Excalibur snatches the win at Comp3 1/8mile "Night of Thunder", Fram Autolite dragway, Meremere NZ!! The bazaar sequence of events that enabled Excalibur to seize the championship lead began when championship leader (Greg Pratt) failed to turn up. Excalibur started the twilight meeting struggling with air shifter gear change issues, however luck went our way in each of the elimination runs. Also we were top qualifier. Before the final pairing against Ian Hilder's "Rice Rocket", the Prostock bike suffering ECU problems eventually failing to make the start. This forfeited the winner's trophy to the Triumph with Jamie only needing to appear, which he did with a convincing 6.87 @ 97.6mph for the 1/8mile.
Pic taken at earlier Meremere motorcycle drags 2014
Jamie staging at twilight
The engine was fitted with the thinnest head gasket I made from an old copper toilet cistern!! It's about .015" thinner so the compression will be approaching 10:1. The pistons required relieving at the squish band for a 1mm clearance. Also the inlet valve-clearance-to-piston was tweaked.
A rare new-old-stock pair of +.020 10.5:1 compression pistons was purchased. The downside is that they are 1mm (.040") smaller than current so engine capacity would decrease but the extra power from added compression would more than make up for it. Another issue is finding a barrel set at std (or +.020 in good condition). Naturally I'd be cutting the fins off. Ideal would be a fin-damaged std barrel that could be freshened up to size.
The air shifter proved to be quite a battle with a variety of ECU settings trialed. Kill time was progressively widened, more/less leverage, lubricated clevises, larger air line, etc, all to no avail. Finally the drive chain was tightened up tighter than any normal rigid road bike would be. The advise received was to make it tighter than would seem reasonable. This appears to be the solution at the time of writing.
Lowering the footpegs showed decided advantages. It allows staging of the bike in the absolute vertical position unlike previous "lean to the left" posture nicknamed "tripod". A minor issue is the clutch drag which becomes an issue in the higher rev range. With toes on the ground and heels on the pegs, it doesn't allow much holding of the bike from rolling forward. Hence lower staging revs are used. Lowering the pegs still further is being planned.
Planned upgrade before Comp4 at 2March is "oil-in-frame". The upper right frame tube will be utilized as the oil tank with strainer, filler cap, return line, breather and sight-level-glass fittings.
Ironically, an original ('71-onwards) Triumph 650/750 uses oil-in-frame so it's a kind of 'retro fit' in a manner of speaking.
Can Excalibur win the Compbike championship, leading the points with one round to go? Check back shortly for official points tally and at 2March for championship result..
Please see Excalibur Facebook page: https://www.facebook.com/ExcaliburTriumph
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