What makes a pull on the dyno harder on the engine than a pass at the dragstrip ?
Randy
Moderator: Team
What makes a pull on the dyno harder on the engine than a pass at the dragstrip ?
Truck pulling lasts about 20 seconds at wide open throttle...Some run vehicles at longer periods on chassis dynos.. My vintage LSR race bike junk is run at full power for at least 30 seconds for durability testing...
You said it much more eloquently than I did. I had picked up on the fact the engine's were supposed to represent what a hot street motor could be an dby implication that means last a while. Having said that, if I was involved in a competition like that and there was no endurance test, I'm sure I'd try to win vs trying to have the engine with the least amount of wear at the end of it.CamKing wrote: ↑Mon Oct 15, 2018 10:56 am As for the "Dyno Queen" term.
Maybe this will make it easier for some of you to understand.
The Rules for the REC, are to try and keep the engine representative of a engine that will run over 3,000 miles, not under 300.
Anyone that has spent a lot of time building circle track engines knows that you can build a qualifying engine, to make more power then an engine that has to live for 700 miles.
Shoving a ton of compression into the engine, to the point the tune has to be perfect to live, or running a cam that wears out the springs in 50 miles, is not representative of a Street/Strip engine that you would sell to a customer.
Right, dynos such as most people use, aren't nearly as hard on an engine as what you described, nor a bouncing truck/tractor during a pull. Plus lots of oval track engines blow up at high revs with the throttle shut at the end of the straight.houser45 wrote: ↑Tue Oct 16, 2018 8:11 am Have you ever stood in the infield and watched a dirt oval circle track engine bounce through the holes on a rough race track spin the tires and then become hooked up again ? There is no way even close but an engine Dyno is as hard on those conditions plus you have oil control issues with racing on the track.
One could see how this might happen with pre-mix: closed throttle = no air = no fuel = no lube... Not with oil injection of course.nitro2 wrote: ↑Wed Nov 07, 2018 11:14 am...Also in some other types of racing, such as 2 stroke marine racing, there can be weird on/off throttle scenarios that cause engine failure in a race, but there is seemingly no way to duplicate it on the dyno (the engine on/off throttle scenario can be duplicated, but not the failure).
Not that kind of failure.MadBill wrote: ↑Wed Nov 07, 2018 2:47 pmOne could see how this might happen with pre-mix: closed throttle = no air = no fuel = no lube... Not with oil injection of course.nitro2 wrote: ↑Wed Nov 07, 2018 11:14 am...Also in some other types of racing, such as 2 stroke marine racing, there can be weird on/off throttle scenarios that cause engine failure in a race, but there is seemingly no way to duplicate it on the dyno (the engine on/off throttle scenario can be duplicated, but not the failure).