We got the salt bug. Face it; you gotta do some shit like this before you die!
BIKES, WORK & FUN :
done Sumo's double panther LSR frame in July 2010, and aware that He,
Chris Ireland with his Indian, and a number of other teams were
planning the trip in 2012, the idea must have been bubbling away
subconsciously for a while.
is what we bought. Strictly speaking, its a BVR engine; Brian Valentine
Racing. When Weslake folded in the early '80s, the motorcycle engine
part of the company continued with Ron and Brian Valentune taking it
over. Ron V was very much the driving force behind the companys
motorcycle engine arm. |
The Pushrod Weslake V-twin had been in production for awhile and was sold to sidecar grasstrack racers among other applications. The Valentines along with Ron Jones busied themselves designing & developing new versions of both the single and V-twin engines. Many permutations were made including versions with SOHC, DOHC and SOHC 5-valve heads. Of these DOHC 4-valve engines, I believe 6 were made. The first one was the only one supplied with a gearbox which attached to the back of the crankcase via a 4-bolt flange
With the help of retired journalist and Weslake enthusiast Rob Carrick, some of the original players have been tracked down and much info gleaned. One of the most surprising gems was the fact that this engine was a direct ancestor of the '90s Excelsior-Henderson X-twin.
Anyway, its a 1000cc, Initially I thought it was built for Methanol with about 14:1 compression, but it turns out to be a street motor with 9.5:1 Too high for a blower and really too low for naturally aspirated. Since high-octane race gas is available at Bonneville I'd have been better off with the methanol pistons.
Why not run methanol? well, under SCTA rules methanol means running in the fuel class, which has a considerably higher record level.
The downside of it being overhead cam, is that we have to run against stuff like GSXR 1000s etc. If it were pushrod, we'd only be up against HDs!
The obvious gearbox was the Harley 5-speed. The only other choice would be a Quaife which are megabucks. An Early FXR shell was sourced which was ideal for mating up to the crankcase flange. A pair of 1/2" ally adapter plates were made to set the gearbox high in realtion to the engine. Crankshaft - to -mainshaft distance was made the same as FXR so as to use off-the shelf primary drive bits.
A decision was made for the bike to have suspension - more or less a case of why not! This would allow the engine assembly to mount a-la FXR with the swingarm pivoting on the gearbox. Running rubber mounts theoretically means the frame has to be stronger as the engine cant lend stiffness, but the weight gain caused in this case is negligible; the frame weighs 28 lbs. And in any case, weight isn't a primary worry on the salt.
A set of innards from a late 90s glide was bought off ebay and a Primo belt drive came from Zodiac.
For ease of tuning and basically to bring things bang up to date, I decided to go with EFI rather than carbs. To date a whole heap of components, many from Suzuki TL1000s have been accumulated. Bee kindly got me a Microsquirt ECU for my birthday!
One difficulty was making a crank adapter for the belt drive; but I mananged to machine the internal splines OK by locating it on the minor diameter of the crank
Seemed daft not to have electric start as well since weight isnt a worry, and all the HD stuff was a straight bolt-on. You may think we're getting decadent (!) but it'll make testing and tuning a lot easier.
With the drivetrain in an assembled lump, it was time to think about the frame. Lots of folks consider it a bit of a sin not to put a Wessie into a featherbed frame; and who am I to say its not? So; raked, stretched and lowered, but still recognisably featherbed-like? Coming right up....
But first a swingarm had to be done..
Next, I needed to complete the primary drive. A motor-plate was made from 5/8" ally along with bearing housings, and parts to drive a GSXR alternator via a toothed belt .
The engine has provision to run 2 sets of points on the RH side, one off each cam drive. These are old brit-bike points plates & cams. No good at all!
Since there was a bit of room left, I made a crank trigger setup using Ford crank position sensors and a turned single tooth reluctor wheel.
This started as a £30 ebay purchase. Its a Honda Blackbird swingarm. The front end was modified into a forked configuration to fit the back of the FXR gearbox shell.
The rearend was cut off and new ends were machined from billet with plenty of wheel adjustment to allow easy gearing changes and if needed wheelbase changes.
Provision was also made to mount conventional twin shocks.
With this all welded up, I was able to assemble the drivetrain and swingarm on the jig for frame construction to start.
High-speed straightline action requires a nice chunk of rake, 40 degrees sounded good. The engine assembly was setup a bit tail high. There would be only 3" ground clearance and the swingarm wants to be reasonably horizontal. The main cradle is made of 1.5" x 17g 4130 chrome-moly, the subframe of 1.375" & 1.25".
Big thanks must go to Martin Hagon of Hagon products who have sponsored this effort with a pair of rear shocks. Cheers mate!
Since theres plenty of room under the gearbox, I decided to put the oil tank in there. Its just a basic ally box with a big spout.
One advantage of siting it low is that wet-sumping cant really happen. The engine has no valve to stop oil seeping into the crankcase whilst sitting unused so this cant occur now.
I'm sure the oilpump (which seems to be a modified Commando pump) can draw the oil up an inch or two.
|Forks and wheels were sourced early on. The wheels are also off a Honda Blackbird, whilst the forks are off a CBR1000.|
The rear wheel obviously slotted straight into the swingarm, whereas the forks needed shortening a good bit. I took 4" off the stanchions and a further 1.5" off the damper rods. I dont need 5" wheel movement with 3" ground clearance!
A pair of basic 1" slab yokes were made up along with a pair of clipons. Front disc is an autojumble score, and the front caliper is off an 80s kawasaki.