1. Used the early RV-4 FP prop cowl (40" FW to prop flange)
which is about 1.5" longer than current version
2. Used the RX-5 Cosmo oil cooler which is
shorter but wider than the RX-7 cooler, and has ports more conveniently
located than the RX-7 cooler. It was a gift from my brother Barry who
owned the RX-5 donor car.
Thanks Tracy. That certainly takes the mystery out of
it. I originally had the RV-3 cowl (they're now the same, but you
trim the RV-3 shorter), and Fred made the mount so the prop would end
up where the Lycoming would have been on the stock mount. When I
replaced the cowl, I got the universal RV-3/-4 cowl, and decided to
leave it full length, rather than trimming it several inches to make it the
same as the original RV-3 cowl. I made up the difference with a
very nice Saber prop hub extension. If you have the same length cowl,
and no prop extension, then your engine is several inches farther from
the FW than mine. I just made a note to measure my FW to prop flange
distance, so that will confirm it.
I
would love to put the cooler under the engine like Finn has it, but
there's just no way with my exhaust in the way. I'm pretty happy with
the exhaust system, so I don't plan to change that, which means I have
to come up with another solution.
-I
could easily fit one of the FD coolers, but I don't think that would be big
enough.
-I
could possibly fit an oil to water heat exchanger, and use the original oil
cooler location for a 3rd water cooler. Don't care too much for this
idea, mostly due to the extra weight, and complexity of hoses. Also,
I'd still have to worry about bursting the oil cooler on the exchanger
unless I knew is was robust enough.
-I
could use a stock 2nd gen cooler, and let the back end dip under the
exhaust pipes. This would drop the rear edge of the cowl a
few inches, which would add some drag. On the other hand, it
would block some high speed air from hitting the muffler, and add to
the cooling exit area. Another downside is that it's still
putting the oil cooler very close to, and directly in front of the
exhaust.
-Finally, I could find another type of oil cooler, which would be
closer to the size of the evap core. In the old archives,
Mike Wills mentioned Fluidyne. I had one of their radiators in my FD,
and it was very well built. Here's a link to the oil cooler family I'm
thinking about. They look pretty good to me. What do you
think? http://www.fluidyne.com/pl_theoc.html
Thanks,
Rusty (waiting for a giant estimate for replacing my dead heat
pump)