Van

In the last oil analysis report, one of my cars came back with bearing material that was uncharacteristically high.

The engine has about 120 race hours on it, so I decided to change the rod bearings.

Look at #2 on the left! #3 is on the right (and #1 and #4 are normal, like #3).

944crazy

Looks like you dodged a bullet there!

mytrplseven

Had you X drilled the crank or baffled the oil pan? I was just wondering if those mods actually prevent this as they say they do.

Van

Crank is cross drilled, pickup screen has the strap around it to focus suction downward. It's also a late oil pan and pickup (deeper sump). No extra baffle in the oil pan. It does have a crank scraper.

V2Rocket

this is a good wake up call.
my old subie probably needs bearings too...just ordered a kit from blackstone.

divil

I've always wondered how useful the oil analysis actually is. I note your use of the phrase "uncharacteristically high". Would you say it's essential to have a baseline of previous tests for the same car in order to spot this? Or is it something that stands out on it's own, even if you had never tested oil from that car before?

Van

I use Blackstone Labs for oil analysis. They have a pretty good database built up from other customers - but, also, for this particular car, the metal elements over doubled from the last several samples.

944hal

120 hours, interesting. I replaced my rod bearing a little less than 40 track hours ago. I just took the engine apart for another reason and the rod bearings look great. Just wondering what the suggestive interval would be for changing them out. I'd rather treat them as a maintenance item than replace the motor. I don't have a cross drilled crank, although I am putting in a scraper this time. 100% track car. I also had Michael Mount modify the rods and bearings. I am going to use Miller's oil exclusively this time, so I'll keep some data.

Van

I think this is a total game changer - different bearings from a different manufacturer made of a different compound for a different application!

V2Rocket

Van, is the "Rod Mod" legal in your series?

Van

Yes, because there's no performance enhancing benefits - only engine longevity.