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Ka24de rod bearing clearance questions.


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I'm replacing the bearings on my ka24de and I ran into an issue.

I got my crank and bearings back from the machine shop and checked my clearances with plastigage, my mains are perfect but my rods have .038-.051mm when spec is .010-.035mm. My brand new fowler digital micrometer isn't working so I bought a cheap harbor freight one to measure my inner rod diameter (torqued to spec, no bearings). The spec is 53.000-53.013mm and I'm getting 53.03-53.06mm. So my question is, Is it more likely that with how old the engine is the rods have expanded from heat or something along those lines or could my micrometer be wrong and/or the machinist have made a mistake? And what can I do to fix it? Can I get away with that amount of clearance And just always run a thicker oil like 20w50, or should I get my rods double checked more accurately and get new ones if they are out of spec?


Sorry for the long question but I'm kind of stuck at the moment and I'm paranoid because I know these engines don't like rod bearings, unfortunately from a lot of experience.

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my inner rod diameter (torqued to spec, no bearings). The spec is 53.000-53.013mm and I'm getting 53.03-53.06mm.

So the rod big ends are machined too big. Did your machinist do that? It normally will be adjusted after fitting new rod bolts.


Or if they are new aftermarket rods sounds like they are defective.

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I was told he went 20 under on the rods and he sourced the bearings as well, rods are still in the block because I didn't want to pull the head off, so they haven't been touched. One of the bearings was spun, which I understand that being out of tolerance but the other three matched it as well as a spare set of sohc rods I had that I measured out of curiosity.

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The rods don't look like they were ever previously machined also that would have to be extremely coincidental that my others are the same size out of another engine. Which is why I think my mic might just be inaccurate, but then it doesn't explain my extra clearance. My first time actually getting into bearing sizes and it has to be super confusing.

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