1966 T120C TT Desert Racer Restoration - Update 20th August
Following some initial delays waiting for parts to arrive and other third party work, the restoration project is now moving ahead rapidly. Since the last update, the frame has had the tank mount bracket re-welded, together with a Baxter's Cycle sidestand bracket. Grahame has stove enamelled the frame, subframe, yokes, swinging arm and various other brackets and they look great (you just can't beat stove enamelling in terms of finish and durability - personally I feel powder coating is completely inappropriate for motorcycles of this vintage, not to mention the attendant issues with fitting parts because of the thickness of the finish. Worst of all, if it ever needs replacing, it's extremely difficult to strip it off).
John has also re-welded the rear bracket to the spare slimline tank. I'm still undecided what colour to paint this. Initially I was thinking of having it done in Pacific Blue with White Racing stripes, like a 1966 Trophy Special, then a reverse version: Alaskan White with Pacific Blue racing stripes. Then Steve, the previous owner suggested Alaskan White and Sherbourne Green edged with Gold racing stripes. Sherbourne Gold is the colour used on the 1966 T100C Jack Pine 500s and I like the idea of it. I do have the original tank in Alaskan White with Grenadier Red racing stripes, as per the stock 1966 Bonnies, but I'd just like something a little different - though I will be keeping all original spec parts so it can be readily converted back to stock (if I ever sell it to a purist, or if I just don't like it!)
Engine/gearbox rebuild is nearing completion. LF Harris nitrided rods fitted with E3134 cams inlet and exhaust (originally the TT had the same cams as the T120R, E3134 inlet and E3325 exhaust) to give it a bit more power. 9:1 Harris pistons, barrels honed. Original 1-3/16" Monoblocs are being resleeved. Cylinder head is with The Cylinder Head Shop for valve seat recutting, new guides and stainless valves, vapour blasting and gas flowing, expected back this week. Nucleus Classic Elite stainless steel valves will be fitted - these are a technically advanced version of the originals, with different seat angles and improved shaping to promote more efficient combustion. In a league of their own. The bottom end has been rebuilt with new bearings (no cranlk regrind required) and fitted to the frame by Terry. No rebalancing has been performed _ I'm not convinced by the claims of the proponents of dynamic balancing and will just see how it goes.
The RH fork slider which had been cracked, probably by water freezing inside, was irreparable and has been replaced. Forks rebuilt with improved later shuttle valve internals and fitted to yokes and frame. Together with oil tank and switch panel, which required some welding and were repainted by John
Quality standard Girling reproduction shocks have been sourced from Supreme - these will be kept for reversion to standard spec, if required. Custom-made Maxton shocks will be ordered for the bike - these are widely used for Classic racing and very high quality. They also look period appropriate, similar to those originally fitted to the bike when it was a desert racer.
Hubs have been repainted by John and are off at Bob Wylde's for relacing to Devon Rims with stainless spokes - most likely non-valanced alloy ones (though I'm now thinking styainless). Most TT race bikes in the mid to late '60s were fitted with alloy rims. During the US Sales Conference held in November 1966, JoMo requested a '68 model TT with a number of new specifications including alloy rims (the bike never went into production in the end), so I feel alloys are appropriate (and I like the look of the non-valanced ones in particular). (But now I'm thinking stainless - corrosion resistant and built by Devon Rims so have a longer guarantee than either alloy or chrome. Very imprtessed with the quality of the ones fitted to my TR7RV.
Morgo plunger pump has been fitted. This was removed from the 1965 T120C TT which has the standard timed breather following a blown oil seal in the timing cover - the pump may be a bit powerful for this breathing system, The '66 has been converted to the crankcase breather used on the '67 racers and later T140s, which is more efficient and should be fine with the Morgo pump.
Sammy Miller braced handlebars have been sourced and will be fitted - very similar to the kind of bars suppie by JoMo and TriCor and used by the likes of Bud Ekin.