Thursday, August 13, 2015

The Velobanjogent's recent additional Velocette special......

I've been a Velocette man since I was 18 and I'm 70 now and always had a Velocette or two in my shed...several years back my collection was finally reduced to two...a Venom converted from a Viper ( done by "others" and exchanged for the last of my Mk.8 KTT parts around 1996)...
And a KSS/ Viper scrambler framed special I acquired in the US and used on the annual North American Velocette OC week long Rally/rides yearly...usually somewhere in the Western side of Canada or the USA....something I enjoyed for the nearly 20 I attended and allowed me to see much of the wonderful countryside....
  I brought it back to Sydney some three years ago and the two together with a 1987 Honda XBR500 have been my motorcycling "stable" and what I assumed would "see me out" motorcycling wise.....when the two exhausts on the honda rusted out I had a siamised stainless steel exhaust pipe setup made to suit a Velocette silencer, and yes it does sound like a Velo.....
 Until several months ago when a special Velocette friend in Los Angeles, Mick Felder, mentioned that another of our friends in the LA area wanted another KSS/RS MAC framed special to return to Australia from where he purchased it in 2005 following the Centenary of Velocette National Australia Velocette Rally in October that year.
Now I knew the bike and the builder of it, the late Jack Hogan a great engineer, a bachelor and a successful Velocette racer in the 1940's/50's in Australia...in fact he rode the last Velocette to win a title/GP/TT event at Bathurst in 1955...the lightweight NSW  TT on his 250 DOHC Velocette that utilised a cambox from one of the 1936 factory Velocette 350cc racers...Jack passed away some years back aged 90....
I'd helped Mike pack the bike for shipment, obtaining a metal crate frame from Honda to do the job....but first Mike rode it south into Victoria to see Velo friends there and to experience riding it through the Australian countryside. 
Overcoming the import difficulties in Long Beach Port in California, Mike fettled the bike a little to his liking, removing the indicators Jack had fitted, replacing the electronic ignition with a magneto, the generator was upgraded to a 12v conversion with a special "box" enabling the bike to run without a battery as it still does....
Concerned at the time delay for the oil pressure to build up in the top bevel box of the mk.2 KSS cylinderhead and deliver oil to the cams, he fitted a special hand pump into the lid of the oil tank and before starting the bike some 20 strokes of the pump sees some 12 plus psi pressure in this area where a permanently fitted 15psi oil guage indicates the pressure....
Jack built the bike as a 400cc  rather than the 348cc the mk.2 KSS is. He utilised a local tractor piston which resulted in a compression ratio around 7:1.
Mike changed the piston in time and used one from a Ford V8 239cu.in flat head, again the CR is in the region of 7:1.
Well it sure pulls well......
After a months trip by ship across the Pacific it arrived without issue into Botany Bay, the now working port for Sydney....following government clearance issues I collected it and arranged for it to be inspected for historic rego and with plates collected from the RMS and fitted took it for a spin locally...
I then attended to a few small items to suit me...Mike is a tall chap and I altered the footrest position, changed the handlebar bend and rear view mirrors and will change the rear tail light in due course to the later Miller type...more for safety reasons....
come for a photographic stroll with me through some of its history.....
Gordon Harper helps Jack Hogan fettle his Smith framed ( copy of a UK Beasley frame) 250 DOHC Velocette racer in early 1950's..
 Jack in action on the bike...
 Jacks 250cc DOHC Velocette engine shortly after he'd sold it....
 Jack at the 2007 NSW section VOCA, Velocette Display day...
 Jack's 400cc KSS special in his shed......


Mike leaves DQs house for his Victorian trip...note the indicators still on the bike...

The KSS prepares to leave Australia....

Occasional pics by DQ of Mike in Los Angeles with the KSS....
 The KSS back in Sydney in a customs holding shed prior to my collecting it.....

The KSS as it arrived into DQs shed....

 The oil pump arrangement in the oil tank cap....it pumps via pipe visible into the top bezelbox and cams...20 or so strike before starting see 15psi on the guage, illustrated below...it is glycerine filled and this is ideal to stop pointer fluctuations...the reason it is half filled is the air bubble is necessary to stop internal pressure of the glycerine when it heats up affecting the bourdon tube mechanism. Liquids don't compress whereas the air bubble will.

Cylinder barrel specially made by Jack for the 400cc larger bore...
 Cylinder holding down studs are of the same principle as the pushrod Velocettes rather than the normal KSS/KTT  type.

A beer can "has a thousand uses".....
 No battery..its all done from this box...
Nifty aluminium gear lever via Mike and a roller kickstarter cover.

Monday, June 29, 2015

The dynamometers at Velocette......

The dynamometers at Veloce Ltd. 
With thanks to Hedley Cox and Dai Gibberson.


Over the years I've researched the dynamometers used at Veloce for the testing of their Velocette engines. 
They never had a rolling road type dyno so power at the rear wheel was never tested. 
Much of the information we have for certain comes from after 1938 when Velocette built a new test house. 
It is pictured, below when opened by Stanley Woods the factories then senior contracted road racer.. 


Pictured is Stanley woods, with wife Mildred by his side and the giant key for publicity. In the white lab. coat is Harold Willis the race team chief and development engineer, sadly to die a year later. The managing director, Percy Goodman's head is just visible over Stanley's shoulder.
 Following the opening of the new test house, the camera moved inside for a pic of Stanley "operating" the throttle of the dynamometer with a factory 350cc SOHC race engine on test. Harold Willis and Percy Goodman look on.
I've formed the opinion that there was only one dynamometer at Veloce before the new test house which when opened contained three. This early Hennan and Froude dyno had a calibration factor of 5500. The comment below is from 1930 and is by Phil Irving in his autobiography, p.160.



 Phil Irving's Autobiography is a mine of information on what happened at Veloce 1930-1943.... regretably the costs of his out of print book today on Amazon and others is in the $1000 range...perhaps a good library may have one to peruse...
The other two dynos installed  in 1938 were new Heenan and Froude DPX2 dynamometers with a calibration factor of 4500.
What does this calibration factor mean?
These Heenan and Froude dynos were called “water brakes” and utilised hydraulic principles with the power developed by an engine on test being measured in the pull on a spring gauge of pounds (lbs).
So the dyno operator..at Veloce, Tommy Mutton, Frank Panes, Hedley Cox,Freddie Owen, Jack Passant etc…would record pull of the dyno in lbs at a given engine rpm and record the barometric pressure and temperature in the room, which was assumed to be the induction air temperature.
This was recorded in a small notebook and occasionally it would show the uncorrected bhp, that is, not corrected for the air temp. and barometric pressure of the day.
The formula was….

uncorrected bhp = rpm x pull in lbs
                                                dyno constant

 As mentioned, early on 5500 then from 1938 on the new dynos, 4500.
an example for say 1939 at Veloce for a factory 500 is....
uncorrected bhp =6250 x 34.6
                                                   4500
                                         =48bhp
Sectioned 1939 Heenan and Froude DPX2 dynamometer


When Heenan and Froude introduced the DPX2 dyno and Veloce bought two for the new test house, the constant was 4500. The new dynos were called the “centre bench” and it was used for the testing of the works racers and the model KTT, the other was specially setup for the new Roarer engine under construction and pictured elsewhere in this post. The old 5500 dyno was called the “end bench”.

Following WW2 in 1949 the “end bench” was replaced by a new DPX2 dyno by Hedley Cox and the old “end bench” scrapped. 
Up to then following the war the “end bench” had been used for running in new mk.8 KTT engines.

During WW2 Phil Irving used this bench to test special MAC and MSS engines for military use.
 The Roarer engine on the test bench during 1939.
The Roarer engine on the way to the test house during early 1939.
Final construction of the Roarer in time to send over to the 1939 IOM TT where it only completed one lap in practice and was replaced by the normal factory 495cc SOHC  racer. Pictured is, left Percy Goodman, Tommy Mutton on the bike and either Harry Thorne or Chris Lomas.
Tommy Mutton about to start a test of a mk.8 KTT engine on the centre bench  in 1939. The mk.8 KTT engines started at engine nos. KTT801


Tests conducted by Phil Irving in 1940 on 495cc MSS engines for coming  military trials, using the older end bench with the 5500 constant.Details from PEI's notebooks of the time.

Following WW2, racing recommenced in 1946 and Velocette re-introduced their prewar factory racers and continued with the mk.8 KTT, which commence with engine number KTT901
Tommy Mutton continued as the senior race mechanic until around 1948 when following disagreements with Charles Udall, then the development engineer he asked to be transferred to another section of the factory. 
He is pictured below in 1947 with Chas. Udall and a factory SOHC 350 on test on the centre bench.
In 1948 Hedley Cox joined Velocette as a race mechanic and details from his lastest book "A Guide to Motorcycle Racing" published in June 2015, p.19,20 the setup in the Test House at that time....
During 1949 the old end bench which Hedley described as worn out and which had only been used to run in mk.8 KTT engines assembled by himself, Frank Panes and Freddie Owen was dismantled by Hedley and replaced by a new Heenan and Froude DPX2 dynamometer...
Very similar to the prewar design....pictured is a 1960 version.

Following Frank Panes leaving Veloce for New Zealand and Hedley Cox's sacking by Bertie Goodman in 1952, Freddie Owens and a new man, Jack Passant were responsible for the last gasps of the Velocette race effort and the cessation of production of the mk.8 KTT.
Jack Owens went on to become the Development engineer up to the factories liquidation and closure in February 1971.
During this time he further developed the MSS and the Venom and was responsible for the  Venom Thruxton engine.
 Veloce supplied several to teams in the 1967 IOM TT 500cc Production machine race, won by Neil Kelly on a machine entered by the London dealers L.J. Stevens.
A Venom on the centre bench starting a test...
Jack Passant with a Venom Thruxton engine on test
The special VMT engine returned to Velocette after its win in the 1967 500cc class of the production machine race...Jack had it on the test bench....Unsure why there is no reading for 6200rpm, but the uncorrected bhp at 6000rpm is 40bhp.
Neil Kelly winning the 1967 500cc class of the IOM production TT...photo courtesy of Bill Snelling, TT fotofinders.


Monday, May 11, 2015

Jack Emmott's Book of Engines, The AJS 7R, Matchless G50 & G45.....

Back in 1964 Jack Emmott ran a business in the UK that serviced racing motorcycle engines, especially the AJS 7R, Matchless G45 and G50 and he published a little blue cover book on the servicing of them....
I've scanned it for you and feel free to download all or part of it....
The sectioned photos above are from "MotorCycle" or"MotorCycling"...