Hole in cylinder 1 piston

[JayH]

dropped a motor in a truck a while ago the owner yanked out of a pick a part truck. swapped the distributor and he was on his way.... more or less rest was his fault and its another story.

What do you mean the rest was his fault? And i have decent heads. They just need machine work. Since my motor had #1 piston with a hole from the intake valve bottom breaking off, what's the chances of the crank being fine? I don't mind doing new rings on all 8 pistons and replacing that one piston with connecting rod and bearings. But from another post i thought the crank was toast which is why i sorta gave up on my motor .Thanks

 

[SnowDrifter]

What do you mean the rest was his fault? And i have decent heads. They just need machine work. Since my motor had #1 piston with a hole from the intake valve bottom breaking off, what's the chances of the crank being fine? I don't mind doing new rings on all 8 pistons and replacing that one piston with connecting rod and bearings. But from another post i thought the crank was toast which is why i sorta gave up on my motor .Thanks

Have you torn down and taken any measurements?

Until that point, everything is just speculation

 

[drakon543]

sent you a pm regarding the side topic. there is a hood chance your crank is good and if one of the pistons from the other motor measure good then you can salvage that and maybe some other parts if you purchased it already. if your going to dig that far into an engine you might as well do rings and bearings anyway. rings and bearings might have been good but as soon as you seperate something and put it back together there is always a chance. but as snowdrifter said also going with my comment its better to measure and check everything than just going on assumptions. get everything back together and have it only last a month or so because 1 journal was slightly under.

 

[JayH]

if it helps, now that the passenger head is off, the rotating assembly rotates pretty smooth now. i think i'll put another motor in for now and rebuild the original, shrink wrap it and keep as a backup. I plan to keep the yukon for a long time.

 

[thompsoj22]

everything posted above is solid advice, "But" just for the fun of it and it sounds like either the budget or your conscience is onboard with the "cheapest way possible" throw an intake valve/spring at it and see what it does? In your initial post you stated that it "chugged to a stop" that engine should have continued to run and not "shut off" on it's own as the valve was seated in the piston and not bashing around in the chamber so there maybe catastrophic damage in the crank/rod area. If the head isnt cracked it would be a good experience for your son to understand doing it right the first time or half "you know" Still for less than $100 it could be back together and running for 10 seconds or 10'000 miles or more. This opinion is based upon the vehicle not being needed as a daily driver for your family, not putting your wife and kids in it for a cross country road trip. you bought it as junk, see how far it will go? If it runs for awhile and you like the vehicle than put a quality junkyard/reman engine it at that point.

 

[JayH]

everything posted above is solid advice, "But" just for the fun of it and it sounds like either the budget or your conscience is onboard with the "cheapest way possible" throw an intake valve/spring at it and see what it does? In your initial post you stated that it "chugged to a stop" that engine should have continued to run and not "shut off" on it's own as the valve was seated in the piston and not bashing around in the chamber so there maybe catastrophic damage in the crank/rod area. If the head isnt cracked it would be a good experience for your son to understand doing it right the first time or half "you know" Still for less than $100 it could be back together and running for 10 seconds or 10'000 miles or more. This opinion is based upon the vehicle not being needed as a daily driver for your family, not putting your wife and kids in it for a cross country road trip. you bought it as junk, see how far it will go? If it runs for awhile and you like the vehicle than put a quality junkyard/reman engine it at that point.

I plan to put another motor in. This will be a daily driver which is why I'm looking for another motor. But we plan to rebuild the original and stash it away for a backup in case the "new" motor takes a dump. We like yukons so we plan to keep this truck as long as possible. I like your advice though, playing devils advocate there a bit lol. But no this will be mainly driven by the wife with the kids so I don't want to stress over the motor taking a dump on 95 while she's driving 70mph.

 

[bottomline2000]

everything posted above is solid advice, "But" just for the fun of it and it sounds like either the budget or your conscience is onboard with the "cheapest way possible" throw an intake valve/spring at it and see what it does? In your initial post you stated that it "chugged to a stop" that engine should have continued to run and not "shut off" on it's own as the valve was seated in the piston and not bashing around in the chamber so there maybe catastrophic damage in the crank/rod area. If the head isnt cracked it would be a good experience for your son to understand doing it right the first time or half "you know" Still for less than $100 it could be back together and running for 10 seconds or 10'000 miles or more. This opinion is based upon the vehicle not being needed as a daily driver for your family, not putting your wife and kids in it for a cross country road trip. you bought it as junk, see how far it will go? If it runs for awhile and you like the vehicle than put a quality junkyard/reman engine it at that point.

From the pictures it seems the valve broke and basically bounced off the piston until finally falling into the combustion chamber and flipping..the valve stem then stated punching the piston sending a shockwave to the crank. The piston had nowhere to go so it couldn't keep running unless the valve punched a hole in the piston deep enough to give it some head clearance.

It may run just fine with a new rod and piston, but the head needs to be replaced as I'm sure the valve guide is shot.

@JayH Any idea what caused the break? What's the head look like where the valve broke and more importantly how does that cylinder look? U can experiment with this motor, but I don't know if I would trust it.

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[JayH]

From the pictures it seems the valve broke and basically bounced off the piston until finally falling into the combustion chamber and flipping..the valve stem then stated punching the piston sending a shockwave to the crank. The piston had nowhere to go so it couldn't keep running unless the valve punched a hole in the piston deep enough to give it some head clearance.

It may run just fine with a new rod and piston, but the head needs to be replaced as I'm sure the valve guide is shot.

@JayH Any idea what caused the break? What's the head look like where the valve broke and more importantly how does that cylinder look? U can experiment with this motor, but I don't know if I would trust it.

Sent from my SAMSUNG-SM-G900A using Tapatalk

The lifter for that valve was in two pieces when i pulled the head, and the pushrod was bent. I'm guessing the lifter was the culprit since the last owner heard ticking but never investigated .

 

[JayH]

So I bought another motor that's in great shape. it has about 170k miles, and the head gaskets were done about a year ago since the heads were removed for inspection. The valves were lapped and everything put back together. Question I have that I just thought about, the motor is an '03, but non flex fuel unlike my original motor. I know that the injectors are slightly bigger, so if I reused my injectors, and intake, would I be fine putting it all back together and running it, or would a tune be needed? Also, is it true that since '02, chevy stopped putting egr valves on the 5.3? I don't see a hole on the passenger exhaust manifold, nor was there a canister looking thing on the passenger head. Thanks again guys!

 

[SnowDrifter]

Not sure bout sure the year, but my 05 doesn't have egr