gollum

iTrader: (1)

These heads will also require COMPS. HD roller lifters because of the 7000 redline these heads are capable of. The stock lifters will not handle the stress. Or will they?

VTESPEED

iTrader: (12)

no...

99C5JA

The real question is will your bottom end take 7000rpm reliably? I don't spin mine past 6500rpm and that is only when I'm racing. Most on this board will not recommend any higher than 6500rpm without at least replacing the rod bolts.

PREDATOR-Z

LS1 6500 >> 6800 (on occasion) depending on mileage
LS6 6800 >> 7000 (OK)

The lifters are not an issue of rpm or duration but more an issue of lift stress. Up to .600 no problems after that ????

I am replacing mine with Comp replacements for a XE-R .581 cam with PP "gold" on AFR 205's.

goober35

iTrader: (1)

i put in XE-R because i had a dead stock one. I would look into a new bottom end before you look into lifters. You will need the cash if you are spinning 7k. Stock bottom ends dont last long at that kinda rpm.

PREDATOR-Z

The weakest link (Assuming you are not over 50>60k) are the rod bolts.
Change those to ARP along with ARP main cap bolts and you can do 7000rpm all day long.

goober35

iTrader: (1)

Yes i do know that rod bolt stretch is what will kill the motor. Hins the pic i posted. But it is a bitch to replace bolts in the bottom end with the motor in the car. I would do it all at ones not just the bolts. O and i think the main cap bolts are a wast in his aplication.

PREDATOR-Z

Agreed on his application. I was just saying for LS1 in general.

Changing rod bolts is a PITA with motor in but not impossible. Hell putting the O ring on the O-pump is a PITA too.

In my case since, i'll be changing the tranny at the same time with H/C. I decided to drop the motor anyways so I'll change my bolts just for peace of mind and to take a look at the bottom end (45K).

goober35

iTrader: (1)

I would not want to do it. I have pulled the pan and the from bolts look like they would suck donkey ***** to do.

PREDATOR-Z

I did it on my Ex Y2K Z in about 3 hours.

Lift motor
remove pan
Remove windage tray and pick up tube
change rod bolts, rotate crank, change another and so on.
put everything back

Changed my motor mounts to poly while I was at it.

Not really that bad but a lift is really helpfull.

Bowtieman4life

iTrader: (1)

The ARP bolts may help but I doubt it will last very long a 7,000 rpms. Most cars that spin that kind of RPM have forged bottom end. We don't. Then again I tend to play on the safe side of the fence when it comes to motors.

PREDATOR-Z

They will do more than help. Many "forged bottoms" that tickle the 7K range do not have forged cranks. Just rods and pistons. Most crank failures on modded engines are due to bad harmonic controls.

I'm not talking "road race in the 7's" I'm talking reving untill then changing gears.

LS6 blocks fair much better because of the better crank oiling journals (Non existant on LS1)

I've blown 2 motors on Nitrous (one by detonation "ring failure") and (one by rod bolt failure) only reving till 6300 but on a 200 shot/wet.

I agree completely that a fully forged bottom will take more abuse (Reliability), but the stock shotblock will fair pretty well to 7K with ARP bolts.
All modded engines have reduced life.

Now TTT the stock lifters will be good to 7K if there is lifts below .600 (Assuming preload is done correctly)