Why are the most efficient markers efficient?

[imped4now]

I'd like to dig into the specific dynamics of this topic, if you guys will entertain it.

Viking, G6R, Insight/Onslaught, Clone 5, VIS, Cyborg. Stuff like that.

Efficient flow paths?
Valve designs that flow a lot of air very quickly?
Valves that snap shut very quickly?

[TheRealKaz]

Mainly it's poppet valves that do all of those things listed. A poppet by design will open and close quickly.

Spoil valves have been able to catch up in efficiency by having really low operating pressure so it's literally using less air.

[imped4now]

Mainly it's poppet valves that do all of those things listed. A poppet by design will open and close quickly.

Spoil valves have been able to catch up in efficiency by having really low operating pressure so it's literally using less air.

Pressure and volume are inversely related, FYI. Spool valves have not been able to catch up because of operating pressure. They've been able to catch up due to designs that prevent the shot chamber from dumping air to atmosphere and improving flow paths.

Vanquishes and Luxes operate at relatively high pressures (160-200 psi) and are not efficient because of their valve designs. Clones, Primes, IV Core Geos, etc operate at much lower pressures and still use less air due to smart valve designs and efficient flow paths.

[AGDRetro]

It sounds like you already know why. When you combine low operating pressure AND low volume with optimized flow paths you're gonna get an efficient design. A Prime and a Nova 700 may both run on 100ish psi, but the Nova requires more of that air at the same pressure to do the same job. Lobe my Prime, is it the most efficient thin out there? No, but it is simple, reliable & more efficient than any Mag I've ever owned...

[AGDRetro]

...Lobe my Prime, is it the most efficient thin out there?

In my defense I am drinking and "lobe" and "thin" are words...

#weeditnothing

[imped4now]

It sounds like you already know why. When you combine low operating pressure AND low volume with optimized flow paths you're gonna get an efficient design. A Prime and a Nova 700 may both run on 100ish psi, but the Nova requires more of that air at the same pressure to do the same job. Lobe my Prime, is it the most efficient thin out there? No, but it is simple, reliable & more efficient than any Mag I've ever owned...

To be fair, I'm fairly educated on this topic. I was just hoping to raise that bar from input from those more educated on it than me.

The Prime is a great example, and one I'd like to discuss, as I own one as well. It's a very simple dwell-insensitive high volume dump chamber, similar to pre-IV Geos and the Regency Crome (but with a supply shutoff). But, it manages to be quite efficient, even with its 100 psi operating pressure and with no reactive valve to shut off the chamber. If you look at it, the bolt handles the "shutoff" duties with its grooves. I'd be curious to see its efficiency ceiling with a minimized dwell, as I've never tested it with mine. They are lovely markers, though....highly underrated, ergonomically awesome, and stupid simple.

[Sandman]

Guns with lower operating pressures can shoot lower into the airtanks...The weight of the components makes a difference too. Lighter bolts, rams pistons, etc...less energy to move. It's not just about airflow.

[imped4now]

Guns with lower operating pressures can shoot lower into the airtanks.

I'm looking at this from more from a "volume per shot" perspective. Yes, a marker that operates at 100 psi can shoot a little deeper into a tank than one that operates at 200 psi, but it doesn't matter much if the 200 psi marker uses less volume per shot.

I'm with you on the "lighter components" point. A lighter ram, for example, takes less energy to accelerate, which also allows the valve to close faster. I run my LV1.5 with the light ram for that reason.

[snoopay700]

Higher pressure as a rule would wind up being more efficient, since the minor losses due to flow path would be even more minor comparatively. But then you have the issue of not being able to shoot as low in the tank.

The most efficient design would be a short burst of air that is the exact amount you need to get the ball up to speed with optimized flow paths and as few reductions as possible since that is your biggest flow loss.

Also, inner sides of "bends" are more critical to be smooth than the outer side due to the formation of a vena contracta, which essentially reduces the effective flow area due to separation.

So the most efficient marker is a poppet valve that operates at a high enough pressure to have the minor losses be as minor as possible while still being able to shoot low in the tank, and has transitions with smooth inner edges so the flow separates from the inner wall as little as possible.

[imped4now]

Excellent post, snoopay.

I fully agree with your evaluation of the most efficient marker. What about these very efficient, very low pressure dump valve spools such as the Clone 5, Prime (C5 without shifting valve), CS1? It's pretty astounding that a marker that operates at 100 psi, like the MacDevs, can be so efficient. Low pressure and short valve duration (low volume) is an impressive combination, so does that indicate well designed flow paths to reduce energy loss? Or is there something else going on that I'm missing?

[snoopay700]

Excellent post, snoopay.

I fully agree with your evaluation of the most efficient marker. What about these very efficient, very low pressure dump valve spools such as the Clone 5, Prime (C5 without shifting valve), CS1? It's pretty astounding that a marker that operates at 100 psi, like the MacDevs, can be so efficient. Low pressure and short valve duration (low volume) is an impressive combination, so does that indicate well designed flow paths to reduce energy loss? Or is there something else going on that I'm missing?

I would assume better flow paths along with proper dwell times. I am not extremely familiar with spool valve markers released in recent years, but I know the original Ion had the dwell set such that it would use the same amount of air dry firing or shooting a ball, implying that it was using all of the air whether it needed to or not.

You also have to keep in mind that even 100 psi is pretty high compared to the minor losses you'll see due to flow paths. Even a hole in an infinite wall constriction is on the order of a few psi maximum (if memory serves, been a while since I've dealt with fluids, it might be even lower).

The thing that drove this point home for me was when I asked my professor why you saw smooth transitions on the intakes of cars but exhaust was always the worst possible loss into the atmosphere, and he told me to calculate it by hand. It was so small comparatively that it wasn't even worth worrying about.

That's kind of the same thing with the markers that operate at 100 psi. They should be able to still reach a pretty good efficiency. You would only net about a 1% increase or so (guesstimate) by increasing the pressure significantly.

[imped4now]

Good info.

The Ion is a bit different, as the bolt acts as the "valve" and the system is dwell-sensitive.

If you take a look at the PE IV Core and MD Clone 5 bolt systems, the bolt and valve actions are decoupled, allowing for higher dwell times without a change in air usage thanks to the breech-sensing valves.

[snoopay700]

Good info.

The Ion is a bit different, as the bolt acts as the "valve" and the system is dwell-sensitive.

If you take a look at the PE IV Core and MD Clone 5 bolt systems, the bolt and valve actions are decoupled, allowing for higher dwell times without a change in air usage thanks to the breech-sensing valves.

That's true, but you could probably turn the dwell down on an Ion and it would still operate fine and be more efficient; I haven't tried this to confirm, but it would make sense to me from the results of Gordon's dry firing test.

The downside of having a decoupled valve is that you have a more tortuous path for the air, which can have a negative impact on efficiency.

I think blow poppet valve could allow for a better flow path, and may possibly yield slightly better efficiency. I've not done the calculations personally, and there could be another design consideration I'm overlooking that would make it more of a detriment.

[imped4now]

That may be, but two of the most efficient spools out there are the Clone 5 and CSR, both of which have valves that are decoupled from the bolts. I'm also failing to see how the flow paths on those two are more tortuous than on something like an Ion or Quest. Can you point out the specifics of what exactly you're looking at there?

And what do you mean by a blow poppet?

[snoopay700]

That may be, but two of the most efficient spools out there are the Clone 5 and CSR, both of which have valves that are decoupled from the bolts. I'm also failing to see how the flow paths on those two are more tortuous than on something like an Ion or Quest. Can you point out the specifics of what exactly you're looking at there?

And what do you mean by a blow poppet?

These are the ones I was looking at when I said that. It's not drastically more tortuous in the clone, but it is slightly. This may also be an old design.

A blow forward poppet, I'm thinking something like the Mini I guess, where it's a poppet valve that opens to push a bolt forward. Not the mini design exactly, but that sort of design seems like it would allow for the most freedom in ensuring you have smooth flow to me. That's just speculation though.