Wrist Pins Too Big Forged Rods and Pistons

[BrianV8]

I just purchased a kit of forged CP pistons and Manley Rods. I put my caliper on the small end of the rods and the pistons and they all measure out exaclty the same.

Problem is the wrist pins that came with the pistons are 0.050" bigger than the holes in the pistons and the small rod ends. Now i'm told they are suppose to be free floating pins, so are they oversized so a machine shop can properly clearance everything or did they just give me the wrong pins?


I tried some stock rb26 pins they slip in perfect and fit just right. So not sure why these would be bigger

Thanks Brian

[jdms13rhd]

Interesting.

I would give Manley Rods a call on that one. I would assume myself that they would be machined to a std size out of the box. But give them a ring, they should be able to give you a quick answer.

[BrianV8]

i did a whole bunch more measuring and stock pins, pistons, and rods are all made for a 21mm wrist pin. The ones supplied with the cp pistons are 22mm. I think there was a packaging error. Going to make some calls see what i can come up with

[markc32]

throw the pins in the freezer over night

[Bugsly17]

What did you measure with?

Use a micrometer. Wrist pins are the tightest clearance in the engine. Measure to the ten thousands.

[BrianV8]

I measured to the thou, I called CP and the guys i bought them from. They were packaged incorrectly they packaged them with 22mm wrist pins it should have had 21mm pins. So long story short they are a great company and the correct set is in the mail as far as i know.

So having said that, anyone doing a big build and need some 22mm wrist pins? great deal haha

[collector240sx]

You might be able to sell it to someone that wants to use SR piston's or just sell it to someone with a SR (with 2 spare).

If my memory serves me right, they are suppose to have 1mm bigger wrist pin, but not 100% sure.

Worth a check tho.

[BrianV8]

oh perfect good to know. My goal is a reliable 500whp but i hear the standard wrist pins that are coming are only rated for 5-600 crank. Any opinions on this being enough or should i look at getting another upgraded set?

Found many posts of people making 1000 hp on standard pins but input is always great