Years ago I machined a Subaru engine for a guy and after he paid for it and loaded it up he told me that he was building an experimental airplane and using the Subaru engine in it. I never heard back from the guy. I don't know if that is good or bad.
That is a really nice engine case. Obviously they put a lot of research, engineering, metallurgy and beautiful machine work into that part!
Just curious, what does this case sell for versus a new Subaru case? Must be a lot more inspiring for you as a builder to start with such a nice part!
Years ago I machined a Subaru engine for a guy and after he paid for it and loaded it up he told me that he was building an experimental airplane and using the Subaru engine in it. I never heard back from the guy. I don't know if that is good or bad.
Years ago I walked into my buddies shop and observed a VW flat 4 with watercooled heads on it....what's someone restoring an old Midget? I asked....guess again, guess the worst case scenario for this application was his reply....after I failed the "test" he informed me that it was a homebuilt helicopter power plant
Same guy same shop.....3 rotor Mazda with a serious turbo set up.....guy is putting that in a Lancair experimental plane, I've been offered a ride in it when it's done....I'm taking a PASS on that one....my buddies a real comedian!
I wonder what some of these people using these engines in aircraft applications are doing to address the thrust issues. Are they machining the block and crankshaft for a big roller thrust bearing?
After going through a Lycoming and a Continental flat 4/flat 6, I can't see any reason the subaru or VW engines aren't suitable...there is some stuff in that 7:1 compression air-cooled flat six Conti that just made me shudder.
#2 engine (not this one) with stock STI cams just had a dyno session.
They are going easy on the tune, whole car is new so staying conservative & not even into the sweet spot on the turbo yet (apparently this particular precision turbo starts to get real happy around 36psi boost).
On 29psi & conservative tune it made 705hp atw.
It'll do 4 race meets at that level & once they are comfortable with the car it'll get another 15-20psi wound into it, then some decent Kelford cams when the limit of the stock cams is found.
Airplane engines need to turn about 4000 to 5500 to make torque while the prop needs about 2500-3000.
A PSRU (prop speed reduction unit) to handle the thrust loads and slow the prop speeds to subsonic. Going over subsonic creates shock waves that are hard on mechanical parts. Less expensive ones are belt driven and others mechanical gears or even chains.
That being said air cooled flat fours converted for use are common for smaller planes.
A boosted flat four in a plane would make a mighty fine ride especially with a billet block for durabiltity. Can these block use a dry sump of some sort?
ZEOHSIX wrote:Years ago I walked into my buddies shop and observed a VW flat 4 with watercooled heads on it....what's someone restoring an old Midget? I asked....guess again, guess the worst case scenario for this application was his reply....after I failed the "test" he informed me that it was a homebuilt helicopter power plant
Same guy same shop.....3 rotor Mazda with a serious turbo set up.....guy is putting that in a Lancair experimental plane, I've been offered a ride in it when it's done....I'm taking a PASS on that one....my buddies a real comedian!
I'd ride in a rotary powered plane no problem. You could lose all coolant and the rotary will keep running, it won't sieze up.
It won't ever start again after it cools off, but you'll be able to land at a place of your choosing! How long will a Subaru or other liquid cooled piston engine run with no coolant?