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...

 

i ran my ls1 with an MS4 (peak power at 6400 RPM) hardened pushrods, LS7 lifters and patriot gold duals. i shifted it at 6800 RPM with the rev limiter at 7200. of course i had ARP rod bolts.

 

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.

 

yes, rev limiter is only for fuel cutoff and timing retard, not mechanical overrev.

 

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?

 

i would look at the RPM range of your cam and base your shift points and revlimit off that...

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.

 

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.

 

with stock internals i was pushing mine to 6400 with the limiter set at 6500. that was in an auto car obviously, but you get my point.

 

I would be more concerned about the valvetrain than the bottom end.

 

I wouldn't call you crazy. But your leaving power on the table. The stock revlimiter is set at 6200. STOCK as a rock.

 

ill admit i was nervous about it at first, but the car was dyno tuned and spun that high on the dyno without a hiccup. I ran it for over a year like that

 

Straight from TSP when talking about an MS4

 

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.

 

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...

 

I read TSPs website, and those threads you posted before you posted any of it. Gotta get up earlier in the morning then that Focker.

 

Come here Focker...your now outside the circle of trust...

regardless, peak power is at ~6400 RPM. just because you rev it past this doesnt mean its still making power.

 

I just always thought of the MS cams as rev to 7k kind of cams.

 

i'm running the same cam with a stock bottom end and pac 1518 beehives and bolt on's. i'm shifting @ 6200 no problems here. not sure about running it past 6500 though, on the dyno it only makes power to about 6200 or so.

 

Don't get me wrong, they do rev to 7k. But there is no power up there really. I ran mine to 7000ish but only to keep the r's up after I shifted

 

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.