On Dec 1, 1:56*pm, wrote:
On Dec 1, 9:20*am, Andy wrote:

On Dec 1, 6:24*am, wrote:

Slow water dump was a problem for many folks. Many ships have this
improved by now.

Did the factory ever do anything to improve the dump speed on the 27
or was that improvement a result of owner modification to venting and
fitting (your) larger dump valves?

I know the 28 was modified sometime before serial 48 by adding an
additional vent line to the wing tips but the dump is still stupid
slow.

Andy

28's configured from factory to accept big valves without modification
shortly after mine(done as special to work out change) was built SN
28015.
Ships with factory water system got original small valves. US ships
ordered without valves could be set up with big valves as plug in
upgrade available from Eastern Sailplane. There is also a conversion
for the few that originally had samll valves. Same applies to 27B's.
During this time Gerhard and I exchanged numerous messages resulting
in 2 vents(I wanted 1 vent with tubing 1 size larger). Airflow in this
long vent is choked at flow rates required to replace water with air.
Next improvement is venting fill cap and adding smal check valve to
get air in better.
Last mod is to add a vent on the bottom of the wing at the outboard
end of the inner tank. This has a ball check valve. Not popular
because people got all itchy about cutting holes in theri shiney
gliders.
With all mods, I test dumped 50 gal in under 3 minutes with most out
in about 2 min. Stock valves and std vents on another ship dumped 50
gal in about 5 1/2 or 6 minutes as I recall.
FWIW
UH

Thanks for the info. For clarification though are you saying that
28048 (mine) will accept the larger valves with no modification.
After talking with Murray I thought the lower wing surface had to be
milled back to accept the larger valve retaining ring. However that
conversation was when only his prototype was in US and that would
predate 28015.


Andy