SCOTT GUTHRIE REMEMBERS:
50 Years at Bonneville
Chapter #28
Helping Harley Photo - Leading edge Promotions. HOW could ANY Harley Davidson owner and rider NOT recognize the intrinsic connection between a thundering V-twin motorcycle and a Bowling ball ?................nope, me neither.
In 1969, Harley Davidson Racing was in a bind.
The overall motorcycle sales business was not doing well, and Harley had been sold to AMF; ?the Bowling Pin Company.? Detractors said that the new owners brought all the forward-looking technology of bowling pin manufacture to one of ? what had been - America?s most iconic brands.
The Harley factory racing motorcycles were still winning races and national championships, but the handwriting was on the wall. The little bikes, like the 250cc sprint, a pushrod operated single cylinder, had to compete increasingly with Japanese multi-cylinder 2-strokes, but with diminishing success. The Iconic KR750 racer was a flathead, which would soon have to compete with equal-displacement overhead cam and 2-strokes.
It was NOT a path to continued glory.
In the late 1960?s, I had started converting a 900cc Harley Sportster from iron to aluminum heads and cylinders, using European parts. This conversion offered a better bore-to-stroke ratio, and the cooling ability of the aluminum alloy. Also, if used, replacing iron cylinders and iron heads should have resulted in a 35 pound weight savings.
My design, by varying bore and stroke, would allow any displacement from 750cc to 1,300 cc. Any length stroke from around three inches to five inches could be installed, and any bore from as little as two and one half inches to almost four inches ? Chevy small block numbers.
That would allow the design to be used from 750cc racing up to full road-going touring bikes. The result looked a little like a combination of a Vincent Black Lighting and a Sportster.
In 1969, I showed the work to the Harley racing department, and they liked the basic concept. By 1972, - three years later - the new Harley XR750 embodied many of those concepts, and it was immediately a race winner, and it remained so for 40 years.
I had considered using my ?special engine? for my Bonneville efforts, but it would put me in a ?tougher? engine class; something I was unwilling to do at the time. However, the overriding reason for not using my ?special? engine was that Harley was unwilling to sponsor me if I used ?too many visible? non-Harley parts.
Photo -Brian Eriksen would power his modified Yamaha RD350 street bike to a 350cc record on gasoline of 159.895 mph ? which still stands, and is faster than any record set be a factory 350cc RACE bike ! Racing pal Ron Acers helped out for many years. My Harley ? borrowing Ellen?s low bike number five (5)- with 1250cc never set a faster record than Eriksen on the 350cc Yamaha.
Is there a lesson in that ?
Through the years, I had grown closer to Brian Eriksen, who had a sharp wit, insightful mind, and a true gift for running 2-stroke bikes at Bonneville He had helped us with all the engine problems that Ellen had experienced last year?... His success with racing pal Ron Acers with not without it?s low moments, however???
2-stroke tuning at Bonneville in the 1970?s was never easy, what with changing air density, temperature and humidity. After good success in prior years, Brian was a little befuddled with his tuning questions in 1977, and was NOT setting records.
For the first time in my memory, SPEED WEEK was NOT being run in August, but in October. Tuning notes from prior speed weeks were almost useless.
Brian was also without the help of his school-teacher wife, Diane. Since Bonneville fell during the school year, Diane stayed home, and sent Brian off with Ron to fend for themselves.
After my crankshaft failure, I devoted my time and meager tuning skills to helping Brian with the Yamaha RD350 street bike.
Photo ? Brian and Diane Eriksen in 1976. Primary sponsorship from Puerto Rican Anti-Defamation league with assistance from Bikers For Buddha. Thoughtful streamlining of humble Yamaha RD350 street bike helped show almost 160mph from 350cc. and pump gas. Chiavaroli supplied fairing and handle bars. I loved the bars, and used them on a lot of bikes. Trick rear fender under seat MAY have also been forbidden streamlining. Does the familiar #66 number plate partially conceal the rear wheel and tyre? Despite ordinary beginnings, under Brian?s hands, this became a VERY sophisticated Bonneville tool; even Don Vesco came over to compliment Brian. Rearward seating position no doubt helped avoid tire-spin on soft or loose salt - always a problem at Bonneville
In those days, making long distance calls from the hotel room was outrageously cumbersome and expensive, and cell-phones were not yet invented. The most economical solution was to use the pay-phone booth near the Stateline hotel.
After a frustrating day at the track, Brian gathered a king?s ransom in quarters to call Diane at home in the evening after school. Brian had cleverly gathered with him both carburetors, both spark plugs, and the spark timing numbers. To Brian, the speeds and the plug readings did not make sense.
In the cooling evening air, Brian explained to Diane the findings. Diane had a good mechanical head, and actually had already patented several inventions.
She ?got? motorcycles.
Brian discussed how he had changed the running, and how the plug readings made no sense. The plugs looked like he had made no changes, when he actually had made changes. Actually, BOTH plugs looked ?off? by the same amount.
As Brian and I ?shared? the receiver, Diane thought through the problem. We could actually hear her mind clicking??..
After about a minute she said: ?THERMOSTAT !,? and hung up.
We stared at the dead receiver for a moment, and went to bed???..
The next morning, Brian heated a pan of water over a camp stove in impound, while waiting to be called to the start line to run for record.
As the water heated to boiling, the offending thermostat in the water NEVER opened ! The thermostat failure blocked 95% of the water circulation through the radiator, and the bike overheated on EVERY run. No WONDER the plugs looked the same, the engine was NEVER running properly !
With the thermostat removed, Brian promptly ran almost 160mph with a little 350cc street bike, and set a record that STILL stands after 40+ years.
Afterwards, we referred to Diane as ?Dial-A-Tuner?
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Ellen Guthrie Collection ? the Harley in inspection. Grass in the foreground and cement surface tell this as one of the years inspection was at the Wendover airport. This allowed teams to unload their trucks, pass inspection, load back up, drive to the track, and unload AGAIN !, all in 8 hours??Wire spoke rear wheel mounts the Firestone automotive rear tire. Increased ?coverage? of fairing probably helped raise speeds. My lowest entry number of the Harley years. Later years would bring a number one to my bike.
Photo - Ellen Guthrie photo: The mysterious Firestone car tire on the back of the Harley XRTT. I had taken a stock street hub and put a sprocket in place of the stock drum. That required a disc brake on the other side. Machine work was involved. I found a narrow (3.5?) VW car wheel, and cut out the center section. Banged it as straight as I could with a hammer and my primitive equipment. Sent the rim and hub to Buchannan?s shop, who dimpled, drilled and chromed the rim, laced with special spokes, and returned the wheel with everything trued up. Traction may have improved. We know this photo is before passing inspection because there is no A, B etc. I had visited Parnelli Jones in LA, and bought (from him PERSONALLY) the LAST two ?roadster fronts? in existence, to use for this project. Later, I would sell those tires to Gordon Hoyt for his successful campaign to` join the Bonneville 200 mph Club.
Photo - Ellen Guthrie collection: Last year of the ?Door Handle Dangle? for me !. Later model Dodge B250 replaced beloved but ?cancered? Dodge A100 van. I liked the 318V8 and automatic ! Poor handling car tire on back of the Harley was later replaced with proper motorcycle racing tire, I am off to another (unsuccessful) run. I had planned on going to turbocharging in the future, and had formed a company for the purpose. Named it ?Inductive Energy.?
PHOTO ? Years later, my beloved old van ? painted in the Harley racing black and orange over white was reported in some desolate junk yard, rusting quietly from it?s incurable exposure to the salt of Bonneville. From then on, no more time ?wasted? on fancy paint for either bike or vans ! Time and money better spent on going fast was dear !
I was finally able to accept that, for me at least, this bike was days of future past. The bike, in that displacement, was as good as I would get on gas ? normally aspired.
I continued to think more about turbocharging.
PHOTOS: In the original articles, lovingly published by Wendy at the BONNEVILLE RACING NEWS, there were PICTURES !...It is a little too cumbersome for me with my 75 year old pre digital brain to post those here since it involves photobucket and things like that. IF you go to my facebook account, the pictures are attached to THAT version of these articles..........https://www.facebook.com/scott.guthrie.3154.........