What is Sim Testing and How Does it Differ from Dyno Testing?

Dyno testing – is a test to a engine with it operating out of the vehicle under its own power. This means running and firing under fuel and with a load applied.

Sim tested (or simulation testing) – Is a test performed by all manufacturers of rebuilt engines but is often referred to incorrectly as Dyno testing. Sim testing is the process of using a machine to spin the engine at roughly 750 RPMs. This allows us to test for compression, proper oil pressure and any noises. It also allows the engine lifters to be pumped up thus aiding in eliminating any start up tapping. The engine is not under its own fire or running on fuel at this point.

The reasons it is done in this manner, as opposed to a true Dyno test, are as follows:

  1. The cost (it would increase the cost of each engine by $1000.00-$2000.00)
  2. The man hours involved (it would increase the end time for rebuilding by another 8 hours, due to having to dress, run, and undress each engine)
  3. Equipment (we would have to have in house every computer, harness, fuel management system etc for every engine we rebuild, which is roughly 3500)

So overall – it is not feasible to Dyno test because it would end up costing you twice as much for each engine. The Sim test provides an excellent baseline, and allows us to weed out any mistakes made in the remanufacturing process.

Please feel free contact us with any additional questions you may have…