.060 over pistons for a D301

Spencer 460 · Feb 11, 2012

I am in need of one piston for a D301 that is .060 over the original 3 13/16" bore. This diesel engine has Zollner pistons in it. The D301 is in a 460 puller I bought and it was parked in a barn for several years and the #2 piston has been pitted from moisture collecting in the pipe and running through the head and sitting on the piston.

Janicholson · Feb 12, 2012

If the piston is dramatically pitted down the sides, I would replace it as well. (might be a tough piston to find) a kit might end up being cheaper)
If the piston has pits that are 1.5mm or so deep (1/16") or less, and not down in the ring area, I would run it. Jim

sflem849 · Feb 12, 2012

Like Jim said, a little pitting in a diesel isn't the worst thing in the world. They don't have predetonation issues like a gasser. Another thought is TIG welding up the pits and then machine the welds down. That is what my buddy did to build some hicompression pistons for a 4455 puller. I also agree that those might be some tough pistons to get ahold of.

Here are some pictures of mine and 90% of people said run them. I ended up finding a used motor about 5 hours from me for $150. It also ended up having oversize pistons as well. Now all I need to do is pull the motor and bore out my current sleeves and life is good. I even have another spare motor sitting in the neighbors shed. I guess I should find another 9 series for all my spare parts!

The other thought is you are not too worried about oil consumption since it will only run 15 min at a time BUT you are worried about compression. This would make a rotted out ring area a little iffy.

.060 over pistons for a D301

Spencer 460

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Janicholson

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sflem849

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