Hey Everyone

Unfortunately my junkyard swap 5.2 intaked a bolt into cylinder #8. No idea where it came from, i assumed i lost a plenum pan bolt but those are all in place. I’ve put about 200 miles on it before this happened, i believe my WOT pull dislodged it.

The piston seems to have taken the brunt of the damage. The cylinder walls look and feel smooth with no notable gouges. The head also seems to not look horrible, the valves & seats seem untouched.

My question is, can i put a new piston in this thing and call it a day? Where do i need to be looking to be able to make that sort of judgement call, i have my old 5.2, could i use one of those pistons?
Just trying to lay my options out.
Thanks in advance.

 

Measure the bore, see how it sizes up. Then measure the bore on the potential donor. If neither is bored oversize, then, yeah, you likely could pull a piston out of the old motor, toss it in there, and call it a day. I would be tempted to use the rings from the beat up piston though, as they are already worn into that cylinder. (though a bit of a hone wouldn't hurt either.)

Clean up the rough spots on the head, especially around the exhaust valve there. That'll lead to hotspots, and potentially spark knock. (pre-ignition due to the hot spot.)

 

Thanks for the reply

I like the idea of using the rings from the beat up piston, what do you think about the rod bearing ?

Also, should everything check out, should my oem donor piston be close enough in weight to the one i’m replacing ?

 

Look at the bearing, see what you think. If it wasn't knocking, it's likely ok. If it isn't, then the rest of them likely are not as well.

I don't think the factory was real picky about piston weights. This is probably a case of 'close enough'.

 

Sounds good! i appreciate it

 

Game plan is to pull the piston and check out the cylinder walls, if i can work with it im going to hone and swap in a donor piston with new rings.

 

Have a look at the top ring when you remove it, The bolt may have bent down the top of the piston holding the ring in place and might have more wear in one spot.

 

Before removing the valves today i did a liquid leak test with isopropyl alcohol, the intake didn’t leak, the exhaust had a couple drips.

The intakes seat seems to be smoother than the exhaust which has some pitting.

 

Lap the valves. Should take care of it.