Q: Over the last three years of annuals I have had three different mechanics. The mechanic does the compression check, calls out the cylinder number and I record the values. It appears to me that the mechanics might be confusing the cylinder numbers and I can’t find anything online that tells me in what sequence they are numbered.
My questions: What is the sequential numbers of the cylinders on my Lycoming O320E2D? What may be the primary cause of compression loss? What repair is required to correct the problem?
STEVE SARCHETT, via e-mail
A: This is one of those questions that more people would like to ask, but are hesitant to do so because they may get a few chuckles from their friends for asking such a basic question. Steve, I’m proud of you for bringing up the subject and I can guarantee that many pilots out there are also confused as to which cylinder is located where on their engines.