Crosman valve update!!!

[mudduck48]

Check this out. Now I know why my new 1322 did not shoot as fast as Crosshairs new 1322.
[youtube]https://www.youtube.com/watch?v=Qjf23V1MIEA#]Crosman 1377 US Valve Update[/url]

[arkmaker †]

I'm not convinced that the flat nose makes that much of a difference. Someone run the actual tests and show the numbers please!!

[breakfastchef]

The dude actually lasted 8:21 minutes without lighting up a cigarette. That must be his personal best.

To the core of the post, yes, the trimmed cone is responsible for a loss of fps. Perhaps the spring in the US valve is slightly stronger, also leading to loss of velocity. It is bizzare that he found the 1377 pump handle would not stay shut without one pump in the valve. That leads me to believe the remaining loss of fps is the huge amount of headspace created by an improperly adjusted/manufactured piston & cup. The only reason this would happen is for the piston to not fully push into the valve face to create that needed 'lock up' to keep the handle secured against the pump tube.

[WyoMan]

Great points Chef 
Here's where the video dude got it wrong IMHO:
The snubby valve nose fits the shape of the pump cup better then the pointy model:


There is less headspace with snubby from point to check (in the inlet)
His particular experience with lack of cam over is not the same as mine
manufacture tolerances on a $55 item 

Chef, you been hanging around the Green.....

[mudduck48]

The dude actually lasted 8:21 minutes without lighting up a cigarette. That must be his personal best.

To the core of the post, yes, the trimmed cone is responsible for a loss of fps. Perhaps the spring in the US valve is slightly stronger, also leading to loss of velocity. It is bizzare that he found the 1377 pump handle would not stay shut without one pump in the valve. That leads me to believe the remaining loss of fps is the huge amount of headspace created by an improperly adjusted/manufactured piston & cup. The only reason this would happen is for the piston to not fully push into the valve face to create that needed 'lock up' to keep the handle secured against the pump tube.

I have noticed that on my 1322. If there is no pressure on the valve and you touch the pump handle it will not stay in place. My son's new 2289g backpacker put a pellet all the way through a empy gamo can, my 1322 just put a dent in it. He might have the old valve that is pointed, mine might be the new one.

[cmj21973]

Are the internals [spring; stem; and check valve(s)] the same in both valves?

The internals also impact valve performance.

[breakfastchef]

I have noticed that on my 1322. If there is no pressure on the valve and you touch the pump handle it will not stay in place. My son's new 2289g backpacker put a pellet all the way through a empy gamo can, my 1322 just put a dent in it. He might have the old valve that is pointed, mine might be the new one.

Assuming a complete stock setup, you might want to try and shim the piston cup. Just a little with a washer or c-clip but probably no more than 1/16". It would be an easy mod to try and is non-damaging. The idea is that the piston may not be closing on the valve enough. The shim might do two things: 1) reduce headspace and increase fps per pump, and 2) your pump arm might actually stay closed. If you are up to it, try different shim thicknesses and note if there is an improvement. If you shim too much, the pump cup will come out.

[breakfastchef]

Here's where the video dude got it wrong IMHO:
The snubby valve nose fits the shape of the pump cup better then the pointy model:

Perhaps. One cannot tell from the video if the trim job is more aggressive than necessary to conform to the pump cup.
There is a lot of information we cannot draw from the video. The US valve might have might have a larger valve inlet diameter. The valve spring might be a bit firmer than necessary further reducing velocity. Also, we do not know how many of those US valves made it into production guns, whether there was a tooling/OEM change in midstream, etc. Regardless, there are options to correct the deficiency if we are so moved.

[mudduck48]

Back in september I bought a bunch of parts for  my guns from Crosman. I just looked a the valve I bought and it has the croped nose. I bought it to take apart and put the inside parts in my phaze 11 1377. I hope they fit.

[eric]

this is that guy from canada the makes the 357 grips --- he was a member here as i am sure some will remember .i could say more but it wouldn't be nice

[mudduck48]

In my opinion, it doesn't matter where he is or what he did or what he does. The point of the post was to show you all that Crosman is controlling what our guns do. They have cut down the output. Yes, we can still put new parts in them and get them to put out more, but they used to be great right out of the box.

[eric]

my point is that some info needs to taken with a grain of salt and with him you might need the whole salt shaker .....

[arkmaker †]

Now I am going to have to buy a new pumper! So I can make the mods myself and run the numbers over the chrony......Dang, I hate pumping!!


Anyone else want to run the actual comparison tests of one valve against the other in the same gun??


It would have been nice if the guy in the video had done that. To me it is just his assumption that the flat nose is what is making the difference. My money would be on the spring. In which case the test should include swapping them from one valve to the other and re-running the tests over a chrony. That means 4 sets of testing and taking the gun down for valve switch 4 times as well. It is the only way to put this to rest? Anyone see another way to prove or disprove it?


Rich

[KevinP]

my point is that some info needs to taken with a grain of salt and with him you might need the whole salt shaker .....

[airguns100]

.i could say more but it wouldn't be nice

I have to agree with this statement.