I recently pulled apart a B230FT From a 940 i was planning to refresh and throw into my 240. and discovered this, i am taking the block to have it checked over for any damage in the bores, but incase the engine does not need oversized pistons. im hoping to source some locally to save on expensive shipping as this has already gone well over budget… but thats just how it goes…
The chance of getting used turbo pistons that are within tolerances is very limited. The turbo pistons have a shorter skirt which with wear turns into piston slap. There will be wear in the bore that will also contribute to the slap.
Spending the time and money on building a worn engine is a big waste of time and only good for a shopping car
If every picture tells a story,,,, anyone care to comment on what we are seeing on the piston(s) wear and condition ?
Overheating due to possible lubrication and or coolant loss
Combustion getting past the rings (blow by)
Lack of regular oil changes
Nothing unusual for a typical poorly maintained 35 year old neglected engine
Given the wear on the skirts you will likely find the bores are tapered and oval and need to be oversized to get back into spec. Even on a well-maintained high mileage redblock you would expect this, I don't think I've even once measured an original block and found everything to be in spec.
I agree with @Massey165, it's an own-goal to put your motor back together knowing your clearances are out, and you don't want to machine your bores only to run a sloppy crank, as you might end up having to run a heavier oil to account for the excess clearance on the crank journals, which will in turn accelerate wear on the fresh bores and pistons where the clearances are tighter.
For 030 over, this is what you want. 4 of p/n 271327.
https://www.skandix.de/en/spare-parts/engine/engine-repair/piston-assembly/piston-1st-oversize/1018960/?dc=2&srsltid=AfmBOorNaXlArUvdPPM7ZT3XV9TZ-HPq_mOxcq5TA69gqR7SB1SMjT4A
(at present, FCP has 030 on backorder with no ETA)
For 060 over, you want 4 of these - p/n 271328
https://www.fcpeuro.com/products/volvo-engine-piston-set-740-760-780-940-b230ft-plus-060mm#description
But measure the bores FIRST.
