Rapid-type valve?

[HopelessTuner]

Goal #1 Minimal parasitic loss from sealing material flex.
Goal #2 Interchangeable parts for different stem diameters.
Goal #3 More power at higher efficiency.
Goal #4 20fpe .177 to 50fpe .25. On the same valve and breech.
I'll take 3 out of 4



This is a picture of a Rapid valve and valve stem. Top to bottom- new series valve, old series valve, custom valve stem, factory valve stem. And I think that's a valve cap and spring on the far right.

On my three-piece valve stem project that attempted to remove parasitic loss from sealing material flex, the thin bit of sealing material ended up being destroyed by airflow around it and part of the seal is in my yard or in the woods somewhere. This concept would allow for a tough, one-piece stem. But, it may be a step back in the sheer amount of plastic being able to flex and cause power and efficiency losses. I think it could be viable if a version similar to the old valve was used, simply because of size and strength constraints of working with a Marauder valve, and if a wafer of acetal was pressed/adhered to the valve face for sealing. Something like .375"(dia) x .025" worth.

I think this could be done with a Marauder valve body. For those of us who are looking at trying to make a full-bore .25 build on the Marauder platform, this could possibly be what allows for a very large transfer port, sturdy stem and the usual of wanting one gun to do everything.
I believe Dan Brown did a similar(ish) project, but he wanted a consistent FT/USBR rifle, not a 30fpe .177. I am at 26fpe now, but efficiency is hurting and I want to go higher.

Your thoughts?

Regards,
Devin

[Motorhead]

Way in which an M-rod valve is also the anchor base for upper receiver to screw down onto, valve retention within air tube & location sealing o-ring has to be
Leaves you with far little choice to utilize designs anything like a rapid IMO.

I own both BTW

[HopelessTuner]

Yeah. Crosman valves. For most of us, I guess that's all that needs to be said.
Maybe could use a ring secured by the three valve retention screws for other valve bits to butt up against, except the transfer port is on that same ring/axis/level... I guess if a person was desperate, the tube and valve body could be screwed together like a DAQ, but there is still that problem of breech retention. If I had a mill or milling attachment, I might could make a monoblock to hold crosman bits... But then it would be a CroPid, or in my case a crapid. Oh well. I'll keep fixing on this rifle till there's nothing left, then either make or buy something else and repeat. Never satisfied If YOU were to scratch-build, what might another person compare your creation to?

Headed down to Fontana this weekend for work. Wish I could stop on the way and pick your brain, but the bus won't stop. Learned a lot from you this last year. Thanks.
Merry Christmas, old fart

Thanks again
Devin

[caboose212]

I'm probably way off base here, but I wonder why no one has tried to trim down the valve for volume? Here's what I mean:





Would something like this even work in a Mrod?!