What mm size is the small exhaust valve for the early 1085?
I put up photos in post number 4, I think it is about 20mm, then there is the second with about a 24mm and then finally the 1085 with the 30mm and large manifold and tee. The two screw tee is very restrictive regadless of the exhaust valve size.
IMO, a 26mm valve with a large exhaust manifold is the minimum (Scubapro 109) and even that is noticeably more back pressure than with a 30mm exhaust valve and appropriately designed exhaust tee/manifold. The WOB is at least affected by exhaust effort as much as if not more than inhaltion effort. USD/AL put out a letter to shops in the mid 70s advising caution with the two screw tee models due to high WOB due to high exhaust effort. Lung volume does not change with depth, it is the same at the surface as it is at depth, density changes of course but volume does not. Restricting depth to some X number does not change the abysmal WOB of the early 1085.
This is not about being right or wrong, to the uninitiated, just beware, getting caught in a circumstance where you must sustain effort, a regulator that can barely flow enough air through it at a resting respiration volume is not going to be fun if you are working hard against a current regardless of the depth.
Healthways made a regulator that had even smaller exhaust valves! Yes, plural, as in two, but unlike Dacor who put them side by side Heathways brilliantly stacked them on top of one another. It was beyond horrible. Much worse than the old 1085. And just imagine, none of these were originally equipped with soft, silicone valves, they were stiff neoprene! They were awful!
In this dive we were anchored up current, only bouy available. The curent was not ripping but it got worse over the course of the dive. My insta-buddy took off as usual to parts unknown so I stopped at the plaque in hopes he would rejoin me as that was the agreed upon turn point. It was about then I noted a trickle of water, then more and then nothing but water. The DH regulator had flooded out (Strike Number 1). Turns out the intake hose had split and it was a new hose! Well, whatever, jumped over to my octopus which was a two screw 1085. My buddy never showed up until I found him on the mooring line. I was exhausted from the swim back up current. It was like trying to breath through a straw but worse. That was the first time in the fairly recent era that a little guardian angel told me, you know buddy, you oughta think about some equipment upgrades huh, maybe?
Okay, what is that, oh, an AL Core with a freaking huge exhaust valve and exhaust manifold by any comparison:
Without getting into the specifics of Strike 2 and Strike 3, my current solution:
James
