I just talked to Griffin and here is what they say about the use of
epoxy.  First there are two ways to braze radiators. One is "vacuum"
and the other is CAB.  Griffin uses the vacuum method which they
claim is superior.    They say they are the only company to do so.
After the brazing epoxy is added as additional insurance. Once again
they are the only company to do so, they say.
I asked if their in rad oil coolers in Winston Cup cars were
supported by any other external oil coolers and they said they were
not.  I'm back to a 1000 cu in rad with built in oil cooler to handle
all the cooling, if I can get air to it.

BTW I haven't got a final price on the rad yet, but the initial
estimate including
AN fittings but not the mounting tabs on each corner that I want
added is $675.00.  That sounds fair to me, but it is a strong
argument for the $5.00 evap cores.  Jerry

My recommendations are: stay away from the evap cores.
IMHO they are too thick for good cooling at low takeoff and climb
speeds not to mention excessive high speed cooling drag as just pointed
out by Ken, Mike and last but not least Fred Moreno.

Tracy's evap core's work, sort of, because he uses a water dribble
system on the ground, an obscene looking rad air inlet (:-)) and he rarely
climbs out over 10,000 foot mountains. IMHO he would be going
210 MPH if he had lower cooling drag. He choose a conventional rad
for his new 20B RV8.

Use a stock Mustang 5 liter rad if you want to save money and a separate
stock RX7 oil cooler.

The great thing about the situation in the experimental aircraft
field is we get to verify over and over again what works and what
does not work. Perhaps in ten years we will be able to say
for sure "That does not work!". :-) However, if at first you don't
succeed with cooling the rotary please don't give up and do try again.

Paul Lamar

Ken Powell wrote:

Jerry,
I'm looking at Griffin aluminum radiators in  the Summit Racing
catalog. The 31' * 19" * 2" rad is $181.95.  I have one of these in my
5.0 Mutang and love it.  You could save some real dollars here - mount
the radiator in a sandwich of alum angle lined wiuth closed cell foam
like Mike Will' installation.

KeN Powell

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