Paul McBride, an expert on engines, retired after almost 40 years with Lycoming. Q: I’ve seen this in Lycoming literature — “Keep in mind that all turbocharged Lycoming engines must be broken-in on ashless dispersant oil only” — but why is it true? My engine overhaul shop, Central Cylinder in Omaha, Neb., insists, in writing, […]
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Is 172 with H2AD engine a good buy?
Paul McBride, an expert on engines, retired after almost 40 years with Lycoming. Q: Hi, I am a Mexican looking for my first plane. I found a 1980 Cessna 172 with an H2AD engine that has just 100 hours since overhaul. The serial number ends in 76T; I had read about 76A. Is it OK? […]
A puzzling compression problem
Paul McBride, an expert on engines, retired after almost 40 years with Lycoming. Q: My engine, which now has 300 hours on it, is an O-290-D2B which had a new-limits field overhaul. It has settled-in as a nice smooth-running, economical and reliable powerplant with plenty of power. It gets about 7-8 hours per qt. (Aeroshell […]
Is it possible to convert my engine?
Paul McBride, an expert on engines, retired after almost 40 years with Lycoming. Q: I have a Lycoming O-360-A1F6D that was originally installed in a Cessna Cardinal. This engine has since been used in an Van’s RV-6 and I will be installing it into a Van’s RV-8. It does not have a magneto with it […]
Ask Paul: Are these spark plugs approved for my plane?
Q: Could you please help my pretty blonde wife and myself with our spark plug problem? We are desperate! Our mechanic is going to put the new fine wire plugs we just bought into our 1976 Cessna Cardinal RG, but we have conflicting information on the proper plug. We bought some SR83P plugs from a […]
Ask Paul: Can this be correct?
Q: My Tri-Pacer has an O-320 with a narrow deck (A) engine. It has SL32000N-A1 Millennium cylinders, which are are installed with no plates and splined nuts. Can this be correct? I have no wide deck cylinders to compare them to. BLAIR MOHR, via e-mail A: Let me see if I understand what you’re telling […]
Is new technology worth the investment?
Q: I am about to change my Alfa Romeo boxer engine to a Lycoming O-360A1F1 on my experimental Glastar aircraft. I read your answer recently to a question if LASAR is really useful (Will my engine benefit from new technology? Jan. 12 issue). Its actual price is $2,500. Do you think that it is really […]
Ask Paul: Why do my serial numbers differ?
A: I have a narrow deck configuration in my 1964 PA 30-270. The first entry in the aircraft logbook, made on Jan. 3, 1964, shows radio installation and LE serial #S or L 606-55 and the RE L 640-55. However the engine log books show LE L 938-55 and RE L 909-55 and the first […]
Ask Paul: The seal of approval
Q: We’re building an RV-6A using an O-360 narrow deck engine. There are six studs that hold this engine together. The center studs are wider at the base than the outer four studs. The case has an indentation where the seals fit. All six are counterbored. The size of the center studs at the base […]

