would it be stupid to just install forged rods and pistons instead of a complete forged rotating assembly if i plan to boost to only 10 psi?

 

heck i bet the stock bottom end would handle 10 fine. Seems like a waste to get into the engine that deep and do rods and pistons and leave the stock crank. might as well spend the extra and get a crank.

 

Bingo.

 

it seems the things people are breaking on these motors are the rods, and the spot where the rod connects to the piston. I also heard that the crank was forged from the factory but I don't know if that is true. Is it possible to swap the rods and pistons without removing the crank?

reason i ask is I figure it might be a cheaper, quicker and easier way to go to add a little extra insurance when going forced induction without having to cempletely dissasemble and rebuild the motor... just figured i would ask and see what the experts thought

 

The only difference in the labor without changing the crank would be not removing the crank. You have to completly take apart the motor anyway to get to the rods/pistons. The stock crank is not forged anyway. I honestly laughed the first time I saw the rods from these engines, they are a joke. At 10 psi you should be ok though. It's all in the tune.

 

Yes, I'll second that. Your question seems to imply you think you can just pull out the rods and replace them. In order to do any work on the internals you must take th engine out of the car, break it apart, and remove the internals. There really isn't a cheap way to do it. At a minimum, you are going to pay to replace all of the seals, most of the bolts, all of the fluids, and you'll also have to remachine the block before it gets reassembled. That's why everyone is telling you to go for the whole thing, because you are looking at a minimum of $5-7K in parts and labor to swap internals.

-Darth

 

and that is why I asked

 

Darth I think $5-7k might be a little high. It can be done cheaper. And done right cheaper too. As far as replacing the crank...I've never heard of a stock GT crank breaking, thus I won't be replacing mine when I build my motor.

 

Actually, his estimate of 5-7k is right on. I am having mine rebuilt right now and that is dead on for the cost...While the stock cranks aren't breaking, if you want 700hp + at the crank the safer and smarter thing to do is spend the money on a Cobra crank...

 

You will be fine doing that.

Im going to throw in a good set of rods and slap it back together. How many of you have seen a crank or one of our pistons break?

 

You should be fine. Then you dont need to change to a Cobra flywheel either.

 

The pistons have been problematic. The rings are seated really high on the pistons and that causes them to be weak. Hence being called hyperpathetic pistons. The only reason you don't see cranks breaking is because the rods go before the crank has a chance to take any of the damage. Throw some nice rods and pistons in there and you will only find out what the crank's breaking point is. Maybe it's 550rwhp? Maybe it's 600rwhp? Why bother guessing or taking a chance, just replace the **** thing.

 

For him its a waste of $$$$$.


maybe to see where the limit actually is. How many pistons have YOU seen break? 9 times out of 10 its a tuning issue anyway with pistons. And for the GT crank there are several guys pushing 700 to the wheel and are just fine. Its just the fact that now one truly knows where the limit of the GT crank is they just blindly spit out what they read on the net as fact. It may well be 600 who knows.