Yoeri

Hi all,
I'm currently the owner of a '86 N/A 944 (located in the Netherlands) which I'm in the process of restoring
After having pulled the engine for another issue I decided to inspect the rod bearings for wear, so I pulled the #2 bearing out after reading that this one wears the fastest. Because I have no experience with this I am currently unsure as to whether I should replace them or just put the #2 bearing back in (with new nuts).
The visible 'grooves' can't be felt with the finger(nail)s and the crankshaft shows no signs of wear, or any 'grooves'.
Can someone give a second opinion about the wear on this bearing and whether it should be replaced?
Thanks in advance!
p.s. on the back I can see a vdo logo with a 928 part number so I think they are the originals?

Yoeri

Update: I cleaned the surface with some brake clean, the discoloration between the middle and outside disappeared, the entire bearing surface is now dull grey like the middle part in the picture
I presume this means the bearing is in good condition and not in need of replacement?

Jfrahm

Cheap and easy to replace at this point. In my 968 the rod bearings were at their wear limit and causing reduced oil pressure by 250K km / 155K miles.

931guru

I agree. A lot cheaper than replacing the bearings after a failure.

harveyf

Replace them. All of them. They are probably the #1 failure item on the 944 from that generation of car.

walfreyydo

You are in there, its apart, replace with new.

Yoeri

Seems like the general opinion is to replace them so I'll order some.
Thanks everyone!

Yoeri

I can't catch my fingernail on the scratches, the journal is completely smooth, no visible scratches, I'll take a picture next time I'm working on it.

Should I plastigauge the new bearings or just throw them in?

Jfrahm

If the old and new ones are both marked Standard I'd probably just run 'em, maybe mic the shell thickness first. When I did mine I happened to have a spare rod handy I could use to check them. IMO you are checking to see if you are replacing Standard with Standard (but less worn) and to see if the new parts are correct. If the clearance is too big you should feel it, and if it's too small the crank will lock up.

I'm leery of stretching the bolts so would not want to plastigauge, although maybe OK if only torqued to 25nm for that test.
If the crank had been machined or was badly worn I would want to use plastigauge but just to freshen up a stock engine I personally would just want to make sure I got correct, matching new bearing shells.

jeyjey

I'd plastigauge them. But that's just what I was taught....

StoogeMoe

Absolutely. You never just throw them in there. And torque them to spec with the old nuts, and measure.

Jfrahm

I would agree other than for concern about cycling the rod bolts. Stretching those bolts multiple times gets dangerous IMO.
I feel that's a bigger concern than some inconsistency you would not easily detect by examining the old and new shells and the markings on them. And measuring the rod journals.

Dr. 914

if you have the engine that far apart OF COURSE replace the rod and main bearings!!!

Nowanker

Mic the bearings, mic the crank...
If the new bearing shells are the same as the old, and the crank is still in spec, Assuming the clearance was OK before you took it apart, it'll still be good.
It's a reasonable assumption. Bearings are either going to be correct, or they'll be way off.

Yoeri

Thanks everyone for your input
I placed an order yesterday for all the stuff I need, hopefully I can rebuild the engine next weekend and finally enjoy the car after having rebuilt the entire suspension this past winter!