---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Thu 09/21/06: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:52 AM - Re: Re: 582 vs 912 Safety in a Ktifox (Rob Housman) 2. 09:55 AM - Re: Re: 582 vs 912 Safety in a Ktifox (Jack Kuehn) 3. 02:07 PM - Wandering RPM (frank & margie) 4. 06:42 PM - Re: Re: 582 vs 912 Safety in a Ktifox (ElleryWeld@aol.com) ________________________________ Message 1 _____________________________________ Time: 07:52:42 AM PST US From: "Rob Housman" Subject: RE: RotaxEngines-List: Re: 582 vs 912 Safety in a Ktifox --> RotaxEngines-List message posted by: "Rob Housman" In re: composite props in the rain Ivoprop uses a stainless steel leading edge strip for erosion protection. Although electroformed nickel is preferred for this, that is no reason to avoid a composite prop protected with SS. The protection is still real and the only difference for light aircraft, if any, would be how long the leading edge lasts. Nickel is the choice of most but not all propeller manufacturers primarily because it offers the best compromise between protection from rain erosion and sand erosion (with the emphasis on compromise - there are other materials that are better for rain or sand but not for both). Another advantage of electroformed nickel is that the thickness of the nickel abrasion strip varies from leading edge to trailing edge, and from tip to root, with the tip and leading edge considerably thicker than the trailing edge and root end. This permits a lower mass abrasion strip with longer life than that which is possible with a piece of constant thickness stainless steel bent into the approximate shape of an airfoil. My former employer was the exclusive supplier of abrasion strips to a very well known propeller manufacturer. Abrasion strips for turboprop aircraft sold to that manufacturer for over $200 in fairly high volume. A piece of stainless steel sheet cut to size and bent into a U cross section would cost a small fraction of that, so it's obvious why a prop blade that sells for not much more than $200 has a SS leading edge. Best regards, Rob Housman A070 Airframe complete Irvine, CA -----Original Message----- From: owner-rotaxengines-list-server@matronics.com [mailto:owner-rotaxengines-list-server@matronics.com]On Behalf Of mikePuyallup Sent: Wednesday, September 20, 2006 9:05 PM Subject: RotaxEngines-List: Re: 582 vs 912 Safety in a Ktifox --> RotaxEngines-List message posted by: "mikePuyallup" Wow, thanks for the replies so fast. I am going to buy in the winter or spring, not build, so the differnece in cost seems to be worth it. It seems that catastrophic engine failure is really not that big a worry, it is more of an issue of constant rebuilding and poor fuel burn. Any props to avoid? Someone told me not to use IVO's in the rain due to abbrasion(I live near Seattle) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=62937#62937 ________________________________ Message 2 _____________________________________ Time: 09:55:03 AM PST US From: Jack Kuehn Subject: Re: RotaxEngines-List: Re: 582 vs 912 Safety in a Ktifox --> RotaxEngines-List message posted by: Jack Kuehn I have an Ivo prop on my 912, and though it is OK, I have not been able to get the SS leading edge tape to last more than 10 or 15 hours. If I were to buy another prop now it would not be and Ivo because of this. Take a look at: http://www.ultralightprops.com/gsc_systems/gscsystems.htm Jack Rob Housman wrote: >--> RotaxEngines-List message posted by: "Rob Housman" > >In re: composite props in the rain > >Ivoprop uses a stainless steel leading edge strip for erosion protection. >Although electroformed nickel is preferred for this, that is no reason to >avoid a composite prop protected with SS. The protection is still real and >the only difference for light aircraft, if any, would be how long the >leading edge lasts. > >Nickel is the choice of most but not all propeller manufacturers primarily >because it offers the best compromise between protection from rain erosion >and sand erosion (with the emphasis on compromise - there are other >materials that are better for rain or sand but not for both). Another >advantage of electroformed nickel is that the thickness of the nickel >abrasion strip varies from leading edge to trailing edge, and from tip to >root, with the tip and leading edge considerably thicker than the trailing >edge and root end. This permits a lower mass abrasion strip with longer >life than that which is possible with a piece of constant thickness >stainless steel bent into the approximate shape of an airfoil. > >My former employer was the exclusive supplier of abrasion strips to a very >well known propeller manufacturer. Abrasion strips for turboprop aircraft >sold to that manufacturer for over $200 in fairly high volume. A piece of >stainless steel sheet cut to size and bent into a U cross section would cost >a small fraction of that, so it's obvious why a prop blade that sells for >not much more than $200 has a SS leading edge. > > >Best regards, > >Rob Housman >A070 >Airframe complete >Irvine, CA > >-----Original Message----- >From: owner-rotaxengines-list-server@matronics.com >[mailto:owner-rotaxengines-list-server@matronics.com]On Behalf Of >mikePuyallup >Sent: Wednesday, September 20, 2006 9:05 PM >To: rotaxengines-list@matronics.com >Subject: RotaxEngines-List: Re: 582 vs 912 Safety in a Ktifox > >--> RotaxEngines-List message posted by: "mikePuyallup" > > >Wow, thanks for the replies so fast. > >I am going to buy in the winter or spring, not build, so the differnece in >cost seems to be worth it. > > >It seems that catastrophic engine failure is really not that big a worry, it >is more of an issue of constant rebuilding and poor fuel burn. > >Any props to avoid? Someone told me not to use IVO's in the rain due to >abbrasion(I live near Seattle) > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=62937#62937 > > > > ________________________________ Message 3 _____________________________________ Time: 02:07:44 PM PST US From: "frank & margie" Subject: RotaxEngines-List: Wandering RPM REF: Guy, > > How old are your crank seals? They'll do funny things when just > starting to leak. Email Green Sky or Lockwood and ask their advise. > >Frank Clyma >Jacksonville, FL > Yes. How about 14 years old? I guess it's time for a rebuild. (But Bob Robertson already told me that.) What else happens when they start leaking? ----------------------------------------------- A 2 stroke won't do anything right when the crank seals leak. Basically, the extra air sucked thru the seal leans out the mixture, and then your temps go up (EGT especially). Then you get all the fun stuff from an overtemp (if it goes high enuf) like engine seizure and glider practice. Sometimes you can also see an oil film on the case end where the mixture is being pushed out past the seal, it will leak in both directions. Seals just starting to go will often give intermittent/variable problems like wandering RPM and temp variations. Sorry to be so late with my reply, been out of town. ------------------------ Just finished catching up on newer listings----you've gotten some good answers/info form other folks. However, if it were me, I'd still have the crank checked and the seals replaced, 14 years is too long for aviation use, IMHO. Frank ________________________________ Message 4 _____________________________________ Time: 06:42:28 PM PST US From: ElleryWeld@aol.com Subject: Re: RotaxEngines-List: Re: 582 vs 912 Safety in a Ktifox I have been Flying in the pouring rain with My IVO and it didnt bother it but You might have a problem if you use it on a seaplane and really try to use it as a Submarine Ellery do not archive