GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: rsterne on June 30, 2016, 05:45:14 PM
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I ran across an MRod valve that has an insert, which believe to be a .177 or .22 cal Gen 1, the exhaust port was only 1/8".... There wasn't one in the Gen 1 .25 cal I had worked on previously.... Can anyone tell me whether or not ANY of the Gen 2 valves have an insert inside them?.... If some do, how can I identify them, as drilling out the valve when there is an insert inside can get messy if the drill bit catches on the insert and spins it.... >:(
It appears that you can tell Gen 1 from Gen 2 valves because the Gen 1 only have two milled spots on the bottom to miss the trigger screws, whereas the Gen 2 have a long milled slot.... presumably to make it so you can use a Gen 2 valve in a Gen 1 gun?....
Bob
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Bob, if no one replies soon, you may want to PM MichaelM. I am pretty sure he dealt with one having an insert but I do not recall the particulars.
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Bob,
ONLY the gen 1 valves used in .177 & .22 had the removable inner sleeve.
These valves also have FLAT poppet seats. ( Aluminum color bodies ) Tight .125" transfer hole.
ALL the Gen 1 in .25 cal and ALL gen 2 valves are GOLD anodized with raised poppet seats.
.140" transfer hole.
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Gen 1 had an insert for .177 and .22 , the 25 did not. That was their difference.
Gen 2 and past have no sleeves for all calibers.
Whatcha working on Bob ?
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Just done a gen 1 with a restricted valve and it wasn't a sleeve like I have seen , I drilled it out. I have never seen one like that. David
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Thanks, all I need to know is that the gold anodized valves don't have an insert....
I'm going to be build a pair of BRods from a box of parts graciously donated by Travis at W.A.R. when he was cleaning out his shop.... Winter projects, but I'm just figuring out how to make the valves breathe at least as good as my Disco valve.... They need a lot of work to manage that, pretty restricted in stock form.... I have figured out how to make the ports take full advantage of the stock poppet, which is what I use in my modded Disco valves now.... so they should perform identically, at equal pressure.... That will give me a known development path to follow.... so there should be no surprises.... I will likely build a .25 cal regulated and a .30 cal unregulated.... not sure yet.... but I have a spare LW .25 cal Polygonal barrel and a spare TJ's .300 cal.... I'll be using Gen2 .25 cal breeches, which have a 1/2" bore....
Bob
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Not trying to sound like a douche but could you make a sleeve for a disco valve to fit the marauder tube. I have not idea . Please be gentle.
Reason I bring it up is ,I know Bob can make the disco valve breath well . The marauder valve is a complete redo from what I've read.
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I think it would be pretty tough, because the MRod Breech mounts directly to the MRod valve.... The distance between those two 4-40 screws restricts the ID of the valve to 1/2".... Having said that, if you use the MRod poppet, in either valve, it has a 0.33" OD, so the 0.50" ID doesn't restrict the airflow around it to any significant degree.... The area around the poppet is the same area as a 3/8" port, and twice as big as the 0.266" port that is the largest you can use with a stock MRod poppet.... If you go larger than that, at 3000 psi, the Delrin of the poppet starts extruding into the throat.... The 0.266" throat, with the 0.125" stem, then limits you to about a 7/32" exhaust port.... However, that is well over twice the area of a stock .25 cal MRod exhaust port, and a HUGE improvement in breathing.... It is the same as what I use in my Disco valves.... At 3000 psi, those will produce 115 FPE in .25 cal, 140 FPE in .300 cal, and 190 FPE in .357 cal.... so they DO breathe pretty good.... 8)
The problem with the MRod valve is that the exhaust port is so close to the valve sealing face you can't go much larger than 3/16", and you can't angle the port like you can on a Disco.... The solution is to drill/mill out the existing valve seat, permanently install a longer one with a larger throat, and then machine in a new, 7/32" angled exhaust port.... This moves the poppet further forward.... so you then have to machine some off the back of the valve to get enough valve lift.... This in turn gives you more hammer travel available.... I haven't looked at what that does to the travel of the cocking pin for the hammer, because I plan on making my own anyway.... I'll know better when I get my breeches if there are any issues....
As happens in almost all modding situations.... one mod causes two problems, fixing those creates four more, then eight.... and pretty soon you end up rebuilding the entire gun.... or so it seems....
Bob
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I think it would be pretty tough, because the MRod Breech mounts directly to the MRod valve.... The distance between those two 4-40 screws restricts the ID of the valve to 1/2".... Having said that, if you use the MRod poppet, in either valve, it has a 0.33" OD, so the 0.50" ID doesn't restrict the airflow around it to any significant degree.... The area around the poppet is the same area as a 3/8" port, and twice as big as the 0.266" port that is the largest you can use with a stock MRod poppet.... If you go larger than that, at 3000 psi, the Delrin of the poppet starts extruding into the throat.... The 0.266" throat, with the 0.125" stem, then limits you to about a 7/32" exhaust port.... However, that is well over twice the area of a stock .25 cal MRod exhaust port, and a HUGE improvement in breathing.... It is the same as what I use in my Disco valves.... At 3000 psi, those will produce 115 FPE in .25 cal, 140 FPE in .300 cal, and 190 FPE in .357 cal.... so they DO breathe pretty good.... 8)
The problem with the MRod valve is that the exhaust port is so close to the valve sealing face you can't go much larger than 3/16", and you can't angle the port like you can on a Disco.... The solution is to drill/mill out the existing valve seat, permanently install a longer one with a larger throat, and then machine in a new, 7/32" angled exhaust port.... This moves the poppet further forward.... so you then have to machine some off the back of the valve to get enough valve lift.... This in turn gives you more hammer travel available.... I haven't looked at what that does to the travel of the cocking pin for the hammer, because I plan on making my own anyway.... I'll know better when I get my breeches if there are any issues....
As happens in almost all modding situations.... one mod causes two problems, fixing those creates four more, then eight.... and pretty soon you end up rebuilding the entire gun.... or so it seems....
Bob
Sounds like you need a WAR valve LOL
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Yeah, but that would take all the fun out of it.... *LOL*.... This way I get to pretend I'm a machinist....
Bob
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Yeah, but that would take all the fun out of it.... *LOL*.... This way I get to pretend I'm a machinist....
Bob
You mean like me! LOL Its good to have a master machinist like Jim Gaska on team WAR! I have fun and learn a lot but Im no machinist(not yet). Post pics of your build when you get to the building process.
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You bet I will.... and THANKS for the big box of parts!.... It was an inspiration, and the opportunity to learn about MRods, which I have never done before....
Unfortunately, my wallet has shrunk considerably, as I get more stuff to complete the builds.... but that's the joy of free stuff.... it forces you (c'mon twist my arm) to spend money....
Bob
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HAHAH that insert on the gen1 .177 and .22 valves can be a real head scratcher....... I found out quiet by accident on the first mrod valve I worked on and tried to open up.... at least half hour of head scratching on why my 1/2 inch endmill wouldn't cut... wasn't until I chucked a 1/2 drill bit into the tailstock on the lathe that it bit into the sleeve and pulled it out a touch that I found out something was up.......... Like I said for a half an hour or more I was very confused and felt dumber then normal.........
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Bob,
You should post your valve mods you just put up on the guild.
Pretty much everything you have done on that valve is the same as I have running now in my 25. I too agree that going to .203" on the exit port is in excessive but heck, I had a .357 mounted on a 22 receiver.
I settled into .196" as well.
2500 psi and 43 Eujins
0 turn on the hammer spring = 65 FPE
1 turn on the hammer spring = 70 FPE
2 turns on the hammer spring = 76 FPE
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DONE !.... http://www.gatewaytoairguns.org/GTA/index.php?topic=111416.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=111416.0)
Bob