View Full Version : Is Steve @ VL Heaven starting a ton-up Club?
03-19-2004, 01:28 AM
Speaking of Steve (Euro Chapter) I was really floored by his lates newsletter. He was cursing a bit about the lack of input from members. But MAN! He did a great job! I wonder if Steve could put some of that up on the bulletin board here -so everyone could read it. I really enjoyed the ton-up action. I love the guy! He's crazy! And the 1930 Husqvarna racers. Well pretty much the whole edition. It was great. Dare I say - it was too good.
Great job Steve!
04-05-2004, 07:22 PM
So where can I read what Steve wrote?:D
04-19-2004, 01:10 PM
Steve has very kindly emailed me back with the story and a photo. Great stuff. Thanks Steve! Re post from Euro Chapter newsletter. Below. Photo attached bottom.///
100 mph on a VL by Steve Slocombe, European Chapter, England
1999 was the seventieth anniversary of the launch of the Harley-Davidson VL side valve Big Twin and when browsing through some old ‘Enthusiast’ magazines, I came across a photo in the August 1933 issue. The caption reads “104.04 miles per hour! Jim Underwood, Los Angeles, established this new stock machine A.M.A. Record with his VLD at Muroc, Cal.”. The VLD was introduced as a premium priced sport solo bike for the 1933 model year starting August 1932, with the main feature being the new Y-shaped inlet manifold which gave the bike an increase of 20% in horsepower (all above 3500 rpm) to 36 bhp at 4600 rpm. We can see the longer inlet on the new VLD cylinder by the rider’s right knee. The bike has a 1932 style headlamp, so could be a factory prototype put together to see how the new engine performed.
Sixty-six years later I thought we should be able to manage 100 mph on a VLD again. We have the advantage of higher octane fuel, better lubricants, and some knowledge of the methods used by Harley tuners such as Tom Sifton in the 1940s. Looking round the garage I found the 1934 frame I traded for a new-old-stock ULH cylinder at the 1998 Davenport show, a set of rebuilt forks that had picked up a ding in the front section, the leaking gas tanks off my ’33 rebuild, a pair of wheels with new but non-matching tyres, a pair of cylinders on maximum oversize, and a pair of heavily pitted high compression heads. I had some flywheels rebuilt and sent off for dynamic balancing, told the engineers to mill down the heads as much as they could, had the cylinders bored with a big 0.005” piston clearance and the Sifton gas flow channels put in between the bore and the valves, then put the whole lot together in a pair of 1934 engine cases.
The VL cams are very conservative, with the same ones used on sidecar and solo bikes, and almost no valve overlap. I found a rough set to be reprofiled and these came back as ‘street/race’ cams. The engineers had taken an astonishing 3 mm off the cylinder heads so they were down to 107 cc each, which with my oversize swept volume of 1278 cc would give a blistering 7 to 1 compression ratio. I’d put in hardened exhaust valve seats, so the bike would run on regular unleaded fuel. The engine had been rebuilt with racing bearing clearances and spun easily on reassembly. I fitted a 1932 vintage bronze M2 Linkert carb fitted with the 1 1/8 inch venturi from the first 1935 80 cu. inch bikes and, as a vanity touch, two 50 year old used Harley spark plugs. The bike started first kick after rebuild, and I had gone from loose parts to street legal in just a couple of months! I spent June and July putting 300 road miles on the bike, and noted how cool it was running and how much midrange pulling power it had. With the optional extra high gearing with the 25 tooth drive sprocket, it did not run comfortably under about 40 mph in top. The suicide foot clutch and jockey shift made for relatively quick gear changes, when not missed through lack of a shifter gate and wear in the mechanism.
Now I joined the Vintage Motorcycle Club Sprint Section and signed up for the August meeting at Wroughton airfield near Swindon. I was able to enter both ‘Pre-war’ and ‘Street Legal’ Classes, and booked a dynamometer session to make sure the bike would do its thing on full throttle. The operator calculated 37 bhp at the rear wheel at 90 mph/4000 rpm and we cranked the bike up to 100 mph on the dynamometer, which corresponds to 4600 rpm with 3.72 to 1 overall gearing and 19 x 4.00 tyres. So I was pulling 15 or maybe 20% extra power with my reprofiled cams, higher compression ratio, and gas flowed barrels. Time for the VMCC Sprint meeting!
I took the bike down on a beautiful Saturday in August to Wroughton airfield where, as the only American bike and the only side-valve present, the Harley got plenty of attention.
The bike had been given race numbers 33 and 34, so what better start could I have for a VLD? We walked the one mile runway to pick up stones and litter, and I could see the first couple of hundred metres were actually slightly uphill, and a light breeze would be blowing in our faces. Next was the scrutineering, where bikes, helmets and racing suits were inspected and then we were ready. I was holding back somewhat on my first run, but recorded 35 seconds and 80 mph for the kilometre which was a reasonable start. However, shortly afterwards a Douglas drove into the timing gear so that was the end of terminal speeds for the day. I did a couple more runs, fluffing the gear change, then changed the race numbers and competed in the street bike class.
Next day we were back with different timing gear for the quarter mile and with a larger number of competitors. I had no problems in staging or pulling away, but missed a lot of gear changes from slop in the shifter and ended up changing straight from first to top. It didn’t make a lot of difference though, and 19 seconds/75 mph was a reasonable first effort. The sheer exhilaration of blasting down the track hoping everything holds together is a great feeling, and the friendly welcome from other competitors means first time entrants should not be intimidated.
04-19-2004, 01:11 PM
My main problems were sloppy gear change, remedied by fitting a new-old-stock shifter tower I picked up the following month at Davenport, and expensive noises on the overrun, which turned out to be the rear exhaust valve touching the head and which was fixed with a shim under the cylinders. While the cylinders were off I had the inlet ports and manifold opened out 0.050” to improve breathing. I also weighed the bike at 202 kg (445 lbs). This is 38 kg (84 lbs) less than the standard weight, and 140 kg (309 lbs) less than a modern Harley, explaining why the VL can more than hold its own in modern traffic. For this first season we saw 100 mph on the dynamometer but not on the track, so for next season the plans were open exhaust pipes and fit the ride control as well as the steering damper to steady the front end.
2002 Sprinter update The ride control went on, but I never did fit the open exhausts, as it’s nice to keep the bike (just) street legal. The tanks were changed for a new set in 1934 teak red and black paint. First I put on a prototype speedway silencer, and then a specially made larger diameter straight through item. The rear cylinder head cracked after the first season, and the front after the second, so both have been replaced with stock 5.5 to 1 compression ratio heads. The gearbox jumped out of top gear on the overrun at the end of the first season, which was due to rounded shifter dogs on the slider gear. The gearbox was rebuilt, and checked out again when the worn out clutch linings were replaced after two seasons. Sprint gearing has come down from a 25 tooth engine sprocket to 23. This season I fitted cadmium plated wheel rims and Avon AM18 street/race tyres with a slightly lower profile, thus reducing the gearing again. In my first season my best result was 19.0 seconds/75 mph for the quarter mile, and this year I managed 16.6 seconds/80 mph on a bike that is pulling more strongly and better geared for the event. Next season I think one more tooth off the drive sprocket will be enough, and I can save weight by installing that lightened 80 cubic inch flywheel assembly I’ve put together. If I can keep improving at 0.6 seconds per season I’ll be competitive in a couple more years...
2003 update This year I heard about an annual run on an airfield that allowed both quarter mile sprinting and maximum speed attempts. I fitted the lightened 4.25 inch stroke flywheel assembly - dynamically balanced with a 46% balance factor - which brought the swept volume up to 1358 cc /82.8 cubic inches and the compression ratio on my nearly stock iron heads up to about 5.6 to 1. I had read that gas flow was more important than compression ratio on the flatheads, and also that the old Muroc Lake speed runs were performed in one direction only, and probably with a following wind. So as long as I stayed street legal, I was comfortable stretching the definition of ‘stock’. I fitted the titanium valves I had had made in California the previous winter, which are 50 grams each lighter than the stainless ones I’d been running. This time I had to fit a rear chain guard and a handlebar mounted kill button to meet the race regulations, and also wear a dog tag with my name, date of birth and blood group - this was serious! I fitted the Kevlar clutch linings bought at Oley and the 25 tooth ‘speed’ drive sprocket, and put the bike on my new local dynamometer, having moved house since the last dyno runs. The bike roared away, pulling strongly over the rev range and showing about 36 bhp at 4600 rpm - just like the 1934 brochure figures, except at the back wheel rather than the engine.
Next morning, 16 August, I arrived at Woodbridge airfield in Suffolk, another of those disused Ministry of Defence properties open a couple of days a year for special events. After scrutineering, we lined up to take our turns along the full length of the runway and into the speed trap towards the end. There wouldn’t be many runs that day and I wasn’t going to spare the bike. My first run was timed at 99 mph, so I removed the front plate carrying my race number, thinking this would reduce wind resistance. But the second run was also 99 mph, so I was maxed out at 4800 rpm and past the peak power point for the bike. In fact, I was repeating Connie Schlemmer’s 1935 run, when he told me he took a 1933 VLD to 99 and 97 mph speeds, timed with trip wires and stop watches one weekend.
Now it was time for quarter mile sprinting, so I changed to a 22 tooth drive sprocket and had three runs at that. The ’34 managed 16.5 seconds/81.2 mph terminal speed into a slight headwind, so this is the gearing I shall use for future events. But then I heard there was to be a short top speed session in the afternoon, so I stopped sprinting and brought out the big guns - the 27 tooth drive sprocket and 92 link chain I had had made a few months previously.
Down to the end of the airfield to line up, wait for the signal, then cane down the runway centreline to end up between the chequer boards and into the speed trap. I returned to the control hut to pick up my ticket, and found I had done 102 mph. Yes! Four years tinkering and trying to find suitable venues had finally paid off. A Hayabusa had hit a crosswind and clipped the timing lights at 220 mph, so there was a delay followed by a call for a volunteer to check the set-up. That was me as the sun headed downwards and the day came to a close. The go signal, drop into first gear, plenty of revs, change gear and max it out (70 mph in second!), then the long build up in speed as I tried to tuck myself even more into the bike and make sure the throttle was wide open. It was 103 mph on that run, and no time for any more. There is the electronic ignition to fit, and those aluminium heads when they are finally done, and a little more compression ratio should give more power without strangling the gas flow. How about separate exhausts, or re-tubing the frame in a lighter material? Next year 104 mph would equal that old Harley record, and 105 would beat it. In the meantime I’m satisfied to tick off a goal that took four years to achieve, and look back with increased respect to those throttle snappers scorching across the California sand seventy years ago.
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