I high jacked the thread that was under "2020 rule book" to explain as best as I remember the saga of the no butterfly engine discussed in that thread. I couldn't believe that someone remembered that engine after over 50 years. I should add that engine change my life.
A bit of background:
I first ran at the flats when I was 19 in 1961 with my 1958 Chev 348 cu in. Without any research I would say that was the worst possible car to use at the flats, but at the time it was the only car I had. While working on the 58 I brought a 53 stude for $100 to have transportation In 1962 I built the stude with the same 348 engine and the car then went 25 mph faster. By 1964 I changed to small blocks in the stude. Around 1967 a gentleman owed me some money for driving his boat and paid me with a 170 cu in slant 6. So it seemed only natural to run it at the flats in the stude along with the 2 small blocks (E and C class)
Here's how it came about to run the slant 6 without butterflies. Simple I didn't know any better. I mounted the engine in the car straight up by using a steel plate to adapt the 6 to my chev bell housing. I cut the flywheel flange off of a old chev and bolted it to the 6 flywheel flange and that allowed me to use my chev flywheel and clutch assembly. The engine originally came to me with two carburetors. I knew I wanted to use my Hilborn system. My first idea was to saw off the intake runners at the log that mounted the 2 carburetors and make up 6 butterflies on a single shaft. The engine came with a mag and somehow I made a distributor drive and a Hilborn pump drive for the 6 and I mounted the barrel valve on the intake flange and I used a union to block off the 2 extra nozzle lines. At this point it was clear that there wasn't enough time to make up the butterflies. Like I said I didn't know any better and thinking that some diesel engines didn't use a air throttle, what would it hurt not to run butterflies. I went to a plumbing store and brought 6 chrome drain pipes that had a nice flare on one end. I used some short radiator hoses to make the connection from the runners to the drain pipes. I did run into a couple of problems, to prime the motor usually resulted in a puddle of fire on the ground. Remember this was in the day when gas couple and sedan needed to self start. With the engine mounted straight up the intake stacks then ran down hill. Hence the puddle of fuel when you tried to squirt gas into the stack. My fix for that was to install the stock 6 fuel pump with a one way check valve tied into the main line going to the barrel valve. That fixed the prime problem and the engine started great and idled smooth. The engine came with a split header setup so I ran two long exhaust pipes to rear window. I was hoping to solve two problems, streamline the under car a bit and exhaust into the rear window area which I thought was a low pressure point. This belief came from the fact that the stude would spin the tires and not go over 176 without adding weight in the trunk. I learned this the hard way by spinning the car at about the 1 1/2 mile on a record run going way off course and in fact shutting off the engine. It was running so good (small block) that I restarted the car got back on the course still had about 1/2 mile to the 2 and ended up 10 mph over the record. I doubt if you could get away with that today.
So on to Bonneville I went. Going through inspection was interesting because I don't think they had ever seen a no butterfly system and made me add a second return spring to the small arm of the Hilborn barrel valve. As it happen Isky and Mickey Thompson were standing there and explained to me why such a system wouldn't work. Something to do with flammability limits. So naturally I reached in the car and hit the starter switch and the engine fired right up and idled. Running the car on the track didn't work out because it turns out the engine builder for the boat guy didn't have any clearance for the pistons and the car only ran a little ways before it seized up.
Over that winter Clifford Clark my friend who wanted to make injectors lined up several different engines to try and run without butterflies but none of them would even begin to idle. I rebuilt the engine and got ready for the 1968 meet. I added one feature to adjust the fuel while going down the track and tuned by the tach reading. I made 10 runs in one day that year (the meet was later in the year). Trying different spark and mix I got the car to go as fast as it could and was ready for record runs in the morning. One thing that I noticed was no matter what, the plugs always looked rich. After removing the head for inspection I could see the reason why the engine could idle and why the plugs looked rich. There was a dark soot line that came from the intake valves and circled around the spark plugs. After 1968 I never ran that car again.
I started to work as a mechanic for LA county and I looked after what the county called VIP cars. Board of supervisor, fire and police chiefs etc. Along the way I also was put in charge of emissions testing for the county. What I would do is tune police cars to factory specs and take them to a emissions testing lab in LA. The person in charge of the lab was a gentleman (PhD) who was the father of figuring out why LA had such a smog problem. He showed me the lawn mower engine where he ran his first experiments. I of course told him about my slant 6. At that point in time the holy grail of engines design was what was called "stratified charge". Which you would need if you were looking to run a gas engine without throttling. He thought that I must know something about stratified engines which of course I had no clue. He was also in contact with another 2 gentlemen who had just left Stanford Research Institute to start a new company working on a sonic carburetor. So based on my vast knowledge (LOL) I left the county and went to work with the SRI guys. This is the point were that slant 6 change my life. We hired a young engineer who after a few years of working together we started the data recording company called Racepak which is now owned by Holley.
Interesting point: Several years down the road, I was at a dinner meeting on emissions and setting next to a scientist type who was telling me about all the testing he had performed trying to find engines that could run unthrottled only one they found could and that was the slant 6 and only if you put the injector nozzle right at the intake port face. Of course if your a hot rodder where else would you weld in the bungs to mount the Hilborn nozzles.
As of a few years ago the car with the slant 6 was still around. I give the car to a friend when I started to drive the unlimited hydro's he in turn give it to someone who on fuel ran 183. By accident I was on the phone talking to someone about a Racepak for a Bonneville car and he told me besides his vett he had a older stude so we started talking about it and he was telling me about some of it's features and each one I would remark that I had a car like that and then finally he said well it has a 6 cylinder engine in it without any butterflies.
After looking over what I have written I apologize for the thread being so long. Once I got going I started to remember so many things about that engine and the simpler times.
