Team 3UpRacing Blogs

After acquiring another spare engine with very few miles on it, a new winter project is taking shape. We knew from this year’s track and dyno testing that the valve train wasn’t performing at its best. The springs are likely not ideal probably resulting in some valve bounce and float during the closing cycle of the intake and exhaust valve. With the lightened conrods and pistons together with a re-balanced crank, raising the rev limit to 12,000 RPM is another goal. This will only exacerbate any valve train issues.

We felt the best way forward was to perform some CAE analysis to determine what an ideal valve train would look like, and then go back to the dyno for more testing.

The first round of analysis showed clearly the amount of valve bounce on the intake side. The following sequence (one inlet cam rotation) is at 10000 RPM with our race cams. All other valve train components are standard, including the valve springs.

You can clearly see the valve tappet (beige rectangle) separating from the cam and the valve head bouncing off the seat at the closing point of the sequence. To quantify this further, the following graph shows valve bounce versus RPM and you can see that there is almost 0.8 mm of bounce! All is fine until about 8500 RPM. It’s not so good thereafter.

Needless to say, this doesn’t help! It also explains some of the wear issues we’ve seen on the race engine. So, the next step is to use the simulation software to design an appropriate valve spring to eliminate the bounce and float. Given these results, we feel that the 95 RWHP goal is realistic for next season. Afterall, we’re only 3 HP short now!

What else do we have planned for this engine? We considered increasing the displacement to just under 700cc, but decided against it as it would somehow go against the grain. It would feel like cheating somehow.

We also considered using aftermarket rods. The only ones available off-the-shelf are from Falicon. However, these are considerably heavier than stock. Therefore, we’ll carry on with the standard rod albeit lightened, polished, and shot peened. So far, we have had no issues with the standard, so modified rods.

We’ve moved to an electric water pump. This will allow us to remove the balancer shaft completely. Up to now, we had run a plain shaft with the balancer weights machined off. This plain shaft’s only function, thus, was to drive the standard mechanical water pump. After weighing all the components, the electric waterpump weighs roughly the same as the mechanical pump it replaces. This creates a further weight saving from removal of the balancer shaft in excess of 1 kg.

As if I didn’t have enough on my plate, a friend and I decided to get more serious about the amount of effort we put into bikes. He is the one that helped me build the 95Racer and together we now can provide design and fabrication services for just about any motorcycle. However, our focus is:

1. Chassis modifications and tuning
2. Exhaust design and fabrication (2 & 4-stroke)
3. Full race preparation serivces

We recently designed and built the pipes that none other than a certain Stan Stephens runs on his 2-stroke race bike. Stan was pretty pleased with our work and you can find out more on his website

We also had a few of our projects featured in various magazines, most recently in this month’s Performance Bike magazine.

Have a look at our first commercial venture: 2moto

Well, they say that the next season starts as soon as the chequered flag falls on the last race of the current season. The easy decision was going to be where to race in 2009. However, Thundersport GB has just announced that they will no longer run the GP2 class for 2009! Diminishing grids this year can’t escape commercial reality. Shame, really, but alas. So, that leaves us with a bit of a dilema.

Maybe we can get into Derby-Phoenix Thunderbikes, although we really want to run it against GP250 bikes. We’ll see what we can arrange.

Another alternative is to race it with Thunderbike UK run by Ben Shaunessy. This 4lbs per HP (or 1.816kg/rwhp) series would likely accept our unique machine. However, we would have to add over 40kg or race it with a bog standard engine makine less than 70 HP! Hmmm…not sure that will really be in the spirit of the project.

Stay tuned!

Life’s been pretty hectic: new job, family expanding, etc. So, my apologies for the lack of updates. Unfortunately, I can’t promise that the frequency of updates will improve but I’ll definitely try to do better.

Anyway, I didn’t get to race this year at all, again due to time constraints and also a certain engine tuner letting me down very badly. In hindsight, I should have pulled the plug on him at the beginning of the 2008 season.

The bike has continued its development. I was able to improve both on reducing the weight further and increase horsepower. The weight reduction has come from some chassis changes, but mainly on the engine. So, the engine work has paid off on both fronts. The other increase in performance, again weight and power, has come from exhaust development work. Plus, it now easily meets the 105 dB race noise limit.

The latest news is that Performance Bike magazine will feature the bike (presumably next month). The bike was scheduled to be tested by Guy Martin at Cadwell Park on the same day, but unfortunately we had an oil seal let go and couldn’t fix it on the day.

Here is what the bike looks today:

Thundersport GB have scheduled their launch date for Friday, February 29th. The venue is Mallory Park. This is not a race day but rather a day to sort out any niggles, which I am sure we’ll need.

And, of course, we’ll be there with the 95Racer to make its track debut after a lot of hard work over the winter. Now that the engine has undergone more work, it will be interesting to see how if goes. Recent dyno work would suggest rather well, but you never know until you ride around a track.

If you happen to be there stop by and say hello. You’ll know the bike by now. We’ll post our experiences soon after.