The control column on the Dyno has to be all things. It’s you power, fuses, gauges, hour clock, throttle, clutch, fuel system, and note pad in one. Additionally it needs to move. Designed to be wherever you need it. Exhaust on the right side of the motor? No problem, move the controls to the left.
Like some other projects, I chose to use some CNCed Plexiglas and color from the back. I made the top hinged so you could pull two pins and easily get to the back. It has a full complement of gauges (Rev limiting Tachometer, Oil pressure, Water and Oil Temp and Air Mixture). Also the usual toggles for fuel, coil and fan. We strive for everything to be just like the racecar. Just what you need and nothing else. If we use something different on the Dyno then we do in the car then you are not going to get the same results when the motor goes in the car. We don’t want to be tuning for the bench.
The fuel tank, pump, pressure regulator, and gauge are all on one support frame. With just a few bolts they can be removed as a unit. Again I have gone for a unitized system design. Easier to fix and diagnose. The tank was a hard one to find. There aver few small metal tank options. This one is a vintage steel tank from a 70’s riding mower.
The throttle is a marine style. Since this is a standing position a foot pedal didn’t make much since. It’s another vintage find. Most new ones have gone to drive by wire and they don’t use cables anymore. I had to build up the mount from scratch to fit it in on the side of the panel. Also had to design and 3D print custom parts (grey in the photo) to make the linkage work.
The heart of the Dyno is the Pump. There are two ways to measure motor output, with load (pump or drag break) or electricity. Probably the easiest way would be to measure the wattage output and this would be done with Eddy Current brake (Telma retarder). Not being able to find one of those, I opted for the water break and load cell. If you want to know more urge you to read up at YourDyno https://yourdyno.com/brakeabsorber-dynos/
The principle is simple. Create load, measure force from load with the load cell, calculate the end result. Is it 100%? No, but really you don’t need it to be. It is a loss loss system anyway. What you need is to measure change in load over the arc of the RPM of the motor. If you want to know if your carburetor changes helped, then the measured curve of this run vs the curve of the last run is what you need to know. Did our tuning make the motor stronger or weaker? Knowing if it generated 110hp or 111hp doesn’t really help, it just a number.
Where did I get my pump? I have no idea. It was salvage someone else was getting rid of because it was all locked up. I.E Free! When I took it apart, it turned out to just be full of mud. I think it’s an old farm pump for pumping out pond or lakes. For our purposes I have mounted it on bearings. One front and one rear. This mean the pump is free to swing or pivot. We hold it in place with the load cell. That then measures the drag applied when we close down the valve on the output shaft. A 55-gallon drum provides the water, which just circulates in and out. Simple, right?
Not so much. Not know who made the pump or where it came from means no parts and you get to make your own replacement gaskets. In fact I have had work out all the details. If there is any part of this I’m not sure about, it’s the pump. If I can’t make it work I’ll have to find a truck scrap yard and a Telma retarder. But since the frame design is modular, I can just swap these parts and the rest stays the same.
I was supper thrilled when we were able to pump water. It means that the pump is good and likely to do the job we need. Happy workshoping.
Look for the other articles in the series DIY Dyno Frame and Dyno Load Cell.