Velocette KTT 1079
October 2015, Phil Price tells the back-story on the Velocette MKVIII KTT 1079.
Factory records only note this machine, quite late in the production of post war MKVIII KTT’s was a new export direct to Melbourne, Australia. Not much has surfaced about its history between then and my acquiring it at a Bonhams auction on the eve of the Rugby world cup final, hosted in NZ 2011. Eldee2 has taken most of our enthusiasm since then but this year the dust was blown off 1079 with the intention we always had for this bike which was to develop it a little more than the famous and well documented 1041 from Arthur Wheeler.
The few connections I have made into Velocette folk in Australia tell me Leo Andrews, the owner and restorer of this KTT for some 3 or more decades and who’s estate was being auctioned that spring day was a fine, capable, and knowledgeable chap. Certainly the bike appeared to be correct with all essential bits there, evidence of many hours spent on detail fixings mostly correct. As per usual on Velocette restorations the visual appearnce of the bike was let down by the seat, guards, exhaust pipe, and bars. So while Nick Thomson set to on the all important mechanicals I appointed myself on getting these details more as they should have been in the day.
Among the many developments the factory would have learned in racing KTT’s over the years, was to get weight out of the front, and for that matter both wheels. An early magnesium item on a racing Velocette is quite a piece of engineering, light and effective. The rear conical hub on the Big Velo MT5001 (the first works 500 from 1934), for example has a magnesium cone with an aluminium plate at the big diameter drum and drive side, with a smaller aluminium ring on the small end, both taking the strain from the spokes, while a steel cylinder holds and spaces the bearings. In a recent restoration of this item, including relacing back to a Dunlop style black painted steel rim we were simply staggered at its superb condition after all these years of racing. Many of which would have been on rough roads (can’t imagine the Waiheke Island TT would have been a smooth surface) and it’s a rigid rear end. All good evidence of just how fit for purpose the engineering design was 80 years ago!
One of the few incorrect items on KTT1079 is the front hub, a well made and correct looking item but rather unfortunately the replica is made in Aluminium and what kind of wall thickness?! Looks good in the museum and would have easily satisfied the decorative requirements of the Coleman replica brigade but too heavy for precise high speed steering, and if there was any useful suspension to speak about… (more on this later) just more unsprung weight. Now we all know that a standard MKVIII was no lightweight, a big girl at 340lbs and one of the reasons the 7R and 350 Manx went ahead in the 50s, along with Veloce’s insistence on persevering with the sweated lug style frame construction. Their original wheels however are a thing of beauty. This unsprung weight saving regime extended to the front guard, a long slender aluminium item, attached with flat aluminium bar stays and old fashioned one piece aluminium rivets.
Studied students of the ‘K’ motor evolution will know that the earliest version sported roller followers on the cam end of the rocker. Percy Goodman dispensed with these due to a lack of reliable oiling from the pressurized timing chest and bevel tower system, instead substituting the roller for a hard skid pad running direct on the cam. This system along with the threaded adjuster for tappet clearance is something of a disaster that the factory had many goes at upgrading. Even the most one eyed Cammy Velo Fellow must concede to cam wear being a big problem. Nick had developed roller followers for the push rod engines some years ago with great success and saw an instant opportunity for a sensible upgrade here and did what he had done previously on the Arthur Wheeler KTT by way of making an aluminium rocker, rocking on needle rollers. At the cam end of matters a small needle roller running on the cam, and for the valve end a 6mm flattened ball running in a socket machined into the rocker with the flat on the valve head ala NSU sportmax practice, the small flat controls the tappet clearance and is simply ground to achieve the desired tolerance. Cam profiles worked back through the new mechanism using the valve openings and degrees of crankshaft rotation to achieve desired timings.
So 1079 gets this full treatment along with a Carillo connecting rod, for insurance, and a six speed cluster from Nova. Compression ratio of 10:1 is achievable as a first base with the piston as supplied. We intend this engine to run on methanol from the off through a GP5 carb.
The other great leap forward Nick has developed over the years is a belt drive primary which we now have running on more than 8 racing velos and never one incident. We have seen a couple of other variants but tell folk till we are blue in the face that the only trustworthy belt is the Syncroflex AT10. Nick makes a one piece hard aluminium front pulley, and when I say one piece we are talking internal spline and retainers for the belt, a very good example of a beautifully hand crafted item that is simply right because he wants it to be so, not cost effective in time or material but also and more importantly no mechanical joins or bits to fall off. The clutch has a similar wheel with a few stages of evolution but all use an after market Suzuki plate and thin circlip to retain the big central bearing. To date he has used original backing plates and extended the tongues, along with standard style spring holder and threaded adjuster nut, although there is now talk of alloy items here and less moving parts in the adjustment. I’ll attest to these clutches really being something with the front wheel of Nick’s Venom often leaving the ground off the grid, there has even an airborne Mac front end in NZ racing mythology!
So we are armed with this new KTT albeit having not fired in more than 30, possibly 40 years to Taupo for its first test. Well its starts readily and apart from being initially too rich in the mid range feels good and has good power from the off. The bike is also oil tight and holds a good line, and here we were a little worried as a replacement front wheel would point to damage and possible bending at the front end earlier in life.
Second time out with a good pull out of corners I find myself faster by 2 seconds a lap than on the Wheeler bike, and with a road compound front tyre that’s alright, the six speed feels wonderful. We are pleased enough with that so after a crack right though the exhaust pipe is discovered following a disconcerting vibration through the footpegs (beware the replica part if you want it to do more than look right—and even this is wrong) we put 1079 aside with a big tick beside it and good feeling about her future.
Almost ready to venture south, one more test weekend at Manfield to come early November.
Archival images and photos: Phil Price and Nick Thomson collections
Photography and Desktop publishing: Shaun Waugh MagentaDot Brands