evo 10 engine rebuild: gap between rod and pin
Evolving Member
Joined: Oct 2009
Posts: 438
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From: SL, UT
I think you mean the wrist pin bore clearance, right? Well, it's free-floating, so 0.0010" at most I would say for that diameter of pin. I think nominal is about 0.0005"...
The service manual doesn't say, it's really not something that should vary, especially with new parts. All wrist pins should be machined to the exact right diameter for any given 4B11 rod bushing.
The service manual doesn't say, it's really not something that should vary, especially with new parts. All wrist pins should be machined to the exact right diameter for any given 4B11 rod bushing.
These are not ready to install out of the box. Most aftermarket rods will measure around 0.0005 so that you can pin fit to your desired clearance, not because that is what you should run. The guys in my shop always set to 0.0008 - 0.001. 0.0005 is way too tight!!!
The piston is preset by JE, but depending on the motor sometimes we loosen that up as well. You are fine leaving that clearance alone...as soon as the ignition hits the piston it will get some heat in it and that clearance will open up a bit.
The piston is preset by JE, but depending on the motor sometimes we loosen that up as well. You are fine leaving that clearance alone...as soon as the ignition hits the piston it will get some heat in it and that clearance will open up a bit.
