Shark_Week

I have been reading much about the connecting rod issues with these engines(unfortunately they are 1R rods) and was hoping someone would break it down in new guy language for me. Should i not do anything, should i replace them, if so with what and can i do that somewhat inexpensively. (what a joke)
After reading all the threads it just has me concerned and would hate to do this much and have a different kind of failure. My wife said Porshe should replace them, as they should never of put those crap rods in there in the first place. She's funny. many thanks!!

JWise

Got any pics of the interior you could post?

Great work so far!

namasgt

You probably know more than the GTS rods at this point than me. But I remember reading that Porsche recommends changing them with 2R rods that came on 94 and 95 GTS engines, plus its suggested not to modify the engines with R1 rods for more power, they can break, that’s how weak they are I suppose. I don’t know anything about the 2R availability. You need to talk to people who actually have a GTS,
you might contact 928 international and talk to Mark Anderson,
and I understand your concern, GTS engine are rare and very expensive to replace if you can even find one. you definitely wana make the correct decision on the rods.
Good Luck

Shark_Week

JWise
i'm kinda cleaning up the interior at the moment, but it is in pretty good shape. just been neglected. dirty carpets, dusty, worn bolster on drivers side. there will more pics to follow i'm sure.
namasgt
maybe i have been talking to the wrong people but have not located any II R rods. i'm looking for a reasonable alternative.
any suggestions by anyone

namasgt

Look at post #3, Greg Brown (GregBBRD) can give you the information you need.

https://rennlist.com/forums/928-foru...tyle-only.html

Also If you have not read this thread, read it, it has good information.

namasgt

Also look at this link, they tell you were to get 2R rods.

https://rennlist.com/forums/928-foru...-chime-in.html

docmirror

There are two issues at hand here. The first is the 2/6 rod bearing. This is a function of several problems that come together to starve the journal of oil. It can be made better, but there is no guaranteed fix AFAIK. I had the lower cradle off, and cleaned up all the radii of the oil passages from the pickup to the journal service. I also took off all the flashing at the outside of the crank case V where the oil drains back down from the heads. This with new pump gears and a GTS baffle in the pan should keep the rod lubed well.

The other problem is the early GTS rods. I don't have a GTS so I don't know much about it, but I've heard of a very few breakages. Prolly at high RPM. So, if you're gonna push the engine, I guess it's a complete do over. Once the pistons are out, the rings should be replaced, and have the recip stuff match weighed and balanced. I had all my recip balanced. The only thing you can do to the bores is to just scuff it with a green scotchbrite pad and some kerosene.

It's up to you. I think the rods you have are suitable for highway, and some spirited driving once in a while. If you're gonna be on the track, and you drive aggressively I guess you gotta get the good stuff.

Also, talk to Roger at 928sRUS. He's doing some kind of deal on GT style cams right now. Ask him for details. That, combined with some injector work, and a bit of software tuning and you'll wake the engine right up.

namasgt

The technical bulletin from Porsche as mentioned in the above link is saying that once the 1R rod nuts are undone the rods cannot be reused. Talk to Greg Brown he has very good knowledge on 928 engines and looks like he has rebuilt several GTS engines.

Rob Edwards

If it were my GTS 5-speed, I would split the block, buy a set of the 2R rods ($1000), have the pistons drilled by Greg Brown ($??), measure the crank and get a new set of main bearings ($300-350 depending on 'regular' vs. 0.25mm over - there are still a few sets in Germany), and a complete engine gasket set ($500) (note- the GTS engine gasket set (928.100.901.04) does NOT include valve stem seals, while the S4 set (928.100.901.03) does. Learned this the hard way.....)



Yes, it's an extra $2K in the rebuild. But the GTS engine is notorious for crappy rods and crappy oil control- fix both of them while it's apart. What if you don't address the pistons and it turns out that your brand new rebuilt motor drinks a quart every 300 miles?

namasgt

yep, some GTS do consume alot of oil as Ive been reading because of the oil hole issue on the pistons.

Shark_Week

Rob
i was under the impression(threads i have read here) that once i pull those pistons then it's time for piston rings? will it be necessary to machine the crank?
someone once mentioned "be carefull it's a slippery slope"
yes indeed!

Rob Edwards

Hi Martin-

Bottom line, I am not qualified to answer the question, I'm just a parts washer/collector. (But that won't stop me from hypothesizing/commenting.... )

I have to confess that I don't understand how pulling a piston out, cleaning and drilling it, changing out the rod, then putting the same piston with the same rings into the same cylinder necessitates new rings. Maybe stretching the rings off the pistons messes up the end gap or something (?) Hopefully someone with a clue can comment.

If the crank mains and rod journals are in spec then again, I can't imagine why you'd need to cut on it. Maybe have it measured and magnafluxed to make sure it's straight, but other than that.....

Mrmerlin

As far as machining goes about the only thing i would suggest , if the bearings loog good is to have the crank polished and then clean it out yourself, the oil lines will get filled with abrasive so it needs to be cleaned with atleast 2 cans of spray cleaner, then washed with detergent simple green and hot water then blown dry the sprayed with WD40

Shark_Week

Rob
no worries, i won't hold you to anything. I too think of no reason not to re-use rings and such. Still a little cautious of this 928 thing, trying to catch up and learn as much as everyone has already experienced. Bear with me and all the questions, especially the one's i probably already know the answer to.

Rob Edwards

Ask away, that's what we're here for! I know lots about breaking GTS motors (https://rennlist.com/forums/928-foru...eap-twice.html), and taking them apart (https://rennlist.com/forums/928-foru...gine-pull.html), but my expertise does NOT lie in re-assembling them.... I will be very interested to see what the consensus is on re-using/not re-using rings.