About This Series
This article is part of an ongoing monthly series on Dragbike.com featuring select chapters from Elmer Trett and the Gods of Thunder, the 2012 biography by Senior Editor Tom McCarthy. Released throughout 2026 to honor the 30th anniversary of Elmer Trett’s passing, this series chronicles the life, legacy, and impact of one of the most influential figures in motorcycle drag racing history. Each chapter explores Trett’s journey from humble beginnings to global Top Fuel dominance, while also preserving the deeper history of the sport and the pioneers who shaped it. New chapters are published monthly exclusively on Dragbike.com.

Before reading this article, read the previous article posts:

• Series Intro
• Book Intro
• Chapter 1 – Humble Beginnings
• Chapter 2 – The Origins of Mountain Magic
• Chapter 3 – The Teen Years
• Chapter 4 – North to Ohio
• Chapter 5 – Fuelish Intentions
• Chapter 6 – Class Dismissed
• Chapter 7 – Fateful Liasons
• Chapter 8 – A Terminal Lesson

Chapter 9 – Single Solution

Elmer was a visionary in Top Fuel motorcycle drag racing from the start.  He instinctively knew that a single-engine, fuel-injected, supercharged motorcycle was the only solution to staying competitive with the Jap bikes.  Elmer knew two years into his Top Fuel racing career that the days of the double-engine Harley were numbered.  He was even so brash as to say to Joe Smith at a race during the seventies, “You know, we really can’t keep racing and winning against the Japs with these doubles.”  That was a mighty bold statement coming from a Top Fuel motorcycle rookie when addressing a three-time NHRA event champion who had been racing fuel bikes long before Elmer had his first whiff of nitromethane.

Despite being only in his sophomore season, Elmer had ideas about how to take his Top Fuel bike and his team to the next level, always swirling in his head.  Brilliantly, he initiated his first major change in December of 1978.

Elmer’s primary brainstorming partner was John Shumaker, of Shumaker Racing Components in Van Wert, Ohio.  Not only was Shumaker the magical machinist who supported Elmer with his innovations, but they were also the best of friends.  So, when either had an idea that might help Elmer go faster, they compared ideas.  During the fall of ’78, they had a fateful exchange.

Elmer called Shumaker and asked him, “Hey, if we took a car motor crankshaft, cut it up so only two connecting rods were in use, could we machine up a crank case that would be near bulletproof to build a motorcycle engine from?”

This is how the brainstorming session between Elmer and Shumaker began.  Elmer knew his double-engine Top Fuel Harley could not continue to compete with the Jap bikes that were evolving into lighter, quicker, faster machines.  If his beloved Harley-Davidson motorcycles were to remain competitive with import bikes, they too would have to go single-engine, fuel-injected, supercharged nitro burners if they wanted to stay alive in Top Fuel motorcycle drag racing.  The question was how to do that and keep the motor in one piece.

John Dixon started experimenting with the combination in 1974, but had no significant racing accomplishments with the bike because it was just too powerful for the antique Harley-Davidson design.  A completely different bottom end to the motor was needed.  This also required a much stronger set of engine cases to be created if the combination was to stay together long enough for the motor to be properly tuned.

To address the issue of creating a lower end that would stay intact, it was necessary to start with a one-piece lower end.  Elmer suggested they start with a Chevrolet 454 motor crankshaft.  The idea he formulated with Shumaker was to start with the original snout at the front of the Chevy crankshaft, save the first rod journal and the next main shaft journal, then cut off the remainder of the crankshaft.  The front snout would then have to be machined to accept a Harley-Davidson pinion shaft to drive the Harley camshafts.  The rear of the crank would also need to be machined into a configuration that presents an output shaft to the motor’s primary side, sending power to the clutch basket.

If they could do this, the motor would have a one-piece lower end that would better withstand the tremendous loads generated by a supercharger force-feeding nitromethane, coupled with a large volume of air, into the motor.  If they could create a lower-end model that would handle the load, they could generate close to 400 hp, and they needed that to compete with the Jap fuel bikes.  The original Harley-Davidson motors they had raced for years were barely designed to handle one-quarter of that power.  Elmer was forced to come up with a completely new design.

In December of 1978, Shumaker took a Chevy 454 crankshaft that Elmer had given him, put it into a band saw, cut off three-quarters of the crank, and then threw the remainder into the trash.  He then spent many a night after work in his machine shop working on the crank ends to create the first one-piece crankshaft design for a Harley-Davidson type engine.

A few months later, Shumaker got another call from Elmer, who told him, “Come on over to the house tonight.  I’ve got something to show you that will help with our latest project.  Be sure to bring your pick-up truck when you stop by.” Shumaker broke into a smile. If this was what he thought it was, this project was going all the way.

That night, when the two inventors met, casual conversation started things off until they walked into Elmer’s work area.  That’s when Shumaker broke into a big grin, as he surveyed the job ahead of him.  This new motor concept they were kicking around was no longer a concept.  The dream was no longer a dream.  There before him was a large shiny object on a wooden pallet on the floor.

The object was an enormous solid block of 6061-T6 aircraft-grade aluminum that measured roughly 30” square.  Elmer said to his friend, “We have work to do.”

Shumaker replied, “Yes, we have a lot of work to do.  Good God, where did you get this?”

Elmer smiled and replied, “The aluminum fairy stopped by,” and they both laughed.

The men started discussing how they were going to turn this solid block of aluminum into a Harley-Davidson engine block that would accept the new crankshaft in progress.  The ladies, who were present, headed upstairs from the Tretts’ basement, where Elmer’s workshop was at that time.  Jackie and Shumaker’s lady friend put coffee on as the mad scientists discussed how they would approach Frankin-Motor. As soon as the ladies were gone, Elmer motioned Shumaker back into the adjoining room adjacent to the workshop.  He then moved a ceiling panel from the drop-down ceiling while thrusting one of his big hands up into a special location.

When he brought his hand down from the upper reaches, there was a moderate-sized coffee can in one of his big mitts.  Elmer reached into the can and came out with a large wad of cash held together by a bunch of rubber bands.  He tossed the cash to his friend.  “That’s fifteen hundred dollars there to get us started,” he said.  “You keep track of your time on this project, I’ll see to it you get paid.”

Shumaker nodded and responded with, “This is gonna take a while but we can do this.”  The Trett–Shumaker one–piece crank lower-end motor was now becoming a prototype engine.

By eliminating the overly complex multi-piece Harley Davidson lower end and replacing it with a heavy-duty Chevrolet crankshaft, they now had a lower end that could withstand enormous loads far beyond anything a conventional Harley engine could.  There were operational issues to address, as well as visual problems Elmer and Shumaker would need to accommodate to use an automotive crankshaft.

A Harley-Davidson engine has one cylinder directly in front of its twin, and the two cylinders are in line with one another.  Using a car crankshaft made this no longer possible because of the crank.  A crankshaft rod journal is a location where two connecting rods can be mounted side by side.  This tried and true design differs from a Harley, which has a knife and fork type arrangement of the connecting rods that mandates the motors cylinders be located in line on the same plane.  For the new side-by-side connecting-rod motor, the cylinders would have to be offset by the distance between the connecting rods.  This configuration is not true to the Harley-Davidson motor design, and it troubled Elmer.  Visually, their new motor design would not look exactly like a Harley engine.  There was one more area of their new motor that deviated significantly from the factory design, the degrees of the cylinder base locations could not be true to the H.D. design because of the crankshaft rotational plane.

The Chevrolet 454 crankshaft was indeed from a big-block car motor, and car motors operate with a 60-degree cylinder spacing when viewed vertically from the front of the engine. Harley-Davidson cylinders are spaced on a 45-degree plane, so the motor fires at 45 degrees of flywheel rotation.  Automotive engines fire off a 60-degree crankshaft, so this new motor Elmer and Shumaker were designing from scratch needed a lot of work to make it mimic a Harley Davidson engine.  By the time they were done building this prototype, the only components in the engine that would be true factory Harley-Davidson components were the camshaft drive train and the cylinder head castings taken from Shumaker’s personal Shovelhead-powered street bike.

Once Elmer and Shumaker realized they could actually create their own motor from scratch and move the project from a concept to a reality, Elmer gave Shumaker the green light to machine up whatever they needed.  Elmer would buy the engine’s internal components.  Shumaker was to keep track of his hours of machining to be paid at a later date, and together, they made the first one-piece crankshaft lower-end assembly for a V-Twin design engine using a side-by-side automotive connecting rod configuration.

This historic prototype engine was completely hush-hush.  Less than a handful of people knew of its undertaking in 1979.  The bulk of the machining processes was done on a hand-operated Bridgeport milling machine.  Turning operations were done on a lathe without the support or assistance of modern computer numerically controlled (CNC) machinery.  A lot of patience, effort, and heart went into the building of this highly experimental engine.

Elmer was out to create an engine that could produce the power of two motors with the weight of one.  If his beloved Harley Davidson drag bikes were to continue to do battle with the single-engine, blown, injected nitro Jap bikes, Elmer needed to not only match, but one better, the import bikes.  This had to come one step at a time.  First, he needed a single-engine, blown, injected Harley to do battle with.  That’s what the new motor was all about; developing an engine to go Jap hunting with.  But there were huge concerns before this engine could see a race track.

Elmer’s biggest concern was the money to produce the engine.  Where would it come from?  Shumaker was Elmer’s friend; friends don’t let their friends work for free.  Hundreds of man-hours would go into machining all of the one-off components to create this engine from scratch.  Shumaker, as well as Elmer, needed to get more than just a high-performance engine from their significant time investment.

The secondary concern was whether the motor would take the loads they needed to stress the engine with.  When Elmer started pouring in the nitromethane, force fed by the supercharger to cause a single engine motor to produce as much, or more, horsepower than his double engine bike did: would the new engine design stay in one piece?

Perhaps just as important a question to Elmer was, with a side-by-side connecting rod configuration offsetting the vertical cylinder locations and a 60-degree engine block, the motor would not really look like a real Harley Davidson engine: would people still accept that Elmer was racing a Harley?  This was a major concern to Elmer, the sign posted in Trett’s Speed & Custom said “Harley’s Only.”  Elmer was loyal to the Harley Davidson factory, his life and his business revolved around Harley Davidson motorcycles.  Elmer needed help to get this project into high gear, so he turned to the factory.

In the late nineteen seventies, the Harley-Davidson factory was supporting Marion Owens and Ray Price, who were racing Harley-Davidson motorcycles.  Elmer also needed factory support if his project was to get off the ground.  So, Elmer, with help from his friend, Marion Owens, approached the factory for money to fund his new project.

Dick O’Brien was in charge of the racing programs for Harley-Davidson at the time.  The factory poured thousands of dollars annually into its racing budget to fund racing teams that kept the factory name in the public eye.  It was advertising money spent on high speed billboards with two wheels.  Elmer needed a piece of the pie if he was to develop this new motor to its full potential.  Elmer knew there was no way that financially, he could achieve this alone.  So, Owens helped Elmer get in touch with O’Brian to start negotiations.

Elmer started off slowly in getting to know O’Brian as well as his assistant Clyde Denzer.  This was a huge step for Elmer to be talking directly with the racing department in Milwaukee.  It was an honor and a privilege for the man from Kentucky to, not only ascend into Top Fuel motorcycle, but after three years in the class, he was now elbow to elbow with the top brass.  This was really big for Elmer.

Elmer’s single-engine Top Fuel motorcycle project was top secret while it was under construction.  Less than a dozen people in the whole world knew of its construction during the early phase in the spring of ’79.  Elmer let the factory know it was in progress and asked them for help.  They replied with basically, “Please keep us informed of your progress and we’d like to see what you come up with.”  Elmer said he would, and set out to convince them he was worthy of their money.  While Shumaker was whittling up a lot of metal chips in his machine shop off the new engine block, Elmer started carving up the competition to prove his worth.

From the start of the season, Trett’s Speed & Custom as a race team came on strong like a raging bull.  Elmer concentrated most of his racing efforts on the DRAGBIKE! sanctioned in 1979, but also raced some races with the I.D.B.A.  From the early spring of 1979 to late fall of the same year, he began taking over in the Top Fuel motorcycle.

The season opener began in Bradenton, Florida, at Desoto Memorial Raceway on March 3 and 4.  The Trett Family was a low qualifier for the race, and had they not suffered a blown motor in the semi-finals, they certainly were headed for the final round of racing.

For the weekend of June 15, the family made the long trek north to New Hampshire for a race at New England Dragway in Epping, NH. This time, Elmer made it to the final round of racing but lost to Roy “Frog” Thacker.  In the first two races of an eight-race season, Elmer’s driving and tuning skills were motoring his team to the top.

Once Elmer got a handle on the fuel injection system, he experimented with the clutch settings.  As soon as he got the bike to leave the line hard and stay in one piece, it was Elmer’s job to drive the bike to its full potential.  This he knew how to do.  In ’79, Elmer already had close to a decade of motorcycle drag-racing experience.

The summer of 1979 was when Trett’s Speed & Custom achieved their first Top Fuel win.  They announced to all in the class they were a force to be reckoned with.  Prior to this event, Elmer’s Top Fuel bike was consistently running middle eight-second elapsed times at close to 175 miles per hour.  Occasionally, Elmer would go a little quicker or faster, but mid-eighties was his norm.  Then came the Union Grove, Wisconsin, IDBA race on the weekend of July 28.

Elmer’s drag bike came on like a raging bull!  He unleashed a string of 8.0 elapsed time runs for two days straight that won them their first race.  He also met one of his favorite racers in the finals, Mr. Pete Hill of North Carolina.  Hill’s supercharged Knucklehead-powered Harley Davidson was no match for the rampaging Elmer, who thundered to an 8.0 elapsed time to defeat his old friend.  Elmer won again at their next race in Atco, New Jersey, as the team gained momentum in their first winning season.

At the DRAGBIKE! World Finals held in Gainesville, Florida, Trett’s Speed & Custom won the race and secured their first National Championship not only as team, but as a family.  At the awards banquet, Elmer and Jackie, along with Kelly and Gina, accepted their championship trophy together.  As Team Trett finished wrapping up their first Top Fuel winning season, Shumaker was beginning to bring the super-secret engine parts into the finishing phases of development.

Shumaker was not the only one machining components for the engine.  Elmer was an accomplished machinist as well, so he was creating components for the oil drive system and camshaft galley.  Shumaker, with the bigger machines, concentrated on the one-piece solid engine block and the crankshaft.  For a job that required extra manpower, they worked together so no one outside the Trett-Shumaker team would see what they were doing.  By January of 1980, they had the major components of the engine almost ready for assembly.

Elmer showed the factory what he could do during the 1979 season by winning his first Top Fuel championship with the DRAGBIKE! sanction.  They also finished runner-up with the I.D.B.A.  Now, it was time to inform the factory of his progress with the new motor as he’d promised them.  So, at the start of the 1980 season, Elmer called for a meeting in Gainesville, Florida, to show them the major elements of the new prototype engine.

Dick O’Brian and Clyde Denzer were in Florida for a race early in 1980 so Elmer arranged for them to meet so he could show them his accomplishments.  Elmer was joined by Shumaker and his assistant, Steve Stordeur, who were also present when O’Brien and Denser arrived at a hotel room to see what this new prototype engine was going to look like.

Prior to the arrival of O’Brian and Denzer, Elmer had spread out a blanket on one of the hotel room beds.  Then Stordeur and Shumaker laid out the one-piece crankshaft with two aluminum connecting rods attached, the one-piece billet aluminum engine block, four custom lifter blocks, and a separate camshaft galley that was ready to be bolted to the engine cases.  A wondrous addition to the collection of components was the aluminum cylinders Shumaker had machined up that were off-center so as to fool onlookers about the offset cylinder bores in the engine crank case.  These masterpieces of machining as seen from the side, to the untrained eye, completely hid the fact that this was not even close to a real Harley Davidson engine.  Elmer and Shumaker succeeded in visually creating a motor that closely resembled the Harley factory design.  They were ready for their presentation.

When O’Brian and Denzer entered the room, Elmer and Shumaker took turns showing them the components that were just mind boggling to see.  The Harley factory men were quite impressed with what they saw, they had never seen racing components like these before and with good reason: they were truly one of a kind Trett-Shumaker creations.  After the general conversations ended, Elmer took a short walk with O’Brian to discuss business.

Elmer stated his case; there was no way he could continue to develop this engine, let alone race it, without factory money.  His request was simple, would the factory help him out financially?  The response from the factory representatives was affirmative; they would write him into the 1980 budget.  Elmer was all smiles.  This was it!  1980 was going to be a season to remember.

The Next Installment of Elmer Trett and the Gods of Thunder will be released on June 15, 2026 on Dragbike.com

For those interested in owning a printed copy of the original book, please contact Tom McCarthy. Limited copies are available. E-mail Tom on Facebook

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