Are the factory powder metal rods forged????

 

No they are powdered metal which is a differnt manufacturing technique. They are however stronger and cheaper than the "pink" GM forged rods everyone loved for decades,new aftermarket forgings should be stronger yet.

 

So I should go with say a 5140 forged rod. The powder metal rods are good to 500hp right? So Ive heard forged rods are only good for 500hp also or is it 1000. Steel cranks only good to 500hp. I'm building a 383. Will stock rods hold up?

 

Get 4340 forged rods(Howard=800+HP),forged aluminum pistons(Probe)and a 4340 forged crank(Scat) and that will stand up to most anything ya throw at it 900-1000FWHP, Your block will not last long at that power level,even a 4 bolt factory block. An aftermarket block would make it bullet proof.

 

The stock rods have proven pretty reliable at that level BUT for the cost of rebuilding them you can get aftermarket pieces.

 

Why would i have to rebuild the rods?

 

I just read that the 5.7" LT1/LT4 powdered metal rods can be used up to 500hp and they are 4340 forged steel rods

 

Might want to look at it again...

 

I am not in the mood to write a book. But briefly, "powdered metal" (PM) is a manufacturing process. "Forging" also describes a specific method of manufacturing metal parts."4340" describes a specific steel alloy. 4340 is used for high end forged rods and cranks. 4340 is NOT used (to my knowledge) to manufacture rods via the PM process. IOW, it is not typical usage to refer to PM rods as "forged rods". The manufacturing technique (as well as the material) is different. If you wanted to refer to PM rods by the manufacturing technique and material, it would be accurate to say they are "sintered powdered metal rods", but that is not common usage and might be confusing.

From an article on Howards PM rods: The new rods are made from sintered powder metal, a specialized mixture of metallic elements that is pressed and heated to form super-strong, lightweight parts. It's an alloy part, really, and sintering is the heating process that bonds the powdered elements together, but without melting them. (Some elements in the powder mixture are added for their bonding capability.)

The elements of the metal composite mixture, like the Colonel's chicken recipe, are a secret GKN Sinter Metals keeps close to its corporate chest. There's not a single magic formula for all powder metal parts, either; it varies from product to product, with the Howards Racing rods using a mixture different from other parts manufactured by GKN, with the primary component being ASTM 4260 steel.

http://superchevy.com/technical/engi...510sc_howards/

Rich

Addendum: part of the process used to make PM rods nvolves a "forging" operation on the rod. But it is still misleading IMO to call a PM rod a "forged rod".

 

http://web.camaross.com/forums/showt...highlight=rods

 

Well this is the GM's specs that they gave me.

High-performance rods on a low budget.
Put a set of GM Performance PM connecting rods in your engine. They are guaranteed performers and have been proven time and time again in the popular LT1 and LT4 engines. Whether you're rebuilding your late model or putting together a budget street pounder, a set of PM rods will get the job done. These powdered metal rods are lighter and stronger than the GM "pink rods".

Connecting Rod Length Center To Center (in): 5.700 in.
Connecting Rod Beam Style: I-beam
Connecting Rod Material: Powdered metal
Connecting Rod Finish: Polished and shot-peened
Wrist Pin Style: Press fit
Clearanced for Stroker: No
Cap Retention Style: Thru-bolt
Connecting Rod Bolt Brand: GM Performance Parts
Connecting Rod Bolt Diameter: 3/8 in.
Connecting Rod Bolt Material: 4740 chromemoly alloy
Fastener Yield Strength (psi)VL: 140,000 psi
Connecting Rod Bolt Head Style: Hex head
Pressurized Pin Oiling: No
Big End Bore Diameter (in): 2.100 in.
Pin End Bore Diameter (in): 0.927 in.
Advertised Horsepower Rating (hp): 500 hp
Advertised RPM Rating: 6,500 rpm
Weight Matched Set: No
Remanufactured: No
Balanced: No
Magnafluxed: Yes

That's the truth about it all.

 

Not 4340 but 4740 chromemoly alloy which is said to be as strong as 4340.

 

I would have to see the test on that. The overstressed cycle to failure test.

 

Thats the bolt material, not the rod material

 

Of course, thanks for the correction. The powdermetal is still great.