Kf82 crank and connecting rod

[cptnbarboza]

I bought a new crank and piston rod for 87 kf82,
341 flathead. Do I have to have the new crank and rod machined before installing? Had a guy tell me that you had to. I don’t know him so not sure if he knows what he’s talking about.

[Springbok]

Originally Posted by cptnbarboza

I bought a new crank and piston rod for 87 kf82,
341 flathead. Do I have to have the new crank and rod machined before installing? Had a guy tell me that you had to. I don’t know him so not sure if he knows what he’s talking about.

That was me. On Facebook...lol

When I posted that I didn't think you had a brand new crankshaft, I thought you only had a new rod.

If your motor threw a rod off the crank, and you just bought a new rod to use on the old crank, you would definitely need to have machine work done. But...if you have a brand new crank and a brand new rod, then you do not have to have machine work done and they should bolt up together right out of the box.

You probably could have sent your old crank to J&M for machine work and a new rod rather than buy an expensive new crank. Last time I checked, a new crank costs around $500. The machine work on your old crank which includes a new rod would be around $200 total.

[cptnbarboza]

That’s crazy. Lol. No disrespect, I figured I wasn’t explaining myself very well. I’m a rookie at this stuff. I had a guy I know put the crank and balancing rod in. Do U think if he put it in wrong that would be causing the banging? I took the motor back out and use a mechanic stethoscope then try to turn it fast by hand and I can’t hear any clanking. But idk if I could by only hand spinning.