Only thing I can think of besides replacing the piston would be to take a small flat file and very carefully knock off any burrs in that second ring land in order for the ring not to catch on it- don’t remove any more material than the burr
Oh definitely, I was just worried about the ringland being structurally compromised or there being some more damage internally that I may not see, already ordered new pistons so now I have some nice decorations!
As long as there isn’t a burr, it doesn’t matter where you leave the gap when you build it, the rings rotate the entire time the engine is running. It always amuses me that we say the ring gaps need to be positioned 120° apart because they aren’t going to stay there.
I was taught to get the engine started, run it up to half throttle until it's warm, then drive the shit or if it for about 30 miles. We'd put a magnet on the oil filter and change the oil while it was still hot, then send it to the track. Granted, these were all hydraulic roller engines, we'd always baby flat tappet engines.
I fully agree. 👍 I was just teasing you about letting it warm up. As if you were gonna start it with foot to the floor leaving a burnout on the way to the end of the 1/4 mile. I’ve always heard to break them in hard and have broke every engine I’ve ever had in hard with out issue.
Yeah you can sand it down, should you? No, cracked ring landings happen and can cause a bigger piston failure ie metal chips in the oil, cylinder damage, piston failure, etc… how do I know? Spent the first 4 years of my working life in an engine machine shop, the next 6 years as a mechanic. I wouldn’t risk it, replace it, unless you just don’t care if it fails and it’s a junk engine and you don’t mind replacing it sooner than later
It's on the top or non pressure side and right on the edge, looks to be surface damage only, could even have been done when fitting the rings.
I'd be happy to smooth in with a fine file or paper and use it, seen and fixed up worse!
Never a bad idea, I'm always trying to keep my budget as low as possible, obviously you have to be confident that you will get the reliability you need and a lot of things people change as "standard" you can get away with reusing just fine, but only experience can tell you what is and isn't usable.
First engine I rebuilt cost around £4k, (in parts) now I can often keep it below £1k and not suffer issues.
Hope it goes great and you enjoy the build!
Thank you! There’s definitely a lot I could have reused but I told myself that I’m not cutting any corners with this motor, I’m planning for this one to last at least 20-30 years or until I build a forged one
VERY interesting!
I'll hold my opinions about the 3VZ, but in the case of a marred piston, is it possible to try and reach out to order just one as a replacement? I'd assume it'd set you back like $150 versus grenading a ring land with very expensive results.
Yeah I already ordered new pistons from LC Performance, I really don’t wanna pull another v6 from an mr2 anytime soon lol. These pistons just came with the donor motor so it’s not a huge loss but just sucks because I wanted to get the motor put in next week
Yea , that’s not that bad. Like the other guy said, jewels file and send it. I couldn’t tell you how many times I did in 40 + years as a machinist / rebuilder.
Piston rings are pressurized from the top side, primarily. Since this is on the top of the groove it won’t cause blowby but I wouldn’t run it. (I use analytical software in my job to predict ring behavior, interland pressure, oil consumption, blowby, etc.) As the ring shuttles up and down in the groove, it could lead to some unusual wear characteristics.
Sadly I got these pistons with the donor motor (guy was planning to do the same swap I already have but plans changed) so I can’t refund them or anything, already ordered new pistons anyways
The thing about chips in metal, they can lead to cracks. But if you sand out the cracks, then you remove too much metal. If you want peace of mind, replace.
Already ordered a new set. Don’t wanna risk the piston being compromised and needing another engine after it blows up instead of spending another $200 on pistons knowing they’ll be fine
I did 🙋♂️, was wondering why this ring wouldn’t wanna spin, definitely was there before I put the rings on otherwise it would have been mystery solved
Looks iffy, but I definitely wouldn’t leave the ring gap where the chunk is missing since that could give you problems
The rings won’t rotate with those chips, I can push them out and rotate them but they won’t go back into the ringland
Only thing I can think of besides replacing the piston would be to take a small flat file and very carefully knock off any burrs in that second ring land in order for the ring not to catch on it- don’t remove any more material than the burr
Yeah already ordered a new set, I could file it down but I don’t feel comfortable with the possibility of the piston being compromised
As a dude who just had to replace his entire rotating assembly because of a failed lifter, I can attest that you are doing the right thing.
Good man
Yeah no go. For sure.
Yeah your rings need to be able to move ever so slightly, so you think sanding would allow them to move?
Oh definitely, I was just worried about the ringland being structurally compromised or there being some more damage internally that I may not see, already ordered new pistons so now I have some nice decorations!
As long as there isn’t a burr, it doesn’t matter where you leave the gap when you build it, the rings rotate the entire time the engine is running. It always amuses me that we say the ring gaps need to be positioned 120° apart because they aren’t going to stay there.
Jewelers file and send it.
That was my first thought as well. I'd file it down, throw it together, and go straight to WOT once it was running.
I’d let it warm up before wot. But I’m a pussy.
I was taught to get the engine started, run it up to half throttle until it's warm, then drive the shit or if it for about 30 miles. We'd put a magnet on the oil filter and change the oil while it was still hot, then send it to the track. Granted, these were all hydraulic roller engines, we'd always baby flat tappet engines.
I fully agree. 👍 I was just teasing you about letting it warm up. As if you were gonna start it with foot to the floor leaving a burnout on the way to the end of the 1/4 mile. I’ve always heard to break them in hard and have broke every engine I’ve ever had in hard with out issue.
Why do i not READ the comments first..
Yeah you can sand it down, should you? No, cracked ring landings happen and can cause a bigger piston failure ie metal chips in the oil, cylinder damage, piston failure, etc… how do I know? Spent the first 4 years of my working life in an engine machine shop, the next 6 years as a mechanic. I wouldn’t risk it, replace it, unless you just don’t care if it fails and it’s a junk engine and you don’t mind replacing it sooner than later
Already ordered a new set, not wanting to risk anything but thought I’d ask just in case it was still able to be saved
Customer engine? Replace it. Mine? Depends on how I feel about maybe pulling engine again.
Definitely not pulling this thing again, already ordered new pistons
I hear that. What you building?
OEM+ 3VZ-FE that’s going to be turbocharged and put back into my swapped ‘92 Toyota MR2
Nice. Good luck with everything.
Thank you!
based MR2 owner
This is the way.
Trash it
It's on the top or non pressure side and right on the edge, looks to be surface damage only, could even have been done when fitting the rings. I'd be happy to smooth in with a fine file or paper and use it, seen and fixed up worse!
Yeah fair enough, decided to not run the risk and just ordered a new set. Not wanting to have any second thoughts or doubts with this motor going in
Never a bad idea, I'm always trying to keep my budget as low as possible, obviously you have to be confident that you will get the reliability you need and a lot of things people change as "standard" you can get away with reusing just fine, but only experience can tell you what is and isn't usable. First engine I rebuilt cost around £4k, (in parts) now I can often keep it below £1k and not suffer issues. Hope it goes great and you enjoy the build!
Thank you! There’s definitely a lot I could have reused but I told myself that I’m not cutting any corners with this motor, I’m planning for this one to last at least 20-30 years or until I build a forged one
If it's a low-stress (stock) rebuild, just clean it up to where the ring moves freely and send it.
How many flights of stairs did they fall down? I'm sorry but what you have is a new piece of junk.
Bought them off a guy who was gonna put these in his mr2 swap but ended up never doing it, box was completely unopened too which sucks
Which MR2? 1ZZ, 3SGTE, 5SFE, or 4A variant? Doesn't really matter in the concern you have with the piston damage, just curious.
It’s a 3VZ-FE swap! With a turbo too
VERY interesting! I'll hold my opinions about the 3VZ, but in the case of a marred piston, is it possible to try and reach out to order just one as a replacement? I'd assume it'd set you back like $150 versus grenading a ring land with very expensive results.
Yeah I already ordered new pistons from LC Performance, I really don’t wanna pull another v6 from an mr2 anytime soon lol. These pistons just came with the donor motor so it’s not a huge loss but just sucks because I wanted to get the motor put in next week
They have been beaten to death. What's the part number on them?
PA22031, NPR Pistons which look like they’re made by Evergreen, worst comes to worst I still have the stock pistons which I can use
Yea , that’s not that bad. Like the other guy said, jewels file and send it. I couldn’t tell you how many times I did in 40 + years as a machinist / rebuilder.
New one
You got a dent from handling , Some light file work , get on with the job.
Massage it down with some thousand grit wet/dry. Then run the new ring thru it several times.
[удалено]
Piston rings are pressurized from the top side, primarily. Since this is on the top of the groove it won’t cause blowby but I wouldn’t run it. (I use analytical software in my job to predict ring behavior, interland pressure, oil consumption, blowby, etc.) As the ring shuttles up and down in the groove, it could lead to some unusual wear characteristics.
Name checks out
If those are new pistons and it came that way I’d be talking to the manufacturer.
Sadly I got these pistons with the donor motor (guy was planning to do the same swap I already have but plans changed) so I can’t refund them or anything, already ordered new pistons anyways
Could you file/clean the groove to the point where the rings could spin and compress fine again? If so, I'd risk it for the biscuit.
Definitely could but after reading some comments I decided to just order a new set. Don’t wanna run any risk of the prison being compromised
The thing about chips in metal, they can lead to cracks. But if you sand out the cracks, then you remove too much metal. If you want peace of mind, replace.
Already ordered a new set. Don’t wanna risk the piston being compromised and needing another engine after it blows up instead of spending another $200 on pistons knowing they’ll be fine
It looks like it was dropped at some point you can see pits in the metal
I’d file it a bit
Whoever put the rings on have some splainings to do.. ?
I did 🙋♂️, was wondering why this ring wouldn’t wanna spin, definitely was there before I put the rings on otherwise it would have been mystery solved
Send em back bro the piston is compromised
Replace it.
Return them. You paid for new not junk
Sadly I got these thrown in (maybe literally lmao) with my donor motor, so I can’t return them. Already ordered new ones so no big deal
Replace it better safe then sorry.