Ask Paul: What are these aluminum specks?

PaulMcBride

Q: I lost the left mag on my O-540. When I took it apart, I found four aluminum specks in the top oil screen. I pulled the rear housing off and found the aluminum gear still in the engine. I sent it off for repairs to Tulsa, where they installed a new oil pump, shaft, gears and housing, as well as a new fuel pump and dry vaccum, and two rebuilt mags. I ran it for 1.5 hours, then pulled the screen and found a few specks again, but not as many as the first. Any ideas?

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Ask Paul: What to do about oil-fouled plugs?

PaulMcBride

Q: My partner, Lou, and I just had our Piper PA 28 235 overhauled and are having problems with the lower plugs getting oil fouled. The plugs have been cleaned a couple of times but she runs rough and they foul again. The mechanics are talking about putting a thin wire plug in. My concern is that we could have a leak in the valve stem seal, rings, or head or valve cover gaskets. The cylinders were rechromed and we had new rings, the valves machined, etc. One shop did the machining and cylinders, another shop assembled everything.

Where should we start?

TOM CAMP, via email

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How to break-in your engine

PaulMcBride

I recently received a letter asking about engine break-in following overhaul. This is a subject that should be of interest to everyone, even though you may never actually have the opportunity to break-in an engine during your flying years.

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The importance of keeping current

Q: I have a Glasair with a Lycoming IO-360-B1E engine. After reading your article in the May 11 issue, I tried to get a copy of Lycoming’s SI1325A to see if I should change the timing from 25 to 20 degrees BTDC, but was not able to find that instruction. Can you help?

RON WALTERS, via email

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Ask Paul: Too much information about our engines?

PaulMcBride

Q: I have a factory reman Lycoming O-540 E4B5 with 300 hours and 2.5 years on it. At idle (1,000 rpm), my JPI is showing alarms on the #1 EGT for having a large differential — #1 EGT is only 600° while the rest are 1,200-1,300°. Above 1,500 rpm and higher everything seems fine with normal readings and maybe #1 CHT a little lower, but I expect that since it is first in the airstream. I have full data printouts from the JPI.

I have checked the plugs even though my mag checks are fine and replaced the probe on #1 EGT with no change. I’m scared to think I have stuck valves. [Read more...]