Calculating new motor redline
08-12-2003, 07:12 PM
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Calculating new motor redline How does one go about figuring out what the new redline is of a built motor?
Say for example, stock crank, forged pistons, H-rods, LS6 block with windowed crankcase, balanced internals, dual springs, 224/227 .563/.569 114 LSA cam?
Say for example, stock crank, forged pistons, H-rods, LS6 block with windowed crankcase, balanced internals, dual springs, 224/227 .563/.569 114 LSA cam?
08-12-2003, 08:45 PM
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Re: Calculating new motor redline 7K sounds like cake for a stock stroke motor...how big are the pistons though...the heavier they are the harder it's gonna be on them switching directions at 200something feet per second aka 7grand.
08-12-2003, 09:06 PM
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Re: Calculating new motor redline i say dyno it, and see where it peaks, and add about 400rpm... that cam u have shouldn't peak that high, maybe 6500 at the most with good heads...
08-12-2003, 09:27 PM
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Re: Calculating new motor redline The pistons are 452 grams each.
What determines redline? Peak power? Valve float? Centrifugal weight? Piston speed?
What determines redline? Peak power? Valve float? Centrifugal weight? Piston speed?
08-12-2003, 09:33 PM
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Re: Calculating new motor redline Well, the first things in your case will be valve float and cam selection. The cam you are running will start to drop power after a certain rpm, assuming the valve springs can handle the job. Your redline will only be as high as the weakest part in the equation.
08-12-2003, 09:37 PM
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Re: Calculating new motor redline Redline for valve float? Mean piston speed?Piston acceleration?
Conservatively using the stock stroke I would say to not move the pistons past 4,000 FPM. a 7,000rpm redline works out to approximately 4,225fpm/70.42fps/48mph (ignoring rod angularity). With upgraded springs,rods,and a properly balanced motor. You should not incur damages at that speed for short amounts of time.The limit I propose is based almost solely on mean piston speed and does not take into account valve float,puhrod flex,etc.
A complete list of specifications icluding:piston,rod,pushrod,lifter and retainer weights as well as rod length,spring rates,etc. would allow someone to give a more accurate answer.
Conservatively using the stock stroke I would say to not move the pistons past 4,000 FPM. a 7,000rpm redline works out to approximately 4,225fpm/70.42fps/48mph (ignoring rod angularity). With upgraded springs,rods,and a properly balanced motor. You should not incur damages at that speed for short amounts of time.The limit I propose is based almost solely on mean piston speed and does not take into account valve float,puhrod flex,etc.
A complete list of specifications icluding:piston,rod,pushrod,lifter and retainer weights as well as rod length,spring rates,etc. would allow someone to give a more accurate answer.
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08-13-2003, 12:31 PM
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Re: Calculating new motor redline The GM engineers that designed the LS1 have been quoted as saying the biggest problem with getting an LS1 to run higher than 7000 rpm was reduced oil film thickness. So even if the motor is strong enough, you might see accelerated wear on the pistons and cylinder walls.
