just for my understanding,
what is bad?
I cant see any difference between 2 pistons...
should this be my problem ?my car is dead.....
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mxysxy
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khunjeng
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they are not the pistons...your looking at the vavles...and the hole where the plug goes i.e. the head where the valves let in the air/fuel in. Look at all the wear..its being hit i.e the piston is getting right up to the top and hitting...I'm no expert but the reaosn this may happen is cos the timing is wrong and the exhaust value is leting stuff out on the compression stroke i.e not enuf in that compression and its hitting..thats not cool...look at the wear around the valves..could also be cos the engine is worn and a valve is leaking...
the compression and leak down test will show if a valve is leaking...then you have to work out why and how to fix it...
I'm no expert though.
the compression and leak down test will show if a valve is leaking...then you have to work out why and how to fix it...
I'm no expert though.
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poster
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oh...i dont know wats bad either... -.- maybe kev can explan better
the picture shows that the right shineing part (which is the one i have got a close up) has been scared from the piston hiting metal against metal there is about 1mm worth of metal been bashed in....
and from what alex was saying that this happend because over 1 year ago they didnt do a perfect job when they were fiting the water pump and replaceing timing belt ect... -.-
the picture shows that the right shineing part (which is the one i have got a close up) has been scared from the piston hiting metal against metal there is about 1mm worth of metal been bashed in....
and from what alex was saying that this happend because over 1 year ago they didnt do a perfect job when they were fiting the water pump and replaceing timing belt ect... -.-
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FTO338
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Damit, I knew we need a better camera to get some decent shots.
Anyway from looking at the engine, & he did open it right in front of us. So no tricks there. The piston is a goner, & so is the header, they both is defiantly need to be replace. So I would start to look for a new engine regardless who’s right or wrong.
I've also notice there are lots of oil everywhere, so the moon seal looks like are worn as well.
Alex version of how this happen was, someone replaced the water pump previously, & didn't do the timing belt properly, since the tappet noise is louder then this engine knocking noise, everyone just assume its the tappet. Plus it was only one Cam gear was out, so it will be a "slow death"
It was only noticeable once he changed the engine oil & adjusted the tappet.
Now since Dave (poster) & I aren't expert when it comes to worn piston & header, we can't really tell if the damages are really caused by couple of start up with faulty timing or it happen over a period of time.
I suggest that Dave should go back with a proper camera & take some decent pics, so everyone can see how badly the damages are. And hopefully we can get some mechanic to give their second opinion. E.g. take the pics to either Lee or Craig, as they both had experience with screwed up 6A12 engine.
Anyway from looking at the engine, & he did open it right in front of us. So no tricks there. The piston is a goner, & so is the header, they both is defiantly need to be replace. So I would start to look for a new engine regardless who’s right or wrong.
I've also notice there are lots of oil everywhere, so the moon seal looks like are worn as well.
Alex version of how this happen was, someone replaced the water pump previously, & didn't do the timing belt properly, since the tappet noise is louder then this engine knocking noise, everyone just assume its the tappet. Plus it was only one Cam gear was out, so it will be a "slow death"
It was only noticeable once he changed the engine oil & adjusted the tappet.
Now since Dave (poster) & I aren't expert when it comes to worn piston & header, we can't really tell if the damages are really caused by couple of start up with faulty timing or it happen over a period of time.
I suggest that Dave should go back with a proper camera & take some decent pics, so everyone can see how badly the damages are. And hopefully we can get some mechanic to give their second opinion. E.g. take the pics to either Lee or Craig, as they both had experience with screwed up 6A12 engine.
DISCLAIMER: The above text is the personal opinion of the author and does not represent the indisputable truth. The author is not responsible for any deaths, injuries or mental illness caused by the above statments.
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khunjeng
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something is wrong for the piston to hit the head...since the FTO (from my understanding) is interference engine the timing is critical to ensure everything is in sync. also I think the FTO uses a water pump driven by the timing belt so if something is done wrong then all kinds of issues may occur. i.e. what has happened...
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Bennoz
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I think you're all barking up the wrong tree - there is no way a cam out of time could cause that that...
Think about it - the piston is connected to a finely toleranced gudgeon pin, which inturn is connected to the 'small end' of the conrod. The large end of the conrod is connected to the crank. You have 5 points of failure there, the gudgeon pin that connects the piston to the rod, the area of the piston that connects to the gudgeon pin, the end of the conrod that attaches to that gudgeon pin, then the large end of the conrod & inturn the crank shaft. All these connections are lined with a metal bearing.
This is a conrod wiith a gudgeon pin - normally the pin goes through the piston base - the bottom end goes around the crank
At a guess I would say you had either a seized gudgeon pin or a collapsed bearing (either piston end or crank end)
The bearings are not roller bearings like you would find in a wheel hub, there are a VERY finely toleranced peice of metal with a brass lining
Pics are of worn crank bearing shells. Note - these bearing shells are sized up down to the thousanth of an inch. These bearing shell are NOT meant to move - the crank is and pistons are the parts that move. Ever heard the term 'spun a bearing' when reffering to a motor?? If they spin - they wear horribly - when they do that the distance the piston moves up & down is increased A LOT in engineering terms. Enough to pound the sh*t out of your head. A sezied gudgeon will prevent the piston from rotating on the conrod - also enough to pound the sh*t out of your head because of the odd angles it will come to the top of the stroke with.
Your analysis of this motor will not stop with just removing the head. If you really want to find out what went wrong - pull the motor & strip it to pieces. I want to see the condition of the crank and the conrods.
My advice Poster - be looking for a half-cut. I hate to sound depressive, but you've just killed a motor. All these sprouts of $800! replacements are rubbish. PM panelhouse & see what they have. It will be cheaper than rebuilding that.....
Without stripping it down you will never know what the cause was. Whether it be dodgy mechanics or not. By the looks of it that could have happened to anyone if the motor was not properly looked after or flogged - even when it was in its infancy.
if you really want to know more about the innards of these things, by all means ask - I've built more motors than I'd care to remember
And from what I see there... yours is well & truly fucked 
Think about it - the piston is connected to a finely toleranced gudgeon pin, which inturn is connected to the 'small end' of the conrod. The large end of the conrod is connected to the crank. You have 5 points of failure there, the gudgeon pin that connects the piston to the rod, the area of the piston that connects to the gudgeon pin, the end of the conrod that attaches to that gudgeon pin, then the large end of the conrod & inturn the crank shaft. All these connections are lined with a metal bearing.
This is a conrod wiith a gudgeon pin - normally the pin goes through the piston base - the bottom end goes around the crank
At a guess I would say you had either a seized gudgeon pin or a collapsed bearing (either piston end or crank end)
The bearings are not roller bearings like you would find in a wheel hub, there are a VERY finely toleranced peice of metal with a brass lining
Pics are of worn crank bearing shells. Note - these bearing shells are sized up down to the thousanth of an inch. These bearing shell are NOT meant to move - the crank is and pistons are the parts that move. Ever heard the term 'spun a bearing' when reffering to a motor?? If they spin - they wear horribly - when they do that the distance the piston moves up & down is increased A LOT in engineering terms. Enough to pound the sh*t out of your head. A sezied gudgeon will prevent the piston from rotating on the conrod - also enough to pound the sh*t out of your head because of the odd angles it will come to the top of the stroke with.
Your analysis of this motor will not stop with just removing the head. If you really want to find out what went wrong - pull the motor & strip it to pieces. I want to see the condition of the crank and the conrods.
My advice Poster - be looking for a half-cut. I hate to sound depressive, but you've just killed a motor. All these sprouts of $800! replacements are rubbish. PM panelhouse & see what they have. It will be cheaper than rebuilding that.....
Without stripping it down you will never know what the cause was. Whether it be dodgy mechanics or not. By the looks of it that could have happened to anyone if the motor was not properly looked after or flogged - even when it was in its infancy.
if you really want to know more about the innards of these things, by all means ask - I've built more motors than I'd care to remember
And from what I see there... yours is well & truly fucked 
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Bennoz
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FTO338
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It makes sense to me Ben, ahahahah my god that must be part of chingrish. 
So from what you saying, this engine could be screwed from the day Poster had brought it? And this damage would be most likely cause by a period of time? But just to confirm, it would be better if we get the guy to strip it right?
Well since its fuc*ked anyway, mind as well pull the dam thing apart & see what’s going on. I can call Alex for you Dave, if you not confoundable with calling him.
So from what you saying, this engine could be screwed from the day Poster had brought it? And this damage would be most likely cause by a period of time? But just to confirm, it would be better if we get the guy to strip it right?
Well since its fuc*ked anyway, mind as well pull the dam thing apart & see what’s going on. I can call Alex for you Dave, if you not confoundable with calling him.
DISCLAIMER: The above text is the personal opinion of the author and does not represent the indisputable truth. The author is not responsible for any deaths, injuries or mental illness caused by the above statments.
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Bennoz
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Hehehe, "I see my chingrish is as big as yours"
Yep, it could have been on the way out for some time. I'd get them to pull the motor - as its gotta be done anyway - and yeah, the only way your gonna know how it happened is if its stripped to bare bones.
And in a sick kind of way (no offence poster
) I want pics!
Yep, it could have been on the way out for some time. I'd get them to pull the motor - as its gotta be done anyway - and yeah, the only way your gonna know how it happened is if its stripped to bare bones.
And in a sick kind of way (no offence poster
) I want pics!-
Bennoz
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dannyboyau
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I can't be certain. But it looks to me that something has been floating around inside the cylinder. Need better pics of the top of the cylinder.
1. if the cam is out on one bank of cylinders then the effects should be on all three cylinders on that bank.
2. if the valve hit the piston then the damage should be to the valve and the valve recess on top of the piston.
3.the areas that are damaged are known as the squish areas and is where the piston comes closest to the head.
4 the valves are made of a much harder metal than the head and piston so it will be hard to see any damage on the valves.
5 detonation will normally cause a ring land to fail long before you would see that sort of damage to the piston and head.
6 the top of the piston and combustion chamber is nice and clean, no carbon build up like the other pistons.
It would be easier if i could see it in my hand but to me it looks like a small nut had been floating around in the piston.
1. if the cam is out on one bank of cylinders then the effects should be on all three cylinders on that bank.
2. if the valve hit the piston then the damage should be to the valve and the valve recess on top of the piston.
3.the areas that are damaged are known as the squish areas and is where the piston comes closest to the head.
4 the valves are made of a much harder metal than the head and piston so it will be hard to see any damage on the valves.
5 detonation will normally cause a ring land to fail long before you would see that sort of damage to the piston and head.
6 the top of the piston and combustion chamber is nice and clean, no carbon build up like the other pistons.
It would be easier if i could see it in my hand but to me it looks like a small nut had been floating around in the piston.
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Bennoz
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dannyboyau
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it is unlikely there would be any signs of damage to the bore as it is much harder metal and the signs of damage seem to be to the areas where the clearance is at its least, if there is damage to the bore it would be at the top of the cylinder near where all the damage to the piston and head was. The head and piston are made of amuch softer alloy than the cast iron block. I think you might find that there will be slight damage to the valve seats and this is causing the loss of compression. If there was a foriegn object floating around in the combustion chamber. The foriegn object would sometimes get caught between the valve and the valve seat, this would explain the noise coming and going. Eventually it would fit through and be in the exhuast. If you removed the catalytic converter you would probably find it in there.
That is if the mechanic did not remove the head before you got there and remove the object then put the head back on. When the head was removed infront of you, it should have been difficult to break the seal of the head gasket. If they just lifted it off then it could have been removed before you got there.
That is if the mechanic did not remove the head before you got there and remove the object then put the head back on. When the head was removed infront of you, it should have been difficult to break the seal of the head gasket. If they just lifted it off then it could have been removed before you got there.
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Bennoz
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I was thinking it may have possibly spat a peice of ring out, thats where I was going with the bore question.
Even with the valves being hard steel as opposed to alloy head & piston, Im curious as to why there is hardly a mark on any of the valve faces (perhaps the photos dont show much)
The more I look at it the weirder it looks... almost an eroded look
And yes.... very shady point made re disassembly
Even with the valves being hard steel as opposed to alloy head & piston, Im curious as to why there is hardly a mark on any of the valve faces (perhaps the photos dont show much)
The more I look at it the weirder it looks... almost an eroded look
And yes.... very shady point made re disassembly
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SILVERFISH
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poster... if you're after a non-mivec engine to save a few $$$
http://www.hondaspares.com.au/index.htm
spoke to the fella there today on an unrelated topic and asked
him about engines for ya. no mivecs in stock but he's got a couple
2nd hand non-mivecs. he said around $1100.
dunno how much they go for elsewhere.
i'll let you know if i track down a mivec for ya
http://www.hondaspares.com.au/index.htm
spoke to the fella there today on an unrelated topic and asked
him about engines for ya. no mivecs in stock but he's got a couple
2nd hand non-mivecs. he said around $1100.
dunno how much they go for elsewhere.
i'll let you know if i track down a mivec for ya
.
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dannyboyau
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looking at the damage it dosen't look like broken ring damage. The dents look too blunt, and you would have the top ring land broken off.Bennoz wrote:I was thinking it may have possibly spat a peice of ring out, thats where I was going with the bore question.
Even with the valves being hard steel as opposed to alloy head & piston, Im curious as to why there is hardly a mark on any of the valve faces (perhaps the photos dont show much)
The more I look at it the weirder it looks... almost an eroded look
And yes.... very shady point made re disassembly
Need better pics of the piston as you can only see half the piston.
The lack of damage outside the squish areas says to me that what caused it was getting sandwiched between the head and piston. and when it fell into the other areas it just cleaned the carbon off as there was enough clearance for the piston to go up and down.
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FTO338
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I heard some really bad story about them......S1LVERFISH wrote:poster... if you're after a non-mivec engine to save a few $$$
http://www.hondaspares.com.au/index.htm
spoke to the fella there today on an unrelated topic and asked
him about engines for ya. no mivecs in stock but he's got a couple
2nd hand non-mivecs. he said around $1100.
dunno how much they go for elsewhere.
i'll let you know if i track down a mivec for ya
DISCLAIMER: The above text is the personal opinion of the author and does not represent the indisputable truth. The author is not responsible for any deaths, injuries or mental illness caused by the above statments.