600HP on stock crank?

[Rickey_Bobby]

Ok, everyone has heard that the 4.6L grenades at 500HP...
And everyone knows that its because of the powered metal rods.
...And everyone says "if u build the motor, put a forged crank in!"


...but what if you dont? what is the limit of the stock crank?

..not the whole motor, but JUST the crank.

All I want to do is put 500 ft/lbs of torque to the rear wheels.
I don't want to buy stuff that is overkill.

 

[Red2000GT]

If you keep the rpm at 6000 or less you should be fine. Yes,you don't have much room to play on the tune though.I wouldn't feel safe running much more hp than that.

 

[Rickey_Bobby]

sweet, now another thing....
I saw that many piston/rod kits come in std size..... Can you really drop in a piston w/o boring the cylinder? just do a fresh hone and drop them in... I was under the impression that you should bore the block to fit the pistons... which makes a lot more sense.

 

[jstreet0204]

Ok, everyone has heard that the 4.6L grenades at 500HP...
And everyone knows that its because of the powered metal rods.
...And everyone says "if u build the motor, put a forged crank in!"


...but what if you dont? what is the limit of the stock crank?

..not the whole motor, but JUST the crank.

All I want to do is put 500 ft/lbs of torque to the rear wheels.
I don't want to buy stuff that is overkill.

The stock crank is pretty strong. Many people try to put a number on the hp limit, but I have yet to see hear of one actually failing.

 

[LaserRed01GT]

I don't think there is any magical HP rating for any stock crank. There are so many variables between different motors.

I have also never heard of or known anyone to break a stock 4.6 crank.

 

[Rickey_Bobby]

Cool. Ordering the rods and pistons now.
What is a decent price for a shop to bore the block .020 over?

A place here local called yow's wanted $400 (seems high)... and when I asked if he used a torque plate he sounded like he didn't know what it was.

 

[mrvax]

I always hear the stock rods will let go at about the 400 HP range.

 

[Dan_Soprano]

if you are going to spring for new rods and pistons, do yourself a favor and send it to a reputable shop to get machined, assymbled, balanced and blueprinted. You will be way better off in the long run. Also, make sure they use all new bearings, and QUALITY hardware.....AKA: ARP bolts and studs.

 

[gtsr281]

that much TQ I would build the motor from top to bottom, I have recent EXP with blowing **** up because no matter what hear say you may have, anything stock is not to good considering you have boosted the HP/TQ by almost 300. Dont forget about the Trans, and rear end, all that needs to be considered.

 

[LaserRed01GT]

I would agree that if you are going to have the shortblock torn down anyway, you might as well go with a nice forged steel crank. There are a few aftermarket forged cranks out there that are much lighter than the nodular iron stock crank. Even the Cobra and FRPP forged steel cranks can be heat treated and knife edged for even less rotating mass and reduced windage.

Always make sure the shop doing you work maganafluxes not just the block but the crank as well. They should also check the crank for straighness, inspect and micropolish the journals, and properly balance it.

Most shops nowadays will automatically square and ensure the block decks are truly perpendicular to the crankshaft centerline, but just make sure they do. Also before they perform the final hone on the block they should AT LEAST use a torque plate or fixture, but most of the reputable machine shops now will additionally use a hot oil injection machine to keep the block at a simulated normal operting temp before performing the final hone. Also make sure you tell the shop what rings you plan on using. That can effect what is called the roughness average of the final hone.

One more thing....make sure they properly align hone the main bores with the main caps properly registered and marked.

There is alot more to the block prep process, but I was just trying to think of some of the important factors that stood out in my head.

 

[WillDuhhBeast]

I would agree that if you are going to have the shortblock torn down anyway, you might as well go with a nice forged steel crank. There are a few aftermarket forged cranks out there that are much lighter than the nodular iron stock crank. Even the Cobra and FRPP forged steel cranks can be heat treated and knife edged for even less rotating mass and reduced windage.

Always make sure the shop doing you work maganafluxes not just the block but the crank as well. They should also check the crank for straighness, inspect and micropolish the journals, and properly balance it.

Most shops nowadays will automatically square and ensure the block decks are truly perpendicular to the crankshaft centerline, but just make sure they do. Also before they perform the final hone on the block they should AT LEAST use a torque plate or fixture, but most of the reputable machine shops now will additionally use a hot oil injection machine to keep the block at a simulated normal operting temp before performing the final hone. Also make sure you tell the shop what rings you plan on using. That can effect what is called the roughness average of the final hone.

One more thing....make sure they properly align hone the main bores with the main caps properly registered and marked.

There is alot more to the block prep process, but I was just trying to think of some of the important factors that stood out in my head.

I just want to say that this was a spectacular reply. He's right on.


An engine, especially ours, is not something you should just try to get by on.

 

[XxMustang281xX]

how much will a 4.6 GT stock block handle? just the block?