996.1 Potential Purchase - Need Engine Work advice

Morning all. Viewing a very early (Nov 97 build) 996 tomorrow. It has 160,000kms and has had some fairly extensive top end work back in 2015 due to a cracked head. The ad says "engine rebuild" which this is not, as from what I can see the head was replaced with an overhauled 2nd hand one and a lot of new bits ordered at the same including chain rails/guides....piston rings?.  Owner has had it for 6 years, so after the work was done. He also has other another Porsche (991.1) and I'm not gettting bad vibes from extensive chatting to him. Trying to understand what this job entailed and why certain other thing were not done. Why the rings and conrods and not new pistons?. Why no clutch?. Some of these questions are my lack of familiarty with the M96 and some (like the clutch) may be explained in that it had an IMS replaced in 2013 by AutoArt, but they admitted that the paperwork was lost in the system and I have that confrimed from AutoArt....would've made sense the clutch was done then. It looks a very tidy car overall and even has the rare LSD option so I'm keen. Would appreciate some pointers though. Receipt attached, there's another one (I've not included) that details about $4.5k in labour

Re: Clutch - does say they did the thrust bearing, maybe everything else was ok? And agree clutch might have been done with the IMS. I had to do a top end rebuild on mine when I had it for the same reason - cracked head... Did some similar 'while you're in there' things, but plenty of stuff was alright, so, already facing a big enough bill, didn't replace 'everything' just because it was out - just whatever Autohaus recommended. I thought I might have posted more details and the invoice at the time but apparently not - did find some notes I wrote here . If I had my time over, would go for a higher km car that has had this sort of work done than a (relatively) low km car where I had to do tons of stuff in the few years I had it... Once it was done though, was like new to drive. Still kind of regret selling it, although I really wasn't driving it, and worried that was bad for it, I really wish I'd hung onto it... Good luck with the inspection - lets us know how you go!!!

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Will do!. Looking forward to nice Friday arvo test drive

If you are on the Central Coast, go see SImon and the boys at AutoWerks. They are amazing and have done all the work on mine thus far...Cannot rate them highly enough.

Will do. Only moved up recently and a mate with a Macan takes it to them, also speaks highly of them.

Speculation from me..... I'm not 100% certain but with the head off, I think the rings can be changed while you're in there sort of thing, and they will eventually wear or maybe there was concern about coolant and corrosion (...I don't know enough about this stuff), and I'm pretty sure you'd have to pull the main engine block apart to get new pistons etc fitted. It's odd that a new clutch wasn't fitted while they were there for the thrust bearing but if the one that was in it wasn't very worn then it's kept and money saved. A noisy thrust bearing is always worn and will certainly fail, so it can't be ignored. It does say conrod bolts on the invoice but they are quite deep in the engine (and would replaced during a full rebuild), so maybe they meant the head bolts rather than conrod bolts.

How’d you go?

Purchased!. Pick it up next weekend. There’s a risk element as no PPI but the car is in such amazing condition, and drives strongly, backed up by extensive engine work, IMS etc that I’m willing to have a punt. Low $70’s. 2nd gear synchro is a concern on the horizon. If you rush it, there’s some reluctance. Smooth shift and warm and it behaves. Knocked a bit off for that. LSD was optioned but I doubt it’s working now (no maintenance I could see) so that’s on the list. It has a rorty header allegedly from a 997?. Stock mufflers, newish and stock front suspension, brake pads, fluid etc. Really hangs on and rockets out of corners. No weeping oil before or after the drive (weird) and no nasty tappet noises. Overall,  I’m very happy. I’ll grab some pics when it’s in my garage. Here’s a couple of mediocre ones and an interior one I took. The rear seats and carpet look like it did in 1998!.

Great outcome! Well done!!

<I wrote the below this morning but got distracted, will post it anyway as it clarifies some of what has been discussed and might help for future maintenance.  Congrats on the purchase, she looks beautiful!> When faced with this sort of thing the owner might be very much in the hands of what the shop advises, and might be trying to keep a cap on costs and not get too much scope-creep (aka 'while you're at it')  if they're not strictly required (happened @ 100k) If the IMS was done in 2013 and the cracked head happened in 2015 at 100k, then the mileage would have been about right for them to recommend a clutch while they were doing the IMS - afterall, they wouldn't have been expecting the later problem.  Also explains not doing any of that 2 years later.  Changing the IMS at all is a different matter, since they likely removed a perfect double row and replaced it with an almost certainly inferior aftermarket one! (do you know what type?) Cracked head implies intermix, which tallies with the line items for oil cooler (impossible to clean) and 'Radiator and pipe clean' (difficult job!).  If the rings and 2x thrust bearings (presuming crank ones) shown were fitted, then it was certainly stripped to a bare crank as you can't do any of that without splitting the cases - was it purely for cleaning purposes?  If the parts list is complete, then there are a few things you'd rather see included.  At that age and mileage and with the level of disassembly I would have expected main and rod bearings and chains "while you're at it' (I did them on mine).  Weird to do tensioner rails etc (which can be changed later) but not chains (which can't). Crank cradle bolts are not strictly single use, but early head bolts like these were, Neither are shown here (PS you should really redact the owner and shop details!), but it's gone 11 years and 60k since, so no reason to suspect any of that is a problem.  Perhaps there were other parts invoices. There are 24x head bolts required, so it was not mixed up with the rod bolts, of which there are indeed 12x.  There are a fair few other single use bolts if you follow the letter of the manual, though some of them have you wondering why. My impression would be there's no reason to think of the engine work as a negative, but at the same time the preventative maintenance items which should really be done 200k+ are still original so will be on the radar in future along with clutch again and IMS too, depending on type.

All good analysis thanks Steve. When I realised the limited extent of the work, I parked the cost of an LN IMS and another clutch in my mind!. The oil fed solution was (I think) around in 2013 but only just….odds on that it has an inferior one. Your summary is exactly what I needed as you’ve clearly been there and done that!. The omissions are puzzling and as you say, may have been on other invoices or maybe a $ decision by the previous owner on a relatively young motor. I’ll investigate with Auto Art and see if I can uncover more. I’d rather some work was done albeit odd choices made. They’re a reputable shop and I’ve seen their work on another (off market) car I was looking at. $29k rebuild with everything (crank, pistons, bearings etc). Time will tell if I inherit some big bills, but I think if we enjoy keeping these cars running  then that’s a given sooner or later. The car is so well presented that I think it can be justified. Hopefully down the track!

Congrats on your purchase it looks really tidy 👍 I’m sure you’ll love it. These are older cars now so will always need something doing at some point it’s just a case of making an allowance for it

AutoArt did the work?  he's very well regarded in Vic for 996s

They did. Invoices were all legitimate. The more I think about it, the more I’m sure that the previous owner decided (for dollar reasons) that his sub-100k kms motor wasn’t getting a full rebuild. I kind of get it, but if it was me…!.

First thing on your list is to install low temp thermostat.  996.1 heads are prone to cracking (rennlist.com) according to many.  Standard thermostat opens at 83C.  The recommended low temp starts to open at 71C. This gets coolant flowing sooner helping to reduce (stop?) the risk of hot spots in a 996.1 head. Also consider reviewing water pump and replacing with genuine if age isn't known or if the pump is metal impeller

Thanks Minke. Much appreciated as I’d like  to check and /or carry out as much preventative maintenance as I can after I’ve picked it up.

What I've found useful (I'm 2 years in) Join rennlist.com ( https://rennlist.com/forums/996-forum-60/ ) https://www.facebook.com/groups/591859944843493 (Hartech UK / Slakker Racing Dev) https://www.hartech.org/images/downloads/Hartech Engine Guide (interim).pdf

Long commute tonight. That’ll keep me going. Thanks again. Just watching the latest 9Werks  video of his 996 rebuild as well. Soaking it all in

I watched Lee's rebuild with interest. Just went and spoke to Ryan and Steve at Autowerks to start teh process of gettign mine done.

I've now seen a few invoices from those guys, and they are solid. Please keep us informed of the journey. Be good to know that we have a few options for this level of work. Be even nicer if we had a Hartech option like Lee does!.

interested the outcome.  I wrote to Hartech about shipping my donk to turn into 4.1L and the responses were to the tune of "we'd prefer you had a local builder and only ship the block to us."

Could be worse, I spoke to Jake Raby (Flat Six innovations ) in America a few years ago who does a lot of 996 rebuilds ( along with Charles Navarro he came up with the IMS Solution )  and will build motors that are larger and remove the whole oil starvation risk so they are trackable as well.  He has gotten so busy now now in addition to an 18 month waiting list he requires you to ship the entire car over to him America otherwise he was reluctant to deal with you 😆

Hi, That's interesting. I was visiting a Sydney based 'so called' Porsche specialist trying to get my sunroof fixed (nope) and I saw Driven Racing Oils on the workbench.  When I asked "Oh you know about this oil..." "No... the oil is for this 997.1.  It has recently had a rebuild out with parts out of the USA and this oil is required for warrant" When pressed further he said "yea I had tp make a few calls to Chicago during assembly..." "Charles Navarro?" I asked. "Yea.. that's right...anyhow this car does Challenge Bathurst and it is a weapon..." etc.. Interesting no special sump for oil flow control... Anyhow there is at least one 997.1 LN  4.0??? running around in Sydney and unless I mis understood was somewhat assembled here.

Charles Navarro is LN Engineering, while Jake Raby is Flat Six Innovations.  They have a professional association and there are linkages between the two but they are separate companies.  I think their co-operation/collaboration comes from their work developing and patenting the IMS Solution. LN Engineering will do a rebuild and from what I understand it is a good engine and they will ship to Australia  However, that is not a Jake Raby engine which needs to be purchased from Flat Six Innovations. About 8 or 9 years ago (well before COVID) I contacted Jake Raby regarding an engine rebuild and basically got a quote that worked out to be about $30k AUD (plus freight/shipping) to get a 3.4l engine rebuilt into a 3.8l engine that produced somewhere around 350bhp  The time from ordering to engine finished was 18 months and you made payment in three blocks of $10k AUD.  That engine solved the IMS problem and the oil starvation problem and was designed so you could track it.  I was at the time keen and I liked 18 months as it meant I could make payments in blocks which was easier financially.  Plus 350bhp meant it was around the same horsepower as a 997S in a lighter slightly more raw car. Post COVID I contacted Jake Raby again, he has become a very popular engine rebuilder for M96 and M97 engines and at the time a similar engine configuration was closer to $50k and he would not sell me the engine unless he fitted it or it was fitted by a certified installer, of which there were none in Australia at the time. From an entirely uninformed position I suspect there is a significant price premium to a Jake Raby engine due to popularity and unless you are planning to build a track monster I would prefer to use LN Engineering or closer to home  I would have a chat to PR Technology in Warringah who would certainly have the expertise to a 996 engine rebuild but I cannot speak as to their willingness to do so. The problem I found was it was really difficult to get a quote on having an engine rebuilt in Australia until they had pulled the engine apart and had done a detailed assessment.  This meant that I was up for a minimum cost of $1,500 just to get a quote as I would need to ship the car to Sydney or Melbourne and pay them to pull it apart to quote and then if it was too much put it back together and refit in the car and ship it back to Canberra.  I contacted the late great Peter Fitzgerald and he kindly rang me one evening after work and spent a couple of hours on the phone taking me through my options and what I could be doing and he helped me massively in getting my head around how to manage the whole engine problem in my car.