Apparently, I've demolished my valve seat (back to that old stupidity issue, my fault), but heard there are upgraded valve seats out there. Anyone know where I can pick up the stronger valve seats? (Older model, manufactured February 2017 in .25 cal)
Impact Valve Seat
- Thread starter Saltlake58
- Start date
Personal inexperience with the gun (stupidity, but I learned the lesson). In way over my head with an Impact, and enjoying it every minute.
Removed the original ST barrel to upgrade to a new X-Barrel. Didn't realize the gun was cocked and knocked the trigger. BANG! and did my ears RING!
demolished the Regulator O-Rings, got that repaired (Thank you FX USA and Ernest Rowe for the FX Master Series).
Now appears the valve seat got smashed in the process. The valve rod didn't have any resistance when it hit the seat, so it appears the seat got smashed in the process. The valve rod extends into the space where you insert the magazine which indicates a smashed valve seat. I'll be dismantling the gun shortly to confirm.
So, lesson learned, if you have the barrel out, DO NOT pull the trigger. All sorts of bad things happen.
Removed the original ST barrel to upgrade to a new X-Barrel. Didn't realize the gun was cocked and knocked the trigger. BANG! and did my ears RING!
demolished the Regulator O-Rings, got that repaired (Thank you FX USA and Ernest Rowe for the FX Master Series).
Now appears the valve seat got smashed in the process. The valve rod didn't have any resistance when it hit the seat, so it appears the seat got smashed in the process. The valve rod extends into the space where you insert the magazine which indicates a smashed valve seat. I'll be dismantling the gun shortly to confirm.
So, lesson learned, if you have the barrel out, DO NOT pull the trigger. All sorts of bad things happen.
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I'll be interested to know if you find any of the larger valve seats. I wish I had bought one or two on Ebay when Ernest was selling them. I need to enlarge mine, so I'll probably order a couple to have on hand just in case I screw it up. That's about the next step in my need for speed.
Rusty
Rusty
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I didn't see any mention of it on their site, but I sent an email. Worst case, I can enlarge the ID on a stock seat, but I'd be happy to avoid having to do that now.
Thanks,
Rusty
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Hey thanks mate to fessing up to your whoopsies so we all could learn. I would have assumed, falsely apparently, that discharging the gun without a barrel in place would have been no problem on the FX because of the flow restrictor wheel. Learn something new every day. 
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STO - Yup, it really damaged the gun, so please don't do it.
On the other hand, it's been fun tearing into the Impact and fixing bits and bobs. I've learned a lot about the gun and the internal workings. Maybe when I retire, I'll get a job as an entry level airgun tech and rebuild guns for fun. I've enjoyed it.
Fantastic gun, wouldn't hesitate to buy another one. Plus, I'll have spare parts by the time I'm done rebuilding this one!
On the other hand, it's been fun tearing into the Impact and fixing bits and bobs. I've learned a lot about the gun and the internal workings. Maybe when I retire, I'll get a job as an entry level airgun tech and rebuild guns for fun. I've enjoyed it.
Fantastic gun, wouldn't hesitate to buy another one. Plus, I'll have spare parts by the time I'm done rebuilding this one!
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For the few of us in the UK with high power impacts and no access to the uprated valve seat... Would anyone be kind enough to put the dimensions up? I would like to try and make one one the lathe.
Thanks!
Thanks!
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I ordered a care package of parts from FX today, so I guess I'm cleared to destroy mine with mods
My understanding of the upgraded valve seat is that the ID is larger. Otherwise I believe it's the same, aside from possibly being made from different materials. I was told that the stock ID is 5.5mm. Ernest sold some titanium seals for a while that were advertised as 5.8mm. In older threads I ran across, he mentioned dimensions as large as 6.2mm. In a fairly recent email, he mentioned valve seat bores up to 6.15mm, and said he was working on a new valve and seat up to 6.75mm. Sounds like stock valve is the current limit to the valve seat bore size.
I'll be attempting to enlarge a stock valve seat, but haven't decided how far to go yet. My goal is higher velocity for slugs.
Rusty
My understanding of the upgraded valve seat is that the ID is larger. Otherwise I believe it's the same, aside from possibly being made from different materials. I was told that the stock ID is 5.5mm. Ernest sold some titanium seals for a while that were advertised as 5.8mm. In older threads I ran across, he mentioned dimensions as large as 6.2mm. In a fairly recent email, he mentioned valve seat bores up to 6.15mm, and said he was working on a new valve and seat up to 6.75mm. Sounds like stock valve is the current limit to the valve seat bore size.
I'll be attempting to enlarge a stock valve seat, but haven't decided how far to go yet. My goal is higher velocity for slugs.
Rusty
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It would be difficult to post the information you need. Simply copy the original and open the hole to 5.8mm. I would use titanium as Mr Rowe did.
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I ordered a care package of parts from FX today, so I guess I'm cleared to destroy mine with mods
Rusty
What did you order and what is your plan? We need a Impact mod thread to make it easier for others to copy what works. I'd like to see FX sell drop in kits to achieve whatever power level, such as .30 50gn at 1050fps.
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He was selling them on Ebay for a while, but not recently. I had asked about buying some of the modified parts, but he never replied with any details of how I could do that. Since I'm able to make my own, I didn't pursue it.
Rusty
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I ordered a care package of parts from FX today, so I guess I'm cleared to destroy mine with mods
Rusty
What did you order and what is your plan? We need a Impact mod thread to make it easier for others to copy what works. I'd like to see FX sell drop in kits to achieve whatever power level, such as .30 50gn at 1050fps.
There should probably be a sticky Impact mod thread. I have always said FX should sell a special high power version, with all the mods, even if they couldn't warranty it due to the extra stresses.
I'm trying to get close to 1050 fps with a .22 cal 30 grain slug. I started at 820, and I'm up to 920 (180 bar). So far I've only upgraded the regulator, added 9g of hammer weight, and ported the TP. I'm doing a little more porting today, then moving to the valve seat and milling some slots in the valve tube for extra air space. The parts I ordered are just some stock spares to try different ports, and to cover the inevitable screw up here and there.
Rusty
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I ordered a care package of parts from FX today, so I guess I'm cleared to destroy mine with mods
Rusty
What did you order and what is your plan? We need a Impact mod thread to make it easier for others to copy what works. I'd like to see FX sell drop in kits to achieve whatever power level, such as .30 50gn at 1050fps.
There should probably be a sticky Impact mod thread. I have always said FX should sell a special high power version, with all the mods, even if they couldn't warranty it due to the extra stresses.
I'm trying to get close to 1050 fps with a .22 cal 30 grain slug. I started at 820, and I'm up to 920 (180 bar). So far I've only upgraded the regulator, added 9g of hammer weight, and ported the TP. I'm doing a little more porting today, then moving to the valve seat and milling some slots in the valve tube for extra air space. The parts I ordered are just some stock spares to try different ports, and to cover the inevitable screw up here and there.
Rusty
In which direction did you change the barrel transfer port. I'd like to open mine some but I don't want feeding problems. The new valve tubes have three slots milled. I think there may be some gain from easing the valve tube to valve tube transfer port transition. There are a couple of dead corners at the rear of it.
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I did some searching, and came to no real conclusion about the best way to do this. The one sure thing is that you don't want to get the hole so large that the pellets/slugs fall into it. This is a .22, and the original hole is 5mm. I used a 3/16" (close to 5mm) end mill, and milled the hole 1mm larger in each direction along the length of the barrel. That makes it essentially a 7mm x 5mm slot, which increases the area by about 50%.
Today, I made a (very rough) delrin jig that shows me what valve tube sees through the hole in the frame. Obviously it's a round hole, that ends up being a oval slot. I decided to hand shape the outside of the barrel TP to match the round shape of the frame hole, then let it transition to the oval slot. From the inside of the barrel, nothing changed, only on the outside. I found that I don't have any polishing attachments small enough for this, but I will in a couple days, and I'll try to make this smoother. Of course today I averaged 911 fps instead of 920 from yesterday, but it's more likely due to it being really cold outside, and certainly not from today's porting efforts. Smoother transitions are always better for flow.
Best I can measure, the hole though the valve tube and frame is 7mm, and the rear edge is just in front of the rear o-ring on the barrel. I don't plan to mess with that hole at all, since it's already plenty big for .22, but if I were doing this for .30, or even .25, it would be more of a consideration.
Rusty
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On my .30 the valve transfer port measures 7.18mm, the rear block port above it measures 7.18mm and the barrel transfer port measures 7.10mm.
I think the valve seat and pellet probe are the biggest restrictions.
My Huma regulator has stopped working. I depressurized the gun for two days and now the huma reg won't let air past it. I tried everything. I removed 1 washer for a total of 13 as a test and it started working again but it won't stay sealed. With 13 washers it blows the piston o-ring in less than a day. As another test I put the same 14 washers on the FX regulator in the same configuration as the Huma and it works fine. I don't know if it will creep or not but I'll have to keep it this way until I hear back from Huma.
I think the valve seat and pellet probe are the biggest restrictions.
My Huma regulator has stopped working. I depressurized the gun for two days and now the huma reg won't let air past it. I tried everything. I removed 1 washer for a total of 13 as a test and it started working again but it won't stay sealed. With 13 washers it blows the piston o-ring in less than a day. As another test I put the same 14 washers on the FX regulator in the same configuration as the Huma and it works fine. I don't know if it will creep or not but I'll have to keep it this way until I hear back from Huma.
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Can you point me to a picture of that? I've seen tubes that Ernest milled 4 slots in, and that's what I'm planning to do, though I suppose I could do 3 if that works out better somehow.
Also, I completely agree that the valve/valve seat has to be the biggest restriction. If the stock hole is 5.5mm, and the valve rod takes up space in the middle of that, it's already smaller than the stock transfer port on the .22 barrel. Even at 6mm, minus the valve, it's probably smaller. I can see why Ernest seems to be considering a larger valve and seat combo, if we've maxed out what can be done with the stock valve.
Rusty
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