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:
- The cost (it would increase the cost of each engine by $1000.00-$2000.00)
- 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)
- Equipment (we would have to have in house every computer, harness,
fuel management system etc for every engine we rebuild, which is roughly
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...