Gary Conley has been selected as the Metalworking Craftsman of the Year for 2012 by the Joe Martin Foundation for Exceptional Craftsmanship. Gary has long been known in model engineering circles for the quarter scale V-8 engine he produced (photo below - click on photos to enlarge).

Unfortunately, after five years developing of a running quarter scale model of the Viper V-10 engine, a catastrophic fire at the foundry destroyed Gary’s moulds for both engines.

Gary’s original quarter scale V-8 was available for many years in finished and kit form. The story of the production of that engine, plus a Viper V-10 and the cataclysmic fire that led to the design of the new Stinger 609 V-8 is one of both talent and perseverance. Not many people can make a living in model engineering, but Gary has managed to do it for more than 30 years despite setbacks that would have caused most others to give up. Luckily for the world of small engines, Gary Conley didn't, and his latest creation has just hit the market.

“Perfection is almost good enough.”

The motto at Conley Precision Engines is: “Perfection is almost good enough”. Gary says he has found that it is better to explain a delay than apologize for the quality of workmanship later on. His business has been in the same location and has grown steadily over the past 30 years, and he firmly believes this longevity was due in part to the way customers are treated. The customer loyalty he inspired though the quality of his craftsmanship has paid dividends when he really needed it.

After completing his Masters Degree in Industry and Technology at Northern Illinois University, Gary spent about five years teaching Vocation Machine Technology at Morton West High School in Berwyn, Illinois. During this time he involved many of his advanced students in machining and constructing various steam and internal combustion engines. When education became, for him, more “baby sitting” than teaching, he decided to start his own business with one product, a very limited budget, and a lot of hopes and dreams.

The first V-8 engine from three decades ago was crude in comparison to his current engine. It was machined completely from billet material. Each component was hand made without the use of any CNC equipment.

During this time the engine went through some major changes. Being on a limited budget, it was difficult to make significant running changes in the production and machining. As money became available it was spent on new machines. He eventually went from one Anilam CNC retrofit on his Bridgeport Mill to three additional pieces of CNC equipment. Since he is not a “job shop” there are now several machines, each dedicated to a specific purpose.

From billet to cast parts

Another significant change was having a lot of the parts cast. Some of the parts were sand cast” while others were either die cast or investment cast. Not only did this alter the appearance of the engine but allowed for considerable internal changes. The most notable of these was the investment cast crankshaft and connecting rods. This allowed Gary to increase the bore from .750 to .952. Over the years there were too many changes to list.

Chrysler asks for a model Viper V-10

There were plenty of ups and downs during this time, but in 1996 two representatives from Chrysler Corporation approached Gary. Since he was already making a V-8 engine they asked if he would consider building a ¼ scale Viper V-10 engine (photo below). At that time he was contemplating building a ¼ scale V-12, and after some serious thought the V-10 seemed to be the more logical choice. After receiving a licensing agreement from Chrysler the next step was to get a full-size engine for the purpose of ‘reverse engineering.’ One day he got a knock on the door and a truck unloaded a complete Viper V-10 engine in his driveway. At that point he began to wonder, “What have I had gotten myself into?”

Since this engine was mainly a shell with limited internals, it was dismantled and each piece analyzed and evaluated to see if the engine could actually be reduced to ¼ scale. Little did he know that this was only the beginning of a very long uphill battle. There were many technical problems to be solved including eliminating RF interference in the ignition system and oiling problems. (Not too little but too much!) The entire project should have only taken one to one and a half years. In actuality it took almost 5 years.

Tragedy strikes

After all of that hard work Gary received the devastating phone call. The foundry had been consumed in a catastrophic fire that had destroyed everything. All of the V-8 and V-10 moulds were gone, and there was no insurance to cover any of his losses!

All of the deposits for every engine had to be returned. It would have been very easy to declare bankruptcy, but this was not an option for Gary. He could not do that to his customers, but at the time no other alternatives seemed to present themselves.

New direction

About that same time the company that was making the model carburetors that were used on his engines was being sold. With some very strong soul searching and lengthy conversations with his wife, he decided to purchase the entire line of Perry products from Varsane Manufacturing. This included not only the model carburetor line but also the model engine pumps and fuel control valves. This purchase proved to be his saving grace. Slowly, all of the deposits were returned and he started to see a little light at the end of the tunnel. Things have continued to improve, and after exhausting his entire existing V-8 parts inventory, he decided to build another V-8 engine in late 2005

The only things that he had retained from the fire were all of the masters from the V-10 engine. Instead of trying to revive the V-10 project, the decision was made to modify and shorten the V-10 into an all-new V-8 engine. Something called “transferable knowledge” became very evident when he decided to build the new engine. Remember, almost five years were spent on its design and construction. Some of the internal components did not change, and since he had a lot of parts in stock he put them to good use on the new engine. Surprising, the only moulds that survived the fire were the mould for the head and the mould for the intake and exhaust runners. With a lot of measuring and careful machining, the mould for the V-10 head was shortened to make a great V-8 head. The runners did not change. Somehow, all of the masters were modified for the new Stinger 609 engine. The rest, as they say, is history. The new engine (photos below) is now in production, and Gary is most grateful to the many customers who stood by him through good times and bad.

New Stinger 609

The name is derived from the displacement: 6.09 cubic inches or almost 100 cc.   The new Stinger possesses no parts used in prior V-8 engines. The bore is 1.00", with a .970" stroke. It weighs about 11.25 pounds and measures approximately 14" long (from the front timing belt to the end of the transmission), 6" wide, and 8-1/4" tall. The supercharged version is about 10" tall. More details can be found on Gary’s web site at:

Among the numerous innovative features like the large oval shaped intake ports, D-shaped exhaust ports and investment cast parts, two bold attributes stand tall: the dry sump pressurized oiling system and a full ignition system firing the tiny 10-40 threaded spark plugs. The engine even has a user replaceable oil filter, and there are a number of performance and dress-up options. A transmission with forward-neutral-reverse is expected in the very near future.

This good looking engine has been featured as a magazine centerfold in issue #26 of Model Engine Builder magazine along with an article on the development of the engine.


Now the Joe Martin Foundation has awarded Gary a $2000 cash prize, engraved gold medallion and the title of Metalworking Craftsman of the Year for 2012. The award will be presented to Gary in person at the North American Model Engineering Society Exposition ( in Wyandotte, Michigan April 21, 2012. More photos of Gary, his shop and his engines can be seen at

The foundation was established by Joe Martin, the owner of Sherline Products Inc., manufacturer of precision miniature machine tools. Mr. Martin has dedicated the profits from this company to support excellence in craftsmanship at the small end of the size scale. Learn more about the foundation and its goals on their on-line museum web site at