In my plane the largest radiator I could fit under the cowl and not under
 the engine was an MR2 radiator.  Its core size is 26 x 12.  What radiators
 are the high HP p port guys using?  Primarily I would be looking for
 size,material and number of cores.  If you used a remote fill container
with
 the radiator cap, did you buy it or make it?

 Aluminum welding isn't easy to learn and even more difficult to have the
 equipment to do it in some places, so an off the shelf version would be
 nice.  However, if you cant get one find a way to make it.  That requires
 dimensions.  Next time you are in the hangar, take a pic of the cooling
 system and send it over.  Notes help, and a measuring tape in the picture
is
 worth its weight in gold.  KA The ideal core is out of a Dodge pickup.
 Probably overkill.  With our asymmetric motor mount and motor plate the
rad
 core will fit vertically on the plug side of the engine.  The turbo will
 also fit with the asymmetric motor mount.

KA

 I don't recommends using the stock Cont. mount. The motor mount is the
last
 thing to be designed.  First one fits all the major components.  Then one
 builds the mount around them.  A good 3D program like Rhino is essential.
 The stock cowl shown will work fine, No room under the engine with a nose
 gear for the rad core.  Several airplanes are flying with this
arrangement.
 Nothing new here.

 I still need the dims on the firewall hard points to finish this..  A
stock
 Corvette pressure can works well.  http://tinyurl.com/d6p3s9p Paul Lamar
I
 will confirm the dims of the mounting points today after the sun comes up.
 The stock Cont mount has a few more bars than some of the other mounts,
but

 the only ones that are in the way are the ones for the retractable nose
gear
 brackets.  I am holding out hope that I will be able to make the retracts
 work at some point.  Now that I have the radiator mock up in the cowl, the
 tubes aren't in the way much at all.

 I cant get a Dodge truck radiator in the cowling- 14 inches high is about
 the max and be able to close the hood.  The MR2 rad gives me a few inches
 either end, and room above and below tor get my hands around it.

 KA

 All rads are aluminium now a days. Back about 5 years ago everybody had
 cooling problems before we got a handle on it.  It takes about 600 cubic
 inches of rad to cool a 200 HP rotary.  For a 250 HP turbo it takes about
 750.  That is for a 3 inch thick rads.  Knock off 25% for a 1 inch thick
 rad.

 BTW Here is a simple way of looking at cooling drag as it affects rad
 thickness.  Lets say we have a 1 square foot cooling scoop.  If the scoop
 was completely blocked the drag would be full dynamic pressure.  Dynamic
 pressure at 200 MPH is 100 pounds per square foot.  200 MPH is about 300
 feet per second.

 Therefore the HP consumed is 300 x 100 or 30,000 pound foot per second.
 550
 pound foot per second is one HP so our blocked scoop is consuming 54 HP.
 If
 the scoop was totally open and the air went straight through with no
 restriction the drag and HP consumed would be near zero.  Only a little
 bit from skin friction. Thinner rads have less restriction but more
frontal
 area for the same volume.  The job of the diffusers is to increase the
area
 of the duct.  If you increase the area of a duct the air velocity is
reduced
 but the volume of the air passing through is the same.  Since drag is air
 velocity squared.....By now you can see where I am going with this.

 This is why Kays & London wrote: "the use of highly compact [efficient]
 surface geometries is that the resulting core shapes are characterized by
large flow frontal
 area and short flow lengths for the gas-flow
 path".

------------------------------**------------------------------**-------
Close the NACA scoop. NACA scoops don't work when feeding restricted
ducts. The air merely bypasses the opening due to positive pressure in the
duct.

Ideally you want the nose scoop half way down the rad. Moving it down
from where it is. Nose scoops are best as they see full dynamic pressure.

Here is a pictures of the MR2 rad mock-up sitting in the cowl.

The rad can be 4 or 5 inches higher. Every little bit helps.

The motor mount is workable but the aluminium plate between the pan and
the block will flex causing oil leaks. Making it thicker will help.
The rad comes close but the mm tubes do not significantly block the flow.

I don't think the stock RX7 oil cooler is going to work with a turbo.

Your on the right track with the diffuser for the rad.

Paul Lamar


Thanks Paul.
The stock ford truck radiator is about 29 inches long and 18 inches high. I
think I can get it in there. I was trying to keep the rad down in the lower
cowl only so that I can have more room to work on the engine with the top
off without a ladder.

I have been looking for an alternative to the oil cooler, but with the
volunteer work at the school the past 2 weeks I havent had time.

I have put the turbo on a couple of different ways, and no matter how  I
mount it, I have interference with the p ports. It looks like I will have
to space it out as much as 3 inches (I have a spacer) to make it clear the
p ports enough to get intake tubes on them. I am sure I will have to mount
the throttle assembly more upstream than at the p ports.

I have thought about the aluminum plate under the engine and built in a
solution- first the bending moment is confined to the last 1.25 inches from
the edge of the engine to the mount. The aluminum sheet is .250, 6061- T6
and should be sufficient to take the bending moments that it will see.  The
spacer under it is a composite with a layer of plywood top and bottom- the
outside is sealed with epoxy and the interior is bare. Remember that cork
gaskets swell with the oil and this swelling causes them to seal better- I
am looking for the same effect here. The added benefit of the 1.25" spacer
is another 3.4 quarts of oil capacity.

If it doesnt work, I will change it later. I was and am still apprehensive
about the metal to metal to metal interfaces that I see some of the
builders use in this area. I would anticipate some flexing here moreso from
the gyroscopic effects than from engine torque, and with only a bead of
silicone to keep it sealed I would expect a leak at the block/ plate/ pan
junctions. Also, to alleviate some of the torque I will likely incorporate
some sort of stiffener in the area of the turbo that will brace it down to
the mount- the turbo is heavy and needs some type of support. This support
will also serve as an anti-torque strut to keep the unit from twisting.

I will try to spend a few hours on it in the next few days- but the church
is cooking meals for about 500 families in our area and I will be helping
them out with that.

KA