Sounds like plenty of core area to me
Monty.
Thought I had made my final decision
on the oil cooler but still having trouble getting all my design goals to work
with the fluidyne cooler. Those darn evap cores are hard to beat for
weight, performance & size. I'm back to figuring out a way to make the
evap core reliable in oil cooler service.
Rusty is the resident expert on
failures on these things so a couple of questions for him.
Were the connections on the end tanks
welded on? I'm wondering if the heat may have weakened the furnace
brazed joints there since the failures were always on the ends (I think).
I noticed there is an aluminum strap welded to the end tanks from top to bottom
on some Harris cores. Did yours have this? I am wondering if they
are to resist the expansion force trying to split the tank segments
apart.
I have built a test evap core
cooler with bonded plates on the ends tied together with threaded
rod. This serves two purposes. It resists the expansion forces and
provides a thicker plate to drill & tap for AN fittings (no welding
required). Even with all the added hardware it only weighs 5 1/2
lbs. The Fluidyne I was looking at was 12 lbs (and still would not fit in
the space available). Weight is so important to me that I place a value of
$100 per pound on weight savings. For example, the 12 pounds I
saved with aluminum landing gear cost an extra $1200.00.
This may turn out to be a total waste
of time in which case I will need a custom cooler. Ed K., what is the
maximum core thickness that you can get for oil coolers?
Tracy
Tracy,
The flluidyne coolers I am looking at using are
plate type furnace brazed units. They are rated at 150 psi. The Earl's coolers
are a bit more expensive and are rated at 175 psi with burst at 350 psi. The 3rd
gen RX7 is a plate type oil cooler. They all seem to be made the same way as the
evap cores. Evap cores can see some pretty high pressures in service. I don't
see why they couldn't work. Looks like we need to do a failure analysis on
Rusty's core. How was it mounted? Did the plumbing exert any forces on the
cooler? Perhaps weld two more aluminum straps to the tanks to help them resist
pressure forces.
Trying to decide if the stock oil cooler volume is
enough. If so I can get by with the Earl's 3 in tall cooler vs the 4 in tall
fluidyne. They cost the same, but if you guys think that the stock cooler
is marginal I may just go with the extra capacity of the Fluidyne. I am partial
to Earl's products from a trust standpoint even though I know the
Winston cup guys use Fluidyne coolers for trans and diff.
Monty