by mrpilotron » Fri May 19, 2023 12:01 am
We're still making progress on this rebuild project. The engine went to a professional VW performance shop for a teardown inspection. They found inconsistent compression ratios of 6.7 - 7.3 and some of the valve geometry wasn't right. It ended up with new valves, new pushrods, several new seals, and all 4 cylinders are the same 6.82:1 compression. They also installed the new 2-part oil pump that's needed with the turbo upgrade, replaced the starter ring gear, and did a real nice cleaning of the heads before they bolted it all back together. I am sure I could have done the engine work cheaper myself, but I am also sure I couldn't have done it better so I'm happy to write the check and relax.
We did run into a little snag with the Sonex factory built turbo exhaust manifold hitting against the engine mount long before it got to where it would bolt onto the heads. I'm baffled at how this turbo setup was introduced almost 10 years ago and I seemed to be the first tri-gear plane to get a turbo that doesn't fit. We're talking about almost a full inch of interference, not a little .020 nudge that could have been just some variance in how my engine was hung. There is zero chance that I could have made it fit without cutting and welding so anyone who bought this kit before me must have just fixed it, shut up, and moved on. I'm a little more of an S.O.B. about expecting factory parts to fit so I made a fuss and Mark got his guys to redesign it and make me a new one that does fit. It was a 6-week delay for me, but now the next guy who needs a turbo should have an easier time.
The wings got leading edge LED landing lights installed and LED tip lights. We pulled out the 3/8 fuel line tubing that was used for anti-chafe wire loom and replaced it with proper sleeving and LED-sized wiring. (AKA: Small and light weight). We found a few places where rivets had been set into the fluting crimps of wing ribs so that needed attention along with remaking a damaged area disguised as an inspection port. We discovered a few pivot point bushings that had been installed wrong and damaged so those got replaced with all new parts. Somewhat surprising was that all the aileron hinges and flaps were located properly and adequately straight so there is no repair work needed on the control surfaces.
One of the rudder cables was routed through a strange location about 5 inches away from where it's supposed to come through the right side of the fuselage. I'm completely confused about why that was done because the correct hole was cut where it's supposed to be, but then they abandoned that spot and moved it to the wrong spot where it rubbed and chafed. They also used the wrong spec rudder cable and crimped the clevises with a chisel rather than a proper swaging tool. As you might guess: I ordered new cable and clevises.
Last thing for tonights update: I decided the Stratomaster Enigma wasn't up to par so we pulled the entire dash out and it's getting a modern EFIS, new ADS-B transponder, autopilot, and all new switches and breakers. I have a friend who is a professional avionics technician who specializes in retrofitting modern stuff into old certified airplanes so he's helping me with the panel. The CNC system will really come in handy for that work!