Engine power spread

[Ext User(matt vk3zmw)]

Anyone have a good idea of the sort of spread of power outputs from an
assembly line are? On what basis are engine outputs given anyway? Is it
a statistical average of some sort, a guaranteed minimum or something
else again?

Specifically, I'm thinking of Ecotec motors, but I'm just curious in a
general sense.

[Ext User(John_H)]

matt vk3zmw wrote:
>
>Anyone have a good idea of the sort of spread of power outputs from an
>assembly line are? On what basis are engine outputs given anyway? Is it
> a statistical average of some sort, a guaranteed minimum or something
> else again?

AFAIK it's a minimum covered by the Trade Practices Act. The relevant
laws were originally enacted in the early seventies in response to
both outlandish claims and devious methods of measuring power.

The manufacturers took it sufficiently seriously at the time that
there was actually a brief period when a few of them ceased to specify
power figures for fear of prosecution. Since it coincided with the
introduction of emission rules, they generally copped the blame for
the halving of power figures undergone by some engines.

Unless they've since found a loophole you ought get the power you pay
for. I'd also be surprised if there were significant variations
between individual examples of modern engines, as was once the case.

Having talked to a couple of people in the industry who ought know,
the general consensus seems to be that you could probably expect a
couple of percent above the specified figure if you went to the
trouble of running your engine on a Prony Brake.

--
John H