RPM range question
03-29-2009, 05:27 PM
#1
Launching!
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RPM range question I have been reading various places and have done a search with no result. My rev. limiter is set at 6200 I've driven an LS3 with a 7k limit i believe... I see various dyno charts with 65, and 6600 rpm
what is done to allow the engines to safely run at that speed? or is it safe since the LS3 was a brand new vette I would guess it's safe.
some thoughts running in my mind are lighter valves, retainers. roller rockers nessicary? heavier valve springs to prevent float?
Thanks for the help!
what is done to allow the engines to safely run at that speed? or is it safe since the LS3 was a brand new vette I would guess it's safe.
some thoughts running in my mind are lighter valves, retainers. roller rockers nessicary? heavier valve springs to prevent float?
Thanks for the help!
03-29-2009, 06:31 PM
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How fast you can spin your valvetrain without wrecking it a function of valve / retainer / lock / rocker arm / pushrod / lifter mass and the k (spring rate, lbs/in) of your spring. You can't cycle your valvetrain at a rate higher than its natural frequency. Think Physics 101. A spring with a mass attached to it will oscillate at a given frequency. Reduce the mass, or increase the spring rate and the frequency goes up.
Probably the most common thing folks do is just upgrade the springs to one that is more robust and has a higher spring rate and higher seat pressure. Reducig the reciprocating mass is something else you can do.
But if you have a stock cam that doesn't make power above 6000 RPM, increasing the RPM capability of your valvetrain won't gain anything.
Probably the most common thing folks do is just upgrade the springs to one that is more robust and has a higher spring rate and higher seat pressure. Reducig the reciprocating mass is something else you can do.
But if you have a stock cam that doesn't make power above 6000 RPM, increasing the RPM capability of your valvetrain won't gain anything.
03-31-2009, 07:16 PM
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no other opinions ideas/suggestions?
I was thiking an extra 300 or so RPM so redline at 6500 wouldn't be totally unattainable. and if i upgrade cams?
I was thiking an extra 300 or so RPM so redline at 6500 wouldn't be totally unattainable. and if i upgrade cams?
03-31-2009, 11:01 PM
#6
I always took my 02 346 with stock bottom with the MS3 cam and springs to 7000rpm, revlimiter was set to 7500. No problems ever, it had 82000 miles on it when I installed my 408. I will be taking the old one down in the next week or two to see how it all looks now.
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04-09-2009, 10:01 PM
#8
No, I have it on the stand. I pulled the cam and sold it. It was in perfect shape as well as the pushrods and timing chain. I have been working on my car trailer, finishing up the 408 install, and tuning the 408. I will be pulling it down soon though.
