Justin S2

I was reading a thread about connecting rod failures in the early 968 motors. The 944 S2 supposedly uses the same connecting rods. Has anyone actually heard of an S2 engine failure due to the connecting rods? Is there a significant weight difference between the late 968 and the RARST rods used in the late turbo motors?

Also, are the connecting rods the same dimensions between the late turbo/late 968 rods and the s2 ones?

Thanks!

Voith

Rarst are forged, rest are cast. Dimensions are same but rarst have angular shoulders, S2 are round. Rarst will probably interfere with S2 griddle, but that can be
solved with dremel tool.

740grams without bolts..

Justin S2

Voith, thank you for the information. Can anyone confirm that the connecting rods will interfere with the S2 crankshaft/girdle?

FRporscheman

I don't know for sure about the interference issue. But most of the times there are such issues, it'ss when a 2.5L block is stroked with the 3.0L crank. However, a 3.0L block has reliefs to allow for the longer stroke (I just don't know if those reliefs are big enough for the 951 rods).

I've never opened up an early 968, but I've seen inside of a few later 968s. Their rods look pretty slim/light. They are forged (people scoff at this, saying they're only sinter-forged, but if you read the 951 manual, those RARST rods are also sinter-forged).

I have also opened up an '89 S2 engine, and the rods look pretty much identical to the 944 NA rods.

What makes you ask about failures? If an engine is taken care of and never pushed beyond its design parameters, the internals should last for ages. In reality, if you don't boost it, the rods shouldn't give you problems.