I corrected this post based on Howard's note 2 posts below (that the OEM is 2497cc, not the 2449 that I orig had in the post), and another miscalc that I found (my .100 over bore is actually 2646cc, not 2665).
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Sorry, I’m going to sound a bit naïve here, but bear with me. Let me see if I understand this string correctly. It seems like we started with the same dynamic compression ratio. Is this because dynamic CR relates to detonation, and we want to compare the HP that the two engines will make at the same pain threshold level?? Or was there another reason that we compared the two engines starting with the same dynamic CR?
Anyway, from Howard’s info I get that HP is directly proportional to 1) thermal efficiency and 2) volume of air, all other things being the same. And, I’m also assuming that torque, and thus HP, is directly proportional to cubic inches of displacement.
If this is all correct, then this should be the math for my engine (2646cc, 8.8:1CR) as compared to a KL03 with 2497 cc, and 9.2:1 CR.
Thermal Efficiency factor: ==> 53.3/54 = .987
Volume of Air Factor ==> 9.2/8.8 = 1.04545
Cubic inch Factor ==> 2646/2497 = 1.05978
So, the HP of my 2646 cc, 8.8 CR will be: .987 x 1.04545 x 1.05978 times that of the KL03.
Or, my build will put out 1.094 times the HP that the KL03 will put out, if they both are run at the same dynamic CR. Or, for a 250 HP build KL03, my build will put out an additional 23.5 HP.
Note that most of the extra HP, roughly 2/3 comes from the increase in cc’s, and the reduced CR only nets roughly 1/3 of the gain. Is there another benefit from the lower compression that doesn’t show up here, or is the gain that slight?
Let me know if I’ve done any of this wrong
____________________
Sorry, I’m going to sound a bit naïve here, but bear with me. Let me see if I understand this string correctly. It seems like we started with the same dynamic compression ratio. Is this because dynamic CR relates to detonation, and we want to compare the HP that the two engines will make at the same pain threshold level?? Or was there another reason that we compared the two engines starting with the same dynamic CR?
Anyway, from Howard’s info I get that HP is directly proportional to 1) thermal efficiency and 2) volume of air, all other things being the same. And, I’m also assuming that torque, and thus HP, is directly proportional to cubic inches of displacement.
If this is all correct, then this should be the math for my engine (2646cc, 8.8:1CR) as compared to a KL03 with 2497 cc, and 9.2:1 CR.
Thermal Efficiency factor: ==> 53.3/54 = .987
Volume of Air Factor ==> 9.2/8.8 = 1.04545
Cubic inch Factor ==> 2646/2497 = 1.05978
So, the HP of my 2646 cc, 8.8 CR will be: .987 x 1.04545 x 1.05978 times that of the KL03.
Or, my build will put out 1.094 times the HP that the KL03 will put out, if they both are run at the same dynamic CR. Or, for a 250 HP build KL03, my build will put out an additional 23.5 HP.
Note that most of the extra HP, roughly 2/3 comes from the increase in cc’s, and the reduced CR only nets roughly 1/3 of the gain. Is there another benefit from the lower compression that doesn’t show up here, or is the gain that slight?
Let me know if I’ve done any of this wrong
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