12-27-2025, 12:45 AM
(Edited 12-27-2025, 02:46 AM by Jared Hartzell.)
Hi,
I just wanted to tell all about some of my improvements to the cooling system both H2O and oil and the new fuel system on the RW.
I have managed to gain 3" more MAP by this improvement.
the gist of the idea and I have since validated the improvements by very experienced flight instructors is delete the belt driven fan, it takes about 10HP to drive that fan, thus the power saving.
1- I replace the radiator by a more efficient radiator used in racing.
2- I totally cover the top of the radiator with a shroud which has a bum shape deflector in the middle of it.
This stops all the hot engine air from being forced through the radiator as in the stock setup, the internal deflector changes the incoming air from 2 x side scops to travelling downwards.
3- I fully enclose the bottom of the radiator with another shroud in which I mount 2 x 11" dia electric fans, these fans are controlled by a thermostat mounted in the radiator that turns the fans on / off as needed. Trials has shown that in the hover the fans cycle on off but once in forward flight the fans remain off as the two side scoops capture enough air to keep temperatures stable.
4- I also delete the standard oil tank that the coolant runs through with an oil only tank and then I install an air to oil cooler in the bottom of the tub fed air by a NACA scoop, behind the oil cooler I mount 2 x 5" electric fans that again do the job in the hover and the NACA scoop does the job in forward flight.
5- I also delete the entire fuel system and replace with a TBI, this needs the exec90 carbi manifold which I invert and add a Y manifold to mount the TBI below the fuel tanks so no fuel pumps are needed, the TBI has a fuel mixture adjustment in the cabin (same as in a fixed wing setup) so the engine can be tuned to suit the day temp pressure etc to get the most out of it, I run a fuel mixture gauge which samples the exhaust gasses to display the reading on the instrument in the consol.
6- I also install the air filter in the tup to feed directly into the TBI, (cold air induction)
7- I fit a fuel sump and modify (shorten) the stock RW fuel filter and on off valve this gives me a large fuel sump to test when doing the daily fuel drain test for water.
I also do a lot of other modifications and get made special parts that are hard to find
I just wanted to tell all about some of my improvements to the cooling system both H2O and oil and the new fuel system on the RW.
I have managed to gain 3" more MAP by this improvement.
the gist of the idea and I have since validated the improvements by very experienced flight instructors is delete the belt driven fan, it takes about 10HP to drive that fan, thus the power saving.
1- I replace the radiator by a more efficient radiator used in racing.
2- I totally cover the top of the radiator with a shroud which has a bum shape deflector in the middle of it.
This stops all the hot engine air from being forced through the radiator as in the stock setup, the internal deflector changes the incoming air from 2 x side scops to travelling downwards.
3- I fully enclose the bottom of the radiator with another shroud in which I mount 2 x 11" dia electric fans, these fans are controlled by a thermostat mounted in the radiator that turns the fans on / off as needed. Trials has shown that in the hover the fans cycle on off but once in forward flight the fans remain off as the two side scoops capture enough air to keep temperatures stable.
4- I also delete the standard oil tank that the coolant runs through with an oil only tank and then I install an air to oil cooler in the bottom of the tub fed air by a NACA scoop, behind the oil cooler I mount 2 x 5" electric fans that again do the job in the hover and the NACA scoop does the job in forward flight.
5- I also delete the entire fuel system and replace with a TBI, this needs the exec90 carbi manifold which I invert and add a Y manifold to mount the TBI below the fuel tanks so no fuel pumps are needed, the TBI has a fuel mixture adjustment in the cabin (same as in a fixed wing setup) so the engine can be tuned to suit the day temp pressure etc to get the most out of it, I run a fuel mixture gauge which samples the exhaust gasses to display the reading on the instrument in the consol.
6- I also install the air filter in the tup to feed directly into the TBI, (cold air induction)
7- I fit a fuel sump and modify (shorten) the stock RW fuel filter and on off valve this gives me a large fuel sump to test when doing the daily fuel drain test for water.
I also do a lot of other modifications and get made special parts that are hard to find

