lq4 teardown - how far to go
- Thread starter dns87
- Start date
Don't touch the bearings. I would put a set of rod bolts in from ARP or Katech for insurance. Also an LS6 oil pump and LS2 timing set. That's just what I did you do whatever your budget allows.
just remember. at about 400 hp that stock bottom end is just about at its max. be careful what you throw at it.
327mali said:
Where did you hear that? My junkyard 6.0 makes every bit of 460hp, bone stock bottom end including bolts.
Truck cranks are known to last to 1000hp, rods and pistons usually start to let go up over 700hp. Nitrous/boost w/ poor tunes kill the factory cast pistons, otherwise they can live a long and happy life. Just ask parish who ran a stock 6.0 bottom end into the high 10s if I remember in a 1/2 ton pickup, or ran a bone stock 5.3 w/ cam into the 9.30s (dyno'd up over 600hp at the wheels) in his turbo fairmont.
GM did a dam good job w/ designing and building a motor that is reliable and can take a beating. The single biggest problem with LS bottom ends are the rod bolts (early motors mainly). Swap these out and have fun. I use to go thru the traps w/ my motor at 6800 and its been spun to 7000 on occasion, I haven't even touched my bottom end.
78Bu88SS said:
http://www.maliburacing.com/forum/viewtopic.php?f=29&t=78113
thats actualy a friend of mine. both times the car made a few passes. was pushing somewhere around 400-500 hp n/a. rods came apart like they where a bunch of pencils. both motors where stock bottom ends. the motor is a awesome design. the rods and pistons they cut costs on.
turbo motors seem to hold together maybe because the compression on the piston is forcing the rod to hold together. im not totally sure. thats the only thing i can think of.
I remember reading thru that post, you can't blame factory rods and pistons on the fact the TTY rod bolts weren't replaced when the caps were pulled.
Rods can fail for a few reasons. The big one is when the piston reaches the top of the bore and is switching directions, the force created by this is huge (and has just as much to do w/ RPM as it does with power) and puts the most force possible on both ends of the rod (IE rod bolts and wrist pin). Boost has nothing to do w/ a rod staying together, plain and simple. The heavier the piston, the stronger the rod has to be to withstand the same RPM and power, since its trying to stop a larger mass and make it switch directions.
Seriously go searching on LS1tech or even google it, you will find 100s of stock bottom end LS motors surviving countless poundings w/o any issues. The earlier motors had problems w/ the #7 piston letting go (this tends to be leanest cylinder) and rod bolts typically were always said to need replacing up over 6500. The later model LS engines (mid 2000s) got better and had better bolts from the factory. Like I said, do some research. There is no reason why a stock bottom end LS motor should blow to pieces making sub 500hp, that comes down to whats been "done" to it and the tune.
Rods can fail for a few reasons. The big one is when the piston reaches the top of the bore and is switching directions, the force created by this is huge (and has just as much to do w/ RPM as it does with power) and puts the most force possible on both ends of the rod (IE rod bolts and wrist pin). Boost has nothing to do w/ a rod staying together, plain and simple. The heavier the piston, the stronger the rod has to be to withstand the same RPM and power, since its trying to stop a larger mass and make it switch directions.
Seriously go searching on LS1tech or even google it, you will find 100s of stock bottom end LS motors surviving countless poundings w/o any issues. The earlier motors had problems w/ the #7 piston letting go (this tends to be leanest cylinder) and rod bolts typically were always said to need replacing up over 6500. The later model LS engines (mid 2000s) got better and had better bolts from the factory. Like I said, do some research. There is no reason why a stock bottom end LS motor should blow to pieces making sub 500hp, that comes down to whats been "done" to it and the tune.
im gona break this down to logic. if you know the rods are powder pressed and they have an issue including the rod bolts. wouldnt you want to just go out and buy a new rotating assy just to know your bottom end is good. if a rod lets go it just doesnt knick those blocks. it take the ENTIRE motor out in 1 shot. block/oil pan/heads/crank/cam. if your willing to buy another complete motor thats 1 thing. but for the extra money id rather put the good bottom end in which is exactly what i did on my motor and made it a 408.
have you actually look at the one of those rods? they take the rod, freeze it. then bust the top of the rod of to make that cap. thats pretty cheesy if you ask me. the motors are awesome motors. as for the rods and pistons....i wouldnt take the chance and i didnt. especially if you have a good set of heads on the motor like i do which are 3500$ mast heads. id rather not have the piston smack that head.
have you actually look at the one of those rods? they take the rod, freeze it. then bust the top of the rod of to make that cap. thats pretty cheesy if you ask me. the motors are awesome motors. as for the rods and pistons....i wouldnt take the chance and i didnt. especially if you have a good set of heads on the motor like i do which are 3500$ mast heads. id rather not have the piston smack that head.
After seeing what stock bottom end LS motors are capable of, I don't plan on running anything else unless I truly plan on hitting it with some ungoddly power. And if I pop a stock 5.3 or 6.0, who cares. I'll go the junkyard and grab another, maybe a 6.2 since by then those will be popping up.
And yes I've seen the rods, they look like a stock rod that didn't cost a mint to make, yet work pretty dam good...
And yes I've seen the rods, they look like a stock rod that didn't cost a mint to make, yet work pretty dam good...
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