View Poll Results: What is a safe RPM for a stock bottom end with aftermarket springs?
6300 RPMs
38
8.46%
6400 RPMs
25
5.57%
6500 RPMs
89
19.82%
6600 RPMs
44
9.80%
6700 RPMs
45
10.02%
6800 RPMs
118
26.28%
6900 RPMs
29
6.46%
7000+ RPMs
61
13.59%
Voters: 449. You may not vote on this poll
Safe RPMs on a stock bottom end with springs
08-22-2006, 05:29 PM
#61
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Originally Posted by ishot2pac69
I only shift at 5900 rpms and my cars been in the shop for like 4 months on and off(should have got a honda if you wanna rev)
08-26-2006, 04:27 PM
#63
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Originally Posted by bigdsz
I've heard a story for years that when GM was developing the LS1 that they ran a whole room full of engines at WOT [6,200 rpm's] for 500 hours without a single failure. The original design parameter was 50 hours but they continued for 500. If true, these engines can take a lot of abuse.
thanks.
08-26-2006, 07:54 PM
#65
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You'd be suprised at how far OEM's take the motor on a stress test. I did work on the HEMI project for Chrysler and the stuff we did to those motors for stress testing would boggle your mind.
08-26-2006, 10:28 PM
#66
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Originally Posted by Phoenix_Master
Damn! if this is true props to GM.
thanks.
thanks.
08-28-2006, 08:22 AM
#67
Originally Posted by DONAIMIAN
7k+ for me
At 7000 RPMs the fuse is lit..you will find out just how long your fuse is one of these days..the rods and crank are good ... the rod bolts are the weak link..I could show you photos
that would make you change your mind on what stock bottom ends will handle ... 
PS Give me your email address an I'll send you some pics. A 99 has the real short fuse ... those are the old rod bolts that are the weakest of the ones GM used in LS1s..
Last edited by slt200mph; 08-28-2006 at 05:17 PM.
08-29-2006, 10:16 PM
#70
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My 5.3 had a stock bottom end in it and i turned it 6800 everyday, im still tryin to decide if it my rod or piston that came apart..not the rod bolts, im leaning more to the piston coming apart since there was nothing left of it, but my rod was broke also, usually from what ive seen in my circle track motors when the rod breaks most the time the piston will still be in the cylinder..so now im kinda leary about taking my new 6.0 that high
08-30-2006, 12:25 PM
#71
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Originally Posted by 300bhp/ton
So whats the weak point on the bottom end? What usually lets go?
11-02-2006, 07:54 AM
#73
I can spin mine up to over 7K if I wanted to..I run Comp 921 springs..the springs are not the weak link it is the rod bolts..the offer still stands if you want to see what a LX series engine looks like when the rod bolt fails...I have some photos that will make you cringe when you see them ... you can look through the block and see out the other side ... the object of the game is to make lots of reliable horse power and keep the engine in one piece... 
...
... Last edited by slt200mph; 11-13-2006 at 08:31 AM.
11-02-2006, 08:21 AM
#74
6300 RPM w/ rev limit set to 6500 RPM here. Don't want the transmission crapping out & my goal is engine longevity. It makes in the 400/390 range @ the wheels & I'd like her to last 150K + (mods. in sig.).
11-02-2006, 09:01 AM
#75
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Rev limiter set at 6800rpm and I shift right before it hits. By then, power is falling off too much to be worth staying in it to 7,000rpm. I think I make the same HP at 6800 that I do at 5600. Have to double-check the dyno sheet on that one. That and shifting at 6800 drops me into peak torque (4400~4800) for 2nd and 3rd gear....4th is a little north of peak torque at 5200.
Last edited by SSpdDmon; 11-02-2006 at 09:07 AM.
11-03-2006, 08:00 AM
#77
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Originally Posted by RocketCutlass
so to get your motor to rev around 7400 all you have to do is change the rod bolts? anything else need to be changed just as an insurence policy?
11-03-2006, 08:47 AM
#78
Originally Posted by SSpdDmon
If you're going to upgrade the rod bolts, why not throw some forged rods/pistons in there? The motor is apart...put some good **** in so you can throw a shot at it later and not think twice about whether it'll hold it or not.
11-03-2006, 09:46 AM
#79
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Originally Posted by GuitsBoy
Motor dosnt need to come out for rod bolts. Drop the K member and drop the pan. Replace one bolt at a time. There are a few howtos floating around.
