Torque BS Filter ``

[Stuart Woolford]

On Fri, 21 Feb 1997 07:50:36 -0600, DICK BREWSTER wrote:

>Stuart, a very good smell test to use on torque claims for 
>naturally aspirated four stroke gas engines the 1 to 1.1 ft-lb 
>per cubic inch test.

Well, perhaps if you think a bit about the fact that 8.5 l is around
518 cu.in, then 500+ ft-lb of torque would be quite doable?

>Very few streetable engines get much over 1 ft-lb per cubic inch 
>torque.  Some of the better engines get up to about 1.1, but 
>that's about it for an accurate dyno test under real conditions.

and then if we figure in the fact that I never said this was in a streetable
car, as infact the application is an aircraft engine, running at more or less
a constant 3000RPM, would you not say that this is quite an easy target?

>The reason is it's hard to get much over 100% volumetric 
>efficiency and the effective compression ratio is pretty much 
>limited by pump gas.

and who even mentioned pump gas?

and remember, allow for the fact that the combustion chamber on a stock jag V12
engine is capable of running 12.5:1 compression with a mechanical distributor on
91 octane fuel (just)..

BTW. this same setup is reputadly good to over 800 ft-lb
supercharged (as it is in full use in the airframe..)

>>I believe people have got over that from stroked V12 jaguar 
>>engines, supercharged.
>>around 500lb-ft without the supercharging. running around 8.5l 
>>of capacity, and on avgas.
>>however, these have a VERY good head design (for the time), 
>>which allows this, a
>>standard jag. XJ12 is 12.5:1 compression on 5.3l, but they have 
>>a VERY advanced
>>distributor (and later computer controled ignition) to control 
>>detonation problems.
>
>>not exactly a bus but...

so would you like to repeat your claim of me presenting BS?
or am I really missing something?
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Stuart Woolford, stuartw at kcbbs.gen.nz

               >>>>In VI Where Available<<<<
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