swftiii

Track Listers,

I'm considering a 997 which will be primarily used for the street, but hope to be able to get some track time in at some point in the future. As you know there are a lot of concerns and discussions about the IMS Bearing on the 997.1 engines (06-08). I'm sure it is an issue, but how big of an issue is it? There are plenty of 997.1's participating in DE and CR, so what have you all done to address the concern to make the engines more reliable or to overcome the concern?

Thanks,
-Skip

sako

I have been using my 2008 997.1S for 2.5 years now for DE. It's not my daily..I had 28k miles when I started and now have 49k miles. I am in the advanced group with bmw cca. I have done around 20+ track days.

I live in so cal so it can get hot sometimes. I haven't had any problems with the car yet. The temps can get up there...I have had the water temp move from center and the oil temp get up to 270 and lose some oil pressure on a couple of occasions so I backed off for a lap or two (outside temp was 100+F)..so I added a 3rd radiator. I may get a deeper oil pan as well.

I also run Bridgestone re-11, hawk red track pads ,stock rotors, brake fluid for track, short shift with numeric cables..mostly for reliability. I also change brake fluid every 2-4 track days and oil change every 2-3 track days..I love the car and just purchased gt3 control arms for negative camber. Contemplated getting gt 3 but 40k difference not worth it imho..I also use rear seats for kids..my mechanic told me to drive the heck out of it and do preventive maint..he has quite a few customers with 997.1 and says it's the cars not driven and long oil changes that cause problems with ims...also make sure oil is up to temp prior to going past 4.5k...

Gary R.

Skip, it's a crap shoot. You can go with a deeper sump, have the oil analyzed every change, and cross your fingers or you can have the LN IMS solution installed and cross your fingers nothing else let's go. If buying the car have the oil analyzed as part of the PPI, if A-OK make your decisions based on that...

LostSouth

Hard to say on the IMS bearing. The incidence are lower than the attention it gets would have you believe, but it's catastrophic if you're the one who draws the short straw.

From what I can gather it seems the biggest problem with the IMS failure is oil circulation and letting the oil drain out of the bearing. Cars that aren't driven regularly seem to have more problems. I have been tracking my 996 now for three years. I bought it with the upgraded bearing. I test the oil fairly regularly (not every track weekend). At a minimum get yourself a baffled deep sump oil pan and use a good quality oil made for track use (I use Joe Gibbs XP9). The next step would be a motorsports AOS. Once you start driving harder, you will need the third radiator.

With the exception of the AOS, all of these are a pretty easy DIY. You can do the AOS yourself as well, but you need to know where everything is by feel and also be a contortionist.

Dave DE

It's worth mentioning that any IMS bearing upgrade for '06-'08 requires engine disassembly.

Ritter v4.0

My 996 raced hard +80 hrs with stock IMS bearing without failure.
Ran another 10 or so with IMS retrofit after rebuild, also without failure.
YMMV but draw your own conclusions.

RobT 394

The 996 model years are the ones that made IMS failure famous. In this model year you can get the LN upgrade and it is not that challenging to do. Problem solved.

Porsche improved the IMS for the 997.1. While it can still be a problem the failure rates are much lower than those in a 996. Oil circulation will be a bigger problem and based on the number of 997s seen at the track it is not a huge issue.

Buy it, track it, enjoy it.

177mph

+1

Gary R.

What about 05 since you seem to have the knowledge and its the same block?

Dave DE

According to the LN web site, '05 is ok. The engine changed in '06 to incorporate a larger IMS bearing that cannot be pulled out thru the hole in the block. Model year changeover isn't always clean, so I would be careful with a late date code car.

http://lnengineering.com/products/ims.html

Here's a description of 06-08:
http://imsretrofit.com/my06-08/

dan212

As others have said, an overrated concern also addressed in later generation engines. I actually raced a 996 crate engine for some 200-250+ hours before I did a rebuilt. Lost some steam by 175+ hours but that had nothing to do with IMS and didn't stop me from racing. (just forced me to drive better)
That is a lot of WOT abuse.

I did a full rebuild and it was a no brainer to add the IMS kit at that point because everything was in pieces, steam cleaned, polished, licked and kissed.

So these engines are pretty durable and can take a beating.