luckett

Here are some pics of my con rod bearings for reference. These are out of a '92 968 with about 160K miles and quite a few track days. The clearances on all four bearings were well within spec.

What is not as clear in the pictures is the difference in wear between #1/#2 and #3/#4. There is clearly more wear on the #1/#2 bearings than the #3/#4 bearings.

Enjoy!

#1

#2

#3

#4


#1

#2

#3

#4



#1

#2

#3

#4

FRporscheman

Not even a hint of copper showing at 160k miles. These motors truly are good for 200k miles before possibly needing a rebuild.

What kind of oil do you use?

luckett

From about 90K when I bought it to 160K, I used Mobil1 almost exclusively.

FRporscheman

Mobil 1, as in the fully synthetic type? I have heard in recent years their formula has changed and isn't exactly the best synthetic stuff out there anymore. But I believe their dino oil formula has not changed.

Regardless it seems Mobil 1 did a great job in your engine.

RajDatta

+1, I always use Mobil1 on my Porsches.
Raj

luckett

Full synthetic. Aren't internet rumors great fun? I heard Elvis is living with JFK in Zimbabwe.

FRporscheman

If you don't like internet rumors why are you online.

Here's what I learned with a few minutes of research. Who is to say that any of this information I found is factual. I have chosen to trust the information on the amsoil, mobil, and other websites.

When Exxon and Mobil mergered 8 years ago, Exxon had a huge impact on the marketing and development on Mobil's products. ExxonMobil has since reformulated its synthetic motor oil too many times to count, and has been through stints where they release new formulas and immediately recall them, only to continue selling the old version until they can fix it.

There was a whole fuss about Castrol's synthetic oils not actually being based on synthetic bases, and Mobil sued them. When Castrol won and was legally allowed to get away with calling a refined dino oil "synthetic", Mobil started doing the same thing, to save money.

In the early 2000's Mobil 1 was sometimes risky and seemingly a different formula every week. I think they have settled down and are finally making good reliable products again since mid 2000's.

In the end the best oil in all regards is amsoil. Other great brands you can grab off the shelf would be mobil 1 and valvoline synpower. Castrol syntec is pretty good too. All have varying strengths and weaknesses but mobil 1 and valvoline synpower are both great oils. Mobil is the most popular champion oil so people like to buy it. As far as dino oils, the best off the shelf stuff would be mobil clean and valvoline.

RajDatta

Just a side note. All new BMW's except M's use Castrol Synthetc which is labelled under BMW brand. Most of these cars have a 15-16K interval depending on driving condition and are often sold as CPO's (6 yr/100K warranty).
Something to think about..
Raj

Jason Judd

I change my rod bearings on a regular basis, every other year...have the cross member to facilitate the job, and save the cost of the many hours of laborat my shop...Actually, they were the ones who reccommended it as a labor/money saver!

Jason

luckett

Not everything on the internet is untruth. You just have to be cautious when you are hearing BS from an internet "expert".

This is where you can get more info then you ever wanted to know about oil. The are quite a few industry professionals on the forum there.

http://www.bobistheoilguy.com/

luckett

What kind of mileage/hours do you put on your car each year and what is the resulting condition of the bearings when you replace them?

Do you use the lindsey crossmember? Any issues with it?

Jason Judd

Chris,

Yes, it's the Lindsey unit...no problems whatsoever.

I track my car exclusively, it's not street legal these days. I do the bearings as part of a regular winter maintenance on the car.

Keep in mind that I've built it up to turbo-rs spec...little more heat and such.

Jason

luckett

How do the bearings look when you replace them?

Jason Judd

Ah, sorry...forgot about that part.

The first time I changed them, which was after about 3 years on the new engine, there was a good amount of wear on them, and I felt lucky that I had taken the advice of my new mechanic/shop and looked at them!

Since that time, we have not seen especially significant scoring, wear, or any such damage. So, every other year seems to be about right for now.

Jason

FRporscheman

That car must take a lot of punishment.