Subaru FF Alternatives

[rv6ejguy]

I've started this thread for people interested in Subaru power to keep the other Subaru/ Lycoming thread on track.

Please, no debate about Lycoming vs. Subaru here, that horse has been flogged enough over the years. If you're not interested in Subaru power for your RV, move on to some other thread you are interested in.

Vendor offering new Subaru 4 and 6 cylinder packages:

http://autopsrus.com/subaru-ej25-fwf-package

http://autopsrus.com/subaru-ez30-fir...orward-package

[kbelue]

You have a lot of hours on your subaru conversion - how about details on your plane? I don't think I've seen that anywhere.

Kevin Belue
RV-6A
RV-10

[rv6ejguy]

Everything you'd probably want to know is documented here: http://www.sdsefi.com/air9.html

Trials, tribulations, mistakes/ lessons learned.

A short video covering some of the engine details: https://www.youtube.com/watch?v=wPtuUZzm3Cs&t=7s

You can search rv6ejguy on YouTube to find several other videos on the plane.

[Canadian_JOY]

I believe in many other discussions here and elsewhere we've seen a fairly strong consensus in describing unproven PSRU's as the weak point in many Subaru conversions. How is the (former) Geared Drives PSRU in terms of field experience and overall technical merit?

(Disclaimer: I fly a Lycoming and a Continental, but I drive a Subaru. After a 12 year build cycle for our current aircraft I'm the first to admit it will be quite a while before I'm ready to install any new powerplant on any airplane again. I remain very interested in seeing how a modern-technology engine from the automotive world can be made to work well in an aircraft.)

[rv6ejguy]

Originally Posted by Canadian_JOY

I believe in many other discussions here and elsewhere we've seen a fairly strong consensus in describing unproven PSRU's as the weak point in many Subaru conversions. How is the (former) Geared Drives PSRU in terms of field experience and overall technical merit?

I posted the autopsru links for those possibly contemplating a vendor solution.

I know of only 2 Subes which have flown with their 200Z gearboxes. One was an EZ30 (6 cylinder) and it suffered a tooth failure at around 30 hours I believe. There was a post on that by the builder, Jetmech I believe. Not sure what the cause was. The second one is an EJ25 and had over 350 hours on it trouble free, last I heard.

I'm not sure how many of the Autopsru conversions have flown and how many flight hours on the fleet. I suspect not many given the price and amount of time on the market.

Perhaps the company owner, Stuart Davis, will speak to that if he sees this thread.

[bigwheel]

I'm a Subaru fan and really wanted to install a Subaru EE20 in my airplane but I couldn't make it happen. I didn't want to extend the build time that much.

I'd really like to see someone develop a PRSU for the Subaru that encludes a governor pad for a hydraulic prop. If that existed I'd probably have a Subaru engine on the nose if my plane right now.

[rv6ejguy]

Originally Posted by bigwheel

I'm a Subaru fan and really wanted to install a Subaru EE20 in my airplane but I couldn't make it happen. I didn't want to extend the build time that much.

I'd really like to see someone develop a PRSU for the Subaru that encludes a governor pad for a hydraulic prop. If that existed I'd probably have a Subaru engine on the nose if my plane right now.

Autopsru builds such a drive.

[rv7charlie]

I want there to be some good alt engine packages out there, too. But pragmatism and rational analysis is essential for success, for both vendors and users.

According to the info from one of their reps in the alt engine tent at SNF this year, just the clutch alone in that system weighs around 30 lbs. That's over half the weight of entire high quality drives from other mfgrs. Perhaps others who can speak with more authority than me, will address whether a clutch (even if it didn't weigh 30 lbs) is the best way to handle the engine/drive interface.

They had a mockup of their proposed rotary engine setup at SNF. When I questioned the rep about it, he had so many things wrong about the rotary's characteristics, it was almost frightening.

Anyone notice that the weights on all their stuff are 'TBD'? I would have thought that if they've got flying engines, they would need to know that, to get the a/c weight & balance right.

Charlie

[tspear]

Originally Posted by rv7charlie

I want there to be some good alt engine packages out there, too. But pragmatism and rational analysis is essential for success, for both vendors and users.

According to the info from one of their reps in the alt engine tent at SNF this year, just the clutch alone in that system weighs around 30 lbs. That's over half the weight of entire high quality drives from other mfgrs. Perhaps others who can speak with more authority than me, will address whether a clutch (even if it didn't weigh 30 lbs) is the best way to handle the engine/drive interface.

They had a mockup of their proposed rotary engine setup at SNF. When I questioned the rep about it, he had so many things wrong about the rotary's characteristics, it was almost frightening.

Anyone notice that the weights on all their stuff are 'TBD'? I would have thought that if they've got flying engines, they would need to know that, to get the a/c weight & balance right.

Charlie

AutoPSRU is a newish company. Assuming I recall the history correctly, Stuart bought the rights from Bud's estate. Stuart has since embarked on a redesign to make the system more economical and lighter. Further, Bud was constantly evolving the system, so there were many variations of the design over the years.
Hence, a lot is TBD.

Tim

[rv6ejguy]

I'm not a fan of these clutches which don't do anything to alleviate TV above idle rpm. The 2 most successful drives out there, Autoflight and Marcotte don't use clutches.

I'd be interested to know how many packages are flying. I don't think any vendor should be selling FF packages unless several examples have accumulated at least 500 hours each with no issues.