I believe my norton could do 150mph easily if I rode it over a cliff. I found the comment about the cams interesting. I built my Seeley in about 1978, about the time I stopped racing regularly. When it came to the camshaft department, I simply walked into one of the race shops in Melbourne, where I knew they had a nice new cam grinding machine. Chucked the old cam on the counter and said 'just give me your best norton grind' - knowing that what ever that might be, I could probably get sense out of it. When it came to timing the motor, I heated the sprocket to soften it, and had two more keyways broached in. The initial timing looked as though the cam was combat profile, and because I am using a two into one exhaust, I advanced it 15 degrees from standard combat settings. It means that the exhaust closes early, but with the pipe the result is excellent. For the last ten months I've been stuffing around fitting a six speed box to the bike. When I had the fight with the sprockets and chain adjustment, I believe I must have ended up one tooth too high on both the engine, and gearbox drive sprockets. Day before yesterday, I took it to Winton Raceway to fire it up and get sense out of it. After a lot of stuffing around, we finally got it going, and I decided t o ride it around the pits. I had fitted the gearchange lever too low, but I am certain I was in first gear. The gearing was absurdly high, but the motor still pulled it. I gave it a short burst down the next pit lane which was empty, then back up the next, slipping the clutch to get it going. It took off like its backside was on fire and for a split second I thought I was going to take out the fence at the end of the lane . I grabbed a big handful of brake. When I raced the bike for the first time years ago, it was over revving but going nowhere, so I upped the gearing to knock its backside in, - it simply went faster. The effort the other day amazed me, I would not have thought it had so much torque. One thing I believe in, is that the table in Phil Irving's 'Tuning for speed' is a good guide towards optimal timing, especially as it lists the 1959 7R AJS which was probably the best 350 of its time. I've used a two into one pipe on my short stroke Triumph 500 years ago, but had the advantage of separate cam shafts for inlet and exhaust. I learnt a couple of things - the tail pipe must be as big as the total area of the two header pipes, and opening the exhaust before 85 degrees before BDC makes the exhaust louder, and the bike slower.
I know all this stuff will sound crude to you guys, but it actually worked. I've only raced the bike a few times about 8 years ago, but first time out I won a couple of races at the old farts meeting at Mount Gambier in South Australia. It has been difficult to ge t off the line with the old four speed CR box - hence the new six speeder is now fitted. The boxes with the high first gear were great when we had push starts years ago, the se days everyone uses five speed boxes with a very low first gear for the clutch starts.