Hey John Bell, What radiator are you using?
Thanks,
Rick in Alaska

Hi Rick,
I will have one made after I get the exact dimensions from my airplane
installation after I set the location of the engine. I havent yet gotten
my radiator yet. I think I know the basic sizing I'll need, but I dont
know all the details. I should know by late this summer.

John Bell

You don't need to get one made John. Just buy a two pass from Summit racing
or Jeggs. Worse comes to worse you can modify a single pass into a two
pass.
What kind of airplane are you building John? For a 300 HP three rotor you
will need about 900 cubic inches with an average duct and a bit less
if you do a real good duct.

Mark Steitle is flying a three rotor and as far as I know it is cooling
down there OK in hot Texas.

Paul Lamar


Hi Paul,
Thanks for the info. I am building a Velocity SE RG. Similar (and I hope
half as nice!!) as Al Gietzen's beautiful plane. I plan to install the
rad under the engine with 2 oil coolers in the cowl next to the engine,
ducted out of the cowl into the prop wash. I am in the initial stage of
fabbing the intake. I am planning to use a single-throttle body type
intake (aluminum) that will allow three injectors into the intake, plus
the stock secondaries from the 20B. I want to get some Inconel 625 for
the muffler, and plan to weld a piece of 16 gauge into a 6" can and tehn
pipe the exhaust overboard via a 3" inconel pipe. I am interested in
getting more info on the Hatch-type flange for the header. I built mny
engine last year using the high compression rotors and a mild street
port (porting done by Mazdatrix). I used Tracy's rebuild kit. I am using
his EC-2 and redrive. Last time I was at Velocity in Florida, I saw one
of their Franklin mounts and due to the geometry, it appeared easy to
modify it to accept the 20B. Turns out Al did that already. I originally
ordered a Conversion Concepts mount but am one of the many who got
defrauded by them. I do have the mount bed form them so I may use it. I
havent done the math on using it...I am a little concerned about the
loads transferred into the 20B through the oil pan bolts...I have been
thinking about installing inserts into the pan fastener locations.
Anyway, lots of decisions still to make, but I am excited to get hard
into it. I may have to move in the next month (now in Maryville, TN) or
so but that will only delay me for about a month I hope.
Best wishes,
John

Al went through a lot of cooling troubles. The only pusher installation that had no cooling problems from the get go were Bulent's fine installation.
I don't recommend a NACA duct for liquid cooled engines.

Paul Lamar