As I promised, here is the story of the Worlds Fastest Flathead…. Motorcycle !

1^st off I want to acknowledge that there is an article online on this motorcycle. Please go read it at -

http://www.allpar.com/history/plymouth/motorcycle.html

Next up I want to make it very clear that in my opinion Jim Benjaminson is one of the

most dedicated Plymouth Historians on the planet and I am very happy to call him my hero !

I want to say that right up front, because some of what I am about to say may not be the same as what is in his article or other articles I will refer to. While I fully believe in Jim’s case he used the best available information, and in the case of two magazine articles published in 1935, they published what information they were given. Lets just say they were not quite given the full story and the reason why, well what my Grandfather said was they were very concerned about information being disclosed to the public, for fear that someone else would use the information to best them.

At issue, really is what the engine was capable of turning from a RPM standpoint.

But I digress..

Lets start off with a direct quote from the start of Jim Benjaminson article -

“Despite the bleak economic condition of the country in the mid thirties, the spirit of adventure was very much alive and well, especially in the world of speed. It was an "Age of Speed" and the place to be was the Bonneville Salt Flats in the uppermost corner of the state of Utah. The challengers on "the Salt" were British mostly, with specially built race cars sporting monster engines to assault the time clocks in quest of the magic title of the "Fastest Man on Earth." Even today, men still talk about the greats like Capt George Eyston and Sir Malcolm Campbell and their monstrous thundering machines. $10,000 was a lot of money then and it was reported that this huge sum would be paid to the first man to drive a motorcycle at a speed of 300 miles per hour.”

Enter one Californian named Fred Luther. Luther was an employee of Chrysler and he prevailed upon the company to supply him with motive power in his challenge to become this man. Chrysler responded by supplying Luther with a complete 1934 PF six cylinder engine and transmission. Already an experienced motorcycle racer, Luther began the necessary modifications to a 'cycle to accommodate its new power plant”

So now let me jump in here.. My Grandfather whose name is Earl Bolton worked for Chrysler with Fred Luther.Fred had left a career of board track racing, and had opened up a Garage on LA in the late 20's. I believe when the crash of 29 came, he was working for Chrysler.

The picture which ran in the July 1935 Modern Mechanix would be Fred on the motorcycle in a riding position (with the stands down) and my Grandfather looking like he is adjusting the carb on the bike although from what I know it should have been Jimmy McNeil who did the major modifications on the engine according to the notes my Grandfather made.

Now let me move to the details of the bike. The bike was a 1926 Henderson Deluxe Super 6, referred by many over the years as a Henderson “X” although the Henderson “X” was actually a different motorcycle ,so I am told by a Henderson historian . He provided me with a picture of his restored 1926 Henderson and I will attach it here.

The cool thing is the motorcycle was already stretched by the Henderson Motorcycle company and sported a 6 cylinder engine. I believe by Grandfathers notes that in summer of 1933 Fred Luther purchase the motorcycle from a gentleman who had bought it new in 1927. He had in or around “Black Tuesday” which was October 29, 1929 and the end of the big stock market crash lost everything. As I am told that motorcycle was the mode of transportation for this gentleman as he left New York state after the stock market crash. As the great depression or the “dirty thirties” as Grandfather referred to them, was in full force and he could no longer afford fuel or the bike and he sold the bike to Fred Luther.

My Grandfather who had the nickname of “Earl the Squirrel” got the name from his Squirrelling away parts, and information. Grandfather saw the younger fellow Chrysler employee, Fred as a pretty decent young man and when Fred asked for help Grandfather was glad to help out.

So I won’t say who did what, but I will say that Grandfather was pretty tight with Walter Chrysler, and by some miracle a 1934 plymouth 6 cylinder that to quote Grandfather "didn’t pass quality control at firing time" was purchase for the project for the sum of $1. I have the receipt for the engine ! Lol.. I will also say, my other Grandfather Charles Kingsbury (my Dad's father) had a brother who was an executive at Firestone and I know that the bike did sport a pair of 30”x5” specially made 8 ply tires. Whether it was through that connection or as some stories had it firestone was interested in sponsorship I am not 100% sure.

The frame was lengthened and reinforced and is some pictures I will attach here, you can see the bike and its reinforcement pretty clear.

The stock 1934 plymouth engine was rated at 77 hp at 3600 rpm and they got the engine in September of 1934. I know that the 1934 stock Plymouth carb was a carter ball and ball - model 439 which has a 1 7/16” throttle bore and 1 ¼” venture.

By grandfathers notes they built a special carb which had a 1 9/16” throttle bore and the jets bored out. My grandfathers notes, while they could have likely done the machining at work, that Jimmy McNeil sent out the machine work and it could have been to Harry Miller.

I don't know but over time have heard the Harry Miller reference enough that there is likely some substance to it.

I do know the block was decked and 40 thou was removed off of it, and 80 thou was removed off the head. The crank was already balanced coming from Chrysler and they had the rods balanced. The cam was done within Chrysler and had a 375 lift but had the duration highly modified. Yes I know the duration ! tee hee In the end the engine was guessed to be about 125 hp, but what was not a guess was what it rev’d and that was 5300 rpm. Not the 4100 reported in Popular Mechanics, 4250 rpm or the 4500 rpm reported elsewhere. It was actually a mathematical calculation or the rpm, the transmission, the sprocket and the wheel that determined the motorcycle should be able to hit 310 mph which was actually what Fred felt he needed to break the 300 mph barrier.

But I today still remain unsure if it was 300 mph or 200 mph that was the short term goal. I still have a feeling a certified 200 mph run was the goal when it first when to Bonneville.

Ironically in the July 1935 Modern Mechanix on the last page (which I will include a picture of) is Sir Malcolm Campbell endorsing Pyroil after his world record run on the sand at Daytona Beach Florida where he didn’t quite make 300 mph. Over the years that is often attributed to being done on the salt flats but it was instead in Florida. That car weighed nearly 7 tons and costed $200,000 to make according to that Pyroil Ad.

In any case the “Plymouth Motorcycle was finished in April of 1935 and was 115” long tip to tip and weighed just under 1600 pounds, with Fred Luther suited up and on it. By Grandfathers notes, with boots, skull cap and goggles on and the bike full of aviation fuel, 1598 pounds. The bike was taken out on the Muroc Dry flats for testing and later to Bonneville Salt Flats in 1935 by Fred Luther and 5 fellow Chrysler buddies, however my Grandfather was not among them. It seems my mother’s oldest sister Joyce being born side tracked Grandfather ! I believe Jimmy Mc Neil and a Chrysler employee who was a fabricator named Adolph Thuillier who was involved in the Henderson modification were the key "pit crew"

Going back to Jim Benjaminson article -

….“The bike was built over the winter of 1934-35 and made its appearance on the Bonneville Salt Flats in 1935. There, under the watchful eye of the official timers, Fred Luther set out on his way to fame, glory and hopefully, $10,000 in prize money. The rules at Bonneville were the same then as they are today. To qualify for a record you must run the course both directions--down the course and then back again. The average speed of both runs determines whether or not the record has been set.

Laying into the wind, Luther pushed the bike on the first leg of the record attempt and got the bike up to a speed of 140 miles per hour. On the return run, feeling more confident, Luther continued to "open up" the engine until trouble struck--he broke a connecting rod at about 180 miles per hour--the bike was still in second gear!

Bringing the bike to a coasting halt Luther decided he had enough of the record attempt and never again attempted to reach the 300 mile per hour mark on the bike although he always did feel that the Plymouth Henderson X-Miller combination could reach that lofty figure--if only someone were willing to ride it that fast! There were no takers lurking in the shadows, however. 300 miles an hour on a motorcycle in 1935 was indeed a lofty goal. At the end of the year 1934 no automobile had ever attained that speed.

England's Sir Malcolm Campbell in his "Bluebird" race car set a world's speed record of 276 miles per hour on March 7th, 1935 at the Bonneville Salt Flats. Shortly before Luther's attempt at the Flats, Campbell again climbed into his Bluebird race car this time on the 3rd of September, and became the first man in the world to drive an automobile at a record speed of 300 miles per hour-- he just barely made the record, setting it at 301 m.p.h.”

What I do know is the transmission locked between 2^nd and 3^rd gear, something that could not happen in later 3 speed transmissions. Gee I wonder if this was really the 1^st racing of a Plymouth that saw the “field testing” result in changes to production items. The truth is I don’t need to guess here, because I was told by Grandfather that when the tore that transmission down and saw what had happened they made changes to the mopar 3 speed transmission and the ability for the transmission to get stuck in two gears ended with the new release of the 3 speed transmission in the fall of 1935.

Also ironically by the my Grandfathers notes the Plymouth transmission was not the 1st transmission in the bike when they did the Muroc testing. It was the original Henderson gear box, but it couldn't handle the torque and "melted down" during one of the test runs

and then was replaced with the Plymouth transmission. Given I know my Grandfather was not at Bonneville, I believe he may have been involved with the changeover before it got to Bonneville.

I also believe there was not enough capacity or issues with the original Henderson gas tank and it was replaced because it is the only

way I can explain the Henderson gas tank that was later in my Grandfathers shop.

For the fun of it, read through Jim Benjaminson full article at

http://www.allpar.com/history/plymouth/motorcycle.html

It is awesome !

I have attached the pictures from the June 1935 Popular Mechanics article which says

“Auto Engine Drives Motorcycle at High Speed

Assembled especially for establishing a world’s record of more than 300 miles per hour, an oversize motorcycle powered with an automobile engine has been making speed tests on the Pacific coast. The motorcycle, weighing 1,500 pounds, is powered with a six-cylinder Plymouth automobile engine with fan and generator removed. With special timing and carburetor jets, the engine makes 4,100 revolutions per minute. The wheel-base is eighty-five inches and the over-all length is 115 inches, a standard motorcycle frame being lengthened and reinforced with steel tubing. Two large sprockets connected by a three-quarter inch chain facilitate steering, the handlebars having been moved back several inches from their original position. Two steel plates, one on each side in front of the rear wheel, serve as brakes by actual contact with the ground or track. They can be raised or lowered by a lever.”

I have also attached the pictures and article from the July 1935 Modern Mechanix

To be continued in part 2 of the story.. lol.. because that is all the pictures I can attach to this post !