Piston Crack

[hotford]

Ok. I fianlly got my motor back from the machine shop after 6 weeks. Dude called me last night and siad I got a crack in one of the pistons by the pin. I just got the block honed to run the stock pistons. Should I get 1 new piston and hope for the best? Get a new set of standard sized pistons, or Get a set of oversized and send it back to the machine shop? Any help will be great.

Thanks

 

[towcat]

depends on how loose the hone is.
personally, I'd mic the bores and go with std if the bores mic out. they don't mic used pistons and hone to fit unless it's a high-buck race job.
iirc these pistons aren't forged, so honing loose for material swelling is not an issue.

 

[hotford]

It's going in my towrig for me to pull 10-15k with. I've gone as far as new heads, studs, rockers, push rods, cam, seal, all that. Do you think I'll have issues with just replacing 1 piston. The motor has 140k on it and popped a head gasket. I just don't want to make the wrong choice now and it cost me more down the rode, cuase I'm going to have to keep this truck for a long time. Thanks for the help!

 

[Devilish]

Replacing 1 piston should be fine. I'm wondering if the cracked piston is from where the head gasket failed. While you're at it you should inspect the rest of the pistons for cracks. Your machinist probably has done it already but if you find something he missed it'll be worth it.

 

[hotford]

I'm going to look at it tonight and go from there.
Thanks

 

[oldmisterbill]

remove the rod and have it checkefor "bentness"
Like that new word?

 

[69dieselfreak]

remove the rod and have it checkefor "bentness"
Like that new word?

my theory is that 1 is cracked when are the rest going to crack do you want to go back into the engine again in acouple of months because you **** a piston id personally replace all 8 thats my 2 cents

 

[hotford]

After looking at them, I'm going to. All of them have valve marks in the top and a few have some marks. 2 of my piston nozzles got lost so I'm guessing that is what the marks are from. I'm going to go .020 oversized and send the block back to the machine shop. Damn I'm ready to drive this thing.

Thanks for the advice.

 

[icanfixall]

Give Falcon Blobal or Diesel Direct a call fo pistons. They have the cheapest Mahle pistons anywhere on the net. They are what the motor had in them from the beganing. Now they are hard anodised on the tops... Much better for heat....

 

[hotford]

Got them on the way. Thanks