Re: compression r75/5

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Abgeschickt von Clemens am 08 Februar, 2004 um 18:11:09:

Antwort auf: Re: compression r75/5 von Clemens am 08 Februar, 2004 um 17:48:19:

: : Thank you for the swift reply! I´we never heard of anyone bursting a main block; but it´s definetly worth paying attention to it - it would be quite the anti climax :-)
: : Do you know whether they broke during low rew pull, or at max rew? My plan was to increase displacement (the engine is in dire need of an overhaul anyway; 80psi left bank, 120psi right bank), increase compression to app. 1:10,5 (by the way, how do you measure this?) and then detune the engine a bit by using a touring cam. In short I want more low end torque, peak effect is not in my interrest.

: : Thanks

: : Niels

: I never heard this before by myself, too.
: All the information I have is from the mentioned
: article. It was surprising for me, too, cause the
: both blocks of the /5 and the /6 look very similar.
: There are no further informations concerning your
: questions in this article.
: The geometrical compression ratio can't be measured
: directly. All you can do is calculating the exactly
: displacement and evaluating the volume of the
: combustion chamber by filling it completely with oil
: or whatever. The amount the fluid can be measured and
: the compression ratio can be calculated this way.
: subj: camshaft
: I'm very impressed of the Ro240, the 320°-Schleicher
: cam that is used by HPN for most of their 1043cc conversions.
: I use it in a 1043cc engine. It cuts the torque a little
: in the very lower rev range (near idle speed) but offers
: significantly increased mid-range power.
: I have all the bells and whistles in this engine, like
: twin-spark, high compression and so on, but the main
: responsible for that change in characteristics is the
: cam-shaft in my opinion.

: Regards,

: Clemens

P.S. There's a direct relationship between torque, combustion pressure and the stresses that burst your main-block.
Power is not an issue! The crank-speed that offers the best torque is that one that produces the highest stresses
for your block at the same time! This consideration is not completely correct, cause it doesn't regard any
oscillation phenomenons. But it describes the reality good enough, to show that your 'detuning by toRRRKKK-cam'
intention is not a solution for saving the main block.

But now it's enough of this stuff!
Bye!

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Re: compression r75/5 Niels Hansen 19:39:30 08/2/2004 (0)

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: : : Thank you for the swift reply! I´we never heard of anyone bursting a main block; but it´s definetly worth paying attention to it - it would be quite the anti climax :-) : : : Do you know whether they broke during low rew pull, or at max rew? My plan was to increase displacement (the engine is in dire need of an overhaul anyway; 80psi left bank, 120psi right bank), increase compression to app. 1:10,5 (by the way, how do you measure this?) and then detune the engine a bit by using a touring cam. In short I want more low end torque, peak effect is not in my interrest. : : : Thanks : : : Niels : : : Niels : : I never heard this before by myself, too. : : All the information I have is from the mentioned : : article. It was surprising for me, too, cause the : : both blocks of the /5 and the /6 look very similar. : : There are no further informations concerning your : : questions in this article. : : The geometrical compression ratio can't be measured : : directly. All you can do is calculating the exactly : : displacement and evaluating the volume of the : : combustion chamber by filling it completely with oil : : or whatever. The amount the fluid can be measured and : : the compression ratio can be calculated this way. : : subj: camshaft : : I'm very impressed of the Ro240, the 320°-Schleicher : : cam that is used by HPN for most of their 1043cc conversions. : : I use it in a 1043cc engine. It cuts the torque a little : : in the very lower rev range (near idle speed) but offers : : significantly increased mid-range power. : : I have all the bells and whistles in this engine, like : : twin-spark, high compression and so on, but the main : : responsible for that change in characteristics is the : : cam-shaft in my opinion. : : Regards, : : Clemens : : P.S. There's a direct relationship between torque, combustion pressure and the stresses that burst your main-block. : Power is not an issue! The crank-speed that offers the best torque is that one that produces the highest stresses : for your block at the same time! This consideration is not completely correct, cause it doesn't regard any : oscillation phenomenons. But it describes the reality good enough, to show that your 'detuning by toRRRKKK-cam' : intention is not a solution for saving the main block. : But now it's enough of this stuff! : Bye!

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