Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ihnp3.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!ihnp3!cfiaime From: cfiaime@ihnp3.UUCP (J. Williams) Newsgroups: net.aviation Subject: Re: T.O. in Cessna 172 Message-ID: <176@ihnp3.UUCP> Date: Thu, 31-Oct-85 09:33:00 EST Article-I.D.: ihnp3.176 Posted: Thu Oct 31 09:33:00 1985 Date-Received: Sat, 2-Nov-85 04:34:25 EST References: <769@bgsuvax.UUCP> Reply-To: cfiaime@ihnp3.UUCP (45261-J. Williams) Organization: ATT Bell Labs Lines: 37 In article <769@bgsuvax.UUCP> dewitte@bgsuvax.UUCP (Anne Dewitte) writes: >In the 172 that I rent I noticed my take-off r.p.m. was only 2200 which is >just the beginning of the green arc. I had 3 others in the plane and was >getting a bit nervous. I learned from the mechanic that the engine is a >0-320-H2AD and it is a piece of (junk). I'd like to know what other's >take-off r.p.m.s. Is it this particular engine or characteristic of all >0-320-H2ADs? If you watch the RPM on any fixed pitch prop airplane, you will notice that takeoff and climb rpm is somewhat less than red line. It seems that with the pitch of the prop on a 172, it is particularly noticable. BUT, 2200 rpm is a bit low. At that point, if concerned about the engine, I would have aborted the takeoff and had the mechanic look the engine over. When in doubt, DON'T FLY. As for the O-320-H2AD itself, this is not one of Lycoming's better contributions to aviation. Early ones had valve lifter problems, oil pump problems, and (I think) cam shaft problems. This lovely little engine :-) was so reliable that in 1978 all of the engines were grounded pending inspection. We had one that had under 3 hours from the factory and needed replacement. (I was working for a ferry service in Wichita at the time.) Another problem with later Lycoming designs in general is the wonderful invention of the "twin pack" magneto. Let's face it, gang, a mag typically dies because of a mechanical failure in the drive, not an electrical failure within the mag itself. Sure, Eiseman mags blow condensors, and old Case mags may have swollen rotors, and there is an AD on the coil in old Bendix mags, but MOST OF THE TIME the failures are in the nature of a broken drive. So what does Lycoming do? Sure, a common drive for both rotors. You lose the drive, you lose all spark in your life, so to speak. Don't you love what companies do to save a few dollars in production costs? jeff williams ihnp3!cfiaime AT&T Bell Laboratories