Was the Zephyr piston seal sold to home tuners/tinkerers?

[averageplinker]

Hello,
I recently picked up a 1987 HW80 project gun. Chronoed it yesterday and it was a bit uncomfortable
So tonight I have had her apart to tame her errant ways and have found it has a zephyr piston seal and a very well finished square section spring with v.little preload. So was the Zephyr seal available to us mere mortals? I am guessing so as the spring guide is still a standard Weihrauch one.
Cheers all.

[Geezer]

Yes, it was. I can remember seeing them advertised as a replacement part.

[averageplinker]

Yes, it was. I can remember seeing them advertised as a replacement part.

Thought as much. It is always interesting to pull apart an old Springer that has had work! I didn't think it was dieseling but there was loads of grease in front of the seal. In fact this grease left a witness mark around the transfer port showing the zephyr seal was upside down!

[averageplinker]

PS the compression part of the cylinder is nicely honed. Did they do this at the factory?

[jonnyone]

As you've already found out the zephyr seals were indeed available to the general public. I.bought two back in the day and my regular HW80 still runs on one.
In order to ensure that the seal lines up with the port the seal has a small lug located.on it s base seating flange. You need to drill a corresponding small hole into the piston head seating groove for this lug to sit in, so that the seal doesn't turn in use and.mis- align itself. If someone has removed the lug then I guess you would need to set the head.in.place with some form of semi permanent glue or silicone.
I never perceived any reputed decrease in recoil by using them but by virtue of the fine rear edge of the seal acting as a scraper they do appear to produce fairly consistent velocities by preventing excess lubes migrating forward. As long as they haven't been altered that is.
A nice discovery and blast from the past. Incidentally I tried to obtain a similar seal for my mates HW77 but Theoben were not marketing these to the public back then. Unsure why? Perhaps they didn't want peeps benefiting from their 77 seal in their own guns as they were marketing the modified gun and offering the work via the Aigun.Centre?

[Hsing-ee]

It looks like a marketting scam from the 1990s. Does compressed air really behave like that? Being 'channelled' into the transfer port? In which case the old Mk 1 and Mk 2 Airsporters should be super-efficient with their conical cylinder ends and piston heads. But they aren't.

Perhaps they were good seals from a materials point of view, but the design of channels in the piston face looks like a silly fantasy idea.

[Mach 1.5]

Yep just a marketing idea the grooves don't really do anything. You could send you own 77 / 80 to the airgun centre and they would carry out the conversion. There was talk of them doing the conversion on a HW85K but don't think it took off? Did them also for the 335. Mach 1.5

[averageplinker]

The good news is she is now comfortably within acceptable power levels.

I cleaned up the main components and slipped in a TBT short stroke kit & piston etc. that I picked up off here a little while ago. I will swap the .22" barrel for a .25" one I have to satisfy my curiosity about whether that will increase or decrease the power.

In the meantime I will clean and check the original piston and zephyr seal with the intention of putting them back in in due course. Thanks as always for your wise counsel.