YardstickThere is an old adage that you don't race dynos and flow benches. Manufacturers of test equipment use different standards and test procedures that will affect the results. This brings me to the yardstick. You need some type of gauge, and engine dynamometers are the ruler used. Flowmaster has had a SuperFlow SF-7100 engine dyno since 1993, and it's been my toy since 1988. This dyno was state-of-the-art back then and used the latest in computer controls, temperature controls, and the latest correction factors to create very repeatable numbers. When testing exhaust components we are sometimes looking for numbers as small as 1 or 2 hp. You can check with any engine-dyno manufacturer and they will tell you that an acceptable repeatable is at or below 1 percent. Well, as the power levels increase, that 1 percent can be a very big number. Through refinement we were able to hold the repeatable of our dyno to 0.3 percent.
Well, time marches on, and dyno technology does too. Our SF-7100 used electronics that were designed back in the early '80s, and it was starting to give us trouble from time to time. SuperFlow released its SF-902 system several years ago with complete NSE (new-style electronics), a completely digital data-logging and control system. This is a major advancement from the old analog controls. SuperFlow makes an electronics package to upgrade the 7100. It's tough to beat the hardware of the 7100, and the new electronics brings us right into the 21st century. With this comes a whole new set of testing parameters and computer controls that takes the operator out of the testing loop. This is where I had a little trouble. Turning the controls over to a computer after having run engine dynos for over 20 years, I wasn't very happy. This is one of the ways that SuperFlow has been able to raise the level of repeatability of their engine dynos. It takes the operator's opinions and decisions out of the picture. It brings the engine up on load and to full-throttle the same every time. You basically turn the engine over to a computer. For an old dog that can be very tough. What do you mean a computer knows how to run an engine better than I do?
Well, we got everything up and running with SuperFlow's help, and we tested some new exhaust components this past week. We had the data on the same engine and same components with the old system. This gave us a chance to put the dyno through its paces. It came through with flying colors. The test-to-test repeatability was better, and we were able to run all our testing without one hiccup. One other thing, with the new testing parameters and the operator being taken out of the loop, I believe we should be able to compare dyno tests from other SF-902-equipped shops. This will bring up the level of all dyno shops running this type of system-and give everyone better numbers to compare.
Leak PathQ I was looking at articles posted on the CHP Web site, in particular the article on the Squeaker Mouse 355 by Henry De Los Santos. In the article is a picture of the balancer with the caption "prior to mounting, Jun applied a small bead of silicone inside the balancer to ensure a solid, leakproof assembly." Can you help me understand this? I can't tell from the picture where the silicone is placed. The caption says inside the balancer. If "inside" means the machined surface inside the keyed hub, that doesn't make sense to me, because the balancer hub presses on the crank snout. I could be wrong, but this doesn't sound like a place that would leak. If "inside" means on the outside of the keyed hub of the balancer, that doesn't make sense to me either, because isn't the oil seal on the timing-chain cover supposed to keep oil from leaking past the balancer? What am I missing? Thanks.Richard MouselVia e-mail