Highest compression ratio on a 1340 motor with pump gas

ZeePopo

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What is the highest compression ratio you seen run on a 1340 motor on pump gas? Started looking at the S1000rr and I believe they are running 13.3 on pump gas. Wondering how a Gen 2 motor running these kinds of compression and a tighter squish the kind of power they will put out.
 
What is the highest compression ratio you seen run on a 1340 motor on pump gas? Started looking at the S1000rr and I believe they are running 13.3 on pump gas. Wondering how a Gen 2 motor running these kinds of compression and a tighter squish the kind of power they will put out.
i'm running 13.5:1 on a 1407cc Gen2 motor

i use UK style 95RON (US Style 91 octane ) and 99 RON (93 Octane) fuel no problem
mapped accordingly

Ducati panagale run 14:1
 
Nice. What kind of HP and Torque are you putting down?
OK i have 2 wild cams , 205hp@9800 and 117 lbf @ 7,400
but my below 6k its lacking in fact my 1340 was quicker
i think due to too much valve lift, duration and overlap, with the ported head option

in the winter going to stick a little tamer cam option in
i wish more mid range should expect 122 lbf and more bottom end hp , without losing nothing on top end
 
CR numbers we use everyday is the static CR, it’s only a reference number determined by the parts we use, dome, stroke, volume etc. dynamic CR (running CR) is determined by those same parts but adding in the number of degrees past BDC when the intake valve shuts and the cylinder starts making compression. The dynamic CR is what requires different levels of octane. The bigger the cam or the more valve timing overlap will reduce dynamic CR while the static CR remains the same. As you increase overlap you can increase static CR, in fact you should increase the static number or if you add too much overlap you will drop the dynamic CR too much and not make good power because you turned your engine into a low compression engine even though you didn’t change the static number. Yes I know I get long winded. Lol
 
CR numbers we use everyday is the static CR, it’s only a reference number determined by the parts we use, dome, stroke, volume etc. dynamic CR (running CR) is determined by those same parts but adding in the number of degrees past BDC when the intake valve shuts and the cylinder starts making compression. The dynamic CR is what requires different levels of octane. The bigger the cam or the more valve timing overlap will reduce dynamic CR while the static CR remains the same. As you increase overlap you can increase static CR, in fact you should increase the static number or if you add too much overlap you will drop the dynamic CR too much and not make good power because you turned your engine into a low compression engine even though you didn’t change the static number. Yes I know I get long winded. Lol
exactly explains why i can run 13.5:1 without detonation - because of the performance cams
 
not trying to bad mouth anyone but i never understand why some people want to spend lots of money and build race/hi perf engine only to stick pump gas in them. just like good oil, its “cheap” insurance. pinging and/or detonation can trash an expensive set of piston in no time.
 
not trying to bad mouth anyone but i never understand why some people want to spend lots of money and build race/hi perf engine only to stick pump gas in them. just like good oil, its “cheap” insurance. pinging and/or detonation can trash an expensive set of piston in no time.
Because this isn't a track only bike. The purpose is to push the limit of various techniques outside of specialty fuels and forced induction. Of course reliability is a must. It's all math in the end. For the most part people running high CR past a certain point run into trouble when not taking into consideration rod stretch and piston swelling . Correct choices on the metallurgy of your parts is essential to a reliable build.
 
Because this isn't a track only bike. The purpose is to push the limit of various techniques outside of specialty fuels and forced induction. Of course reliability is a must. It's all math in the end. For the most part people running high CR past a certain point run into trouble when not taking into consideration rod stretch and piston swelling . Correct choices on the metallurgy of your parts is essential to a reliable build.
pump gas is still an issue. the amount of ethanol isn’t consistent in pump gas. the info at the pump will say contains up to 10% ethanol so you dont get the exact same every time. if you trying to push the limit but your fuel isnt the same, then your tune will be off. also, doesnt matter what type of metallurgy you look at, if you start getting detonation or pinging, that will destroy the most expensive of forged pistons. race gas doesnt mean track bike.
 
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