Using .060" pistons in 4g63

[SBR Joe]

Well thats the problem. I think they did bore the block. So I'll either need to get .020 over pistons or another block that is still standard bore.

If they did, they came up about .25mm too short then.

 

[defrag010]

so I remeasured the block and I'm getting 85.24mm, 3.356".

What measuring method are you using? The bore measurement throws up a red flag for me, because no automotive based machine shop would ever bore at an incriment less than .020" over STD unless it's for custom made pistons with an exact bore size.

I would recommend decking the block before boring it again to properly locate the cylinders.

Are you speaking of the procedure for proper boring with a portable bar? I'm confused as to why the deck would matter otherwise.

Usually if you order STD bore pistons, theyre a bit fatter than OEM spec to accommodate for boring....

I have personally never seen this with any STD piston sets from multiple companies. All shelf stock direct-fit pistons from any companny are sized to yield a specific clearance in a bore the size of the industry standard incriments: std, .020, .030, .040, .060, .080. So a STD (3.346) piston should mic out anywhere between 3.3435-3.3445 (.0015-.0025 clearance).
Some rebuilder piston companies will decrease the compression height of the pistons .010-.020" to account for any possible deck machining the block may have during a rebuild, though.

 

[joat09]

Never decked?

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To the OP - if you email me or PM me with the original purchaser information or the PN stamped on the block - I will see what info I can provide if you need it!

Mike Huml

I've called several times and you guys couldn't help me out. As I was looking at the block with the original purchasers name.