.22 Cricket mini Carbine Power Tune

[zx10wall]

C’cut, no the Taipan reg is not hard to change pressures on. It’s different though. Watch Ernest’s video on it.

It can be done without a reg tester as long as you don’t get lost. The gun tells you where the reg is set. When you refill you can confirm where the pressure is at as the reservoir begins taking pressure. When all is set well, the gun will get 2-3 shots that are tight with the spread even as it comes off reg before fps starts heading South. I, personally, don’t like to see the fps climb as the gun leaves the reg. That indicates that the reg is set a bit high for the fps or you need to dial-in more HST. 



https://m.youtube.com/watch?v=eVg_KkaPOu0

 

[Centercut]

Thanks much. Do you have a schematic for the Taipan Mutant showing all parts and orings? It was easy to get for the Cricket and Vulcan, but can’t find for Taipan. When Nick decides and I get back, I’ll start the mods.

Yeah, I have to go to Hawaii 4 or 5 times a year, same for VA Beach.

 

[zx10wall]

This is an exploded view of the Taipan Mutant Standard. It is also one with a different mag configuration. The most important parts are the same though. Link below also has the Taipan’s o’ring specs and the EV in a better viewing quality.

https://airgunwarriors.com/airgun-talk/taipan-veteran-schematics-o-rings/

 

[Centercut]

Thanks!!! Between my FX and Crickets/Vulcans I have almost all the orings for the Taipan. Appreciate it Derek. 

Mike 

 

[zx10wall]

 









https://www.youtube.com/watch?v=81Qj1R-dXVQ







And check this video out below as well on porting/polishing the firing-valve of the Taipan.

https://ernestrowe.com/mutant

Diamond burr for the brass valve:

 

[zx10wall]

I really wonder what the poppet OD and seat OD of the crickets are…and their poppet material.

-Matt

Matt, the poppet is 8mm and the seat is 7.6mm. The sealing material is, I believe, black Delrin. The poppet head is aluminum. 

 

[ackuric]

I really wonder what the poppet OD and seat OD of the crickets are…and their poppet material.

-Matt

Matt, the poppet is 8mm and the seat is 7.6mm. The sealing material is, I believe, black Delrin. The poppet head is aluminum. 

You sure? That would leave only 0.0078" of a sealing margin. That very small and has no margin for error or reduction if thats the case. I run .015" - .025" depending on application.



Guess they're already on top of minimizing the sealing margin if thats the case, can't say I don't believe it...but it is quite shocking to see a manufacturer run that small a margin. Kudos!

 

[zx10wall]

Just tuned a .25 pup tonight and measured it. I didn’t get crazy precise about it. Measured poppet at 8mm and could see the impression of the seat on the Delrin. Measured it at 7.6mm. Valve-stem is 3mm. 

 

[Centercut]

@zx10wall, @frear42-_. I ran into an issue I’m not sure how to handle. The breech port isn’t .20 as I thought. There appears to be a brass insert or liner that reduces the port diameter. It’s not easily removable.

I’m hesitant to burr it larger since it seems like it would be an all or nothing proposition. I’ve enlarged the valve port as much as possible. 

I’d work in the barrel port but it seems pointless unless I get over the issue with the breech block port? So all I did so far was taper the edges and polish. Any suggestions? As it currently is I’ve got to 895 FPS (plateau at 905, reg at 138 bar) with the 18.1 JSB, starting point was 830. Thanks.

Mike

 

[zx10wall]

The brass is in the action port?

 

[zx10wall]

I’d definitely open the barrel port. Oval it. I’d consider opening that brass up some too but test again after the ovaling the barrel port and see what you have. 

 

[ackuric]

Document what you can.



Interesting thought for you zx10. If what you say is correct about actual valve throat/seat being 7.6 MM that is basically .3", which with a 3mm valve stem, that is enough area to flow FULL bore and actually OVER bore...



Ideally with a 3mm stem and full bore porting on a .25 cal the throat/seat would only need to be ... .285"...which would allow an even thinner poppet for better air flow AND ease of opening...just a thought. Tolerances are tight as is but seems to be set up to handle up to .30 cal on the same valve....JMO. For a .22 cal those numbers could be GREATLY reduced.



Notice the above is FULL bore, for a .25 cal running 90% bore with a 3mm stem you'd have a .265" valve throat/seat and ideally a .305" poppet head. This would allow the throat to flow 10% more air then all the porting forward of it..



For a .22 cal @ 90% bore, the valve throat with a 3mm stem only needs to be .24" which would allow a .28" poppet which would require roughly 25% less hammer energy than a valve with a .315~" poppet...


HTH,



PS. The above is an inherent issue with mass produced rifles available in multiple calibers, generally designs are minimized to work across all, this is basically always the case with valves, while a very well tuned valve operating in a .177 cal should ideally be setup way differently than a .25 cal, more so than just transfer port choking, which is common practice. 

-Matt

 

[Centercut]

Yes, the brass liner is in the breech block port. That’s what the first photo shows. Couldn’t get it in good focus. Thanks for all the help Derek. 

 

[zx10wall]

Matt, I was in a valve earlier today. Measured again for you ~ throat: .295”, poppet: .315”, VS: .115”. 

The numbers you are crunching are interesting. I haven’t used math to inform or light the way on modifications. I’ve operated on advice, trial/error and a lot of testing. Radiusing the firing-valve does help considerably.

 

[zx10wall]

This is what I’ve seen in both .22 & .25 firing-valve. I can only assume the Cricket Mini Carbine has the same set up. 

 

[zx10wall]

Mike, it almost looks like Kalibrgun squeezes down the action port by pressing that brass sleeve in. I’d open that booger up. 

 

[zx10wall]

I just got done with a .22 Cricket Carbine (not pup) tune. Port/polished all TP and radiused firing valve with oval barrel TP. My word, opening the ports makes a world of difference. No added plenum. .25 Cricket HS and no added weight to hammer. Installed a slightly weaker firing-valve return spring. “Swiss cheesed” the reg spacer and again, no added plenum tube. Reg set to 140 bar. Plateaus at 920 fps with the 25.39gr RD Monsters. I backed it down to 900 fps with HST. 

I will test shot count and accuracy later. It has a wonderfully smooth shot cycle and is very tight over the chrony

I ended up turning this guy down to 880 fps with the .22 RDs. It’s very accurate. I have the reg at 136 bar and can get 32 regulated shots from a 240 bar fill. Groups are 5-shots each from 40 yards in wind today.

 

[ackuric]

Yes, a .295" throat with a .115" valve stem can flow enough air to support forward porting equal to .26"....and STILL have 10% more flow than the porting ahead...



So all the numbers I crunched in the prior post apply zx10, even MORE so with .22 / .177 if the same throat/poppet values hold true. 

I am quite impressed through with how well they come from the factory for air flow...definitely a valve staged to work from .177-.30 cal. The .01" sealing margin is wicked, I do mine by hand so I only go as low as .015"-.02". Nothing wrong with .01" though at all, thats quite an achievement to produce on their scale.



If one were to go crazy for a .22" cal they'd machine a new valve seat + throat (looks like an insert as is) that is roughly .24". That will flow ports up to .2" with 10% more flow than forward porting, PLUS the poppet on that seat would only need to be .27"-.28" or even as low as .26'...the .27" poppet would have 114 lbs @ 2000 psi against poppet where as the stock .295" has 136 lbs. Roughly 16% decrease in required hammer energy, plus the benefit of LESS wasted volume due to over sized throat. Nothing but benefits!

 

[Centercut]

@zx10wall, yes, it looks like it’s pressed in to reduce diameter of the action block port. I’ve asked a few people that seem to know and it’s pressed in not epoxied in. Too bad since some heat and it could be removed. Should be much easier to use a burr and drill it out since it’s brass than if it were steel. 

And yes, the firing valve set up is the same as you pictured in your previous post. 

 

[Centercut]

As of Dec 22nd, this is where we are with Nick’s @socaloldman .22 Cricket mini Carbine power tune. 

- installed Ernest Rowe power plenum.

- installed Huma Reg set at 138 bar 

- enlarged and polished valve port, radiused edges

- polished barrel port and radiused edges

- installed metal HST adjuster and installed .25 caliber Cricket Hammer spring

- installed DonnyFL custom side plate

- used stock valve spring. I had considered a longer weaker valve spring but was concerned about shot count

- radiused and polished fill port holes, and cut down the overly stiff fill port dust cover spring to make it easier to insert the fill probe

- replaced stock pressure gage with a WIKA gage

- resealed entire gun, every oring replaced with Viton oring

Tuned gun for 885 FPS, plateau was just over 900 FPS. As Huma broke in speed increased for a hundred pellets and settled in at 895 FPS. 18.1 JSB Heavy .22 pellets.

Performance is stellar. On Saturday, Nick filled to 250 bar. He shot four full magazines of 14 shots each. Pressure after 4 mags was still at 170 bar, so about 20 bar per 14 shot magazine - I think another full mag would have still been on reg. At that point he filled again since the paintball shooting was going full blast and he wanted to keep on as the “target whore” On another note, accuracy is as good or better than the stock 830 FPS tune (same as AEAC got on his Cricket mini review). I watched Nick shoot 4 paintballs in a row at 64 yards. If you don’t know, they are 0.6 inch diameter. Then he went on to shoot quite a few that we had at 85 yards. Nick has a very nice Sightron 4-16x42 Big Sky on this gun, super nice glass. This little gun is now a 32 FPE Laser Beam. And it shoots the 17.9 grain H&N Sniper pellets every bit as good as the JSBs

Not sure we’ll do any more with this gun, like opening up the breech block port or the barrel port, or replacing the valve spring or raising reg pressure. It’s totally up to Nick, but over 65 accurate shots on reg at 32 FPE is pretty darn good...