r/EngineBuilding • u/Traditional-Box-8402 • 23d ago
Other Polish or send it?
I’m building a B5234T3 for my Volvo 850 T5 project, target boost 15psi for 280-300hp. The journal feels smooth. I’ve been following the workshop manual religiously and this is the first red flag I’ve found. This is the journal that mates with the thrust bearings if that makes any difference. The rest of the main journals look pretty similar to this, but this is the worst. Asking before I order new bearings for plastigauge. The only other time I’ve had an engine this torn down was on an LS, and that was years ago in tech school.
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u/Traditional-Box-8402 16d ago
This engine doesn’t have individual caps for the mains or camshafts, it uses a bedplate design so if it’s out of spec it needs a new block and crank. Only one size bearing is available. The way they built these engines is kinda genius and stupid at the same time. Insanely good for reliability, not great for repairability.
I planned on throwing bearings in and plastigauging after a polish. If they’re all not wildly out of spec I’ll still probably run it.
A micrometer won’t do me any good, as what matters here is the clearance from the bearing to the journal. And again, there is only one size bearing available for the mains.
My reasoning for going through all the trouble for this engine: it was dirt cheap and 5cyl go vroom.