how similar are the Oz250s and the US250s?
- Thread starter Asa
- Start date
Different bell pattern, different cam-crank spacing, different oil pan size, different crank snout/damper/crank sprocket/timing cover.
The Oz 250 incorporates all the "useful" variations required to make a larger version of the 200 block, based on lessons learnt in designing the 221. The US 250 is substantially a hurdle to performance builds because of timing set issues and overall dimensions.
Anyway, you've got a virgin bore Oz block and a bunch of bellhousings...
The Oz 250 incorporates all the "useful" variations required to make a larger version of the 200 block, based on lessons learnt in designing the 221. The US 250 is substantially a hurdle to performance builds because of timing set issues and overall dimensions.
Anyway, you've got a virgin bore Oz block and a bunch of bellhousings...
If you have a block that's good except for needing a sleeve, I'd say do it. I've used them on many engines.
A sleeve is a very acceptable way to repair a block and in many cases the sleeve material is better than the block material. My crossflow has a sleeve in one cylinder because we hit a casting void when boring it.
There is no easy way to use a US250 rotating assembly in an Oz 250, though. Between the bearings, rear main seal, journal width, crank snout, etc, they just can't be interchanged. Look at http://home.cfl.rr.com/mustangsix/Engine/crossflow.htm for some of the issues I encountered several years ago.
A sleeve is a very acceptable way to repair a block and in many cases the sleeve material is better than the block material. My crossflow has a sleeve in one cylinder because we hit a casting void when boring it.
There is no easy way to use a US250 rotating assembly in an Oz 250, though. Between the bearings, rear main seal, journal width, crank snout, etc, they just can't be interchanged. Look at http://home.cfl.rr.com/mustangsix/Engine/crossflow.htm for some of the issues I encountered several years ago.
Doesn't the later 2V use a one piece rear main seal like the crossflow? Also, I think the 2V crank snout is different than the US250. Not sure on the bearings, but those two differences alone would make it "un-swappable".
One piece rear main seals came in around '85-'87 (X or MarkZE will know).
Jack, I meant both Australian variants interchanged cranks/pistons/rods etc. Up to the point of metric flywheel bolts, anyhow. There is some difference with the thrust bearing - one is a half circle and the other a full thrust from memory - but not sure if that's a fatal discrepancy.
Evan, your motor from what I observed, had been "puttered" about. It showed no signs of having been beaten on long-term, or any old redneck fixes. Think it only had a re-ring. Pull the head and slather the bores in grease, anyhow. Then just tack it back together for the time being.
Jack, I meant both Australian variants interchanged cranks/pistons/rods etc. Up to the point of metric flywheel bolts, anyhow. There is some difference with the thrust bearing - one is a half circle and the other a full thrust from memory - but not sure if that's a fatal discrepancy.
Evan, your motor from what I observed, had been "puttered" about. It showed no signs of having been beaten on long-term, or any old redneck fixes. Think it only had a re-ring. Pull the head and slather the bores in grease, anyhow. Then just tack it back together for the time being.