[Ryan]

OK...I have seen the difference between the early rod design and the changed version. Was there a problem that caused Porsche to change the design or was this just an improvement? The early rods were forged, so they were no slouches compared to many other makes. If it was a problem, why wasn't there a recall?

That being said....I have never heard of a failure. I am wondering this because I have a 92 and I know this was a year with the early design.

When was it changed?

Was the S2 rod the same?

Anybody got definative info on this????

Thinking of the S/C and results from added forces.

[img]style_emoticons/<#EMO_DIR#>/unsure.gif[/img]

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[Johannvb]

I was actually wondering if the change to the newer rods didn't have something to do with money. Porsche removed many things from the later cars to cut prices and save costs...so i'm just thinking maybe this was one of them?

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[flash]

they changed the rods for reasons of failure - it was in a tech bulliten

This is covered in Technical Bulletins, Book K, (PNA 000 082E)
Jan 1994 - Dec - 1994 page 11.

For the 968, "as of October 1, 1993, engine #42R0958 - #42R50621"

#944 103 111 2R (17.0mm thickness) vs. the original casting #944 103 111 1R (10.0mm thickness)

while it was the bolt surface area that was addressed, as far as we have been able to figure out though, it was due to an rpm thing, and not a compression stress thing

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[Dubai944]

I ran a full race season last year naturally aspirated and half a race season this year low boosted, and my early 968 rods look perfect. I haven't bothered to have them crack tested, but they seem to have held up well to some hard duty, so they will not automatically self destruct with normal rpm.

Having said that, Santa did bring me a set of Arrow con-rods which are going in now as I will be running a bit more boost...just in case!

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[Ryan]

Good to hear about the raced and boosted engine with no problems.

Are the tech bulletins available anywhere?

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[flash]

i would caution against saying "there were no problems" - this is perhaps one case where they did not fail......yet - we also have not seen the rods yet - maybe they are ok - maybe they aren't

we know of quite a few engines that have broken early rods, so it is a reality

the other reality though is that porsche went out of their way to generate a tech bulletin about this, create a new part, and advise people to change them to the new part

none of these were boosted engines, which can only add to any stresses

if indeed it is an rpm related issue, there is a theory that a boosted engine would actually put LESS stress on the rods, as you would be shifting earlier due to that increase in power coming on earlier, and not need to hold it at 6k to maintain power

we really just need more data before we can suggest that it is "ok" to keep the early rods - if one fails, you just bought a motor - that's a pretty big risk for most folks

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[Scott Collins]

Flash et al.,

I have been following this discussion and appreciate the information that has been collected and shared in this community. One aspect of the 968 that I value is the fact that the car has been around and put through its paces on the street and track. And since there are many owners who are skilled and knowledgeable with this and with cars in general and who participate in discussion here and elsewhere, we are all better for it.

I am just about to hit 79K miles in my '92, and in the next couple of years I will be continuing the regular upkeep of the car, with special interest in performance upgrades along the way. I don't see the beefed up rods for sale at the usual places and wonder where we get these for the upgrade that Porsche recommended so long ago.

Tomorrow, I pick up a minivan (Hyundai Entourage Limited) to replace the Toyota Avalon, because Collins #3 is due in March. This means that the 968 is safe where it should be, right under my back yard! I believe that my car has benefited by being driven every day and I plan on doing that for some time to come.

Happy New Year to all. Cheers!

-Scott

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