checked on my block today...
- Thread starter OhioMike
- Start date
It's already bored out .030", so boring it another .030" would make it a .060" overbore. I think Snitty was asking if it would clean up with the remaining .030" bore that you need to reach .060" over or if you were going to have to find another block?
What broke and flugged up the cylinder so bad that a .030" overbore won't clean it up?
Going .060" over isn't a bad thing..... just enjoy the extra cubes and compression, and start looking for a virgin 4.0 block for the next rebuild.
What broke and flugged up the cylinder so bad that a .030" overbore won't clean it up?
Going .060" over isn't a bad thing..... just enjoy the extra cubes and compression, and start looking for a virgin 4.0 block for the next rebuild.
The 4.0 is a bigger bore/shorter stroke, where the 4.2 is more old school I6 with a smaller bore/long stroke. Both engines share the same basic design, so the bottom ends are interchangeable. By taking the long stroke crankshaft from your 258 and putting in the big bore 242 block, you get a bigger engine that combines the best of both worlds.
I have a 90 258 bored out .60 over and zeroed planed the deck, you should have plenty of room to go over if needed but stick with .60 over if you can, going over increases the compression. By the way the Felpro head gasket will fit a .60 bore, this you will need. You will also need oversize pistons and rings, Have you had them check out the crank that may also need grinding.
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