Having run the 1967 Triumph T-120 Bonneville on the salt last fall and run afoul of a cosmetic technicality, the suggestion was made by the tech officials to return and compete in a less-constrained class. Being the free-spirited types we are, the decision was made to go back with a similar bike in class to the Ducati we ran last year and are returning with this October.
The first question was “what”, then “how” and then “why?” Jim Haraughty was the principal of the project, so he elected to stay with the 650cc pushrod format. The logical choice was to stay with the Triumph 650cc pushrod platform. This answered the “what”.
The record he opted for was the A (special chassis construction) Pushrod Blown Fuel. This will involve a chassis built by guess who (the “how”). The Blown part caught my attention as I had just found a cute little 2-lobe Roots-Type supercharger and didn’t want no stinking mufflers or exhaust restrictions (turbos) on this one.
I haven’t built a blower bike in many years and the thought of blown Methanol with a whisper of Nitro sounded sort of fun. Poor Jim’s eyes got about as big as pie plates when the mention of Nitro came up and a visit to Arnie Heller’s shop on a billet aluminum buying spree didn’t help. Arnie is my frame of reference on turbo/gas/nitrous used on the Ducati project but he has always had an aversion to Nitro as being unpredictable and destructive (coming from a guy who replaced cases and cranks every two races with the gas/juice combination that made enough hp to go 219 mph). Discussing his current project and his exposure to Nitro got Jim going, but at the end Arnie did admit that “there isn’t anything like it”.
The “why” is answered by the open record in that class. I guess nobody else has decided it would be a good idea to supercharge a 40 year old engine and take the pains to make all the parts needed to do it. It sounds sort of like building a house of cards in a hurricane.
We returned to the shop with the basic materials needed for the intake manifold and started in.
Then came the purchase of Alan Jelle’s ex-dragbike Triumph lower end and help from Jim Morin in the hopes of preventing a stock Triumph head from splitting like an overripe melon when the boost was applied. This reunited the trio behind the Top Fueler Steve Suter ran to the 1982 championship. That top fueler, by the way, started out as a turbo gasser but wound up as a blown nitro bike, running up to 70% nitro and being the tenth bike in the sevens in the world.
The photos show the billet chunks, intial setup, after facing and the victims lineup on the frame jig.
Next….. Blower manifold construction and lower end preparations.