yet another RPM question
#1
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yet another RPM question
Ok first off, i dont plan on revving my motor more than a few hundred RPM past peak power. when i started this project i intended to build an almost bulletproof motor. its a forged LS6 (346) with all the ARP goodies inside, so im sure thats good for a lot of RPM. what im more concerned about is the valvetrain. i dont have a crazy cam, its a COMP XR281HR (228/230 .571/.573 112) but im using GM LS7 lifters, COMP chromoly pushrods, and patriot gold dual springs (.650). the springs came out of my old motor that blew up (kissed a bunch of valves. i was not driving at the time so i dont know what happened but my guess is my ''friend'' was beating on it and accidently shifted back into 2nd at the top of 3rd, 6700 rpm limiter couldnt stop it). i checked them and they're all identical and dont have any apparent damage. hell the pushrods out of the old motor are still straight, but i got different sized ones to go with my milled heads (AFR 205 shaved .020) and i'm reusing the stock rockers. my thought was to set the rev limiter at 7k, but if someone has spotted a weakness in my setup then please let me know. i will set the limiter at 6k if i have to, i can NOT afford another blown motor within the next few years! thanks!
oh yeah and i know what youre thinking, and my first precaution is to not let anyone drive my car any more...
oh yeah and i know what youre thinking, and my first precaution is to not let anyone drive my car any more...
#3
You've already solved your problem. The same thing happened to my brother's 68 Camaro years ago. Tagged all the valves. Changing your rev limiter won't prevent the scenario you mentioned.
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Yeah he tried to bullshit me and even said it was impossible for the motor to go past the rev limiter. fyi, this kid was a mustang driver who was too scared to install his own CAI and LT's! he may have actually believed that! anyways, operator error aside, you think im safe for 7k if thats what it comes to? honestly my main concern is the springs but you think theyre up to the task?
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Yeah he tried to bullshit me and even said it was impossible for the motor to go past the rev limiter. fyi, this kid was a mustang driver who was too scared to install his own CAI and LT's! he may have actually believed that! anyways, operator error aside, you think im safe for 7k if thats what it comes to? honestly my main concern is the springs but you think theyre up to the task?
for instance...on my MS4 i went 400 RPM over peak power just to keep the engine in the power band, which worked out well for me, and works for many others. as far as the springs, as long as they are still doing their job i wouldnt be concerned. however, since the pistons kissed the valves, i would take the springs to a machine shop and have them tested on a spring tester and compare them with new specs of the same spring, just to be sure the springs are still good.
just because you have a patriot gold dual or whatever doesnt mean its still got that strength left in it, you may have a gold dual that is no stronger than an LS6 spring or a 918. i found this out the hard way.
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well, you might call me crazy, but i'm thinking about setting the limiter at 6,200 and later raising it when i can afford to put new springs in. planning on buying HPtuners Pro anyways.
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#13
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straight from TSP's website on the MS4
http://texas-speed.com/shop/item.asp...d=666&catid=44
think about what you say and whats being said before you post it. they said you could get more power by running it to 7k because it keeps the r's in the powerband after you shift. they are not talking about peak power. the MS4 falls off after 6500 RPM. peak power is around 6400 RPM. end of story.
http://texas-speed.com/shop/item.asp...d=666&catid=44
think about what you say and whats being said before you post it. they said you could get more power by running it to 7k because it keeps the r's in the powerband after you shift. they are not talking about peak power. the MS4 falls off after 6500 RPM. peak power is around 6400 RPM. end of story.
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https://ls1tech.com/forums/dynamomet...6-results.html
https://ls1tech.com/forums/dynamomet...-ms4-dyno.html
looks like they are all peaking around 6400 RPM to me...
https://ls1tech.com/forums/dynamomet...-ms4-dyno.html
looks like they are all peaking around 6400 RPM to me...
#18
Ok first off, i dont plan on revving my motor more than a few hundred RPM past peak power. when i started this project i intended to build an almost bulletproof motor. its a forged LS6 (346) with all the ARP goodies inside, so im sure thats good for a lot of RPM. what im more concerned about is the valvetrain. i dont have a crazy cam, its a COMP XR281HR (228/230 .571/.573 112) but im using GM LS7 lifters, COMP chromoly pushrods, and patriot gold dual springs (.650). the springs came out of my old motor that blew up (kissed a bunch of valves. i was not driving at the time so i dont know what happened but my guess is my ''friend'' was beating on it and accidently shifted back into 2nd at the top of 3rd, 6700 rpm limiter couldnt stop it). i checked them and they're all identical and dont have any apparent damage. hell the pushrods out of the old motor are still straight, but i got different sized ones to go with my milled heads (AFR 205 shaved .020) and i'm reusing the stock rockers. my thought was to set the rev limiter at 7k, but if someone has spotted a weakness in my setup then please let me know. i will set the limiter at 6k if i have to, i can NOT afford another blown motor within the next few years! thanks!
oh yeah and i know what youre thinking, and my first precaution is to not let anyone drive my car any more...
oh yeah and i know what youre thinking, and my first precaution is to not let anyone drive my car any more...
#20
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yeah i ran my old setup (220/224 .571/.573) to 6,700 on stock internals and it was just fine for 3k miles before that dude blew it up. and during autopsy i found all the rod bolts intact, just a few broken rods and pistons and 12 bent valves. i'm sure my bottom end is more than up to the task, i'm just hoping the valvetrain is too.