Midget open-wheel racecars and the Stock (S Class) and Modified (A Class) inboard hydroplanes have provided thrills and chills for racing fans since the 1930s. And as the speed and performance of these radically-different racing machines has improved, so have the engines that power them.
These engines have varied from stock four and six-cylinder automotive-type engines. There have been engines that have been built from scratch to be race engines, then there have been basically stock engines, modified stock engines, and finally, engines that were designed by backyard engine designers. And amazingly, there were company and private ‘combo’ engines, which consisted of joining major engine parts together to create a new, and often quite potent, engine. Dozens of engine builders of all types have tried their hands in building race engines within the required displacement. Quite frankly, it’s a story of Yankee ingenuity.
Initially, there was no standard displacement for these race vehicles. The early versions many times were less than two liters. But over time, the ruling groups decided that it would be 2.5 liters, and it’s remained there ever since. It proved to be a good decision, when in the 1960s, there was a shift away from the big blocks and toward small engines of the right displacement for these race machines. An example of that phenomena was the use of a destroked Buick 215 engine.
The point must be made of the differences in cooling the two versions. With the midget, there is a lightweight aluminum radiator with a water pump. However, with the hydroplane situation, the cooling water is provided by a water pick-up below the waterline. The water flow is provided at speed easily satisfying the cooling needed by the engine. Also, with the hydroplane, there is no radiator, no radiator hoses, water pump or thermostat.
Next, let’s get into more of the engine specifics of these versatile engines, beginning back in the 1930s. The engine that was used initially by both the midgets and boats was the so-called Ford Flathead V860 engine. Initially, the limit for these classes was only 135 cubic inches but that would grow to about 150 cubic inches, i.e., 2.5 liters.
This was one of the aforementioned engines that had been completely built by Ford for street car use. Built during the 1937-1940 time period, it was a dream to modify and upgrade, capable of producing considerably more horses than the stock version. Compared to the modern powerplants of today, the V860 was small and had only 60 horsepower, but that was sufficient for the period with its slower speeds.
To be an effective performer in either venue, however, it was necessary to be up to full speed at the start of a race. With the midgets, the field is packed together at the start of a race with the green flag coming out just before the field hits the starting line. The advantage of having the top power just prior to the competition often gave drivers a quick shot to the front.
Hydroplane racing was slightly different, requiring the boat to be at full speed before the starting line during the flying start.
Early 2.5L Midget Engines
The V860 and Offenhauser
The V860 remained competitive with midgets into the 1950s. Then, it was surpassed by a pure-race engine which had been optimized for flat-out performance in oval track racing.
Built in the 1940s, the famous Offenhauser (Offy for short) powerplant was built from scratch to be a racing engine. It was a smaller version of the famous Offy engines that were so successful in Indy Cars. The smallest Offy was perfect for midget applications and was used from the 1930s to the 1950s.
Competing in the early days really wasn’t a fair situation if you didn’t have an Offy – these engines had so much more power that the midgets often competed on Offy or non-Offy racing circuits.
The Offy was hardly ever modified, but with the V860, there was a little bit of everything going with tons of aftermarket performance parts available. One of the most important contributors to the increase in performance was one Eddie Meyer who provided custom heads, hot cams, with Evans heads, Edelbrock carbs and intakes, Stromberg carbs and even Offy heads. There were even some attempts with fuel injection along with the use of alcohol fuel.
The V860s could also be easily bored and stroked. Also, a good percentage of the V860 engines carried multiple carbs, two being the most popular set-ups.
Then came World War II and racing of all types was shut down cold. Wartime didn’t prevent engine builders from thinking about the V860 and they came up with an amazing development, which effectively doubled its horsepower and was coined the “Reverse V860.”
But for the most part, the Offy still was the king of midget tracks as was evidenced by the top traveling teams using them. But as the years passed, engine technology continued to evolve and the Offy was evenutally left behind.
One of the most interesting engines of this period was the so-called SESCO engine, a unique design by skilled engine builders Ron Hoettels and Don Boorse. Hoettels’ technique involved cutting a Chevy V8 in two pieces lengthwise and using only one bank of the pistons, thus bringing the displacement into midget territory. Hoettels explained that the Bowtie SESCO was used by superstar Mel Kenyon in his early USAC days.
Next, a 351 Windsor Ford received the same SESCO treatment. The engine builder indicated that the engine provided excellent straightaway speeds.
Also during this period, Hoettels cut another Chevy crosswise, this time creating a V4 engine with the same displacement as the aforementioned lengthwise-cut engine. The quick-revving, opposed-four engine was highly successful with some of the national midget series.
This automotive engine was a perfect fit for this class and filled the gap with a more modern powerplant. It worked well with both the midget class and the hydroplanes. Introduced in the 1960s, the injected four-cylinder was the period choice of many midget race teams.
Other Early Midget Engines
It was also during this same time period that individual engine builders tried just about everything imaginable to get their midgets to go faster. It wasn’t strange to see modified versions of Studebakers, Ferguson tractor engines and even Evinrude outboards powering midget racers. There was even a destroked 215 Buick engine attempted with some success.
It’s interesting that a surprising number of identical powerplants were used in both applications. Then, there were cases when one engine would be used only in the hydros, and not cars, and vice-versa.
But the surprising aspects of this engine class was the number of foreign engines that were introduced to the sport. Some were on the scene for just a fleeting second, while others remain in place today. Foreign engines on the scene included the likes of Volvo, VW, Datsun and BMW.
Current Midget Powerplants
It’s hard to call the VW a modern engine since it was first used in midgets starting in the early 1970s. Now, over five decades later, the engines are still being built by the Autocraft Company. Today, the engines are a far cry from the 150 horsepower stock versions that were initially produced.
Autocraft President Mike Seymour explained that today’s engines produce about 350 horsepower and now incorporate roller rockers and lifters and that longer push rods have allowed the displacement to be increased to about 1.74 liters.
During its early years, it was the state-of-the-art and all the top drivers used the VW, including the likes of Mel Kenyon, Rich Vogler and Sleepy Tripp. Underpowered by today’s standards, these engines are found in abundance in indoor midget racers and on short outdoor tracks.
They are also used in Australia and New Zealand and in many vintage midget cars. Seymour explains that there is still a strong market for these engines.
The Honda HPD
Developed in the past couple years, a new engine was proposed for the entry level USAC Midget series. Honda was selected as the engine builder, certainly an appropriate selection since its Indy Car engines had powered racers to more than 200 wins.
It’s a 2.4 liter straight-four engine, which produces about 240 horsepower. To date, the engine is only used in one series, which carries the name of the USAC Honda/HPD Midget Series. The series consists of six regional series competing on both dirt and pavement.
The engine is based on the Honda Civic Si engine and the race version carries all Honda OEM parts. The racing modifications include a custom aluminum oil pan designed for dry sump lubrication, a three-stage oil pump, competition alternator, intake manifold and a custom air inlet system.
The Pontiac ‘Iron Duke’
The so-called Pontiac Iron Duke engine was a venrable engine used by Pontiac on its smaller cars. It had a long production run from 1977 through 1993. It was used into the 1990s in the midgets.
It also powered Jeff Gordon’s first midget race, the USAC Night Before the 500 race. Not only was it Gordon’s first race, it became his first win.
The stock version at its introduction was 151 cubic inches, but in its race configuration, it was a legal 166 cid.
The Gaerte 1600cc/Possible Future Engine with Honda
The four-cylinder inline Gaerte engine was built from scratch to be a competition engine by this racing engine builder. It was built in the 1980s, but is no longer in production. Its age is certainly no detriment as it is still an active race performer.
Rick Paradis of Gaerte explained that the company is now combining with Honda for a national midget engine development. “The final specs of the engine are not available at this time. But it will be an injected engine with an inline four/four valve configuration.”
Ed Pink/Toyota Midget
During the early 1990s, this company started designing engines for USAC open wheel machines including midgets. The company became associated with midget owner Steve Lewis and the results are a part of USAC Midget history.
The engines were inline fours with 166cid displacement. Weighing in at about 250 pounds, the engine was capable of 325-350 horsepower on methanol. There were 10 years of winning with those engines before a change took place with Toyota when Pink built the first Toyota Racing Division (TRD) engine.
The involvement continued in the late 2000s as Pink continued to refine the TRD engines. TRD then provided Pink with its NASCAR cylinder head and asked him to design an engine around it. From the design board to its first test only took 10 months. The first time out with superstar driver Dave Steele at the wheel resulted in a win at Phoenix International Raceway in February 2006.
New Chevy Midgets
The battle for midget superiority continued late in the first decade of the new century.
Chevy engineering was involved in this impressive effort and since Tony Stewart drove Chevy-powered NASCAR Cup cars, it wasn’t surprising that his USAC Midget team would be a recipient of the engines.
The 2.7 liter four-cylinder engine produces more than two horsepower per cubic inch at 350 horsepower. It has both an aluminum block and head. There are two valves per cylinder operated with pushrods and rocker arms. In addition, there is mechanical fuel injection and an electronic ignition system.
There’s a belt-driven dry sump oil pump and a high-pressure mechanical fuel pump mounted on the right side of the block. The exhaust comes out the left side of the engine.
Chevy Ecotec Midgets
This engine has been active for five-six years and is still current with economy-class midget race including the POWRi Division 2 Midget Series. Its displacement is 2.4 liters and the asking price is about $12,000.
This company builds several engines to support midget racing. First, there is a 161cid (2.6L) injected inline-four engine, which sports a right-side intake. The 380 horsepower screamer has been a successful performer in USAC’s top midget series with such drivers as Darren Hagen, Brian Clawson, Tracy Hines and others. The base price is about $26,000.
During the 2000s, there was also Esslinger involvement with Ford on a 340 horsepower version, which had the intake on the left side of the engine. It is priced at $23,500. It was driven very successfully by Cole Whitt who took the 2008 USAC National Midget Championship.
Also, there is a more economical 2.4-liter powerplant for the lower divisions where no porting is allowed. Its horsepower is lower at 260-300 but so is its cost – from $12,000-$15,000.
A measure of Esslinger success can be seen in 2015 where it won 62 of 123 reported midget results.
Stanton Midget Racing Engines
This company was formed in the early 1960s by Gary Stanton. During the years he built race engines for a montage of open wheel, drag, off-road, and stock car vehicles. Stanton explained that much of his success came from his associations with MOPAR and Toyota Racing Development. He also re-designed the TRD midget engine.
Engines that have been designed by Stanton include the four-cylinder SR-11 engine, which sports an impressive 375 horsepower at 9800rpm. Then, there is the W9 MOPAR engine, which uses a similar block to the SR-11 and a MOPAR head with horsepower between 345 and 350 at 8700rpm. It is very popular in both Australia and New Zealand.
As strange as it may seem, a number of modern midget engines have evolved, but not always from the expected sources. Many of these so-called combo engines have been accomplished engine builders in their garages.
These engines usually use two major engine pieces usually a block/head combination. An examination of some of the more common midget combo engines shows the Rodeck block used on occasion with Gaerte and Bradenton cylinder heads along with Pontiac blocks and Edelbrock heads. There are also Gaerte blocks with Fontana, Chevy, and Ford heads.
Such conversions are possible because of the bolt pattern commonality. Basically, what you are doing is building a new engine with existing parts and pieces. It seems to work for a lot of engine builders.
Racecars weren’t the only beneficiaries of 2.5L power. Many of these small displacement engines were used on the water in hydroplane racing. For more on that subject, see an enhanced version of this article with additional images at