My first pattern engine was an OS 61 FSR ABC with a Macs header and an OPStunded pipe in something called a "Superfection" - circa the late 70s-early 80s. Next it pulled my side exhaust EU-1A for a couple of years. I followed that up with an OS 61VF ABC in the Deception I flew for a couple years. I ran that engine for many years through the 80s in several Tipo 750s with the pipe straight down the side of the fuselage. Man was that a slick setup. My LA-1 called for a pumped engine due to the inverted installation, so I went with an OS 61RF ABC. I flew that engine until times demanded a 120 sized plane. I had a YS 61R long stroke in there somewhere but we didn't get along very well and I sold it.

WARNING - slightly off "classic" topic but it's a piped 2-stroke. I had a variety of YSs (SF, AC, NC) for my 2-meter birds but finally settled on a Bully (nee Webra) 1.20 LS 2-cycle with a Bolly tuned pipe in a plane my friend Orland McKee built called an OMS. The picture below is yours truly at the Omaha, NE contest in August, 2000. It's the last contest I flew in.

I was looking through my collection of engines the other day. The list goes like this - as you can probably tell, I'm very fond of OS engines. They treat me very well for many years.

OS 60 FSR
OS 61VF
OS 61FSR ABC
OS 61SF ABC
OS 61SF-P ABC
OS 61RF-P ABC
YS 61AR
Bully 145