull the cocking rod back and then feel it transition to hammer spring tension only when the hammer lifts off the valve stem.

[shocker_monkey]

So I pulled out the lower kit from one of them. It has the ID Valve, ID Universal Hammer, and what looks like the stock springs from ID for the valve and hammer. So it must have been a full lower kit I purchased.

Knowing that is this more of a pressures thing at this point? I need to figure out a way to test my reg output.