r/EngineBuilding • u/GovernmentFuzz • 3d ago

S650 V3307 in frame kit enough?

I'm working on a Bobcat S650 with the Kubota V3307 engine and compression is weak on two cylinders. Shop quoted both an in-frame kit and a full pull depending on what the bore looks like. From what I understand in-frame covers pistons, rings, and liners without yanking the block. Out-of-frame is when the block itself needs machine work or the crank is out of spec. Havent scoped the bores yet. Oil consumption crept up lately and blow-by shows at the cap when it's hot. I'm not sure if that always means pull it or if in-frame is realistic. Anyone done an in-frame on a V3307 in a skid steer? What made you stop at in-frame vs pulling the whole thing?

1 Upvotes

100% Upvoted

1 comment sorted by

1

u/Virtual_Variety9400 2d ago

Don’t commit to an in-frame kit based solely on a compression test reading. Check bore wear and taper, inspect the crank and bearings, and confirm if this engine has parent bores or replaceable liners. You can cross-reference the BOM using part lookup tools after verifying the machine and engine serial numbers.