Bonneville Salt Flats 2012
Having had good success last year at Bonneville, with only one 750cc engine I decided that in 2012 at the Salt I would take three engine to do more playing and learning. I named them “BV1”, “BV2”, and “BV3”. All had different pistons, porting and compression ratios. Many of you who attended the SOC12 got to see my Bonneville Salt Flats car, a green 1968 Sonett II, two stroke, up close and personal in August. At the SOC12 we had our “BV2” engine installed. We also had “BV3” ready which was the most recent porting and modification upgrades we had developed on our dyno. We only ran it on the dyno with the triple expansion chamber pipes and it did not pull well in lower gears till it got about 7,000RPM’s. “BV1” engine was our 2011 record holder that had many modifications made to it since it left the salt last August and had suffered a fatal piston failure on the dyno, July 30th, just 3 days before the SOC12. I felt BV2 was the best “starter” engine on the salt since it consistently produced 90HP to the wheels on my chassis dyno. It also started easy and always ran strong. So it made the most sense that it would be the first one to run on the salt a week later for us. We also had installed our newest exhaust system, a triple expansion chamber set made specially for the salt at our shop, for the SOC12. The triple exhaust system was too untested on the dyno for me to be comfortable with for day one on the salt but man did it pull high RPM’s with it on!
A few days before we left for the salt, one of my key guys, Verlyn Gregerson, long time employee and friend, who helped last year, kept saying to me that he thought we should take along BV1 engine. Verlyn is also long time bike racer and two stroke nut and he can weld most anything and is real good at presenting ideas to me. I had no plans to try to fix BV1 in the few days before we left due to its severe cylinder wall damage and other pressing issues that needed my attention. At the last moment I decided to heed Verlyn’s advice and do a “poor mans” repair on the BV1 engine. The bore in the front cylinder was badly scored and would not respond to honing. Also the center cylinder had a chunk out of it about the size of a dime! It looked really “nasty bad” in those two cylinders. After a few hours of work and a couple new pistons, I showed the BV1 engine, all back together and ready for “salt duty”, to Verlyn and he smiled. He asked me how long I thought it would last. I told him I thought BV1 had about 6 runs left in her down the sticky salt. I would be wrong.
So off to Bonneville we headed about 2AM Thursday, August 9th. Missing from this years pit crew was lone time employee and friend Steve Davis. But Steve had made sure the car was “salt ready” and gave us his blessings. I could see in his eyes and face his desire to go but knew this year he must wait at home. The weather on the salt can be cruel and this is not a place for anyone unless they can handle a lot of sun, heat, dry air, extreme stress, and endure long days with little sleep. Having survived last year, Steve decided to sit this year out. In his place was Dave Roe, another long time friend and employee and also a good Christian man. Dave is a real thinker who can make about anything run and fabricate almost anything out of nothing. He spends his days at my shop working on torque converters and managing his department. We took with us in the trailer three motors, three transmissions, two exhaust systems and tons of spares and tools.
Once at the salt, we setup our pit area and left room for my friend and fellow Bonneville record holder Bertil Sollenskog in our pit area. We were lucky to get our car through tech inspect with in a few hours of arrival at the salt Friday early afternoon the 10th of August. That meant we could start running Saturday morning, the 11th, at 10AM when the Salt would open for racing. We spent the rest of Friday planning our first runs. Armed with last years experience, we felt we knew what would be the best setup to start running with. We re-jetted based on weather forecast for the next day (which changes the Density of Air also) and swapped tires around based on the salt “stickyness” we saw. We made ride height adjustments too with our custom air bag setup.
Bonneville is a hard place to setup a non fuel injected engine to run on. I talked to a race crew late in the week from France. The Crew Chief explained to me how they really thought they knew how to setup their two stroke motorcycle engine for the salt with all the dyno work and preparation they had done back in France. He stated you just can not duplicate the type of weather changes the salt presents. One minute you are running at an equivalent to 4,200 feet elevation and soon the weather changes and now you are running at over 7,500 feet equivalents! He went on to say that once they shifted to high gear their engine simply would not pull anymore. The thin air and sticky salt was too much. They were very frustrated, as all changes they made seemed to go un-noticed in the unforgiving salt atmosphere.
On Saturday morning, after a long delay at the starting line due to someone blowing an engine on a run before us, we began running and on our first run the car did not run right. It had a miss and just would not gain enough speed. It still ran 107.199 MPH by the end of three miles, which was only .224 MPH off our 2011 record of 107.443 MPH. At Bonneville it takes two days to set a record. You must first do a “down run” that exceeds the existing world record. If you do that then your car goes to impound to wait till the next morning. Then you do what is called a “back run” or “record run”. If the average of your two days’ runs exceed the current world record, you then have a new land speed record of your own. We knew we could exceed our old record if I could correct mystery “miss” that had suddenly showed up. Once I opened the hood I saw the problem. One of my pit crew had mistakenly installed a dirt/salt screen over the velocity stacks. We did have the screen on for the trip out to Bonneville and also to tow the car to the several miles from the pit area to the starting lines. Also, we did run these screens last year but I had re-jetted to run without the cover that day. My guy saw the screen on the dash of the truck and popped it onto the stacks. I did not see him because of a long delay at the starting line due to a wreck on the track. That was followed by a long period of time me sitting in the car all suited up with helmet on and sweat heavily with the high heat where I only had a little hand fan to help keep me cool and I usually kept my eyes closed cause the sweet kept making my eyes water! With temps in the high 90’s wearing a fire suit and little or no air movement makes for very hot times in the cockpit!
I quickly removed the screen and we got back in the long line to start another run almost two hours later. On the second run the car ran like lighting with a speed of 106mph just after mile mark one then it felt like the car simply ran out of gas. It lost some speed then started to regain power and then I could tell the engine had just, “let go”. I coasted off to the side off the track and opened the hood before my pit crew arrived. It turned out the velocity stack fell off (weld broke (and not Verlyn’s!) the rear carb and I was pretty sure the piston went south too. When my pit crew arrived I popped the spark plug out and could see lots of metal on it, a real BAD sign! So we got back to the pits and spent the rest of the day slapping out the damaged BV2 engine and installing BV1. Verlyn had a look on his face like, “see, I told you we needed this engine!” We were pretty down then with our mood now too. BV2 had performed so well on the dyno and took off like a rocket ship up to 106 MPH. We had ran a 15/1 head on BV2 and felt we needed to play it safer now since we had lost an engine so quickly in the week. So I opted to install our 2011 head on BV1 that only had a 10/1 compression ratio. I also had to install a spare set of velocity stacks that were on loan from Bertil, but they were not tuned properly for this engine (since the correct ones were broken and needed welding to be repaired.) We got the engine running before we left the salt Saturday night and came back Sunday AM to run again with our nasty BV1 bore engine. We ran once and did 108.663 MPH, which did exceed our 2011 record of 107.443 MPH. Run #1 for BV1 and Verlyn was all smiles. We talked a bit and decided a record attempt should be attempted so we went to impound for a return run on Monday August 13th. I made some more modifications to the carbs, timing, and tire size/pressure. We also reset ride height again. By now Verly and Dave were full of great ideas. All these modifications we felt would help the car to run faster for the next day’s cooler temps and wetter salt. In 2011 we normally ran SLOWER the next day. Lessons learned in 2011 could now be applied in 2012! On Monday morning we ran a good speed of 110.36 MPH for a two-way average of 109.514 MPH and new class record. (J/GT) Run #2 for BV1 brought a new world record and bigger grin to Verlyn’s face.
At Bonneville if you break a record with your two-day average run, you then must have your car taken to “Inspection” to be sure your engine and chassis actually meet your ALL your class requirements. As we arrived to the inspection area, a new, “would be” record holder was arguing with, not so nice words, the inspectors as his car was just deemed to be, “not proper” and stripped of his new record. Since we were going to swap out to a different head anyway, I decided to pull our head off to ease the measuring requirements of our engine. All these inspectors are use to four stroke motors, not two strokes, and seem to struggle with the transfer ports. With the head off all the measurements would be easy now. What was funny is that people would walk by, look at BV1’s nasty cylinder walls and then tell me,”Hey, did you know your engine is shot?” Each time someone made such a comment I made them step away for the car and would whisper to them…”sshhh…BV1 doesn’t know it’s bad!” Funny stuff. Anyway we got through inspection easy and had our newest World Land Speed Record to show off.
Monday afternoon, with the pressure to “repeat” our record now gone, we installed a 17/1 head onto BV1 and new fuel cell and replaced the entire fuel supply system right up to the carb nipples. The more I thought about my second run with BV2 on Saturday (that melted the engine), the more I kept coming back to the question…”Did it actually run out of fuel?” I had figured the velocity stack had caused the melted piston but a fuel delivery check and fuel consumption check quickly confirmed it was most likely starved for fuel. We tried to run again Monday late in the afternoon and were only two cars from starting line when windstorm came up and canceled races for the day. I knew what that would mean for me later.
We got up early and ran Tuesday morning, August 14th and ran fast115.13 MPH to exceed our newest Monday’s record and thereby setup another record run for early Wednesday morning. Run #3 for BV1, and more smiles by Big Verlyn and now Dave too! Again our team made modifications to the engine and car for what we felt the weather would be like the next morning. The next morning, Wednesday, August 15th, we ran even faster at 116.099 MPH to set another class record of 115.619 MPH. Run #4 for BV1 and yes more smiles too. Verlyn and Dave had come to the salt and really applied their talents.
We then spent most of the morning installing the new exhaust system of three individual expansion chambers into our little green Sonett and getting it re-inspected to run safely on the salt. Back out to the starting line we headed. With new the modifications made, I could never get the revs high enough to make the new pipes work. The power curve was too far away for us and we were now running in uncharted water as the dyno time had been limited to just a few runs back in Iowa which had ended with BV1 melting the engine a few days before the SOC12. I needed to hit 4th gear at over 7,000 RPM’s and my setup just could not do it. Even taking engine to 9,300 RPM’s in third gear and over 101 MPH was just too short of the power band to pull in fourth gear. I just could not get her “on the pipe” as they say. I pulled off the track short of the two-mile mark rather than continue and risk engine trouble. Run #5 for BV1, and no smiles yet. We got back in line and by now the lines were very short and turn around time was also quick. We did a “NASCAR” type tire change and pressure adjustment, as well as timing and jetting changes. On the next run I pulled away from the push car I knew the changes were working. My speed was climbing up to 112 MPH before mile marker 2 1/4 and then things got slow, real fast. BV1 had finally succumbed to its aliments. A piston ring had finally “hooked” into that dime sized area in cylinder number two and shut things down just short of the 6 runs I had predicted. BV1 died at 5 3/4 runs! Maybe someday I can get better at predicting engine life J !
We talked about what to do over dinner that night with Bertil Sollenskog and his pit crew who were there trying to repeat his 2011 record with his 1966 Monte Carlo. We decided to loaded up Thursday AM and head for home. We still had our best engine in trailer unused. I figured it would jump start us next year should I go again. You see the day we lost our run to wind (Monday) cost us a chance to use our last engine. And I knew it the minute the race was cancelled that night. Remember, at Bonneville, it takes two days to set a record and other commitments I had made were calling me now. I am the defensive line coach at Black Hills State University and two-a-day football practice was starting on Friday August 17th, so I felt I must return to Spearfish, South Dakota. It was time for me to “switch gears” and start working on our eleven game season and our first game with Idaho State September 8th. I would soon be watching film on BYU and Air Force instead of power curves on engines. We are a NCAA Division II school but play higher up every year, as most schools do. In fact, Idaho State plays Nebraska the week after us! Since my wife is from Nebraska and her whole family is HUGE Husker fans, we will have to “rough-up” the Idaho State Bengal’s for Nebraska to have a chance! J
As always, thanks for reading and Safe Saab’in…Tom Donney