Vulcan firing valve tension
Anyone know the correct way to set the tension on the Vulcan firing pin valve?
My .25 Vulcan developed a rattle from the end of the cylinder, just stripped it to find the spring and tensioner cover floating about loose inside the cylinder!
Looks like it could have done with securing with thread lock.
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For anyone interested I heard back from Evgeny.
He’s a top man really. Language barrier is the biggest issue but I did a bit of google translation and wrote in Czech.
Essentially the correct setting for this is the valve pin allowed to fully open just as the spring goes solid. He sent some diagrams and even made me a video but it’s just as I say.
I can post the pics later. It does show the firing pin end (outside) being flush with the valve body, the spring being squashed solid. His diagram also shows a slight dome to the end of the valve pin and just the edges flush so the peak of the dome sticks proud. But I think the pin is flat. I will check.
I did ask him if the spring being solid is so there is no bounce and he said “yes, that’s correct”.
I guess the valve coming to a stop against the spring prevents it flinging further inside the valve and wasting air and being able to bounce.
I fired it down to about 60bar maybe before it dumped the rest of the air.
This newest incarnation doesn’t have a bleed screw on the cylinder.
on the talon some guys were experimenting with valves without valve return spring. since the air closes it.
at low pressure they can have a full air dump which is f.cking scary
Thanks for the replies chaps.
I think I’m just going to set it just in there enough that the threads on the cover are fully in the threads on the valve (if that makes sense)
It didn’t have any thread lock on it.
Just annoying as the gun shot the full string with an extreme deviation over 36 shots of just 7fps! Hope it doesn’t mess things up as the gun was really consistent.
Was still shooting fine even with these bits floating around though.
i had a thread about it a year two ago, no one answered including gurus. hit and miss
in my understanding it does not tune much on a high power .25, go a bit more cw so it does not uncrew itself next time. if you overdo may be missing some fps.i remember zonk was saying his was 3 full turns and that was too much?
zonk were the 3 the numbers of threads visible?
you really want a few treads to hold it in.i dont remember seeing any visible threads so mine is not very deep in.
E mail Ernest. He found the problem with my Vulcan it was the valve stem. Or call him. :8:
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wow, that is impressive customer service. what does evgeny have up his sleeve – there was talk of a synthetic stock & a semi auto?