Adding a Higher Volume Pump to a Stock Blaster

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marauder
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Adding a Higher Volume Pump to a Stock Blaster

Post by marauder » Sun Aug 11, 2013 3:02 pm

Ok, so just wondering how I would be going about putting a larger volume pump, such as one from a broken XP 150, on a different gun. I know it has to be more complex than just sawing off the pump tube/housing and gluing that on to the new gun and then putting in the new pump when that's dried.
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soakinader
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Re: Adding a Higher Volume Pump to a Stock Blaster

Post by soakinader » Sun Aug 11, 2013 4:13 pm

Hmm... nope. Cut, glue, done. At least, it's physically simple to do. It requires some thinking beforehand though, if you want it to work well.
It really depends on the gun and the pumps that are being used. On a gun like the Flash Flood, you could replace the stock pump with a longer pump without too much trouble. If you wanted to put in a pump with a larger diameter, this would require some cutting.
Also, you have to realise the increasing the pump stroke length by 4 inches increases the gun length by 8 inches when the pump is fully extended. Most stock guns have a pretty sensible length so that people can pump it easily. That being said, there are many exceptions where the physical design of the gun limits the length of the pump.

Now this is where things get tricky. When you replace a smaller diameter pump with a wider diameter pump, you get more volume/inch of length. So if you pull at the same rate you get more water, right?
Well, no. This is where the gun's internals matter. If the tubing for the intake and all the parts (check valves, joints, piping) is too small, and restricts the physical internal size that water can move through, you get some flow resistance, and this is where you can get some gnarly pump lag. Additionally, this increases the force needed to push the increased volume of water (regardless of the internals flow restriction). Also, in an air pressure gun, having a wider diameter pump would make it more difficult to pump to the same pressure as before. It would take more force to achieve the same pressure as a stock gun.
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marauder
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Re: Adding a Higher Volume Pump to a Stock Blaster

Post by marauder » Sun Aug 11, 2013 6:16 pm

So, in other words, if I'm wanting to increase the pump volume on my XP Pool Pumper Blaster I will probably need to replace the whole check valve set up and everything, not just the pump? It may be too much to make it worth it. The pump is already pretty long (optimal length in my opinion), so I don't want to make it any longer.
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Andrew
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Re: Adding a Higher Volume Pump to a Stock Blaster

Post by Andrew » Sun Aug 11, 2013 7:07 pm

It depends I guess. The PPB looks like it has fairly generously sized internal tubing compared to other blasters. If you can pump it quickly with little resistance in it's current form, increasing the diameter slightly shouldn't increase the resistance too much. As long as everything before the pump is large enough, lag shouldn't be too bad either. I'd personally prefer to make a pump longer rather than wider as, like soakinader said, they can achieve a higher pressure with the same force applied. With a PRV, this probably won't be a deal breaker as it probably kicks in before pumping becomes uncomfortable. I noticed the PPB has an empty space behind the tubing running away from the pump, so you could always move all of that further back (shouldn't need replacing) and make a longer pump to fit within the existing shell (assuming the grip has room on it's rail to travel further forward than it can currently).

So yeah. You could make it longer within the same body shell (requiring a little relocation surgery on the components directly behind the pump), or you could make it wider (requiring no further modification if the internals have a wide enough diameter), or both! A little wider and a little longer would probably be the best solution.

marauder
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Re: Adding a Higher Volume Pump to a Stock Blaster

Post by marauder » Sun Aug 11, 2013 8:21 pm

My main concern with moving everything back is that I would have to cut and move several parts around which ups the risk of screwing the gun up. The only way I can see making it longer would be as follows:

Cut behind the 2nd most rearward PC. Add pipe to lengthen the pipe between the 2 most rearward PCs. Cut the external shell in half at the same point and somehow lengthen it by the same distance. Increase the length of the pipe that houses the pump, which is the whole point of this mod, and actually the easiest part!

Image

Full size pic
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Andrew
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Re: Adding a Higher Volume Pump to a Stock Blaster

Post by Andrew » Mon Aug 12, 2013 10:50 am

I was thinking more like this:

Image

It reuses one of the connections the the PC line Yyou'll have to make a new connection at the back below the rear PC, a hole with a pipe jammed into it and surrounded by epoxy putty should work, or you could cut a larger Tee in half and solvent weld it to the bottom of that pipe. You could also run a tube to the very back of that pipe.), and keeps the shell intact. You only need to fill the front Tee (just behind the second PC from the rear) and choose how to connect the intake tube (either run the pipe up through the handle and back to the rear, or cut a hole below the new location). I haven't connected that up in the image as both ways have their good and bad points.

marauder
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Re: Adding a Higher Volume Pump to a Stock Blaster

Post by marauder » Mon Aug 12, 2013 12:35 pm

That's pretty good. I would have to make the current track longer or turn the pump into an untracked pump, either of which wouldn't be that difficult. If I used a pump with a larger circumference I'd have to make a new trigger, since the current trigger slides over the pump housing. So, I probably will eventually go with making the current pump longer.

I would prefer to run the intake tube up inside the gun, but I'm not sure how I could do that without pinching or cramping the tube. Cutting a new opening in the shell and running the tube outside the shell would get in the way unless I came up with some truly tactical ways of connecting the tube. Of course, that's possible, just gotta think how, cuz I don't want the tube running down how it is now, just removed 2 inches or so to the rear.
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soakinader
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Re: Adding a Higher Volume Pump to a Stock Blaster

Post by soakinader » Mon Aug 12, 2013 1:30 pm

You have a million and one options. My two cents is, you can always remove the OPRV to make space, and you can even completely relocate the valves and make the hose come out the back (horizontally). Also, while I haven't seen the outside of the shell recently, you can probably extend the track with a little cutting. Or, just put the hose in that spot two inches back from the handle where you don't want it. That's pretty easy. Personally I don't think it's worth the trouble on the PPB, it already has a great pump.
My friends call me Nader. My foes just run.
Photos relocated to: https://www.flickr.com/photos/151868511 ... 8741427445
I find 'em, I fix 'em.

marauder
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Re: Adding a Higher Volume Pump to a Stock Blaster

Post by marauder » Mon Aug 12, 2013 4:03 pm

The stock pump is great for the stock nozzle, but now that I've done a multi nozzle mod I want more. It would be more than sufficient if this thing was CPS, but 50 oz of air pressure does not equal 50 oz of constant pressure. At this point, I'm probably being greedy, but I feel like there's a reason air pressure guns with big outputs, eg the 300, 250, and 275, all had massive pump volumes. It just made it so much better.

Ok, so I might be getting greedy with this thing, but seriously, my whole intent was to go all in and make this the best it can be.
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Andrew
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Re: Adding a Higher Volume Pump to a Stock Blaster

Post by Andrew » Mon Aug 12, 2013 4:44 pm

The beauty of the suggested layout is all the components are stock, and left in about the same place, so it requires very little work. if you want to remove the PRV (I'm not sure which of the pipes the PRV is housed in, I'd guess the pipe nearest the back, but can't be sure), you may be able to get a bit more pump length, but it would require filling more holes and may need to move/replace the first check valve. If you curve the intake tube, so it points rearward and meets the bottom of that rear pipe horizontally, it could be epoxied puttied in place. You could also make the intake tube come horizontally out of the back of the blaster to keep it away from the pistol grip.

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