Here's the Texas Chapter April 2013 Newsletter. The month features an extensive set of photos from the Cactus Fly-In.

Dick Fisher's reproduction Bendix wheels look great on restored antiques, but finding an authentic looking smooth tire can be difficult. Hans Gautschi, in Beinwil-am-See, Switzerland, sent us photos of how he made his own smoothies for his Hatz project:

The tires for 16" wheels are the same size as a Harley, so treaded tires are readily available. Hans tried several different tire brands. The first several tries resulted in tires that didn't rotate evenly. Hans has had success with the Shinko E240 tire, which results in a 25" diameter that weights 11 lbs when smooth. Hans says:

I mounted the tire on an ordinary aluminum motorcycle rim to which I fitted an axle to mount it in a big lathe. Then it took me about 3 hours per tire to cut most of the thread down with a special HSS tool while turning it at the lowest possible rpm, which was 300/min. The tool is like a Stanley chisel, only with a steeper angle and a curved edge.

I quickly found out that it was necessary to sharpen the tool after a short time of use. The cutting angle of the tool seems to be important! Position so you can get off long filaments of rubber (like spaghetti). When down to the last 1/16" of tread it became hard to remove more. It seems that the rubber there is harder.

Then I took a belt sander (#40 grit) and worked against the rotation by just holding it on the tire and following along the section of the tire. Always stop and check if the amount of thread is equal over the whole tire. I found out that it was not even at all places, so I took a disk sander with #60 grid paper and sanded the whole surface for an even tread. Then again with the belt sander and again with the disc sander. When you just see a few marks of the thread, smooth it out with wet sanding fine paper (gradually up to #240).

I hope the tire lives for at least 5 years (if we don’t crash the Hatz in the first flight!)

Russell Williams has written up a summary of the balancing procedure for a Warner 165 engine:

I've been overhauling my Ryan SC-W's Warner 165 engine this winter and one of the last steps before final assembly of the bottom end is balancing the crankshaft. If you are not entirely sure of the operational and overhaul history of your engine it is worth doing at least a static balance, since Warner 165s have been assembled with different piston and counterweight configurations. Performing a balance ensures that your engine will be smooth-running.

The master rod of a Warner 165 prepared for weighing

With the help of Mike Connor, Harman Dickerson, and Al Holloway I've been able to distill this set of instructions. Any errors are entirely my own. Since the engine overhaul manual is not helpful when it comes to balance (e.g. "Send the crankshaft back to the factory"), education is the first order of business: The idea of balancing is to try to zero out the forces acting on the crankshaft of the reciprocating pistons and rods, and the rotating masses of the master rod assembly and the crank throw. Balancing for small radial engines such as the Warner 165 is done with fixed counterweights, no fancy moving higher-order vibration dampers are typically used on small radials.

There are two papers written in the late 1970s by W.B. Richards that outline research into the balancing formula for the Warner 165 engine: Balancing Radial Engines Part 1 and Matching Pistons and Crankshafts for Warner 165 Engines. Based on these papers and practical experience of experts I used the following procedure:

To have a balancer static and dynamically balance the crankshaft you need to determine the "bob weight" mass. The bob weight is a weight temporarily bolted to the crankpin which should exactly offset the final counterweight mass, and result in a balanced, smooth-running engine. The key formula from Richards' papers is W_c = W_rot + .510 W_recip where W_c is the bob weight mass, W_rot is the rotating mass, and W_recip is the reciprocating mass.

To determine the rotating and reciprocating mass you can either send your entire rotating assembly off to the balance shop, or weight the parts yourself and send only the crankshaft. Weighing yourself is not difficult but does require a fixture and a scale. Electronic scales are cheap, and a fixture is fairly easy to make if you can't borrow or don't want to buy one.

Determining the reciprocating mass for the pistons, piston pins, piston pin plugs and rings is easy: just put them all on a scale. A 1000g scale with 0.1g precision is adequate for this task and for all of the Warner 165 other than the master rod weights. Total the weights of all of the above.

Piston on scale. Notice the articulated, adjustable rod end support on the weighing fixture for weighing rods.

The master rod and link rod weights must be split into rotating, or crankshaft end weights, and reciprocating, or piston end weights. The rods should be prepared with all bushings finished, bearings inserted, rod cap bolted up, lock pins, nuts, and cotter keys temporarily inserted into bolts, so that the weight is identical to the finished weight. You should also insert the knuckle pins into the master rod, since they are rotating mass, which on the Warner 165 means inserting them before the bearing shell inserts are installed!

The rod weighing fixture is designed to weight a rod around its CG and isolate each end's weight. The fixture uses a low friction roller pin and movable arm to relieve side loads on the rod end. Some fixtures also suspend the rod end not on the scale using a trapeze like arrangement. One end of the rod is on the scale stand and the other end suspended. The rod must be level when it is on the fixture by adjusting the height of the suspended end. You can find several videos on YouTube such as this one which show the weighing process, although unlike automotive parts we will not be equalizing rod weights using a grinder! Once you get the weights of each rod end, add them together and check against the weight of the entire rod on the scale alone. The two end weights should equal the total weight of the rod within a gram or two, or else you've done something wrong.

Link rod on scale. Rod has been leveled and piston end weight, or reciprocating portion of the rod weight, is shown on scale

I had purchased a balancing stand from Summit Racing which worked well enough except for the master rod. The master rod in a Warner weighs approximately 3.8kg and has a 3" wide big end, which means it falls off the automotive-sized fixture. The fix is to modify the fixture with a larger roller (3" long screw, wider spacer, and support roller) and to modify the scale stand to be taller. To handle the mass of a fully assembled Warner 165 master rod you need a scale with a 4kg or greater capacity. 1g precision should be sufficient for the master rod. There are "gold" scales available with a 4 to 6 kg weight range and 0.1 gram precision for a reasonable cost that do the job well.

Modified weigh fixture stand for master rod big end: wider roller and support bearings, and taller scale stand.

Once the weights are recorded and the bob weight value calculated, send the crank off to a balance shop. Since the crank should be in final configuration the sludge plug and cotter key should already be installed prior to balancing. As of 2013 the balance shop recommendation is Electronic Balancing Company near Long Beach, CA. They will perform a dynamic balance of the crankshaft using a dynamic balancing machine, and add or remove weight from the counterweights as needed. Electronic Balancing is experienced with aircraft parts and has done Warner 165 cranks before.

Alternatively a static balance alone is probably just fine, but requires access to a balance stand, plus the machine tools to build weights for the crankshaft if necessary. Weight can be added using slightly tapered plugs driven into the holes in the counterweights, then punch the end of the holes to keep the weights from backing out.

When assembling the engine, you will see that there is some variance in the reciprocating parts. Attempt to balance out these differences by mixing the pistons + rings, piston pins and piston plugs to find the nearest you can get to equal weights for each cylinder. If there are large variances on the pistons you have a problem but you can do limited material removal on the pistons to balance them (prior to calculating bob weight values). With Warner pistons you shouldn't need to adjust them much.

The master rod being weighed, with modified Summit Racing weighing fixture able to accommodate width of the Warner master rod

All of the link rods and master rod ready for weighing

Greg Wilson sent photos of his Champ on skis:

Just thought I would send a photo of northern Michigan. Yes the Champ is still on skis, we are currently 14*F,and snowing,such is life north of the 45th parallel. These were taken on March third, it is my mostly stock 1946 Champ, A-65 still, on 1950 vintage Northern Light skis. The only modification on the plane was the addition of two 6 gallon wing tanks giving 25 gallons total for it’s last job of power line patrol. I had the Champ at Blakesburg last year and had a great welcome despite my plane not looking like a museum piece,so thank you to every one there. I hope to be back this year.

For the little round engine flyers of LeBlonds or Ken-Royce engines who asked about where the online manual went, AntiqueAirfield.com is proud to be the new host of the Ken-Royce Engine Handbook in searchable PDF format. We will be adding more online reference content in the near future, so stay tuned!

Check the March 2013 Florida Cub Flyers newsletter, where the traveling Cub has left Africa and is now in Australia, plus other stories and fly-in reports.

The Marginal chapter of the AAA/APM recently acquired this "original" sign for their new Marginal Restoration Center! Steady progress on the THP aka "Toby Hanson Project" can been seen on the Marginal Facebook page.

APM Director and restorer Steve Adkisson has the new cowling for Rudy Frasca’s Continental powered Aeronca C-3 finished, painted and installed.

Did somebody steal some paint from Chuck Doyle!?

Here's the March 2013 Florida Antique Biplane Association Chapter Newsletter.

This month's first paragraph sums things up well: "Opportunities to fly to meetings of like-minded folks aren't abundantly available these days. Let those few opportunities pass and they are likely not to be repeated. You can let the beasts sit in the hangars and you can talk about flying or you can actually do it. It's your choice."

Forrest Lovley sent us this update on his Waco QDC:

New wings by Mike Gutenberger of Colby Wisconsin...took 90 days for all four completely new. Cliff Hatz has the fabric on lowers done, and is starting on the uppers this week.