Measuring dynamic cylinder pressure

[Shannen Durphey]

----------
> 
> 
> Has anyone ever installed a pressure transducer in the spark plug hole
and 
> run the engine with that cylinder's spark and fuel injector disabled? 
High 
> speed data acquisition would be required, but it would allow one to
measure 
> the effects of various mods (cam, intake, exhaust, boost, etc).  Higher 
> pressure would indicate better cylinder filling, although some
temperature 
> compensation would probably be required.  The max pressure for a
non-firing 
> cylinder is 120 to 200 psi, well within the range of reasonably priced 
> transducers.
> 
> Bryan Zublin
> bzublin at nlvl.com
> 


Wouldn't it be easier to use a compression gauge?  after all, all the other
changes (cam, intake, headers, etc.) will be hands-on, nuts&bolts changes.
Couldn't be that much more time to install the gauge.  Also.. headers,
cams, and intakes often make more difference at higher rpm.  More cranking
pressure usually indicates indicates more efficient low rpm airflow or
sometimes more advanced camshaft timing.  Neither of these indicate better
airflow at higher engine speed.  Maybe heat sensors mounted in the exhaust
ports, to indicate cumbustion efficiency, would be more accurate.