Torque measurement

[Don.F.Broadus at ucm.com]

A dyno works the same way. The rotor of the dyno is coupled to the engine
under test. The dyno case is supported by trunion bearings. water is
circulated between the rotor and case. The rotor tries to turn the case, and
a load cell on the case reads out torque.  In an engine, the crank is the
rotor and the block is the case, a load cell on the block would read out
torque just like a dyno does. If you want to measure off of the drive shaft
an in line load cell would be needed. The cost of an in line is over $3K a
tension compression load cell is around $500.
                                                            Don    

> -----Original Message-----
> From:	bearbvd at sni.net [SMTP:bearbvd at sni.net]
> Sent:	Friday, April 09, 1999 9:07 AM
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	Re: Torque measurement
> 
> >-----Original Message-----
> >From: Greg Hermann <bearbvd at sni.net>
> >To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> >Date: Thursday, April 08, 1999 10:30 PM
> >Subject: RE: Torque measurement
> >
> >
> ><SNIP>
> >
> >>
> >>Well--you would be measuring the torque output of the TRANSMISSION, not
> the
> >>engine--so you would need to calibrate the thing a fair amount higher
> for
> >>the low gears. Look at the engine-tranny package as a black box to
> >>visualize why this is so. And calibrating with a bar stuck through the
> >>output yoke, with the tranny in gear, might be a lot easier approach.
> >>
> >>Greg
> >
> >
> >Hmmmm(n).  I uderstand what you are saying, but if the transmission is in
> >neutral, and I open the throttle, the engine rotates oposite to the crank
> >direction.  There is no output from the transmission... Is this just the
> >energy that is being stored in the flywheel causing this oposite
> reaction,
> >or am I more lost than I think?
> >
> >Ord
> 
> Yep--in the situation you describe, it is the reaction to the rotational
> inertia of the ratating assembly that makes the engine rock.
> 
> Greg
>