Never had a 1835 so I can not make the comparison. I am going to open a can of worms with this statement, but here goes.
I will start out by saying that I am completely intrigued with the Corvair power. I love Corvairs anyway but what the WW group has done is awesome. Sure wish I could have gotten a ride in one at the gathering. But aside from that my mind keeps going back to the extensive experience the VW conversion has in aircraft and the fact that I already have one. Here comes the trouble I am going to get myself into. With the VW I just feel that there is a lot more reliable power that should be available. I make that statement partly because of all the auto racing ( I know auto racing is not flying) experience the VW conversions have. There are companies like SCAT and others that are able to get lots more out of these engines (VW) and the availability of parts are so extensive for the VW engines that there should be a little more that can be gained by this experience. I know there are big differences in engine RPM's configurations and so on between the SCAT conversions and the VW engines we use,. But I believe that there is also a lot that can be applied to the VW engines from these types of VW engine conversions. Take for example the fact that my last several certified engines ( Cont and LYC) all used very tried and true , but very old technologies in fuel systems and so on. FADAC and several new to aircraft technologies are now being implemented. These seem very similar to systems that have been in automotive use for many years. To me the AERO VEE engine looks a little like the marriage of newer technologies to the older VW engine platform. Ok, I am kinda drifting off here but I am curious as to if a marriage of some of the older tried and true VW can be joined to the newer SCAT and AERO VEE to produce a reliable more powerful engine along the lines of the WW Corvair stuff. Thus giving greater performance with greater parts availability. Now, can I still throw in there that I think what Steve and Linda Bennet have done for the VW engine is absolutely awesome Jeff York KR-2 Flying N839BG Home page http://web.qx.net/jeffyork40/ My KR-2 http://web.qx.net/jeffyork40/Airplane/ to see my KR-2 Email jeffyor...@qx.net ----- Original Message ----- From: "phil brookman" <p...@ntlworld.com> To: "KRnet" <kr...@mylist.net> Sent: Tuesday, November 22, 2005 6:07 PM Subject: Re: KR> Geared vs direct drive Turbo & my 2 cents > hi jeff did you upgrade from a 1835 by any chance just wondered how much > extra power you gained > p > ----- Original Message ----- > From: <jeffyor...@qx.net> > To: "KRnet" <kr...@mylist.net> > Sent: Tuesday, November 22, 2005 10:35 PM > Subject: Re: KR> Geared vs direct drive Turbo & my 2 cents > > > > I love this subject and have contemplated turbo charging my 2180 for quite > > some time. I feel I have extensive knowledge of turbo charging systems as > I > > have done extensive amounts of turbo and turbo engine work on automobile > > applications. > > > > However, and not to slight anyone here, I don't think I would ever > consider > > taking a turbo from one application and believe I could bolt it to my VW > > 2180 or a Corvair engine and expect success. > > > > I cut my teeth in turbo experimenting with automobiles. I will also credit > > much of the knowledge I gained came from many individuals involved in the > > Shelby Dodge Auto Clubs. Here is what I learned. Or, I could just cut to > the > > finish and suggest that if you want to turbo your airplane, start with a > > proven turbo and engine application and then make minor modifications as > you > > need. But back to what I learned. > > > > With a turbo several things are critical to it's success. > > I would say that the most important is proper air fuel ratio delivery and > > the ability to monitor that. In an aircraft , this would be highly > critical. > > I think more engines blow up ( turbo or normally aspirated) because they > get > > to a lean mixture condition. Adding a turbo makes this even more of an > > issue. For that matter, anything that increases horsepower makes fuel > > delivery very important. So, fuel injection would be my choice over a carb > > on this subject. I would also install an air fuel meter. > > > > You would also need to deal with the great deal of increased heat that a > > turbo creates. Both to your oil and probably even your air fuel mixture. > > Cooling the air fuel mixture can be done with and intercooler. The > increase > > in oil temps would be a challenge to your oil cooler and oil delivery > > system. You may also need to deal with the fact that when you shut off the > > engine, all that hot oil from your turbo will drain down to your engine , > > thus increasing oil temps after shut down. The most reliable automotive > > turbo's use both oil and engine coolant to keep the turbo cool. > > > > You also need a reliable way to regulate the waste gate. Or in other words > > you have to be able to keep the turbo from overboosting. Again, I believe > > you need to monitor this with a guage. If not you will never be able to > keep > > head gaskets on your engine. You would also burn holes in the tops of your > > pistons, burn valves and so on and so on. Speaking of valves, my > experience > > leads me to believe that you would need to change the exhaust valves on > your > > engine as well , in order to deal with the increased temps of combustion. > > This goes back to the idea of starting with a reliable engine turbo > > combination. > > > > I could go on and on with the subject of turbo charging. I would also say > > that I think it is the cheapest and best way to get more ponies and torque > > out of an engine. I also would guess that there are people on this list > that > > know 10 times more then me on turbo charging. But I qualify my information > > with the years I spent experimenting with turbo in automobiles and that I > > was able to take a 2.2 four cylinder engine of 140 horsepower and develop > a > > reliable dyno tested 360 HP with incredible amounts of torque. But, I did > > this using a tried and tested engine and turbo combination. I was able to > > take advantage of computerized controls for fuel delivery and waste gate > > controls. I was able to write my own computerized fuel tables and timing > > curves to assure air fuel mixture at various RPM ranges. This was all done > > via Engine ECU and interfacing a laptop computer. And the whole system > seems > > a little complex for a KR2. I also need to mention that I struggled with > all > > the items mentioned above. No big deal when on the ground ( ok maybe a few > > towing bills and head gaskets and parts and such) but I sure wouldn't want > > to have those issues in the air. > > > > I would still like to turbo an engine for my KR2. I am still unsure of the > > best, lightest and most reliable way to do it. Maybe I will start with > some > > Rev Master turbo parts and go from there. > > > > Jeff York > > KR-2 Flying > > N839BG > > Home page http://web.qx.net/jeffyork40/ > > My KR-2 http://web.qx.net/jeffyork40/Airplane/ to see my KR-2 > > Email jeffyor...@qx.net > > > > ----- Original Message ----- > > From: "hussein nagy" <nagy_ta...@yahoo.com> > > To: <brokerpilot9...@earthlink.net>; "KRnet" <kr...@mylist.net> > > Sent: Monday, November 21, 2005 7:40 PM > > Subject: Re: KR> Geared vs direct drive > > > > > > > Hello, Colin, > > > I always enjoy you comments on subjects, I am an observer to the KRnet > > , I bought a KR2 Boat with retractable gear and tail dragger, I have no > > experience of building A/C but opinion of experienced folks count, Now > let > > ask you , I have the wing center Old aerfoil RAF48, Do you think the new > > aerofoil is woth it at this stage of the built, and changing to fixed > gear > > better than the retract fo KR2, when the new aerfoil instaaled do you > think > > that the elevator and the rudder will be resized. would like to know > your > > opinion, > > > Best regards > > > Nagy > > > Jacksinville, Florida > > > 904-543-8183 > > > > > > Colin Rainey <brokerpilot9...@earthlink.net> wrote: Netters > > > This debate about best engines for experimentals, and whether to turbo, > > whether to Gear drive/PSRU or direct drive has been going on for a while > > now, and I suspect will probably continue, kind like the Ford/Chevy > debate > > (Chevy is best, LOL ). I am NOT going to take sides of whether a builder > > should choose auto or aircraft engine, normally aspirated or turbo, or > > direct drive or PSRU. All these things are in the archives, and found in > > literal volumes in other writings, both Internet and books like, "Auto > > Engines for Experimental Airplanes" by Robert Finch, just to sight one > > example. There are many others. > > > > > > What all Netters, especially you new members need to take to heart is > > that engine selection is VERY important. Looking at certified aircraft, > you > > will see that it it the single most important factor when considering an > > aircraft's present value, how many hours on the engine. Of all the > expense > > of owning an aircraft, once it is completed, the most money you will > spend > > will be for the engine, and its up keep/maintenance. Turbo charging is > the > > cats meow for cheap horsepower, but just ask Orma Robbins about how this > > "enhancement" comes with its own unique set of problems to deal with and > > overcome. Also, the article sighted states that turbo charging generally > > adds at least 50% more power. This is out right fiction! The best that I > > have seen proven by dyno runs is approximately 40%, and this is with > > associated engine modifications, AND the use of an inter cooler, which is > > not mentioned in the article at all. B&M, Vortech, Banks Turbo-charging, > > and Paxton all report similar > > > values for their "bolt-on" systems. I am not saying that a turbo or > > supercharger cannot add 50% or more power, but that rather that bolt on > > systems do not give that kind of increase, and do not want builders > running > > out and buying a turbo for their engine expecting to get a 50% increase > in > > power and torque by just hacking the exhaust in order to add the turbo. > > > > > > The same rules hold true for direct drive vs PSRU. There are definite > > benefits to a PSRU, but to set one up on a 2.2 to 1 reduction, just to > > achieve maximum horsepower from an engine from a dyno run, and say that > is > > best does not take into account all phases of flight for the engine, only > > take off. That is the only time you will use max power. This amount of > > reduction although it makes the max power available according to the > dyno, > > it does not allow for a reasonable rpm for cruise. This is because the > prop > > will be slowed to 2000 to 2100 rpm, which begins putting it below its > > cruise efficiency speed. Just compare certified props that are made to > run > > in this range of rpms. They produce max thrust at near redline, and > produce > > best cruise thrust at 75 to 80% engine power. This puts the prop at > around > > 2300 to 2400 rpms on a 2750 redline. This puts the engine in the re drive > > at 5060 rpms for the 2300, and 5280 rpms for the 2400 rpms at the prop. > Now > > your engine is running > > > just like the Rotax family of engines and can expect the same life, or > > simply 50 to 100 hour maintenance intervals with a major a max of 500 > hours > > out. It also makes the combination "peaky", where basically you spend > > literally all your time at or near peak rpm. > > > > > > Robert Finch's book details a lot of engines that have been > successfully > > used in direct drive configuration; the Buick V8, the VW family, the > > Corvairs, and several others mentioned in his book. In larger aircraft > that > > have more generous weight allowances for the engine, the more complicated > > and heavier engines have a good appeal. BUT for our applications, in > order > > to stay in the RECOMMENDED weight range of engines AND their output, > direct > > drive offers the best answers, and air cooled the simplest installation. > > Above all, it takes research and study to decide and engine install, and > > talking to other actual pilots of those engines. Don't get sucked into > the > > trap of some fancy numbers calculations and good advertising on one web > > page where one engine is presented as the experimental airplanes dream > > engine. There are a lot of "assumptions" and over generalizations made at > > the expense of the builder. No quick answers here. It takes years to > build > > a KR, take enough time to > > > study your engine completely BEFORE spending any money. > > > > > > > > > Colin Rainey > > > brokerpilot9...@earthlink.net > > > EarthLink Revolves Around You. > > > _______________________________________ > > > 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 > > > > > > > > > > > > > > > nagy hussein > > > > > > --------------------------------- > > > Yahoo! FareChase - Search multiple travel sites in one click. > > > _______________________________________ > > > 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 > > > > > > -- > > No virus found in this incoming message. > > Checked by AVG Free Edition. > > Version: 7.1.362 / Virus Database: 267.13.4/176 - Release Date: 20/11/2005 > > > > ---------------------------------------- > I am using the free version of SPAMfighter for private users. > It has removed 24549 spam emails to date. > Paying users do not have this message in their emails. > Try www.SPAMfighter.com for free now! > > > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.1.362 / Virus Database: 267.13.4/176 - Release Date: 20/11/2005 > > > _______________________________________ > 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 >
