Engine Block Cracked

[64GunPilot]

So, after a complete teardown of my junkyard 5.3 I've measured the bores after ball honing. Im 0.0015 out of round (1.5 thousandths) and the piston to wall clearance is about 0.005. New standard pistons should bring it down between 0.002 - 0.003 but thats the best Im gonna get before having to go full bore and upsize and rebalance at the machine shop.

Anyone here think 0.0015 out of round is a problem? New pistons (hypereutectic) and send it?

[Supercharged111]

I think you should have left the pistons in the holes, checked a couple of bearings for copper, and sent that lump. There's plenty of money to spend elsewhere in the swap. They usually out down around 275whp junkyard fresh.

[64GunPilot]

I think you should have left the pistons in the holes, checked a couple of bearings for copper, and sent that lump. There's plenty of money to spend elsewhere in the swap. They usually out down around 275whp junkyard fresh.

I don't think this engine was gonna last very long based on what I see. I can tell you a cam lobe was eaten by a bad lifter, cam bearings were shot, and the heads had some exhaust bolts snapped off. So thinking the eaten cam metals might have damaged the lower end bearings, I decided a full teardown was in order. The lower end was amazingly in like new condition.

So thats where Im at. Full bore, or just slap in some new stuff and send it or does anyone think original pistons with 5 thou PTW clearance is ok? Send it?

[Supercharged111]

Take this for what it's worth: back in 2015 I found I'd wadded up a rod bearing. My motor is a 93, I believe it was 95 when they changed the rotating assembly but don't quote me. I nailed a late LT1 crank on Craigslist and had it polished. I found a set of stock takeout pistons and rods on eBay. I installed new rings and bearings, gave the bores a 3 stone hone job 320 grit with moly rings. Didn't measure a damn thing and that's the motor you saw my car run at Hallett. On a motor that needs to be restricted, perfection isn't really necessary IMO. Mine made 292whp unrestricted in 2016. I'm 1 plate size larger than I was then. Is it the book answer? No. But to an extent, good enough is good enough in our class. YMMV.