Piston to wall clearance 2.5 with wiseco pistons

Hi all, so all the bits and pieces to my build are in front of me, took my block to machine shop and got 3.4655" on all four, 12-6-9-3 positions top and bottom. Anyway, I ordered some .020" wiseco pistons from Chris, they all measured out at 3.4610". Which leaves me with .0045" of clearance. This WILL be a high boost engine around 30 psi. Has anyone else ran their clearances a little loose for room to grow? I called wiseco and they stated it should be OK but wanted to see what others are running for high boost applications

That is fine. I usually set my forged pistons at around .004. You may find that not all custom pistons are not quite the same size. Usually the best way to is to have pistons in hand for machinist so they can set bore correctly and individually as needed. Check and set ring gaps before you assemble. That is critical esp. for big boost applications.
Sure, lots of people running Venolias run looser than that. Venolia actually recommends like .007! I don't recommend that unless you like the sound of a diesel engine. Stock 2.5's even have plenty of piston rock/rattle. You don't want to know what ring gaps are at .007, suffice to say, WAY too big.
Todd

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Originally Posted by 4 l-bodies

That is fine. I usually set my forged pistons at around .004. You may find that all custom pistons are not quite the same size. Usually the best way to is to have pistons in hand for machinist so they can set bore correctly and individually as needed. Check and set ring gaps before you assemble. That is critical esp. for big boost applications.
Sure, lots of people running Venolias run looser than that. Venolia actually recommends like .007! I don't recommend that unless you like the sound of a diesel engine. Stock 2.5's even have plenty of piston rock/rattle. You don't want to know what ring gaps are at .007, suffice to say, WAY too big.
Todd

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Thanks for the help. But on these particular pistons they measured out the same. I've been told and can now see that the wisecos are consistent. These were all the same dead nuts. The block i'm having honed actually only had about 500 miles and only had cast pistons. It was ran slightly over for boost. I guess i'm lucky that this worked out without major machining. But it's slightly over wiseco spec

But yes these were the measurements machinist gave me. The spec sheet shows them slightly larger than what my actual numbers were