Bottom End Question
Bottom End Question Hello all, I've been lurking on the forum for a while, and finally saved up enough to start looking at LS1's seriously. Lots are over 100k on the clock, and I wanted to clear up something. I've heard from lots of people that LS1's have a notoriously weak bottom end, but that it was fixed in '01. (Talking about F-bodies here). Anybody know if there's any truth to any of this?
thats funny you say that, ive been randomly hearing some issues with these cars that arent true.
many people on this forum are running 600hp on the stock bottom end. so no, they are fne.
someone said the other day that all trans am have overheating issues, lol. thats all i say.
many people on this forum are running 600hp on the stock bottom end. so no, they are fne.
someone said the other day that all trans am have overheating issues, lol. thats all i say.
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Hello all, I've been lurking on the forum for a while, and finally saved up enough to start looking at LS1's seriously. Lots are over 100k on the clock, and I wanted to clear up something. I've heard from lots of people that LS1's have a notoriously weak bottom end, but that it was fixed in '01. (Talking about F-bodies here). Anybody know if there's any truth to any of this?
who has been telling you such blasphemy... and no its not true, there are some weaknesses with earlier models but nothing significant. if taken care of they can safely hit 200k miles, and you could also get 500-600 hp on bottom end pretty safely like stated above. 
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yeah thats all a bunch of crap. I have 130k on the clock and they are not all easy miles. Car still runs great with no weird noises or no unusual burning of oil. I would say to get one with some miles on the clock and use the money you saved to mod and save up for a bigger and better motor build for the thing in the future.
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There actually is a slight bit of truth to that if you count rod bolts as part of the stock bottom end (which I do). All years can and have handled 500+ rwhp. But the 01 and 02 years did get stronger rod bolts. The 98-00 had weaker rod bolts which make spinning the motor beyond 6500 rpm's a "do it at your own risk" proposition. The 01-02 rod bolts are generally considered ok to 6800 rpms with many spinning to 7K.
So to get 500-600 rwhp on the stock bottom end you are fine with any model year. But if you plan on spinning past 6500 rpm's to get there then I would feel safer with a 2001 or 2002 ls1. Or spend extra money on aftermarket rod bolts.
Either or
So to get 500-600 rwhp on the stock bottom end you are fine with any model year. But if you plan on spinning past 6500 rpm's to get there then I would feel safer with a 2001 or 2002 ls1. Or spend extra money on aftermarket rod bolts.
Either or
I wouldn't push any stock bottom end LS1 much past 500rwhp, especially if it's your daily driver. Also, just don't go with a cam that requires you to rev to the moon - do your research - there are smaller cams that put up great numbers and will be much more streetable. Info stated pertaining to rod bolts is correct. I believe the switch occurred in the late 2000 model year so some of the 2000's built towards the end also recieved the upgraded rod bolts. In any case, make sure the bottom end AND the valvetrain is built to handle whatever RPM you're spinning depending on your cam choice.
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The bottom end on these cars is good for 550-600 rwhp. How you get there (H/C, N2O, FI) is up to you, but 600 is generally considered the limit for the rods.
in 01 and 02 GM upgraded the rod bolts. If you have a 98-00, it is suggested that you replace the rod bolts and bearings if you do any internal engine modifications.
98-00 rod bolts are prone to expand when exposed to heat/friction. This causes the bearings to be starved for oil which results in a "spun bearing" (read 'thrashed motor that needs to be rebuilt').
Hope that helped. BTW OP, "guns up" aggie. Should be a hell of a game this year, but i think my red raiders will be comming out on top!
in 01 and 02 GM upgraded the rod bolts. If you have a 98-00, it is suggested that you replace the rod bolts and bearings if you do any internal engine modifications.
98-00 rod bolts are prone to expand when exposed to heat/friction. This causes the bearings to be starved for oil which results in a "spun bearing" (read 'thrashed motor that needs to be rebuilt').
Hope that helped. BTW OP, "guns up" aggie. Should be a hell of a game this year, but i think my red raiders will be comming out on top!
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Thanks for the help everybody. I wasn't worried about making over 500 hp, more just about the longevity of a mildly modified motor. The expanding bolts and spun bearings is along the lines of what I heard. Anybody know where I could find out more about this?
As for the Tech game, we shall see....
As for the Tech game, we shall see....
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From: Shillington PA
I wouldn't push any stock bottom end LS1 much past 500rwhp, especially if it's your daily driver. Also, just don't go with a cam that requires you to rev to the moon - do your research - there are smaller cams that put up great numbers and will be much more streetable. Info stated pertaining to rod bolts is correct. I believe the switch occurred in the late 2000 model year so some of the 2000's built towards the end also recieved the upgraded rod bolts. In any case, make sure the bottom end AND the valvetrain is built to handle whatever RPM you're spinning depending on your cam choice.
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I was quoted $750 installed for stronger rod bolts at New Era Performance. Most of that is labor since you either have to remove the motor or drop the K-member to install them. But a lot of people end up spending 5-15K for heads, cam, intake, suspension, ect. So spending another $750 for piece of mind when you want to spin a bigger cam high seems justifiable. At least in my opinion.
Last edited by darrensls1; Jul 23, 2008 at 03:24 PM.
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