Seattle Raceway – August 13, 2011
This date was the first time I was to actually race the Excelsior. Yes, I had entered several races previously, but never finished a single one; always some issue, usually related to the lubrication system. My confidence in the bike was pretty low.
At the previous race weekend, I completed a whole practice session, a first. In the race, my $5 ignition switch quit, but I had new hope because the lubrication system continued to work well.. Back in the shop, I put in an $8 switch that was sold to me with the understanding it would NEVER fail from engine vibration.
August 13. It’s the SOTP Big Vintage weekend, and there are (7) 750s and (2) 350s in the Big Class. In practice, my bike sometimes has a false neutral shifting down from 4th to 3rd, and it never happens at a good spot. If I shift carefully, it doesn’t happen. The rear brake is also a little too sensitive, and locks up if you’re not too careful. Both things happened on the first lap of race one, so I backed off a bit. It was fine to circulate on my own. On the straight the engine pulled slightly over 5 grand in 5th, which is 120mph. I have a fairing on my wish list…
Ruby, as I have named her, handles quite well. I did have to get used to the front end being quite light, and my hands really hurt a lot after the first practice session, probably from hanging on too tight. In all, we did two practices and two races. Best lap was a 1:54. She’s good in the corners; stable but agile. No wobbles, but definitely light under acceleration. She pulls well too. Off the line, starting from the 2nd row, I reached turn two in 3rd place before the pack closed in!
Sunday AM. I was checking her over, and one of the rollers in the rear rocker arm was not happy. I should have been oiling them before each session, but I needed an oil can with a specially bent spout to reach the rear rollers, and didn’t have one. It’s much easier to oil the front rollers, and both of those were fine. Learn a little each time. Next Seattle race is on Sept 10-11.
Seattle Raceway – Sept. 10-11, 2011
Ruby Racer is having problems, but they’re not her fault. For example, I didn’t properly oil the rocker roller, and this is what I get. The ones that are easy to oil (the front ones..) are fine. I had to un-torque the heads to change the rockers, and I thought about changing the head gaskets, but reasoned that if I didn’t actually take off the heads, I didn’t have to… BAD call! I got two laps at Seattle before the head gasket went (and it was such a nice day too).
I have just figured out that I don’t have to actually remove the entire motor to work on the top end. The engine hinges forward and down from one bolt.. All the oil lines and electrical are intact. So much easier . . .
Here is the head gasket that let go. I must take spares to the track. Next race is Oct 1-2 at Seattle.
It’s the last race of the season. Stay tuned . . .
Seattle Raceway – Oct. 1-2, 2011
My race motor is very similar to the boardtracker motor, except for 12.5:1 pistons, Spanish Amal carb, electronic ignition, and tuned pipes. On the dyno it had 70.9 rear wheel HP at 6000 rpm. This is likely 85 engine HP.
I had a lot of grief with the lubrication system. It worked fine bench testing on the milling machine, even 15 continuous minutes on the dyno, but would stop scavenging on the track. I would come home, strip it down, modify, improve, and test again.. I think that, if someone were to ride Excelsior 004 down a road and back again, for example, the lubrication system would probably work just fine. With no brakes you would be careful, and the single speed wouldn’t allow huge acceleration. You would be duplicating the dyno, basically.
The oil passages are in the crankcase walls, to keep the historic external look. I made them almost 1/4″, but they need to be bigger for racing. With transmission, brakes and a clutch, I can get some G forces to move the oil around inside the crankcase on a racetrack. This is where the stock scavenge system can’t keep up. The photo (of my race bike motor) shows the bevel drive, oil pumps, oil filter, and a small part of the external oil line to the squirters. At the bottom of the crankcase is the “oil well” and external scavenge line. This is what I arrived at after two seasons of development. It scavenges very well, and oil pressure is usually 40-50 lbs using 10/40 oil.
This is Ruby Racer. Basically, the oil from the tank flows down, enters the oil pump, is pressurized, and immediately leaves the engine case, where it goes to either the oil filter or the pressure relief valve (safety wired to the filter..). If it goes through the filter, an external oil line takes it up to the squirters that will never plug up. Oil going through the pressure relief valve is sent back to the upper oil tank. There is less oil to scavenge. The pressure relief valve is adjustable; even while the motor is running! T his system works very well.
Last race of the season at Seattle in 750 Vintage, I got the holeshot (there were 4 of us..) and led for almost a lap until the head gasket let go. The rear cylinder rear studs are slowly pulling out of the barrel. I will install Timeserts, and solve that problem too! I’m really excited about next season. I think Ruby Racer is going to do really well.
Watch me Go!