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Crosman valve update!!!

Started by mudduck48, December 29, 2012, 11:38:27 PM

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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]
We need to keep going and have fun doing it.

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!! ???
I Am A Natural Mad Air Gunner  -  Full Of Hot Air & Ready To Expel It Quickly!

114 Rifle, 2240XL Pistol, 1861 Shiloh Pistol, 357 Pistols, Titan GP Rifle, PM66 Rifle, 2400KT .177 LW Carbine, CZ T200 Rifle, Benjamin Discovery .177 Rifle, Hammerli 850 Air Magnum in .22

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.
Larry

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.....
Wyo
Welcome to your life :)
Member of the Western Heretic Alliance

mudduck48

Quote from: breakfastchef on December 30, 2012, 02:27:49 AM
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.
We need to keep going and have fun doing it.

cmj21973

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

The internals also impact valve performance.

breakfastchef

Quote from: mudduck48 on December 30, 2012, 03:32:16 AM
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.
Larry

breakfastchef

#7
Quote from: WyoMan on December 30, 2012, 03:05:01 AM
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.
Larry

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.
We need to keep going and have fun doing it.

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
TOO many freaks and NOT enough circuses

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.
We need to keep going and have fun doing it.

eric

#11
my point is that some info needs to taken with a grain of salt and with him you might need the whole salt shaker .....
TOO many freaks and NOT enough circuses

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
I Am A Natural Mad Air Gunner  -  Full Of Hot Air & Ready To Expel It Quickly!

114 Rifle, 2240XL Pistol, 1861 Shiloh Pistol, 357 Pistols, Titan GP Rifle, PM66 Rifle, 2400KT .177 LW Carbine, CZ T200 Rifle, Benjamin Discovery .177 Rifle, Hammerli 850 Air Magnum in .22

KevinP

Quote from: eric on December 30, 2012, 04:47:57 AM
my point is that some info needs to taken with a grain of salt and with him you might need the whole salt shaker .....

;D ;D :-*
Kevin
Albany, New York

airguns100

Quote from: eric on December 30, 2012, 04:19:01 AM

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

I have to agree with this statement.
The OG gangster of the "bling"