Some UNIQUE valve mods .... GREATER flow into valves interior ( M-Rod Valve)

[Motorhead]

I am doing this mod for another GTA member who voiced wanting to try it.  My M-rods valve was modified beyond this, but cap mod is just like it.
Original idea was to keep pressure at poppet seat high as possible during the shot. By NOT having the air HAVE TOO travel into I.D. of spring and pass between the coils we get "In Theory" less flow restriction.
This compounded by poppet spring preload collars of different heights that will be played with also further increasing air drag passing threw valves retention cap.

So ... here is what we are doing, pictures should be pretty self explanatory 
* Head of poppet slightly tapered giving a tad more flow around it's sides.

[rsterne]

Good looking mods.... I drilled the end of a Hatsan AT44 valve to achieve flow around the spring.... didn't make a huge difference.... but it didn't hurt....

Bob

[Bill G]

I'd be interested to see some before and after shot strings if you would post them. 

Bill

[PakProtector]

I'd be interested to see some before and after shot strings if you would post them. 

Bill

hey Bill, there will be data... This valve is going into a 22 cal. though it started life as a 2563 part number.
cheers,
Douglas

[PakProtector]

hey-Hey!!!,
Here is the 'before' string with Barracuda Match 21.3 gr. FIll to 3k( 2k8 indicated), shoot to2k indicated.
838.7
835.6
840.5
846.2
842.3
846.0
848.6
854.5
855.4
849.8
854.8
853.9
848.3
850.0
848.9
848.5
849.8
847.9
837.7
838.9
840.6
831.4
818.2

Now with the new valve. put about 3mm of spring preload spacer in( lost the bag with the dimensions ). Same hammer travel and preload and 3k(2k8 indicated ) fill, shot to 1k6 indicated:
err2
err2
err2---this was getting exasperating)
851.7
863.4
868.8
868.3
869.4
872.8
878.6
896.0
886.0
892.3
905.8
896.7
903.0
899.3
906.8
912.6
909.2
907.8
902.1
907.1
905.4
908.7
903.3
905.1
899.7
898.9
889.8
880.5
876.0
870.5
866.0
849.9

So for 4% spread I get the same number of shots, across the same 800 psi drop in resevoir pressure but at ~18% improvement in power delivery. All this from lower pressure ( about 2k7 to 1k9 as measured with what I think is better gage ). Previous end was 2k2 by that same fill adapter gage.

Peak power is just shy of 40FPE. I am comfortable saying that a pellet weight increase will net more power still( the 25 gr JSB Monsters don't shoot poorly at all ). Centering the shot string on 900 fps with Barracudas is not a bad thing at all for a 22 cal IMO. Nutters beware( assuming there are any ov youse left ).
cheers,
Douglas

[rsterne]

So this is with a .25 cal valve in a .22 MRod?.... What other mods have been done?.... Looks good, BTW....

Bob

[Motorhead]

So this is with a .25 cal valve in a .22 MRod?.... What other mods have been done?.... Looks good, BTW....

Bob

Doug had called me earlier while testing and confirmed WHAT mods were also done for my own info ?
Yes the second sting is the reworked .25 valve ...
VALVE Cap & Tapered Poppet as shown above + Pre-load shim ONLY .... NOTHING ELSE per Douglas.

Spittin 21 grain Barracuda at 900+ .... What an ANIMIAL of a .22 M-rod !!

[PakProtector]

It is the .146" long spacer( between cap and spring ). It started out as a 2563 valve. Scott showed what he did in the lead-off post. I just put it in. Rifle also has the 2563 transfer sleeve.
cheers,
Douglas

[amb5500c]

Very nice results.
Richard

[rsterne]

What is the ID of the transfer sleeve?.... what about the barrel port?....

Bob

[Rescue35]

Nice results. Keep us updated.

I am looking forward to doing a little work on my valve this weekend. I'm looking to make a new poppet and stem and increasing the stem length. Mainly looking to increase opening throw and thereby dwell to get more air behind the bullet.

[rsterne]

I'm looking to make a new poppet and stem and increasing the stem length. Mainly looking to increase opening throw and thereby dwell to get more air behind the bullet.

I think you will find that has the opposite effect.... I would REALLY doubt if the stem is being driven all the way to the back of the valve, and if that isn't happening, making a longer stem will in fact REDUCE the power.... It will have the same effect as lengthening the hammer striker, which reduces the throw of the hammer (ie it's travel).... This reduces the velocity of the hammer at impact, and reduces how far the valve opens.... To increase the travel, and hence the dwell, you need to increase the hammer strike.... That means a heavier hammer, more hammer travel, a stronger hammer spring, or more preload on the hammer spring.... Any/all of those will increase the amount of air the valve releases.... and move the peak of the shot string to a higher pressure....

Bob

[PakProtector]

What is the ID of the transfer sleeve?.... what about the barrel port?....

Bob

Barel port is .152", transfer sleeve is the OE-spec for the 2563 at .140" which matches the vertical passage in the valve...Going to go to match the barrel port at some point. I have not yet gotten to the point of reducing efficiency though the power level continues to increase...y'all have done a fine job teaching me to mod this thing...
cheers,
Douglas

[Rescue35]

Douglas,

Keep it up. I'm a firm believer in the potential hidden inside the stock Marauder.

Bob,

I agree and have moved the discussion of my valve to my thread in the Big Bore gate to prevent the hijacking of this thread.

[lloyd-ss]

Douglas,

Keep it up. I'm a firm believer in the potential hidden inside the stock Marauder.

Bob,

I agree and have moved the discussion of my valve to my thread in the Big Bore gate to prevent the hijacking of this thread.

I agree.  With all the metal in that valve, there is ample material to modify it however you want.  Add to that the adjustable spring and hammer stroke, and transfer port.  Plenty of potential!
Lloyd-ss

[Bill G]

Nice work Douglas!  I've been working on my .25 and have decided that I will put the valve spring and cap back in.  Before I do this, I will do what Scott has done to yours.  I am thinking about drilling 5 or 6 small holes radially in the face of the valve at an angle converging at the center.(missing the threads).  I don't have the valve out right now and can't recall visually what it looks like past the cap.  It seems that without the spring present, the duration is inconsistant and fps differs from one fill to the next. BTW, the factory Transfer sleeve can be drilled out to .156" with no problems using a lathe.  the barrle port is real close already.  As per Bob, 75% of bore is a max and you are far from that.  If you drill the vertical port of the valve to .156 along with every thing else, the area of the porting will be = to .156 from the inlet to the pellet.  The force to open the valve will remain the exact same while the possible flow will increase by alot.  This will equate to really high velocity or gained shots at lower psi with a ballanced tune.  If you tune for efficiency you will get something in between.  My .25 went from 894 avg velocity for 16 shots to 925avg velocity over 16 shots with the porting mods.  I can increase mine to .187" porting still yet.  You can take yours up to .165".  But consider this, if we go any larger than .156 for the vertical port through the barrle port, we will have to increase the throat and or reduce the vavle stem diameter.  Otherwise, we will only increase dead vol and make the throat the restrictive point in the porting.  Just how nasty of a .22 do you want man!!? .  Do they even make pellets heavy enough in .22 to get the potential.  Did the squirrels in your area adopt body armour?

Having fun
Bill

 

   

[Motorhead]

Nice work Douglas!  I've been working on my .25 and have decided that I will put the valve spring and cap back in.  Before I do this, I will do what Scott has done to yours.  I am thinking about drilling 5 or 6 small holes radially in the face of the valve at an angle converging at the center.(missing the threads).  I don't have the valve out right now and can't recall visually what it looks like past the cap.  It seems that without the spring present, the duration is inconsistant and fps differs from one fill to the next. BTW, the factory Transfer sleeve can be drilled out to .156" with no problems using a lathe.  the barrle port is real close already.  As per Bob, 75% of bore is a max and you are far from that.  If you drill the vertical port of the valve to .156 along with every thing else, the area of the porting will be = to .156 from the inlet to the pellet.  The force to open the valve will remain the exact same while the possible flow will increase by alot.  This will equate to really high velocity or gained shots at lower psi with a ballanced tune.  If you tune for efficiency you will get something in between.  My .25 went from 894 avg velocity for 16 shots to 925avg velocity over 16 shots with the porting mods.  I can increase mine to .187" porting still yet.  You can take yours up to .165".  But consider this, if we go any larger than .156 for the vertical port through the barrle port, we will have to increase the throat and or reduce the vavle stem diameter.  Otherwise, we will only increase dead vol and make the throat the restrictive point in the porting.  Just how nasty of a .22 do you want man!!? .  Do they even make pellets heavy enough in .22 to get the potential.  Did the squirrels in your area adopt body armour?

Having fun
Bill

Bill,
what you saying above on sizes hits home with my personal .22 M-rod valve mods. ( Granted its Regulated, but still flows BIG TIME )
Behind poppet is .250" diameter and stem turned to @ .100", Transfer passage out valve body, transfer tube, hole feeding barrel ALL at .165"

Indeed the M-rods valves ( .177 & .22 one style ...... .25 another style ) can be modified in so many ways.

Kinda cool ....

[lloyd-ss]

I am enjoying the thread and learning all the time.
Thanks,
Lloyd

[PakProtector]

from BillG-- Just how nasty of a .22 do you want man!!? .  Do they even make pellets heavy enough in .22 to get the potential.  Did the squirrels in your area adopt body armour?

Nasty is as Nasty does... I think I have the heaviest, easy to obtain pellet that flies well in the 5.53 Match Barracuda. The 28.4 gr E-J don't fly as well( at the previous lower velocity ), and I have not acquired any of the heavier pointed ones. Will have to run some today, and see it higher speed yeilds an improvement... the rifle sees primary duty as a plinker, so I don't want to go below a 20 round count across the 4% spread.

Next up, 3x 211 o-rings for the BStaley trick. The OE 2263 valve will get The Treatment to take it past the modified 2563 valve it is now sporting. .250 throat, .152 transfer port and sleeve and we shall see.

I have not yet seen squirrels in body armor, but then again, I have not seen very many squirrels at all these days...heh-heh-heh.
cheers,
Douglas

[TOM aka critter99]

I wonder where all the tree rats went around your place???  Hmmmm???