| :actually your information is wrong. Pin clearance from a floating pin bore in a forged piston is tighter from the factory than it is from a press pin style from Nissan. Eh, maybe it depends on the piston, but the pin fit is looser on Wiseco pistons, not tighter. I can push them in with my fingers, whereas with the stock pistons the pins are an interference fit
That is why you must hone the pin bores. I hone my to a specified clearance depending on the use of the engine. I've pulled many engines apart and the evidence of wear is significantly lower than if you don't hone the piston pin bore.
You pulled many of your built engines apart again? For what reason? I'm not necessarily disagreeing, but it seems odd that a performance piston absolutely requires additional machining to work properly in a performance application. The piston installation instructions go into great detail about cylinder finish, ring gaps, ring positioning, bore clearance, etc, but I don't recall seeing anything about modifying the pin bores for clearance. Not with Wiseco pistons anyways. Its these attributes that I do to the engines that ultimate allow the engines to run smoother and better. Your engines run better and smoother? How do you quantify that statement? Do you have before/after dynos? Just curious. :The movement of the pin is the critcal variable. Its not just the pin bore in the rod that you should be focusing on. Just like piston rings and lifters...they all rotate/spin.
Piston rings rotate? Then why do piston installation instructions typically say to precisely place the compression rings so that their gaps are 180 degrees from one another? The pin is no different, when you go to assembly and the pin does NOT spin inside the pin bore of the piston once assembled to the rod you will absolutely have premature wear issues down the road. I've never seen galling on the stock pistons I've diassembled. Perhaps that is because the pin bore clearance increases with temperature. I haven't had a reason yet to disassemble any forged pistons on engines I've assembled, but I'll take a look at mine when I pull my motor to install manifolds and refresh the bearings. I'll let you know. It is very vital that you leave NO area of two parts that are in a dynamic environment untouched. Everything must be made more effecient at all times. I wouldn't say it is vital, as many engines run fine without anti friction coatings, modified clearances, etc. But, to each their own.
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