This sounds like a pretty cool mod, if it works.
What has been done to reslove some of the reliability issues that existed with the engine when it was the Thunder/Orenda? I understand there were head warping issues, along with ignition system issues. One or both of the Orenda test aircraft have been converted to turbine because of the reliability issues ... or so I've heard. I would be concerened about trying to get 600 HP reliably out of less than 600 cubes. That is nearly drag racing pwer/cube territory. Will they really last - what is the highest time Trace running, and what kind of maintenance issues did it have getting there? If everything worked as promised, this would blow the doors off a turbine conversion, and be cheaper lb/mile than the 985.
I would be really interested to see one go in a 500 to 600 hr per season commercial operation ... watch the reliability and dispatch rate.
Hornblower, Thanks for asking good questions! I asked the top guy at TRACE, David Czarnecki, to comment. He says:
"Most of the Orenda issues were simply from parts not built exactly to specifications. The design was not the primary issue but the execution of the manufacturing. This was the case with the majority of the components that had service bulletins issued. When the parts were manufactured to spec, tested and flown, the reliability is there.
Many people have no idea how many iterations of design many of the components went through between the Thunder Engine to Orenda and then ultimately to TRACE. At the time Orenda finally achieved type certification the design was solid. TRACE has continued to improve designs to try to extend the TBO and develop and certify a 750 horsepower model of the engine that is the same cubic inches as the current 600 horsepower model. Millions of dollars have been spent on engineering over the years to solve this technical aspect. At the end of the day, the TRACE engine is a refined evolution of both the Thunder and the Orenda engine programs in which the pedigree is good but the teething issues resolved.
As for the two of three aircraft that were converted back to turbines, they were all Otters. The primary reason for that was once Orenda shut the company down in 2003 the customer could no longer get spare parts to maintain the aircraft so they were effectively grounded. The only way to use the aircraft was to change powerplants. On the positive side, the third Otter had its Orenda engine overhauled and brought up to the latest TRACE specifications and will enter service this summer.
That is nearly drag racing pwer/cube territory
As for 600hp from 495 cubic inches, you have to get out of thinking air cooled and compare to liquid cooled for horsepower per cubic inch. Air cooled has been roughly 1hp per 2cubic inches. Almost any production high performance automobile is pushing 1hp per cubic inch. Those aren't close to drag racing numbers. Plus the details for the TRACE are 600 horsepower for 5 minutes, then 500 horsepower for max continuous. The TRACE is also turbocharged so you get the power steady up to 20,000ft.
TRACE has accumulated about 1200 hours max on one aircraft; the longest aircraft being in service is an Air Tractor operating 200 to 250 hours a year. TRACE's goal in the last two years has been to aggressively go after high hour operators in the Ag market to build our reputation and hours flown. TRACE went from having 2 aircraft flying to 7 this year, with more deposits on the books for our Ag STCs. We are hoping to get Beaver operators who run 400 to 600 hours a year to use our product. We believe they will be impressed and prove the product for us. This is a working man's engine and needs to be reliable. It will be more cost effective (more profitable for the operator) than a turbine installation.
Beyond the Beaver, TRACE is preparing to develop another platform to STC: a Cessna Caravan for freight application. TRACE already has the 208B in their hanger in Midland and has begun the design of the conversion kit. TRACE has a high volume freight carrier who will rent the aircraft and compare it to their turbine fleet for dispatch rate and reliability. This conversion kit will utilize our 750 horsepower model engine which is being certified concurrently."