Don Terrill’s Speed-Talk

I finally got my hobby dyno together. It is a 13 inch land and sea water brake, with performance trends electronics. It has a manual water flow control valve. I would like any tips and or advice on the best way to learn how to operate the manual valve better. When I do a pull, I increase the load until I can hold the engine at the rpm I want to start the pull, and then slowly release the load and let the engine accelerate to the end of the pull. The first engine I had on it was a mild 500hp 454 BBC, after the third pull, I got it to work pretty well. The current engine is about a 650HP BBC, My issue is with it, I can hold the engine at 3,000rpm, it is a little harder to get it to stabilize, but then when I start to release the load, the engine wants to cycle too fast, and when I try to increase the load I loose the smooth acceleration, I think is needed to get an accurate test. I understand a learning curve is needed, just asking any advice or tips to make it shorter. I have a gauge on the flow control valve, and it maintains 60psi as I have read its supposed to. I also installed a temp gauge on the water leaving the brake, and so far it has not gotten over 100 degrees. I was reading that the orifice size on the return water out of the brake may need adjustment? Really don't have the money to install a computer controlled water valve at the present time. Not really a business to make a living, just some fun projects to keep my retirement busy and not boring.

I cannot see, is it a double toroid unit. Let me know and it makes it easier to control. Lets take one thing at a time. If you are having control problems and your water is not going above 60* then you have too large a opening in the out flow end. You will find that to have full control, you have to respectfully control out going as much as ingoing. Lets understand. Holding water in the brake is control,,,,BUT you cant hold the water long enough to steam it at 212*. Im normally around 150 to 175. The slower water flows out the longer you can control the rpm incline. I myself prefer and adjustable out flow like a ball valve but you have to watch the temp. What is better is a servo or stepper motor controlled valve. Also watch closely as you make a pull with a large outgoing orifice. This is when you have to maintain 60 psi. If the pressure drops any time, you do not have enough pump. Have some one watch as you are holding engine at 3000 rpm. If need any help pm me.
reed

No I do not believe it is a double toroid unit. I have not had the brake apart but in looking into the fitting holes it is a straight fin unit. One reason I purchased this used equipment was that it had a spare water brake, and a bearing and seal rebuild kit for the brake. I am going to check the diameter of the orifice. So if you control the out flow with a ball valve, do you still control the flow into the brake as well? The way its made it would not be difficult to hook a valve into the outflow hose. I simply hooked it up the way the guy had it before me.