Michael McGee wrote:

Got my 6 port valve today Bulent, looks great.  Thanks a bunch for

putting

this together.

I noticed one thing about the valve that we need to know.  In the

OFF

position you will get cross feed between the tanks as the valve

plug

(or

ball) is a three way unit (rotating tee).  On RV's the vent lines

run

high

enough that you shouldn't get any fuel running out overboard if

you

park

on

a side hill and turn the fuel selector OFF.  I don't know about

other

planes.  Personally the only time I use the OFF position is if I'm

working

on the fuel system or doing an emergency landing.

Cross feed can be eliminated with four check valves arranged

appropriately

between the tank ports and the valve inlets.  Earl's performance
fittings/Holley from Baxter's auto parts or equivalent, sized for

your

application.  Another way would be to plug one side of the ball to

make

it

a "L" instead of a "T", thereby making the valve an

OFF-LEFT-RIGHT-OFF

style.  Have not looked close enough at this to see if it's

feasible

or

not.

What ever your preference this is a great unit and a bunch cheaper

than

an

Andair.

Mike

Mike McGee, RV-4 N996RV, O320-E2G, Hillsboro, OR
13B in gestation mode

The 182 cross feeds too. I am not sure if it cross feeds on off
as I rarely turn it to off. I leave it in both most of the time.

In never seems to be a problem as it takes a steep slope indeed.
Just make sure your vents are anti syphon.
I think the 182 tees the vents together at the center (I could be

wrong

on this point) of the airplane to achieve this  as it only has one

vent

below the wing tanks no less. It faces forward to take advantage of
dynamic
pressure. 104 pounds per square foot or .72 psi at 200 MPH.
The vents should be on the outboard ends of the tanks and go back
to the center of the airplane. Seems like the top of the vertical
stabilizer is a good place for the vent line or lines.

We need a book or good article on this subject. Tony Bingelis mainly
handled the typical high wing gravity feed system in his Engine
book. Be a good article for Home Wings too. We went through a pile

of

this stuff for weeks in years gone by.

BTW does Van address fuel injection return line issues in any
of his plans?

Paul Lamar

Depends on the wing dihedral, tank configuration, and layout of vent
lines. In
order to equalize flow, many tanks have interconnecting vent lines,

few

check
valves, and other vagaries. I have flown planes with minimal dihedral

(<1

degree
overall) whose tanks would vent out 2-3 gal if parked on a slight

incline

at
all. The C210 and C177 are like this. The vents feed out opposite

wings

from the
tank in the other wing, no less and are interconnected, have redundant
vent
paths (caps are vented,
Is there a suggested layout for this valve, I presume it is

manufactured

to be
Left, right and off? The center positron feeds the engine if I am

guessing

right. No "both" position?


Marc Wiese

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