Paul,
As a follow up to my last email, these are the sensors I am looking

for. You

have added a couple that I had not contemplated. What type/who makes

an

appropriate water flow sensor?

That is a very good question. I would love to have something we could
place in a stock radiator hose with a couple of hose clamps.

Drawing from the industrial stuff I've worked with you have the choice of:
1) Mechanical (pressure drop and leak potential as well as parts falling
off going through your water pump).

2) Thermal dispersion/mass flow (too complicated for our budgets)

3) Differential pressure switch and a crude venturi:  This might fit the
bill depending on the cost and robust-ness of the switch.  Would give you
an adjustable or selectable flow velocity (differential pressure).  Piece
of SS tubing to form a venturi and couple of taps for the switch.  Two

hose

clamps and a hot wire & switched wire for the signal.  Would have to be a
very small DP rated switch, on the order of 5 IN H2O.  Much more and you
will be back to too much pressure drop at high rpm.

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

If we calibrated the block pressure drop we would know the water flow.
Anbody got a fire hose?

Paul Lamar

Paul,
Playing off the last post, we might be able to test jig the radiator and
measure the differential pressure drop across it as a function of measured
flow. This would eliminate problems of turbulent flow thru some form of
venturi and orifice plate. Paddle wheels and turbines are just too big,
costly, and temperamental. Of course each owner would need to determine
their on unique DP vs. flow curve.
Dean

Here is an idea. Drive the stock water pump on a 13B with a Briggs & Stratton
3 HP industrial engine (V belt)  and check the water flow through the block and through
the rad into a bucket at various pump RPMs. A varible speed lathe would
also work.
 
Paul Lamar
 
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