Thread: sbc chev zz4

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There are several GM part numbers associated with “high performance” connecting rods. The one most people are familiar with is:

14096846 – referred to as “Pink” rods. These are a forged assembly and very desirable. This rod is made from the well-known heavy-duty 1038 steel. It starts as a “select rod” from the forge and then it is Magna-fluxed, shot-peened, heat treated and balanced as a set. GM slapped pink paint on them to differentiate. It’s the common rod in the 350 HO engine and was used in the 1970–1972 LT1, 1970–1974 Z28, and all L82 350s. A heavier-duty version of the same rod is PN 14095071. (It’s possible for early run ZZ4’s to have either of these “Pink” part numbers.)

10108688 - referred to as “Powdered Metal” and are the replacement for the old "pink" rods however; they are not interchangeable and should be used only as a complete set due to the weight difference between these rods and all others.

In 1994, powdered metal (PM) rods emerged with new technology. Some forged rods were still being used, but the PM rods gradually filled the pipeline on LT1 and LT4 engines. The new rods are literally made from sintered “powdered” metal that is pressed and heated to form super-strong, lightweight part. PM rods are really an alloy and sintering is the heating process that bonds the powdered elements together just shy of melting them. The process typically includes a bonding element in the powder mixture to further strengthen the final product. They are a minimum of 2x as strong as the old school “Pink” rods. All engine manufacturers have pretty much converted to PM rods.

As a side note - the PM rods also use a "cracked” or “fractured" cap. The rod and cap are forged as a single piece and the cap is carefully split apart afterward. The idea is to create a very precise fit that is ultimately stronger and better sealing than machined rods and caps.

It goes without saying – really good bolts are standard. ARP for any rebuild..

Regards ,
Glenn

Originally Posted by glennsexton

There are several GM part numbers associated with “high performance” connecting rods. The one most people are familiar with is:

14096846 – referred to as “Pink” rods. These are a forged assembly and very desirable. This rod is made from the well-known heavy-duty 1038 steel. It starts as a “select rod” from the forge and then it is Magna-fluxed, shot-peened, heat treated and balanced as a set. GM slapped pink paint on them to differentiate. It’s the common rod in the 350 HO engine and was used in the 1970–1972 LT1, 1970–1974 Z28, and all L82 350s. A heavier-duty version of the same rod is PN 14095071. (It’s possible for early run ZZ4’s to have either of these “Pink” part numbers.)

10108688 - referred to as “Powdered Metal” and are the replacement for the old "pink" rods however; they are not interchangeable and should be used only as a complete set due to the weight difference between these rods and all others.

In 1994, powdered metal (PM) rods emerged with new technology. Some forged rods were still being used, but the PM rods gradually filled the pipeline on LT1 and LT4 engines. The new rods are literally made from sintered “powdered” metal that is pressed and heated to form super-strong, lightweight part. PM rods are really an alloy and sintering is the heating process that bonds the powdered elements together just shy of melting them. The process typically includes a bonding element in the powder mixture to further strengthen the final product. They are a minimum of 2x as strong as the old school “Pink” rods. All engine manufacturers have pretty much converted to PM rods.

As a side note - the PM rods also use a "cracked” or “fractured" cap. The rod and cap are forged as a single piece and the cap is carefully split apart afterward. The idea is to create a very precise fit that is ultimately stronger and better sealing than machined rods and caps.

It goes without saying – really good bolts are standard. ARP for any rebuild..

Regards ,
Glenn

I have two LT1 assemblies in the garage. Should they have PINK's rods? One is a 94 and one a 96 I think? Both are 2bolt mains with alu. heads. I am just sittin on them. I have had them for at least 10 years.