Roger Godfrey’s Sonerai IIL
Story and photos by Roger Godfrey, for Experimenter
Roger Godfrey’s Sonerai IIL parked outside the EAA Homebuilders Headquarters during AirVenture 2007.
Ex-Navy pilot Roger Godfrey of Ottumwa, Iowa, spent nearly eight years building his Sonerai while raising a family, building cars, adding on to his home, and changing careers. A phenomenal feat by any measure. During his time of ownership and following a long hiatus, he upgraded the engine after an uneventful in-flight failure and changed out the wings for a different airfoil after Mother Nature threw a hangar door at it. After all this, he finally flew his resurrected plane to EAA AirVenture Oshkosh.
I started building N49RG in the early 1980s. It took me nearly eight years to finish it - not because it was a difficult design to build, but rather because I had four growing children and a full-time job. I also added on extra bedrooms to my home in order to ensure the survival of two girls who initially shared a room. Additionally, I finished custom modifications for the kids and overhauled engines until those projects ran into dead ends. Ever put a Buick V8 in an MGB?
N49RG started as a mid-wing, but when the plans came out for a low-wing, I liked the looks better and thought I’d have less trouble getting my legs over rather than under the spar carry-through box. I already had the mounts fabricated but not welded into the fuselage yet, so I built the low-wing mounts and welded them in. The spar reinforcement plans came out before I started on the wings, and as a result I dutifully included the beefed-up aluminum angle vertical reinforcement pieces in my wing.
The initial engine was a 1600-cc VW out of a 1967 Squareback that lost an intersection race with a train. The engine had just 3,000 miles on it. I shipped the block and heads out to Claudes Buggies (known as CB Performance now, the go-to people for hot-rodding VW engines) in Farmersville, California, to have them fly-cut to receive 92-millimeter cylinders. The shipping company wrecked the heads on the return trip. It looked like the shipping company might have put them under a big-block engine or something heavy like that. The company agreed to replace them for me, so I opted to upgrade to big valve heads and mated them with ball-foot rocker arms to cut down on valve wear.
A camshaft intended for use in a sand rail was also installed. I don’t remember the specifications, although I recall that the duration was stock but lift was increased. It was designed to bring in max torque at 3,400 rpm. The intake, rear accessory housing, and prop hub were all John Monnett pieces (very early AeroVee). The carburetor was a Posa.
I made the first flight in 1989 and flew off and on for the next few years. It was almost as light as the prototype and fairly fast, if my airspeed indicator was accurate (this was well before GPS) which is a debatable scenario since I bought the airspeed indicator at a swap meet and had to redo the face.
With the 52 x 42 “almost constant speed” prop built by the late Bernie Warnke, the plane was very quick. The only other pilot to fly it said it was like his Pitts. I usually flew it solo, and even then, while on final, it had the same sink rate as a Tri-Pacer at full gross. I went back to school for my doctorate and put it in storage for several years.
When I got back into the job market, I dragged out my little plane from storage and started flying it again, but I couldn’t get the Posa adjusted to run well through the rpm range. If it idled, it wouldn’t rev and vice versa. Guys in my EAA chapter predicted I would have this problem, but initially it ran well. I used to invite them over to my garage and run it up and down the rpm scale to prove my superior tuning talent. I had a grouchy old neighbor who introduced me to quite a few Sioux City police during these events, but she had to put up with twice as much noise as the police always wanted to hear it run. Most officers loved it, but I digress.
The Zenith carburetor is simple and inexpensive and features a cable-controlled choke, low-speed idle bleed screw, mid-to-high-range fully cockpit-adjustable mixture control, idle adjustment screw, replacement venturis, and float bowl vent.
Eventually I bought a Zenith updraft carburetor from Great Plains Aircraft Supply Company (GPASC). It looked like something off of an old Model A Ford. It didn’t leak during start and shutdown like the Posa, as it has a float bowl, but I could never get it to run quite as well as the initial Posa ran.
When I got my last school superintendent job, I moved to Ottumwa, Iowa, and had ol’ 49RG sitting in the front yard while we moved into our house. Guys from EAA Chapter 409 saw it and came over to introduce themselves; one fellow had a Nesmith Cougar with Riblett wings. After I got to know him, he started trying to convince me to put a new set of wings on my Sonerai, built with a Riblett airfoil, as it had done wonders for his Cougar which was a ground-loving slug with the original wing. I was too busy and not too interested in building a different set of wings, but the idea was intriguing.
I flew the plane as it was, but during a trip home from a friend’s field I blew the head seal on the engine. I limped into the downwind leg at my home airport on three cylinders, and then it quit altogether. I can tell you that Sonerai aircraft generates very little wind noise. The landing was uneventful with the exception of bending the landing gear on touchdown, but it was the 1/2-inch gear which was really too light anyway.
Another, Larger Engine
Finding the problem with my engine, I discovered that the resizing job for the 92-millimeter cylinders was cut so that one jug sat deeper than the other; the head was cocked when torqued down. A straightedge confirmed this. Steve Bennett at GPASC said I could deck the block and fix the engine, but I had a consistent oil leak at the prop hub and wanted something different. Stock VW Bug engines have no oil seal at the prop hub end of the engine (the pulley end). They use an auger and a slinger to try to keep oil in the case. For some conversions this seems to work well, and for others like mine, it throws oil like an old radial. So next I bought a 2180-cc short-block from GPASC, complete with the Force One prop hub.
A close look at the GPASC Force One hub and bearing, shown without the cam timing gear or distributor gear. Photo courtesy Paul Vermillion.
When installing this hub, GPASC machines a larger hole in the end of the case and inserts a tubelike aluminum main bearing that increases in diameter as it exits the case to support two oil seals. The prop hub is a long steel tube (with a flange at one end) that fits through the aluminum bearing and over the custom-tapered end of the crank. It butts into the timing gears and runs inside the new main bearing, held in place by friction and ultimately a retention bolt threaded through the hub into the end of the crankshaft.
I sent my heads to GPASC and they drilled them for a second set of spark plugs. I installed a dual ignition system which uses a magnet trip to fire two motorcycle coils. A slick magneto with an impulse coupler provides the first ignition system and is used alone for starting. I also installed an AeroCarb (seemingly no longer marketed by AeroConversions due to the advent of the AeroInjector) which is much like a really improved Posa. It works well. I also replaced the 1/2-inch-thick landing gear with a 5/8-inch one which works better for this old Navy pilot.
I flew in this configuration awhile, and then a raging thunderstorm blew the hangar doors in and damaged one wing, so I took my new friend’s advice and built a set of replacement wings with a Riblett 35A415 airfoil. Built much like the original, it’s about two inches thicker at the spar. The spar C-channel is (obviously) two inches taller, and the cap strips are built substantially longer to accommodate the additional 4-foot span. I used a 1/2-inch aluminum angle riveted to the rib and bolted to the top and bottom spar caps. Sonerai ribs are bent 90 degrees as they approach the spar, and this tab is riveted to the spar. Sonerai spars have vertical aluminum angles for spar reinforcement, but I used the vertical reinforcers to attach the ribs and therefore get double duty out of them. I made a new carry-through box to accommodate the taller spars where they come through the fuselage, and my legs still fit over it. I made the tail 9 inches taller for the longer wings and added a jackscrew for trim on the horizontal stabilizer leading edge. I got lazy and added an electric starter on a Diehl case.
The plane cruises at about the same speed, climbs much better, and lands much slower. It won’t stall power off but just mushes along like an old Cherokee. 49RG will haul me and my fellow lard-butt buddies with ease.
I flew ol’ 49RG up from Ottumwa, Iowa, to OSH in 2007 and was there all week. I now proudly wear my official CONTACT! Magazine hat emblazoned with “I flew my EXPERIMENTAL Aircraft to AirVenture ’07.”