Generation IV External Engine - Highest RPMS without touching internals?
06-06-2009, 12:58 AM
Im just curious whats the highest rpm you guys have gotten these to (without breaking crap) with the stock short block
06-06-2009, 01:18 AM
What motor? LS2 | LS3 | LS7 | L92 is the area your in.
06-06-2009, 01:36 AM
the ones that apply best to me would probably be the ls2 and ls7 but im just looking for a ballpark on the limits of these things
BES Stroked Nova
06-06-2009, 04:24 AM
well, with ARP rod bolts I have had mine to 7800 several times, and a couple over rev's from the clutch sticking to 8200... stock crank rods and pistons out of a 08 LY6 6.0L put into a 07 GMPP block.
as far as power, it dynoed 580 at 7400, and thats prolly 500+ at the wheels and I have ran 2 bottle's of a 150 shot through it too.
tough enough for ya??
06-06-2009, 10:46 AM
An example, but its only an LS1. I spun my LS1 with 21k on it to 7200 rpm...
06-06-2009, 12:23 PM
I take my LS7 to 7,200 all the time.
06-07-2009, 06:35 AM
22K miles 7200 here (LS1)
06-07-2009, 07:09 AM
Broke my LS1 at 6500 rpms constant shifting at 84k miles. Some guys get 200,000 miles and over and some guys break them at 34k miles. Push the engine beyond what it was built for and you should be prepared to break something.
06-08-2009, 10:48 PM
i dont see why a stock ls2 wouldnt turn 7000 even with stock bolts.. i would advise to upgrade to arp bolts tho.
06-09-2009, 12:36 AM
thanks im not going to be doing anything too soon i still have 3.5 years and 80,000 miles of warrenty left.... so for now its any bolt ons i can find for this fricking thing
06-09-2009, 08:46 AM
im in the same boat with warranty bolt ons for me right now.. and im debating nitrous for the time being.. but as soon as warranty is up in 2 years.. im doing rebuild with cam and heads! 550whp in my future with nitrous on the side ;) plenty good for me..
06-11-2009, 10:55 AM
i know of a 4.8 turnin 7200-7400 without any problems
Has anyone actually broke a stock rod bolt? or is is the stretching under load factor?
06-12-2009, 10:48 AM
stretching is the issue.. i havent heard of any bolts breaking under stress such as this.. however i wouldnt risk it, arp is always a good safe insurance.
It's more of a function of piston speed, not rpm. For example. the ls7 has a 4" stroke, piston speed is higher at 7200 rpm on that motor than say 7500rpm on a stock ls1. U are moving the piston at a given speed, and then instantly making it change directions and still move at that speed. This is where the weight and durability of the rods and pistons come in to play. Heavy parts and weak bolts= failure. Gm used ti rods in the ls7 and prolly shed 100+ grams of reciprocating mass, this increased high-rpm durability. Another thing to consider is HOW LONG u want to spin it that high, the oiling system in these motors will not tolerate prolonged high-rpm w/o modification. Oil pressure goes away and all bets are off, your engine will now fit loosely in a 5-gallon bucket.
06-18-2009, 02:38 AM
i spun my ole 100k ls1 to 7500 many many times... i ended up stretching a rod/bending a whrist pin and it went click click BOOM