Hey guys, I'm currentlu in the process of rebuilding a spare 5.3 I have. It had 100k miles on it. The thing is the machine shop is telling me I should definately not reuse the stock pistons. It only needs to be honed which is great but is it true that pistons should not be reused? What goes wrong? I assume the wrist pins wear maybe? I have no idea and I'm looking for some insight from guys who have rebuilt higher mileage motors.

Thanks,
Clint

 

make it a 3.898 bore and throw some ls1 pistons in it! what kind of condition are the pistons in?

 

I second this. Replacement 5.7L pistons are only a few bucks more than 5.3L pistons and you gain 21 cubic inches in displacement. Just keep in mind if you order LS1 pistons that most of them are flat top replacement pistons compared to dished 5.3L pistons so figure out your desired compression ratio before ordering anything. 5.3L heads and stock LS1 pistons make for an 11:1 or higher compression ratio, that's why the LS1tech guys like 5.3L heads.

 

With out talking to your machine shop, I would assume that they are either out of spec or possibly because of the well documented piston slap issue with the first design of these pistons.

I had a really clean block with no pistons. I opted for new .020 over pistons because I did not want loose tolerences on the new motor. I might have gotten away with STD size pistons but if the tolerence ended up on the high side or out of spec, Then what... I would have had to end up getting another set

 

I understand the concept I think. I mean I sure would hate to spend a ton of money just for the tolerances to go all to ****. I already have heads that cost me a pretty penny so the bigger pistons are out (too much compression for me). I just want a heads cam 5.3 but the more I talk with the machine shop the more they want to bend me over. It its as clean as i think do you guys oppose the hone/rering ? I'd just like some more opinions besides the shop thats trying to make a buck. BTW this is super low budget.

Thanks for the help so far,

Clint

 

As long as the bore is straight and symetrical from top to bottom, you would be fine with Just a hone and new rings. That is also assuming that your pistons to wall clearance is withen spec. If its not withen tollerance or if its out of round then honing it will not correct those issues it will only make it worse. I understand the whole budget thing. My pistons were just under $300 and I believe the bore and hone to spec was around $150 plus I had to get rings which I think were $80.... I Can't find the recipet. I still need to buy New rod and main bearings, new rod bolts, Lifters, an oil pump, and timing chain kit so I can assemble the short block.

 

Thanks brick for the good info. well $300 for pistons is much more reasonable than I had expected to see. I was thinking more like $600+. Are the bearings something I should source off the internet or have the machine shop order them? Just wondering. Also I see your replacing rod bolts. Are they TTY bolts? or are you just upgrading. Thanks again for the help. i was begining to think I was the only one rebuilding lol.

Clint

 

Going to up grade rod bolts for Insurance... whats an extra $75 at this point for some ARP bolts. Pistons I ended up with are basically a stock replacement type from silvolite but they have whats called an anti Garfell coating on them. I probally didn't spell it right but any way I think there better then a stock un coated piston... Mahle also makes stock replacement type pistons for these motors. I actually asked for those but the other is what came so I just went with it... Mahle I was told actually makes the Pistons for Gm for this aplication. I can try and get you pick if you can wait a few minutes. I got to dig them out....

 

Here I snaped a few pictures and resized them for the forum.

 

I looked around on bearings and I dont really see them any chaeper then getting them through Summit. Plus, after buying the rod bolts and the bearings and what ever else I decide to buy from there, shipping is only 10.95 out the door. No Tax, No BS... So I feel I end up saving a few bucks that way. For lifters, there is a guy on ebay that sells LS1 Parts. He has them in his store for $115. I have seen them claim to be cheaper but there not In any packageaging and there is no way to actually prove there Original OEM . Some also claim they have been supposedly reconditioned.... As they say, you get what you pay for. I dont mind spend the money on an OEM part. Much better then having a cheap no name one turn side ways and wipe out your cam and damage the pistons and valves....