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Imagine watching this at right time..i was about to replace rings after finding this movement once i opened the cylinder head to replace leaking valves.good thing that gave me confidence was finding cylinder walls being fine with no spots of piston slap. So video served me a lot.
Am just here now! On a 1.8T also a bit of movement and I was like god fkn damn replacing already the second engine now and than this. So me searching and searching and all people say baaad replace booo! Than this video comes up, and just made me like. Yeahh let's continue all good now!
Same. Pulled the head on my lawnmower engine to fix what I think is leaking valve seal and see the piston rocking. Was about to go buy a whole new engine because cost is about the same as a rebuild for me. Gonna run it with the new valve seal now first just to make sure it's not still smoking before buying a replacement.
Happened to me, I lifted my head so was just cleaning the carbon off the tops of the Pistons and noticed that rocking back n forth and thought I was screwed! Lol luckily down lower the clearance was in spec
I was all ready to pick this video apart!, damn if he didn't get it rite. I might add that the thickness of material on piston crown also adds to the expansion of this area. The percentage of silicon in the piston material (forged) helps stabilization of expansion and is useful in getting a nice fit. Lastly, as allways, follow the piston manufactures recommendations for fitment of their product. I am off to check out some of your other offerings, good work.
I was losing sleep over this lol, greatly appreciate the insight. Mine don’t rock that much but I was getting way too much conflicting information on this subject. There are too many forum warriors out there that spout absolute non sense with full confidence.
A lot of people are just trying to help not even realising they are giving inaccurate information. It even happens with people making a living in many trades. Either way, glad we could help you sleep easier and cheers for the comment =) - Taz.
@@hpa101 hey mate is there a way you could possibly help me find the size of a rm85 cylinder it’s definitely had work as it’s got extra stamps on it but I’ve got no idea what they mean I pulled a 47.95 piston out and she’s tight compared to what you’ve shown she’s a 2t
I have a 6.0 LQ4 that has about the same amount of piston rock as the one in the beginning of the video.. I was going to have it punched out, and new pistons put in, but after watching this I guess I don't need to.
My dad used to tell me that the most worn piston in the most worn bore (assuming no prior rebuild) will last around 40,000 km in normal driving with a hone and new rings. Obviously this is not ideal to actually do and is at least partially bullshit, coming from the days of 100,000 km engines where people really didn't want to pay to fully rebuild so often... But say I had 2nd hand aftermarket pistons (stock size) to install in a worn-ish engine (200,000 km AU Falcon, for example) with a hone and new rings. Would you expect a dramatically short life compared to a fresh bore and associated new pistons? Scenario: Budget burnout car where engine run time is likely to be measured in hours per decade
No worries mate. You can find a bunch of reviews on our Facebook page: facebook.com/HPAcademy/reviews Let me know if you have any further questions. - Ben
I wish I knew this beforehand. I sent my engine to be rebuild and I was hoping to chuck in a used high comp forged piston and con rods but the engine builder called to let me know that the second hand forged pistons I bought had a bigger clearance than the oem they wanted to put. The bore was 81.0mm and the oem was 80.97mm while the forge ones were 80.90mm. Was I right to go with the oem ones? or the 0.07mm difference would have been negligible?
I have the same thing but it's on a 2 stroke engine that doesn't have compression because the piston rings where stuck but there not eny more stuck maybe it has compression now but there a still wobbly
Does this same concept apply to cast pistons? I have an engine that I honed, and put new standard size pistons and rings and was surprised about the piston rocking back and forth in the bore just like what's shown in this video. Thank you!
I ended up over boring the engine. Measured the piston to bore clearance and it was way in excess of factory specs. They still rocked a bit, but no where near as much.
Not normal, the clearance should be roughly the same on all 8 pistons. Any significant variance in clearance from piston to piston is cause for concern.
one thing that i cant find anywhere: how many combustions the piston needs to expand to proper diameter? I guess its not that long as people say because the combustion heat is intense then its logical to think the piston would expand on the first 10 power strokes, or am I wrong? I know there's the heat exchange with watercooled cylinder walls but still, the heat is constantly built in the piston crown, right....?
the main question is: ok, the engine takes lots of time to warm up completely to operating temperature, but I guess the pistons wont take that long to expand to operating temperature due to the direct exposure to heat from combustion...right??..
@@sgt-willkillu 10min is time for defrosting the front windshield after firing up my old volvo xD for the pistons to heat up and expand i would say is perfectly good after couple of minutes.
@ståle starheim..., yes maybe a couple of minutes. BUT if you have thousands of 💵invested in an engine, then 10mins is a good indication that one can start to go full throttle.
hey please i have a question on bloc engine its marked the bore cylinder class , for example "abac" can i use piston classe "B 71.98" if the cylinder classe "a 72.00" is worn but still in the limit of classe b lets say 72.02" ? the mix is possible ? cause the workshop says that if classe "a" exced the limit , rebore the cylinder 0.1 and use oversize 0.1 piston Cylinder "A" 72,00-72.01 /// Piston "A" 71,965-71,97 Cylinder "B" 72.01-72.02 /// Piston "B" 71,97-71,98 Cylinder "C" 72.02-72.03 /// Piston "C" 71,98-71,99 over size cylinder "A" 72.10-72.11 /// over size piston "A" 72,065-72,07 over size cylinder "B" 72.11-72.12 /// over size piston "B" 72,07-72,08 over size cylinder "C" 72.12-72.13 /// over size piston "C" 72,08-72,09
so wat should the pistonskirt to cilinder clearance be on a smart car ? (63.750 mm bore 0.6 liter 3 cilinder aluminium block metal liners stock turbocharged running on regulair fuel)
When your video reach 0:11 min its piston is faulty or bore is faulty or rings is faulty sir give me ans and suggest me. I have royal enfield engine oil comes from breather pipe what can i do for this
Yes, generally it is more the material your rod is made of that can limit usage rather than forged pistons - Taz. www.hpacademy.com/q-and-a/aluminium-rods-pros-and-cons/?
Forged pistons require a lot more clearance then cast, depending on manufacturer but if I had a stock cast piston I was just reringing for a rebuild that would definitely raise red flags for me and honestly cause me to rethink my plans. At the very least new pistons if not a bore and pistons.
@@jonathonvince3605 Any piston is going to rock a bit, but the exact clearance will depend on the application. If the clearance was so tight it didn't move at all, it would seize up and self destruct within seconds of starting the engine. Kudos for trying to be helpful, but sharing completely incorrect information isn't helping, it's making things much worse for people who don't know better.
@@bambee2556 이 영상은 전문가가 아니라 '자동차 학원 선생'이다. 즉 50년 경력을 갖고 있고 대한민국 정부가 인정한 자동차명장인 카센터 사상 박씨가 학원 선생보다 더 실력이 좋다라는 것이다. 그리고 여기 학원 선생이 말하기를 'might be wrong' 이라고 했는데 이 뜻은 '틀릴 수도 있고 사실일 수도 있다' 라는 뜻이다.
🦸♂ Building a fast car? Get $400 OFF the all inclusive VIP online course package deal: hpcdmy.co/vipy77
🔧50% OFF your first engine building course. Enrol now: hpcdmy.co/offery77
the look on people's faces when I tell them this.....priceless. Good explanation on you
Imagine watching this at right time..i was about to replace rings after finding this movement once i opened the cylinder head to replace leaking valves.good thing that gave me confidence was finding cylinder walls being fine with no spots of piston slap.
So video served me a lot.
Am just here now! On a 1.8T also a bit of movement and I was like god fkn damn replacing already the second engine now and than this. So me searching and searching and all people say baaad replace booo! Than this video comes up, and just made me like. Yeahh let's continue all good now!
@@FlightSimXtreem what a coincidence.
Same. Pulled the head on my lawnmower engine to fix what I think is leaking valve seal and see the piston rocking. Was about to go buy a whole new engine because cost is about the same as a rebuild for me. Gonna run it with the new valve seal now first just to make sure it's not still smoking before buying a replacement.
Happened to me, I lifted my head so was just cleaning the carbon off the tops of the Pistons and noticed that rocking back n forth and thought I was screwed! Lol luckily down lower the clearance was in spec
Emotional roller coaster there! Good work on checking first rather than just assuming 😎- Taz.
I was all ready to pick this video apart!, damn if he didn't get it rite. I might add that the thickness of material on piston crown also adds to the expansion of this area. The percentage of silicon in the piston material (forged) helps stabilization of expansion and is useful in getting a nice fit. Lastly, as allways, follow the piston manufactures recommendations for fitment of their product. I am off to check out some of your other offerings, good work.
Cheers for the praise and extra bit of information there Russell, glad we hit the spot for you. Factual and concise is our goal :) - Taz.
Wow such a simple but helpful explanation 😁
I was losing sleep over this lol, greatly appreciate the insight. Mine don’t rock that much but I was getting way too much conflicting information on this subject. There are too many forum warriors out there that spout absolute non sense with full confidence.
A lot of people are just trying to help not even realising they are giving inaccurate information. It even happens with people making a living in many trades.
Either way, glad we could help you sleep easier and cheers for the comment =) - Taz.
@@hpa101 hey mate is there a way you could possibly help me find the size of a rm85 cylinder it’s definitely had work as it’s got extra stamps on it but I’ve got no idea what they mean I pulled a 47.95 piston out and she’s tight compared to what you’ve shown she’s a 2t
Definitely need the clearance for a forged piston
Your all over it mate,,,you know that feeling when you get ya bbk ,check the slug in the jug,,,,wallop.....2 stroke run closer tolerances.. brappp☘
On a forged racing application.007 to .009 is ok combustion temps are a lot higher so you will have higher expansion rates
Piston slap on start up lol 😂
I have a 6.0 LQ4 that has about the same amount of piston rock as the one in the beginning of the video.. I was going to have it punched out, and new pistons put in, but after watching this I guess I don't need to.
How did it run with the piston like that because I just got a lq4 too with the same piston rock
@Travis Ibarra it's ran fine actually. I didn't even know it had piston rock until I took the heads off.
I just saw thread and it made me feel better about my LQ4 I thought I was going to need to get it bored out
My dad used to tell me that the most worn piston in the most worn bore (assuming no prior rebuild) will last around 40,000 km in normal driving with a hone and new rings.
Obviously this is not ideal to actually do and is at least partially bullshit, coming from the days of 100,000 km engines where people really didn't want to pay to fully rebuild so often... But say I had 2nd hand aftermarket pistons (stock size) to install in a worn-ish engine (200,000 km AU Falcon, for example) with a hone and new rings. Would you expect a dramatically short life compared to a fresh bore and associated new pistons?
Scenario: Budget burnout car where engine run time is likely to be measured in hours per decade
Depends on shape of cylinder walls, are they out of round any? Any scuffs or scratches? How about a lip at top of bore from old rings
Cool idea guys. Would love to see some reviews for the school. Something that I'd consider purchasing after graduation mech E school
No worries mate. You can find a bunch of reviews on our Facebook page: facebook.com/HPAcademy/reviews Let me know if you have any further questions. - Ben
I wish I knew this beforehand. I sent my engine to be rebuild and I was hoping to chuck in a used high comp forged piston and con rods but the engine builder called to let me know that the second hand forged pistons I bought had a bigger clearance than the oem they wanted to put. The bore was 81.0mm and the oem was 80.97mm while the forge ones were 80.90mm. Was I right to go with the oem ones? or the 0.07mm difference would have been negligible?
How did it go?
I have the same thing but it's on a 2 stroke engine that doesn't have compression because the piston rings where stuck but there not eny more stuck maybe it has compression now but there a still wobbly
Does this same concept apply to cast pistons? I have an engine that I honed, and put new standard size pistons and rings and was surprised about the piston rocking back and forth in the bore just like what's shown in this video. Thank you!
How did yours turn out? Was it ok. I did the same thing
I ended up over boring the engine. Measured the piston to bore clearance and it was way in excess of factory specs. They still rocked a bit, but no where near as much.
i have a v8 and only one piston has such kind of clearance while the rest do not move so much. kindly suggest if its normal?
Not normal, the clearance should be roughly the same on all 8 pistons. Any significant variance in clearance from piston to piston is cause for concern.
Hello from iraq well done
one thing that i cant find anywhere: how many combustions the piston needs to expand to proper diameter? I guess its not that long as people say because the combustion heat is intense then its logical to think the piston would expand on the first 10 power strokes, or am I wrong? I know there's the heat exchange with watercooled cylinder walls but still, the heat is constantly built in the piston crown, right....?
the main question is: ok, the engine takes lots of time to warm up completely to operating temperature, but I guess the pistons wont take that long to expand to operating temperature due to the direct exposure to heat from combustion...right??..
a engine idling at 1k rpm cold has 8 combustions per second. so no it will not be that short a time.
@thdmtr.......,10 minutes = about 4800 strokes, depending on the set idle.
@@sgt-willkillu 10min is time for defrosting the front windshield after firing up my old volvo xD for the pistons to heat up and expand i would say is perfectly good after couple of minutes.
@ståle starheim..., yes maybe a couple of minutes. BUT if you have thousands of 💵invested in an engine, then 10mins is a good indication that one can start to go full throttle.
great video!!
hey please i have a question on bloc engine its marked the bore cylinder class , for example "abac" can i use piston classe "B 71.98" if the cylinder classe "a 72.00" is worn but still in the limit of classe b lets say 72.02" ? the mix is possible ? cause the workshop says that if classe "a" exced the limit , rebore the cylinder 0.1 and use oversize 0.1 piston
Cylinder "A" 72,00-72.01 /// Piston "A" 71,965-71,97
Cylinder "B" 72.01-72.02 /// Piston "B" 71,97-71,98
Cylinder "C" 72.02-72.03 /// Piston "C" 71,98-71,99
over size cylinder "A" 72.10-72.11 /// over size piston "A" 72,065-72,07
over size cylinder "B" 72.11-72.12 /// over size piston "B" 72,07-72,08
over size cylinder "C" 72.12-72.13 /// over size piston "C" 72,08-72,09
I have CP pistons in my STI. I have slight slap. Will I be ok?
is this the Australian Shamwow guy?
He wishes - Taz.
Good video thanks
learned something new thx
Same for a 2stoke piston ? Thanks
i was wondering why it was harder to slide on backwarss
so wat should the pistonskirt to cilinder clearance be on a smart car ? (63.750 mm bore 0.6 liter 3 cilinder aluminium block metal liners stock turbocharged running on regulair fuel)
the clearances should be stated in the service manual. They are strongly piston and cylinder wall material and application specific.
When your video reach 0:11 min its piston is faulty or bore is faulty or rings is faulty sir give me ans and suggest me. I have royal enfield engine oil comes from breather pipe what can i do for this
are the rings properly installed?
can you long drive this kind of piston?
Yes, generally it is more the material your rod is made of that can limit usage rather than forged pistons - Taz.
www.hpacademy.com/q-and-a/aluminium-rods-pros-and-cons/?
can i message or email your channel? i just wanna show you my build if it is right or its too loose
may i ask you? when you use stock casted piston. is that excessive clearance is fine? or thats only for forged pistons?
in the video description it says forged.
Forged pistons require a lot more clearance then cast, depending on manufacturer but if I had a stock cast piston I was just reringing for a rebuild that would definitely raise red flags for me and honestly cause me to rethink my plans. At the very least new pistons if not a bore and pistons.
Is it normal if it does that left to right as well?
No. It shouldn't at all
@@jonathonvince3605 thanks but I already talked to a certified mechanic and it's normal.
@@jonathonvince3605 Any piston is going to rock a bit, but the exact clearance will depend on the application. If the clearance was so tight it didn't move at all, it would seize up and self destruct within seconds of starting the engine. Kudos for trying to be helpful, but sharing completely incorrect information isn't helping, it's making things much worse for people who don't know better.
한국인 없나요...?
없어요
이제 올듯 ㅇㅇ
저염
결국 동네카센타 박씨의 엔진유격은 개소리라는거죠 열팽창으로 인하여 기본설계가 실린더 헤드쪽일수로 작게만든다 고로 유격이 원래 존재한다.
@@bambee2556 이 영상은 전문가가 아니라 '자동차 학원 선생'이다. 즉 50년 경력을 갖고 있고 대한민국 정부가 인정한 자동차명장인 카센터 사상 박씨가 학원 선생보다 더 실력이 좋다라는 것이다. 그리고 여기 학원 선생이 말하기를 'might be wrong' 이라고 했는데 이 뜻은 '틀릴 수도 있고 사실일 수도 있다' 라는 뜻이다.
Hai bro..can i get the perfect ring clearance no 1 no 2 and oil ring for piston 1jzgte 86mm?thanks..
Hope guys did t send their motor in for this 😂😂😂😂😂
I have changed piston kit crank is also okk
Fanks bruv
Chur
#COM 29
great clear concise video thanks!
Cheers for watching and glad you enjoyed it! - Taz.
Every high mileage Chevy runs like this