Chris

So the lower halves of my rod bearings were grooved, attached is a picture of the lower half of No2.

Replacements had no grooves and so far no-one else had grooves in their originals. Just wondering when Porsche switched.

These were from an 87 with an 86 date code.

Chris.

dr bob

I haven't had the rod caps off my car yet, so no input on the groove vs no groove question.

But... That looks like a LOT of bearing wear. But I guess that' why you are putting new ones in, right? What kind of wear do you have on the crank throws? Worth taking a micrometer and checking the journal size if there is wear there that's anywhere close to what shows in the bearing picture.

I tore down the motor in my '80 Saab Turbo after the compressor bearing finally gave it up at 120k. I was sure that running a big slug of oil through the engine would be the death of it, with detonation and all. But no. The rod bearings come from the factory with a plastic break-in coating, and that coating was still intact. Seems that 120k of regular synthetic oil swaps kept the bearings and journals in as-new condition.

Most of us are driving pre-owned 928's, and as such have only a stack of receipts if we are lucky to help us know what the PO did to the car. Looking at tire life and gas purchases is a good indication of driving style, and is a telltale sign of how an owner uses or abuses the throttle. It's always exciting to look at a wear part like a rod bearing and see the cululative effects of RPM, oil starvation to whatever extent, and maybe oil problems.

Ketchmi

Hey Chris, pretty ugly bearing you have there. When I changed mine before the last TA, they were in great shape and had no groove. They were date coded 11-85 in my late 86' engine. I do hope your crank is OK.

BTW, I may be up that way soon, feel like a beer or two?

Dave

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Chris

Crank 'looks' fine, I am wondering where these bearings came from now (hence the post). New ones are in so bit late for measurments except that the plasti-gauge measured fine with the new ones.

Most of the bearings looked brand new.

Reason for looking was my oil pressure has never been right since I got it. When hot 1.5 at idle and 5 at 3.5K, no problems when cold.

No1 showed some wear too.

Dave, beer is always welcome, just email me and let me know your schedule.

Chris

SHRKBIT

[quote]Originally posted by Chris:
<strong>Reason for looking was my oil pressure has never been right since I got it. When hot 1.5 at idle and 5 at 3.5K, no problems when cold.
</strong><hr></blockquote>

Hey, Chris, which part of this is not right? I seem to recall reading that testing of the oil pressure should yield 5 bar or more at 4k rpm...

Curt

Chris

Hi Curt

Well thats the factory stance in terms of range ...

However most 928's read above 2.5bar at idle when hot (digital dash's seem to read lower than analog) and then hit 5bar at 2K.

Maybe most wouldn't care, the PO thought it normal but its not where it should be.

Chris

atb

[quote]So the lower halves of my rod bearings were grooved<hr></blockquote>

Wait a minute Chris. Grooved lower bearing halves? Those are small block chevy bearings! You've got a stroker in there!

Or not.


-Adam

BC

Just did my rod bearings on the 81. 200k miles, and very little wear. And where there WAS wear, it was light. That beaing looks masacred. Absolutley gone.

The groove is not something I have seen.

Please remember that rod bearings are the SAME for ALL 928 years, as well as 944s. (The 944s use a 928 part number...)

I have put them on, and there are NO grooves. Is there a date on your bearing?

Chris

Brendan

As said initially the bearings had an 86 date code and looking closer they have the right 928 part number too.

Chris

Old & New

Looking at tire life and gas purchases is a good indication of driving style, and is a telltale sign of how an
owner uses or abuses the throttle. C'mon! gas receipts?

Chris - Don't forget to check your sender???

Chris

Presume you mean the oil pressure sender unit ? Yes that was the 1st thing I replaced after the oil and filter when I got the car.

Chris

BC

Jeez Chris. Wierd. Totally not stock.

I just don't know. I would do an arhcive search.

"Consult the books" like Giles in Buffy the Vampire Slayer would.

Jim V

Chris,
It might just be a supplier thing; supplier "A" is
the main supplier and makes bearing w/o groove, and supplier "B" might be used rarely and only makes grooved bearings.
Where there any other markings on the shell that might tell who built them?