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I bought a set of Wiseco 5523as piston kit. The are for use with the factory Ls2 rods with .945 pins. I received them today and when I was check them and test one on the rod the pin can not go in the bushing. The pin measured .945 exact but the bushing in my rod looks like out of roundness. It has variations from .945 to .943. This is normal with ls2 rods ? Can a machine shop hone the bushing or they have to be replaced?
Thanks
I bought a set of Wiseco 5523as piston kit. The are for use with the factory Ls2 rods with .945 pins. I received them today and when I was check them and test one on the rod the pin can not go in the bushing. The pin measured .945 exact but the bushing in my rod looks like out of roundness. It has variations from .945 to .943. This is normal with ls2 rods ? Can a machine shop hone the bushing or they have to be replaced?
Thanks
Have your machine shop check them. They will probably require a little honing, which is pretty common, to get them to work, unless the rods are indeed badly out of round. At that point you will likely save a little money finding a nice set of rods.
I’m pretty sure the stock floating pins are .943” so when you try to use a .945”, the pin won’t go in. Luckily, it’s not difficult or expensive to have the pin bores honed. I think Wiseco does this on purpose to make sure the pin clearance gets addressed. With a .943” pin and stock rods, the factory sets the clearance pretty tight.
I’m pretty sure the stock floating pins are .943” so when you try to use a .945”, the pin won’t go in. Luckily, it’s not difficult or expensive to have the pin bores honed. I think Wiseco does this on purpose to make sure the pin clearance gets addressed. With a .943” pin and stock rods, the factory sets the clearance pretty tight.
That is what I thought but because was no special notes in the instructions , that is what get me confused.
Because in my garage the temperature was 40 deg to thought that probably bushing was a little bit contracted.
Thanks KCS.
I called Wiseco this morning and the tech person told me that in some engines GM used .945 bushings in the rods and in some others they used .943.
So I have the .943 and just dropped the rods in the machine shop to bore the bushings to .945.
Here is a few pictures in case this information can help someone else too.
KCS is correct and the person at Wiseco is incorrect. LS2 rods were .943 and none of the 4th Gen. bushed rods were .945, Wiseco does indeed make them that way on purpose. If a person ever tried to use a .943 pin in a press-fit rod, it wouldn't have enough press and it would walk out and destroy the cylinder.
Someone else posted a couple of weeks ago they had .945 pins and .943 rod bushings but never clarified why. And for some reason nobody thought it was odd. I was thinking something was just wrong but that got answered above.
Long story short, thanks OP and summit for the clarification
01-15-2019, 09:52 PM
New pins not fit in the rod. 
