could I please ask some of you good folk for some head air flow data so we
can determine where some of the differences with power claims might be
stemming from. Unfortunately, there is no basis to compare the results from
disparate dynos & techniques.
I have got data on numerous TR heads I'm quite happy to share.
basically, useful engine torque is governed by 3 main things
air inlet volume (assuming you can stuff in enough fuel for an optimun mix)
combustion efficiency
internal friction & other losses like energy going to noise & heat
power is the product of torque and speed, so the higher it revs, the more
power for any given torque result. unfortunately, internal losses rise
roughly to the squared power of revs, so it gets harder and harder to get
lots of increases from revs alone
I also have used a heenan & froude water brake dyno . i just finished a
whole pile of tests on 3 differnet engines for a large mining concern.
being a water brake design, they are direct torque measuring devices,
calibration is easy, and is difficult to stuff up. having said that, they
are poor at the low end where they have large internal pumping losses.
finally. i agree with greg lund on the subject of long rods in the 2500. I
have tired this with no measurable benefit. however, we have just built a
long rod 2000 (GT6) engine and it awaits trial.
terry o'beirne
australia
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