jaetee

Hi gang,


A spun rod bearing (cyl 6) is forcing an engine rebuild. Since there is no additional labor charge involved with using the original connecting rods (of which I had to replace one) vs. installing aftermarket rods, my machine shop/short block builder is suggesting I consider purchasing a set of aftermarket upgraded forged rods. He did not give me a recommended brand, but said that rods are common failure failure point in engines that have had other internal upgrades performed. In my case, we are going from 3.4 to almost 3.6L via larger bore and a set of aftermarket Wossner pistons & rings.

Have any of you ever heard of, or better yet, actually used these "Titanizing Forged 4340 aircraft chrome moly quality steel" connecting rods in a 996? Pankl & Carrillo rods are over $1500/set and I don't want to go there... but these seem to be a decent deal.

I just wonder if it's really necessary vs. the risk associated with using OEM rods. Are the OEM rods one of the known 545 modes of failure for this engine too?

Here are the $800 set of conrods I'm looking at:

http://www.ebay.com/itm/Connecting-R...VWqIBr&vxp=mtr


Any constructive thoughts/suggestions greatly appreciated!

JT

strathconaman

Unknown Ebay connecting rods seem like a bad idea.

jaetee

Agreed. Hence my inquiry...

white out

I can get Carrillo rods. PM me if you're interested.

JohnCA58

You would be ok if you upgraded your OEM rods to use ARP bolts. most failures come from the OEM rod bolts.

TonyTwoBags

^^ignore what I wrote

I've seen at least one thread by a turbro noting the same looking eBay c-rods that weren't even in his rebuild plan but the builder used them anyway. Motor blew up along with the $25k he spent on the rebuild.

you get what you pay for

Billup

Don't skimp on one of the main life forces of the car.

Ebay internals are a joke on pretty much all accounts. They are throwing out extra words with 4340 steel, when pretty much most rods are made from 4340 or 300M, so it's not exactly a breakthrough WOW that isn't standard. Not to mention I don't see where titanizing would help since that's mostly for wear and not compression stressors.

You have to remember, there is a reason rods cost a certain amount, whether it be I-beam, H-Beam, aluminum, titanium, steel, etc. A quality company is going to use FEA to make sure the rods are going to hold up at their weakest points, and improve on those spots, so you're also paying for R&D. Ebay rods are probably forged, machined to less standard of tolerancing, and thus losing quality in areas that could cause catastrophic failure.

Like said above, you get what you pay for. Metallurgy is no joke when it comes to internals.

sfv_rider

A set of aftermarket rods from LN Engineering are nearly the same cost as a set of OEM rods, which are supplied with the questionable rod bolts.

The LN Engineering rods are the ones I'd go with. I know comparatively little about Carillos, but I know their positive reputation from other applications.

Chris(MA)

ASFAIK rod bolts are the weakest link of most rods, except really badly designed rods.

I haven't heard of many 996 rod fails that weren't traced to the bolts letting go.

Mike Murphy

I haven't heard of rods or rod bolts failing on M96 engines. It's pretty standard on some Ford, Chevy and BMW designs though.

Porschetech3

Those E-bay rods your looking at will not fit a M96 N/A engine..those are for a Turbo/GT3 Mezger engine. There are no E-bay rods for M96 N/A engines. The only after market rods I know of are the LN(FAA),R&R, Carrillo , and Pauter. all these are $1500-$1800.

The stock rods are a forged/sintered powdered metal. They are good for there intended purpose, high performance street with occasional track days.

The rod bolts have been known to fail(although usually they fail from a spun bearing).The part number has been updated a gazillion times (99710311501)and now ALL M96 N/A M97 N/A and Cayenne V8 Panamera V6 and V8 Porsche engines use the same rod bolts. There are hundreds of thousands of them out there screaming every day, so they must be OK But the Porsche rod bolts can only be torqued a maximum of 4 times (1 time is used during manufacturing, you use 1 for measuring rod/bearing,so that only leaves 1 after installation) and the ARP2000 rod bolts can be torque many times. +1 for the ARP2000

If your someone that lays on the rev limiter or intend to do lots of track days or club racing , go with the aftermarket traditional H-beam or x beam (Pauter) forged rods.

Rickard 993 Turbo

I need a short set.. 127,8mm

Pdyson4