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
