"Also something to keep in mind about Subaru engines that no one has mentioned yet is, most have timing belts. They are difficult to change due to the amount of engine assemblies that must be removed to get to it (less for the plane version). They are also INTERFERENCE engines. This means that when the belt breaks, you have valve damage for sure. A bad day got worse."
Hello all! As this is my first post please excuse any procedural failings on my part. Let's talk engines. Several models of Subaru engines are interference engines. For those who don't know what that means, it is where the valve travel and piston travel overlap. Obviously a bad thing. Like I said, some models of Subaru engines are design this way. Mine is not. It is a 4 cylinder turbocharged/intercooled fuel-injected EA-82. This engine does use timing belts to operate the overhead valves but are external to the engine so inspection and replacement if necessary are easily accomplished. As for other engines, if you want to use an air cooled engine designed in the 30's and who's parts will require a second mortgage, or one that was designed in the late 50's and hasn't been in production for 35 to 40 years, or use a modern liquid cooled engine with it's added weight and perceived complexity, then do it. The point is there are issues with whatever engine you choose. Do your research, look at several sources, especially the ones that don't like your choice, take what any "engine builder" says with a large grain of salt and above all use common sense. Find out the problems with your engine choice, THEY ALL HAVE THEM, and take the steps necessary to minimize or eliminate them. Hope I wasn't to long winded, Stephen ste...@compositecooling.com -----Original Message----- From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf Of Colin Rainey Sent: Monday, October 17, 2005 9:08 AM To: kr...@mylist.net Subject: KR> Engine Ads Netters need to be aware that alot of people talk about what their engine does in one statement when they are actually covering several different factors. People will advertise an economy of so many gallons an hour, while cruising at a high cruise speed. Then in practice actual builder/owners report the speed is achieved but not the economy at that speed. Example: a Corvair engine can cruise at 3 to 4 gallons an hour just like the VW, and can push the KR up to speeds of 150 to 180 mph. But to say it can cruise at 170 mph at 3 gallons an hour is not over exaggerating, it is a lie! It can do one, or the other but not both at the same time. My VW would use almost 3.5 gallons and hour all the time, due to restricted time in climb, and lots of time in cruise testing. But it never got over 140 mph, and would cruise at 125 mph. Talk to actual aircraft owners who are NOT selling their plane for accurate reports of the engine in question. Also something to keep in mind about Subaru engines that no one has mentioned yet is, most have timing belts. They are difficult to change due to the amount of engine assemblies that must be removed to get to it (less for the plane version). They are also INTERFERENCE engines. This means that when the belt breaks, you have valve damage for sure. A bad day got worse. The Corvair is gear drive, like the VW and the GM 4.3 V6 is chain drive. I could go on, but I think all see my point about doing your research and not getting sucked in to advertising. Remember, if it was such a Chariot/cream puff, why is he/she selling it! Also make sure that you check on the CONTINUOUS rated hp for the engine desired and its rpm, not just peak numbers. 2 cycles make good hp, but have to run in the top part of their designed rpms to make any significant hp at all. This will have a big impact on the PSRU/Prop you use. Pump gas is good, but remember it has alcohol in it which absorbs water. Also it will gum up a carb if left parked for extensive periods of time. I would suggest a diet of premium gas for regular running, but top up to park it on 100LL, and make sure that the 100LL is in the carb when at rest/parked, unless you are flying at least every 3 to 4 days. Otherwise, if it sits parked for a month or two due to personal scheduling, the carb is going to start getting this lacquer like brown/gold film in it from the pump gas, and you will have to re-build it prematurely. You will also periodically have to add a gas treatment to absorb any water that you do not get sumped off. 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
