American Aviation Intercoolers
Richard,
American Aviation's intercoolers are no longer available but they still service the product and have spare parts available, such as the induction boot, etc. The units are built pretty tough, and all you're dealing with is a heat exchanger, much like the way an oild cooler is constructed, only instead of oil moving through it, it's hot air. About your only choice at this point is to buy a bird with the units already installed, or contact Riley/Tule Aero for a new install. I'd be interested in knowing what today's 'ticket price' is for admission. I'll bet it's sky high.
As far as specs, max placarded power setting for ISA at sea-level for takeoff is 35.3" hg. The engine produces basically the same horsepower, but it does so more efficiently and with lower power settings, since the heated induction air from the impeller (Turbo Discharge Temperature) is reduced from about 220 degrees F down to about 80 degrees.
Without intercoolers, the compressed induction air can get as hot as 300 degrees F even though the outside air temperature may be at or below zero. Since hot air is less dense and contains fewer oxygen molecules than cold air -- as much as 40% less -- much of the power that could be produced by the turbocharger is lost.
The intercoolers are a great benefit during hotter than normal conditions and at high density altitude airports. Other advantages include better engine detonation protection, improved climb rates and higher cruising speeds.
Typical power settings, fuel flow in PPH, TAS (Knots) and Servo Inlet Temp:
10,000 @ 75% = 33" Hg @ 2400 RPM, 88 PPH, 195 Kts & 57 F
10,000 @ 65% = 30" Hg @ 2400 RPM, 76 PPH, 184 Kts & 52 F
10,000 @ 55% = 27" Hg @ 2300 RPM, 64 PPH, 170 Kts & 46 F
16,000 @ 75% = 33" Hg @ 2400 RPM, 88 PPH, 210 Kts & 65 F
16,000 @ 65% = 30" Hg @ 2400 RPM, 76 PPH, 198 Kts & 56 F
16,000 @ 55% = 26" Hg @ 2400 RPM, 64 PPH, 182 Kts & 48 F
The above figures are 'Best Power' Fuel Flow settings, but by using the 'Best Economy' Fuel Flow for 65% and 55% power, you can shave the fuel flow down to 67 PPH and 57 PPH respectively (running at or near peak EGT).
It would almost be cost prohibitive to add intercoolers because of Mr. Alan GreenSPAM's thing called 'inflation'... as I recall, the American Aviation intercoolers were installed on our bird back in '86 and at that time the total price was around $10K, including the paint. Best to look for a bird with these units already installed.
SkyKing
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