Only the latest engines from Engenfellner? are decent at making good HP and having reliablity, but they are heavy. The EA81 and EA82 engines are heavy for the power produced. The EJ22 is a big improvement, but unfortunately weighs in heavy also. It is also fuel injected which adds to the complexity (may or may not be a problem).
The Rotax cannot compare to earlier Sub's because the Sub was never designed to be run at those rpms continuously but the Rotax was. Like a motorcycle engine they can live all day at 4500 rpms. The Geo metro 3 and Geo/Suzuki 4 cylinder engines have overhead cams and short strokes and larger bores for more power. The piston speeds of these engines at 4500 to 5000 rpms is the same as a Chevy 350 at 3500 rpms, which I know from personal experience will live all day at that rpm. With a good PSRU that engine is reported to last as long as the Rotax or longer (TBO time). They are all aluminum engines with reinforced sleeves where needed for durability. Raven redrives makes PSRU's for them. Their weight is similar to the Jabiru engine installed. Reported they are really popular with the Ultralight crowd. Corvair and VW have simplicity on their side. They have the least to adapt and modify, light weight on install and decent HP. -----Original Message----- From: krnet-bounces+brokerpilot=bellsouth....@mylist.net [mailto:krnet-bounces+brokerpilot=bellsouth....@mylist.net]On Behalf Of Fred Johnson Sent: Friday, August 04, 2006 4:04 PM To: 'KRnet' Subject: RE: KR> Subaru engines Look at the Rotax though, it is a screamer too. At least to make the horsepower. Fred Johnson Product Manager T.E. West, LLC. -----Original Message----- From: krnet-bounces+fred=renotruss....@mylist.net [mailto:krnet-bounces+fred=renotruss....@mylist.net] On Behalf Of D F Lively Sent: Friday, August 04, 2006 12:41 PM To: KRnet Subject: Re: KR> Subaru engines Netters: You raised some valid questions. I have looked @ Subies and observed that they get Max torque somewhere in the low 4000s rpm range and Max power at say the mid 5000s rpm range. Almost all would requre a PSRU because their bearing wont take the prop pull. I would say that running that engine at max torque for a redline might have some durability issues as most in cars driver at highway speeds run in the 3000 rpm range so my thoughts are that limitting the revs to the mid or upper 3000s would be prudent and a PSRU ratio to give a prop rpm in the 2700 to 3000 range appropriate for durability. Whether this would leed to adequate power availability I can not say. What I liked about the Subi is the fact it is liquid cooled which would be nice for cabin heat with NO or a very limited risk of CO poisoning. I think one must look at the RPM settings of the design and the PSRU ratios involved to evaluate engine logevity becuse clearly running an engine at or above its max torque RPM will surely work a hardship on engine life as a general rule. My opinion from a reasoned judgement not from experience or personal knowledge. IT is a Safe bet that neither the Corvair or VW based engines will last as many hours as they do normally if ran "Flat Out" either. Don ------------------------------------------------------------------------ Mark Langford wrote: > Fred Johnson wrote: > > > Hey Mark, since it is so quiet today, do you know of anyone successfully > > using either a Subaru or Geo engine in a KR? > > Steve Makish and Bob Lester have a lot of hours on a Subaru (don't know > exactly which one). They were big proponents until Steve wore his case out > a couple of times at about 300 hours. His opinion is that they can't take > the RPMs, and are not worth the trouble. He's now flying a Corvair. He's > not on the list but his email address is srmak...@aol.com if want to email > him direct and ask his opinion. > > Yes Ken Thomas also had a Subaru and is now running a Jabiru, and is happy > with it. Dave Stroud weighed a Subaru engine installation firewall forward > and came up with 285 pounds, substantially more than "they" tell you it'll > weigh. The Corvair is about 245, by comparison. > > My 2 cents worth, but I've never flown behind a Subaru, so take it for what > it's worth... > > Mark Langford, Huntsville, Alabama > see KR2S project N56ML at http://home.hiwaay.net/~langford > email to N56ML "at" hiwaay.net > -------------------------------------------------------------- > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
