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Fasterd
11-27-2018, 12:00 PM
As the title states, posing this question to myself as well. I have always heard that once a piston is pulled you can't reuse the rings, but if they move thats total bullshit.

Before someone comes in with the cheap argument, its not cost savings. I don't want to buy pistons, and I don't like taking out material and re-using pistons (a piston should be matched to a bore one time)

so...yeah what gives

b6Hate4
11-27-2018, 12:02 PM
Iíve heard of vortex guys reusing their pistons + rings when doing drop in rods on the mk4 1.8tís with no ill effects.

I think it comes down to:

Should you? Probably not.

Could you? Yeah, you can probably get away with it if youíre careful and if itís your own car who cares if a replcement motor is cheap.

Fasterd
11-27-2018, 12:06 PM
Im looking at this from a machining standpoint. I feel like if you touch the walls, you better put pistons in to properly match the clearance.

With finding an ABA crank proving a bit tougher now and the grinding associated with an 058 stroker, I would just rather avoid it all together as the 1500 bottom end isn't worth it in a 20 year old VW (not to me at least)

MetalMan
11-27-2018, 12:20 PM
I did drop-in rods, pulled the pistons, and re-used rings. Then put another 10k on the engine. Afterwards compression was still 170-175+psi, and consistent across all 4 cylinders (except #2 was initially low, but that was due to a crack in cooling jacket that forced combustion gases into cooling system).

You need to be very meticulous and have an engine in good shape if you're going to consider re-using rings. IMO.

Blazius
11-27-2018, 12:29 PM
Im looking at this from a machining standpoint. I feel like if you touch the walls, you better put pistons in to properly match the clearance.

With finding an ABA crank proving a bit tougher now and the grinding associated with an 058 stroker, I would just rather avoid it all together as the 1500 bottom end isn't worth it in a 20 year old VW (not to me at least)

What do you mean 1500 bottom end ? if you gonna stroke it , u bore to 83mm, get 83mm pistons and new rings , no ? I dont see the issue. ABA is not the only crank you can use aswell I am fairly sure.

Fasterd
11-27-2018, 12:35 PM
What do you mean 1500 bottom end ? if you gonna stroke it , u bore to 83mm, get 83mm pistons and new rings , no ? I dont see the issue. ABA is not the only crank you can use aswell I am fairly sure.

do you have any idea what youre talking about?

mahle pistons at 700 bucks plus machining will get you close to 900...add in bearings and rods. This isn't a chevy 350 where a stroker adds significant displacement, the cost isn't seen in results for a lot of people (dyno's be damned, Ive watched on this forum since 2008 where people build shit that drives like ass, or never finish when real cost sets in)


ABA or buy an 06A....considering i have all my left over shit from the last b5 I don't think an 06A will be coming any time soon

Blazius
11-27-2018, 01:48 PM
do you have any idea what youre talking about?

mahle pistons at 700 bucks plus machining will get you close to 900...add in bearings and rods. This isn't a chevy 350 where a stroker adds significant displacement, the cost isn't seen in results for a lot of people (dyno's be damned, Ive watched on this forum since 2008 where people build shit that drives like ass, or never finish when real cost sets in)


ABA or buy an 06A....considering i have all my left over shit from the last b5 I don't think an 06A will be coming any time soon

No I was asking what you meant by 1500 , I guess you mean 1500 usd (not everybody is american ;) ) Also you can use an ABF crank which is not forged but who cares if you are not going to make 600+ chp, ADY crank which should be forged but i am not sure, a 2E crank with adaptor.

Fasterd
11-27-2018, 01:52 PM
See.....or I can buy 400 dollar scat rods and toss in an oil/water pump, then turn it up

https://i0.wp.com/www.thebarbedwiresatire.com/wp-content/uploads/2017/06/1.3.1-e1498171882290.png?resize=481%2C323&ssl=1

thedanplasse
11-27-2018, 01:57 PM
It's going to be more than that. I just built my bottom end. In labor alone, I was up near $1500

Bored .020 over, line honed the mains, balanced the entire rotating assembly, decked the head, and pinned the stock crank.

Let alone the parts, Pistons, bearings, rods, main studs, head studs. But.....I wanted to make sure I did it the right way without cutting any corners.

(not knocking anyones build) Just to be clear.

Fasterd
11-27-2018, 01:59 PM
It's going to be more than that. I just built my bottom end. In labor alone, I was up near $1500

Bored .020 over, line honed the mains, balanced the entire rotating assembly, decked the head, and pinned the stock crank.

Let alone the parts, Pistons, bearings, rods, main studs, head studs. But.....I wanted to make sure I did it the right way without cutting any corners.

(not knocking anyones build) Just to be clear.

Thanks Danny boy, someone with actual experience giving input. (although you went cadillac package sir)

This is why I bought an 058, pistons and head out of the box so yeah not going to start with an 06A and unless an ABA makes itself known soon this bitch will be a hood build (if it wasn't already)

Blazius
11-27-2018, 02:02 PM
I guess european parts are lot more expensive over there, and generally parts isnt that expensive here, but yes the average salary is 400 usd / month too so yeah. Anything international will break the bank like aftermarket forged pistons to work with the crank... unless you get a set from a motor that works :)

For 485 usd I bought an AEB motor with flywheel. new Parts separetly, Timing belt, hyd. tensioner, roller for tensioner, Roller for timing belt, new waterpump, lemforder front snub , oil filter housing gasket, oil cooler gasket, intake gasket, ac belt, accessory belt, FPR gasket set, headgasket, headbolts, thermostat some other stuff too.

Fasterd
11-27-2018, 02:06 PM
I don't think the .2 of a liter really translates in the real world scenarios iv'e seen. considering the limitation of the 01A trans if I want to make power it will be a B7/2.7TT because fuck yeah, thats why

Blazius
11-27-2018, 02:09 PM
I don't think the .2 of a liter really translates in the real world scenarios iv'e seen. considering the limitation of the 01A trans if I want to make power it will be a B7/2.7TT because fuck yeah, thats why

TBF, If I would go for a 2L 058 stroke , it would be cause I want to spend my time outside spending my money lol, not really pushing for the advantages of that 0.2L disp increase. And my plans for the next 10 years is to get a B7 avant with an 1.8t too :D , you cant beat the look of the b7 avant.

Fasterd
11-27-2018, 02:20 PM
B7 wagons make me mess my pants. If my 06 was a wagon it would still be in my possession.

https://wranglertjforum.com/attachments/whitejeep-jpg.49327/

Blazius
11-27-2018, 02:26 PM
So tha 01A trans can hold up to 400 whp , what can the 01W ( FWD ) one do I am assuming it can handle the same, you are more likely to spin tires aswell.

Fasterd
11-27-2018, 02:29 PM
So tha 01A trans can hold up to 400 whp , what can the 01W ( FWD ) one do I am assuming it can handle the same, you are more likely to spin tires aswell.

Tire spin will allow for big numbers, the AWD just locks that brutal stress in the driveline. I forget where exactly it fails but it has to do with shaft flex with 3rd gear if I remember correctly.

Blazius
11-27-2018, 02:33 PM
Tire spin will allow for big numbers, the AWD just locks that brutal stress in the driveline. I forget where exactly it fails but it has to do with shaft flex with 3rd gear if I remember correctly.

Heh one reason to not have quattro I guess :D, yeah afaik 3rd gear fails 1st in that trans.

chris164935
11-28-2018, 11:09 AM
Why do these threads keep getting so confusing? If you want to build a 2L stroker motor, you need new pistons/rings. If you don't want to buy new pistons, then you're VERY limited on building a 2L stroker motor. It's not just the diameter of the piston that matters in a stroker build. The wrist pin height is changed when you swap in a 92.8mm crankshaft. If you use stock pistons with that size crankshaft, you'll smash the pistons into the head the first time you try to spin the motor over by hand.

Fasterd
11-28-2018, 11:21 AM
So youre assuming I dont know what an interference engine is?

Why would I bring up Mahle Powerpack pistons if I didn't know the stroke was different?



The only question I posed is how much rotation is a ring subject to, and almost no one addressed the question in any way. [facepalm]

Blazius
11-28-2018, 11:43 AM
Why do these threads keep getting so confusing? If you want to build a 2L stroker motor, you need new pistons/rings. If you don't want to buy new pistons, then you're VERY limited on building a 2L stroker motor. It's not just the diameter of the piston that matters in a stroker build. The wrist pin height is changed when you swap in a 92.8mm crankshaft. If you use stock pistons with that size crankshaft, you'll smash the pistons into the head the first time you try to spin the motor over by hand.

Yeah, if you go for stroker/bore , you obviously need new/modified pistons because of bore, even if you go for 1.9L , stock crank build. He knows that.

As for pistons rings rotation, I am not a physician, but I do not imagine they rotate too much, they are in there pretty tight, rotation could mess up the blowby.

Fasterd
11-28-2018, 11:49 AM
What would keep them in place? Everything I read in builder resources says rings are subject to rotate constantly and at a rate much higher than one would expect.

The only reason I have second guessed it is due to the spec regarding 120 degree rotation of each ring (which would theoretically be unnecessary if the above statements are correct)

chris164935
11-28-2018, 11:53 AM
Google it.

Fasterd
11-28-2018, 12:23 PM
Google it.

Florida, need I say more?

Blazius
11-28-2018, 12:47 PM
Well. My guess would be because of the grooves they are sitting in, they are doing up and down movement, that pushes them into the sides of the little grooves not allowing to them to rotate, or if they do they are rotate the same rate my guess, But hopefully some expert can clarify on this.

chris164935
11-30-2018, 01:12 PM
Florida, need I say more?
You're the one asking ridiculous questions, like someone is out there taking the time to test and determine if the piston rings in a 1.8t are rotating. Lol. And your reasoning? You think that you need brand new pistons because you honed the cylinder wall... But, I'm the idiot from Florida.

Buy some new rings, hone the block, check the gap on the brand new rings and file as necessary based on power/boost levels. With honing the cylinder walls, you're talking about taking out like .001"-.002" of material. No need for brand new pistons that would be 0.05mm larger in diameter "to match the bore".

Fasterd
11-30-2018, 01:35 PM
Wait a minute here.....

that .002 plus wear of skirt/bore/coating adds up, theres no point in reassembling at the extreme of the limits.

I would bore in order to have CONTROL over the clearance you ass clown.

chris164935
11-30-2018, 02:12 PM
Wait a minute here.....

that .002 plus wear of skirt/bore/coating adds up, theres no point in reassembling at the extreme of the limits.

I would bore in order to have CONTROL over the clearance you ass clown.
I can tell you that coatings don't mean shit in terms of clearance and skirt wear means your pistons are garbage and you need new ones. Even if we took those into account, you're still talking .004"-.005" or 0.1-0.12 mm increase on the bore. I'd love for you to find someone that will make you 81.1 or 81.12 mm diameter pistons. LOL. Fucking tool.
You'd take that out of the gap in pistons rings, which if you're increasing power/boost levels you should increase your piston ring gaps anyway.
If you're boring out the cylinders, then you need new pistons; however, you said you don't want to pay for new pistons, so you're back to square one...

But what do I know, I only have a motor capable of 800+ hp that I have honed several times and installed the same diameter pistons into with new rings that were properly gapped for my motor's build specifications without any issues.

Fasterd
11-30-2018, 03:53 PM
thats why mahle makes the 81.5 in a stock pin height......because you should match the bore to the piston, properly refreshing the block is bringing that clearance back to the original spec.

and why would the argument of increasing ring gap affirm your position? thats irrelevant and a bap reason for accepting extra piston to wall clearance.

chris164935
11-30-2018, 05:07 PM
So, what the hell is this thread about? Piston to wall clearance or piston rings? Honing the bores isn't going the change much in terms of piston rings, except there is the slight chance that it could increase your ring gap (which you should do anyway if you are increasing boost/power levels); but you would measure your ring gap and file as needed for your motor's specifications.

Honing the cylinder walls isn't going to create enough piston to wall clearance that you need stupid custom pistons (like in the example I provided previously). I have honed my motor's cylinder walls a couple of times now, my piston to wall clearance is within the spec I want for my motor and have not had any issues with piston slap, etc. and I'm using JE's 2618 T6 high tensile forged aluminum pistons. And many other people have had no issues with honing the cylinder walls and re-installing their stock pistons with new (and in some cases used) piston rings and have had no issues. But, I guess you're right and we're all wrong?

Anyway, good luck with your perfect specifications without spending any money build. [wrench]

Fasterd
11-30-2018, 05:18 PM
You can get away with that using 2618 but not 4032 as its expansion is much lower.

The question is how much a ring rotates, because if there are several revolutions of the rings within a given "session" then the myth that taking a piston out of the cylinder is detrimental to the ring seal upon reinstallation is false (which is why many feel it necessary to replace every time, other than it being "cheap").

chris164935
11-30-2018, 06:34 PM
Yes, I can get away with it. Any literally hundreds of other people running stock pistons have gotten away with it as well. This is not something new, these motors have been around for about 22 years now. You're not pioneering anything.
A quick Google search: http://blog.wiseco.com/ring-grooves Read the sections about Axial Height and Ring Groove Quality to answer you question...

I would replace it just on the principle that it is a pain in the ass to do the job a second time if the used rings don't properly re-seat (because of bad cylinder wall cross-hatch marks or bad rings).
But it's all personal preference. Do you want to risk it to save $200? Is this car your daily driver? Can you afford to have it sit for a few days while you order new rings and then rebuild the motor? Can you afford to replace some of the gaskets that can not be reused (ie, head gasket)? Does double-working not bother you so much?

EDIT: there's some other specs in there that you might want to measure as well if you want everything to be 100%.

Fasterd
11-30-2018, 07:36 PM
I'm not asking if I can get away with it, I'm asking if there is any real loss of seat quality by re-insterting the pistons into the bore.

In reality the car has 100k left of hard, 300whp+ driving and I want to recycle my aeb pistons so yeah, if I can get another 100k from the rings/crank bearings/IM shaft bearings etc then fuckin a

chris164935
12-01-2018, 11:39 AM
No body can tell you if it will be 100% okay to do that on your motor. It's always a gamble and it seems you're willing to accept the risks.

Fasterd
12-01-2018, 11:48 AM
Again sucktard stop trying to twist my question


The question is how much rotation is a ring subject to in a given amount of time (1 minute to set metric).

Someone with an answer, please oblige

Fasterd
12-01-2018, 11:53 AM
The answer is this:

While you CAN reuse them with no issue, the reason this practice is frowned upon is due to the risk of damage to the ring when removing caused by heat cycling.

This is defendant on age, abuse, and ring materials

demonmk2
12-01-2018, 03:16 PM
So tha 01A trans can hold up to 400 whp , what can the 01W ( FWD ) one do I am assuming it can handle the same, you are more likely to spin tires aswell.

It can handle more but you have to manage your shifts ( donít slam it into 3rd, up or down or dump the clutch in 3rd )
Mike hood ran 10ís using an O1A


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Blazius
12-01-2018, 04:35 PM
It can handle more but you have to manage your shifts ( donít slam it into 3rd, up or down or dump the clutch in 3rd )
Mike hood ran 10ís using an O1A


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Well I am saying generally for safe average driving , from my research, people say 400 awhp is a good ballpark. It doesn't affect me anyway , I got FWD :P .

chris164935
12-01-2018, 05:15 PM
Again sucktard stop trying to twist my question


The question is how much rotation is a ring subject to in a given amount of time (1 minute to set metric).

Someone with an answer, please oblige
Dude, you're so fucking stupid... I don't know why I bother but, here goes: the motor speed is measured by RPMs. Rotations per minute. So, at your 1 minute metric, the motor could make 1000 revolutions per minute or 6000 revolutions per minute. If you bothered to read the article I posted earlier, you'd know that piston rings spin in both directions as the piston moves up and down the cylinder following the hash marks. Here's where the math theory gets a little tricky, so let's hope you can still keep up (I doubt it, but I'll still work it out anyway). Stock motor has a bore of 81mm and the stroke is 86.4mm, if we assume that for every 1 mm of piston travel, the piston ring rotates 1mm, every complete revolution of the motor would mean about 2 complete spins of the piston ring. So, at 1000 RPMs, the piston ring is spinning about 2000 times per minute. At 6000 RPMs, about 12000 times per minute. This is all an untested theory as no one gives enough of a shit to actually test this just so they can make a more informed decision about reusing piston rings. [facepalm]

chris164935
12-01-2018, 05:20 PM
The answer is this:

While you CAN reuse them with no issue, the reason this practice is frowned upon is due to the risk of damage to the ring when removing caused by heat cycling.

This is defendant on age, abuse, and ring materials
Yeah. Risk of damage from removal, or heat welding, or excessive wear. Thanks for telling me what I already said...

Seerlah
12-01-2018, 07:11 PM
^Not one of the forum members to debate or argue with, rather listen to what they say and build off that.

There are those who say that you should never reuse piston rings, due to never really being able to place them in the same way they came out. Then there are those who reuse pistons rings and never have any issue.

IMO, it is always a roll of the dice. For example, current block was rehoned a second time, cheaper Grant piston rings used over Goetze, more blow by that what I want, yet still seen over 150mph and moves just fine. No expert by a long shot, but learned to just do what you want. And that is the joy of modifying your car, taking the good with the bad.

Avant Nate
12-01-2018, 07:52 PM
It's like $80 for new Goetze rings, even cheaper if buy more shit from Germany.

https://www.cs-parts.de/Kolbenringe-18-bis-200PS-27T-GOeTZE-08-502900-00

zandrew
12-11-2018, 12:11 PM
The rings do not move that much. After honing the block you SHOULD always replace the pistons. Personally what is called a plateau hone is best. Then there is the hole thing about different rings require different stone hones to even different hone angles. Those rings do not wear evenly, if you find some used pistons measure them and you will see that. If you look at a pistons wrist pin its location is off set to the rotation side to prevent slap at start up. This side also see the most the wear. So basically if you re use rings your going to be putting an egg shape ring into an egg shape bore. Good luck on getting that alignment perfect.

Rings are supposed to be installed at 90 degree intervals with the 1st and 2nd ring gaps 180 degrees apart. Also the gaps are not supposed to be aligned with the thrust or axial loading points of the piston.

Fasterd
12-11-2018, 12:16 PM
The rings do not move that much. After honing the block you SHOULD always replace the pistons. Personally what is called a plateau hone is best. Then there is the hole thing about different rings require different stone hones to even different hone angles. Those rings do not wear evenly, if you find some used pistons measure them and you will see that. If you look at a pistons wrist pin its location is off set to the rotation side to prevent slap at start up. This side also see the most the wear. So basically if you re use rings your going to be putting an egg shape ring into an egg shape bore. Good luck on getting that alignment perfect.

If rings move at twice the rate of the rotating assembly (posed by multiple members and professionals) the rings would stay round while the ellipse forms inside the bore (which is how blow by is caused, along with badd end gap). I would never put a used piston into a bore it was not mated to from day one. Also, the grit does get determined by the ring material, which has nothing to do with this conversation.

The question was can rings maintain seal when reinstalled, not whether a hone constitues new rings. That being said my determination was not to do this due to the heat cycling of the rings which makes them susceptible to damage during process, the REAL reason they are a "replace every time" item.



Rings are supposed to be installed at 90 degree intervals with the 1st and 2nd ring gaps 180 degrees apart. Also the gaps are not supposed to be aligned with the thrust or axial loading points of the piston.

This is wrong, its 120 degrees for the 1.8t

zandrew
12-11-2018, 03:55 PM
No they do not move that much, this is first hand knowledgde.

The aeb and awm factory piston rings are 3 piece and yes the manual states to place these gaps 120, 120 120 apart. I wouldn't as this will place one of the gaps at the position that exerts the greatest forces either axial or thrust. This is is hard on the rings. All aftermarket rings are 5 piece, those are to be installed at 90 degree intervals. Then again you have jumped from oem to mahle to oem to ????

Now go buy you a dial bore scope and measure the out of round of used bore. Then explain to me how your going to get a round ring to seal, then explain to me if you do get it too seal how it would then move? Did you not see the out of round spec?

This is first hand knowledge. Once the rings seat they do not move much, but hey what do I know.

Blazius
12-11-2018, 05:35 PM
lmao, chill :D

Blazius
12-11-2018, 05:42 PM
I did not say I agree with him but chill with the insults fam.

Yes in my research , they rotate too apparently, 2-6 rpm depending on the speed, it is said they rotate cause of the boring, also they rotate mostly synced.