is it possible to bore a 3100 .119over (3400bore)

[eurolumina92]

i was looking at the difference in bore and stroke on these twoo motors and was just wondering if it was possible

thanks euro

ps is it posible to switch the cranks also thanks again

[robby1870]

I guess its possible, but not safe. GM says .060 is the max safe over bore

[geoffinbc]

Not a good idea.

[bszopi]

No, its not possible. And the cranks are the same (have been since the late 80s?), so that won't get you anywhere. The 3400 block is a meater version of the 3100 block, hence why it is possible for the larger bore.

[xxrollin]

Its possible by resleeve'ing the block, but why when you can get a 3400 from a bone yard for under a grand complete. You can get sleeve's for 20-50 depending on material, so your looking at 120-300 and thats not including labor and a final hone to size...

[SappySE107]

I thought it was done on v6z24. Its not recommended but you can physically bore it that much. Its not like our cylinders are less than .1 thick!

[RacerX11]

The nominal cylinder wall thickness on the 3100 blocks is 4.5mm. Overboring by 0.120" (3mm) will take this wall thickness down to 3mm, whcih isn't really that thin.

The biggest issue with boring the block this much is core shift. If your block has considerable core shift, it will limit how much you can safely bore it. This can be checked with a tool that measures the cylinder wall thickness with ultra-sonic waves.

As mentioned above, you can pick up a 3400 block pretty cheap, so it would be about cost neutral to just get the 3400 block versus paying to have your 3100 bored so much.

Marty

[614streets]

I would not be afraid to go .110 over if it is n/a and will not use nitrous or boost ever.

[SappySE107]

I thought the stock cylinders were thinner than 4.5mm. What would a threshold be for thickness vs power output or pressure? Im not sure how thin the walls should safely be for at most 375 hp at 8500 RPM. Just wondering, cause i overestimated both figures as well so I can be safe

[eurolumina92]

thanks every one