So I have a friend telling me that a stock cube LS1 doesnt NEED a forged bottom end in 700+ crank HP and 14+ psi boost applications. Needless to say, I need a second opinion.

 

You don't really need a forged crank but you will definately need pistons and rods

 

Yes, to clarify, we were talking about the rods and pistons...not the crank.

 

You need rods, it might make it for a while at that level but your gambling with your short block and thats something that I wouldn't do.

Your best off saving up another month or two, getting a set of forged rods with ARP rod bolts, new -dish pistons and getting it done right! Build it at the optimal compression ratio for your power level (Probably 8.5:1) and then put the boost to it.

 

Boostaholic, I totally agree with you and thats what I had planned on doing once I wanted to make it to that power level. But now I have this friend telling me that I dont really need to do it. It just struck me as dumb considering what a lot of guys on this forum have done to their short blocks to support that kind of power output.

 

does your friend have or work on a 700rwhp ls1 with stock rods and pistons?

i bet the answer is aNOha.

 

Your friend is right, you don't have to do anything, but is it better to swap out the rods and pistons on your good block or break a rod and replace a lot more ****?

Like I said, its gambling, some people win others loose

 

I believe the most he's worked on is a 600 hp N2O powered LT1, building and tuning.

 

700 hp at the crank is around 600 rwhp. With good fuel and a very good tune it is doable on a stock bottom-end. 94 Octane + Torco or AI would definitely help.

Mark

 

If something goes wrong with FI, it will take a piston out in a hurry. Do the forged rods and pistons and be done.

 

600 Flywheel u COULD get away with it,anything more your on borrowed time...
JMHO....

 

Friends don't let friends boost stock bottom ends :/

 

We have hit ALOT of stock bottem ends with ALOT of power. Some lasted......some didn't

Pistons: They will do fine with boost as long as there isn't any detonation or excessive heat. The top ring is very close to the crown, and as such any kind of abuse to the piston will usually result in a pinch/cracked upper ringland.

Rods: We have beat the absolute hell out of the stock rods. Prior to the price of rods going down (~ 2 years ago), alot of builds used to retain the stock rods simply because of cost. I run 700 RWHP to a bushed/studded stock rod. Remeber that 700 RWHP on a supercharger system is about 950 HP at the cylinders (prior to supercharger parasitic losses). And I beat the CRAP out of my car on a regular basis.

I have seen plenty of broken pistons, maybe 1 rod separated at the rod bolts, but I have NEVER seen a rod split. You can run the stock bottem end for high horsepower, you just have to be conservative with the setup (lower compression, timing, and rich fueling).

 

... And RPMS, stock rods don't like high rpms for sure, at a minimum get some good rod bolts in there if your going to spin it fast.

 

I have stock rods and pistons, forged pistons, ARP bolts, and I won't take my car above 561rwhp on 9 lbs of boost. With a good tune and the addition of methonal I will likely add 1 or so more lb of boost to give me 600 rwhp with a VERY safe tune, I am still worried about my rods though.

 

Nogo would know as he has dynoed ALOT of setups w/FI.....
IMO though anything over 550RW I'd run good internals,just for piece of mind.

I could detonate my NA setup and probably not hurt it,Do that under boost and IMO the piston will lose a ring land quickly.I cant stress enough that the most important thing in a FI w/stock internals is fuel,tuning..

Thats why u need a qualified tuner like NoGo or Slowhawk....

 

Why chance a 4000 dollar motor for 500 dollar rods? Sure, the stock rods may be OK for what you want to do, but is the 500 dollars you save now worth a couple thousand if you throw a rod and window your block?

 

I agree.

For the price that you can get pistons and rods now for these motors why not build them all the way up.

 

Your friend needs to get out more

 

Plus the sleep and night factor and the ability get up on the pipe w/serious boooooost