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Dan Holmes' Bonneville Bullet

Day 4: Thursday September 4, 2008

Thursday was another beautiful day.

There was a slight breeze that picked up into a stronger wind late in the afternoon. The wind is very important and it can affect your time a lot. It can also be dangerous for total streamliners - especially if it is a cross wind.

We made our first run on the road bike and immediately set an AMA record at just over 110 MPH. Our rider (Johnny) was elated with the way the bike performed. If you make the first run in record time you have to wait at the end of the track and make a return run. Then your times are averaged for your final time. The return run was just as successful and we are now in the books!

While we were elated, it was disappointing that this was with the Road Race bike and not the partial streamliner record attempt bike. We are still at 102 on that bike and it ought to be faster than the Road Bike. We have been chasing the jetting and are getting close. There have been long, unexplained delays for much of the past two days so it has been tough to get as many runs in as we'd like.

Since we have the AMA record at a mere 102 MPH in the semi-streamliner gas clas,s we decided to call it good and change the bike over to the fuel class for our last runs.

A bit about the bikes themselves: the road race bike is the most refined since it has been developed over the past 7 or more years. This bike was number one in it's AHRMA Vintage racing class a few years ago and is a "known quantity". It was also raced on the salt at Bonneville a few years ago. Since it was run in AHRMA, it has the original Albion 4 speed gear box.

Glen Kyle, who is a quiet engine builder and machinist in Indiana, has been largely responsible for building both engines and our success is due in large part to his efforts. The road race bike has the European Crankshaft as it's base. As testimony to that crank, it has been on over 25 road races and several speed record attempts with no trouble whatsoever.

We are also using some very aggressive cams. We are running a very high compression J&P piston that has had the top ceramic coated and the sides Teflon coated. We are running it at 12.5:1 which is pretty high for a Royal Enfield. The compression is high enough that it requires a remote starter unit just to turn it over. It also carries an aluminum alloy cylinder barrel to aid in cooling. The head was hand-ported by Dan Holmes and he says that to date he has not been able to replicate it's flow characteristics. The head has our Kibblewhite valves and heavy duty valve springs. We are running an 1-1/2 inch Amal GP carb to round out the fuel system. We are using a basically stock but refined clutch similar to our miracle clutch as well as heavy duty clutch springs and a clutch pad with roller bearings.

Because this bike was at Bonneville before, it was pretty well dialed-in when we brought it here. We have really not touched it other than to run it since we have arrived. The Bonneville bike was purpose-built for running on the salt flats. The fork neck has a pretty substantial rake on it. It is set up as a rigid frame. This is done because, first of all, the amount of time you are on the bike is limited and with a swing arm moving up and down your chain is lengthening and shortening with this motion. In the fuel class, we use a magneto for the ignition so we do not need any battery. This engine was built up from an ES engine so it does not require a remote starter, but we do have to bring along a power cart to start the bike at the starting line.

We have two engines for this bike (more about that later). The engine in the bike now used our blueprinted crankshaft with the Carillo rod and Alpha bearing. Our second engine for the speed bike also has the European crankshaft in it. They both use a J&E piston and carry about 12:1 compression. We will be carrying a lower compression version of that J and E piston in our store soon.soon. Both use an alloy aluminum cylinder barrel both have the equivalent of our stage 2 cylinder head.

We are using a 38mm Mikuni carburetor and some pretty aggressive cams. These engines have run some very high HP on the dyno. In addition, we have a Nitrous Oxide system installed for when we run in the fuel class. Our original idea was to switch out engines between the gas class and the fuel class so that each engines strong points could be best displayed. Because we have not been able to run as many times as we had hoped and because we are not yet as fast as we know we can be (we are still dialing in the jetting), we had to chuck that idea out the window.

When we switched to the fuel class for an early afternoon run we had to test the Nitrous system, retard the timing a bit, and put in a hotter plug. Nitrous comes in as a cold charge, so a hotter plug is needed. We also have a warming device on the Nitrous bottle. This is needed because Nitrous requires high pressure and as the gas exits the tank it gets very cold like Freon. The warming device keeps the temperature up so that the pressure stays up. It operates on a very small battery that only lasts about 60 seconds.

We are a bit worried that if we make a good run and then have to make the return run for the record we may not have enough Nitrous battery power to operate the heating blanket as much as we'd like. At this point there is nothing we can do about that, so we can only hope for the best.

We were buttoning up the bike when we discovered that the pump was not working. It took several hours of troubleshooting only to find the problem was (as it always is) a very basic item. The battery that runs the fuel pump and the various Nitrous solenoids was no good. It tested at full voltage but when you put any electrical pressure on it, it went south. Of course we did not have a back-up battery.

A bystander offered the battery from his Norton Commando but it was much too large. We had to send our rider into town to the parts store to see what we could find. He came back with a scooter battery which was the only thing they had. We installed it and all was good. By this time it was late and as we started toward the starting line they announced that the runs for the day would be over early. A big wind had come up so it was a the right call although we were very disappointed.

This leaves only tomorrow for us to make the runs that we need to get the bike where it should be. Stay tuned to see if we get there!

Photo Gallery: Day 4 at the Salt Flats

Enfield in Twighlight