Technical discussion on what would cause a piston to explode at idle
Banned
Joined: May 2003
Posts: 6,661
From: LA (lower Alabama)
Re: Technical discussion on what would cause a piston to explode at idle
Originally Posted by Z28SORR
Experience without understanding is useless.
Nice side step. You aren't telling us that you have never rebuilt an engine using stock Chevy replacement pistons.
Nice side step. You aren't telling us that you have never rebuilt an engine using stock Chevy replacement pistons.
I have all the understanding about hyper-u-crap-tic I need.
They are junk.
Registered User
Joined: Jul 2002
Posts: 3,768
From: Friendswood, TX, USA
Re: Technical discussion on what would cause a piston to explode at idle
We are getting a little off track, but someone with your experience has to know, making this kind of blanket statement is going to cause an argument.
This is part of the problem. Almost every major manufcture does use them. It would also help if you defined "performance build".
I think you know this isn't the point. The point is you don't know what caused this failure, yet your willing to blame the pistons because you don't personally like them.
I have an engine that looks exactly, and I mean exactly, like this one.
If I had posted picts. you would have said it was the piston, only it wasn't. It was a main cap bolt that had been left untorqued.
Finally I don't disagree with your conclusion. It's not where you ended up, but how you got there.
Originally Posted by 1racerdude
Every body in the world can use them,but I won't put them in my lawn mower. They are junk for a preformance build IMO.
I won't change my mine either.
I won't change my mine either.
LOL, and double humps are the best head back then and now
IHI,
I can STILL make 600FWHP with a set of angled plug 302 heads and they are cast iron.So don't be knocking something ya don't know about.
Using 1racerdude's logic. The block cyclinder wall failed because it is crappy cast iron and not forged.
Z28sorr
Never said the block failed don't believe it was the cause..
IHI,
I can STILL make 600FWHP with a set of angled plug 302 heads and they are cast iron.So don't be knocking something ya don't know about.
Using 1racerdude's logic. The block cyclinder wall failed because it is crappy cast iron and not forged.
Z28sorr
Never said the block failed don't believe it was the cause..
I have an engine that looks exactly, and I mean exactly, like this one.
If I had posted picts. you would have said it was the piston, only it wasn't. It was a main cap bolt that had been left untorqued.
The STRONG blocks these days are CG=compacted graphite so keep up on things.
One thing the dude has is experience. That's the good part of age
Bret,
Bitten once, lack of knowledge,bitten twice my stupidity. Just doesn't happen twice.
Have seen more than one set of LS1 PM rods hung out the side of the block.
One thing the dude has is experience. That's the good part of age
Bret,
Bitten once, lack of knowledge,bitten twice my stupidity. Just doesn't happen twice.
Have seen more than one set of LS1 PM rods hung out the side of the block.
Registered User
Joined: Jan 2006
Posts: 230
From: Waterloo, Iowa
Re: Technical discussion on what would cause a piston to explode at idle
LOL, did'nt think anybody was tearing anybodies head off yet...and from the car forums I goto it would'nt be a legitimate car forum unless sidetracked off topic posts wihtin posts were started...just means juices are flow'n is all, and often the best info comes out of sidetracked posts since it morphs into a knowledge battle of who knows more, so the deep regions of brain matter are brought back from the dead....where camel back heads should remain LOL!!
I'm going into archyology and will be submitting my new finds to the Smithsonian...60's era fuelie heads LOL!! 600rwhp with cob web infested fuelie heads could easily equate into 700rwhp with stock heads off the wifes 2000 malibu, and that's only a V6
LMAO!!
Back to topic would also agree assembly is the problem just as it is with the majority of any engine catastrophe.
I'm going into archyology and will be submitting my new finds to the Smithsonian...60's era fuelie heads LOL!! 600rwhp with cob web infested fuelie heads could easily equate into 700rwhp with stock heads off the wifes 2000 malibu, and that's only a V6
LMAO!!Back to topic would also agree assembly is the problem just as it is with the majority of any engine catastrophe.
Banned
Joined: May 2003
Posts: 6,661
From: LA (lower Alabama)
Re: Technical discussion on what would cause a piston to explode at idle
Originally Posted by IHI
LOL, did'nt think anybody was tearing anybodies head off yet...and from the car forums I goto it would'nt be a legitimate car forum unless sidetracked off topic posts wihtin posts were started...just means juices are flow'n is all, and often the best info comes out of sidetracked posts since it morphs into a knowledge battle of who knows more, so the deep regions of brain matter are brought back from the dead....where camel back heads should remain LOL!!
I'm going into archyology and will be submitting my new finds to the Smithsonian...60's era fuelie heads LOL!! 600rwhp with cob web infested fuelie heads could easily equate into 700rwhp with stock heads off the wifes 2000 malibu, and that's only a V6 LMAO!!
Back to topic would also agree assembly is the problem just as it is with the majority of any engine catastrophe.
I'm going into archyology and will be submitting my new finds to the Smithsonian...60's era fuelie heads LOL!! 600rwhp with cob web infested fuelie heads could easily equate into 700rwhp with stock heads off the wifes 2000 malibu, and that's only a V6
LMAO!!Back to topic would also agree assembly is the problem just as it is with the majority of any engine catastrophe.
This is how things get screwed up.
People don't read or maybe they don't understand what they read.
I said 600 FWHP and have done it more than once Soooo.
I can STILL make 600FWHP with a set of angled plug 302 heads and they are cast iron.So don't be knocking something ya don't know about.
Last edited by 1racerdude; Mar 10, 2006 at 04:28 PM.
Banned
Joined: Nov 2003
Posts: 1,211
Re: Technical discussion on what would cause a piston to explode at idle
Speaking only for myself and what I've said:
There were three events that occurred in that engine. One event was the piston shattering, one was the top separating from the bottom at the pin are and the other was the valve coming in contact with the piston.
We know the valve came in contact with the piston because the pushrod is bent.
We know the crown separated from the skirt because the pictures show it.
We know the piston shattered because, well... it's in multiple pieces.
It is in open question as to what order those events occurred in.
It is not, or rather SHOULD not be an open question as to whether or not the piston shattered because it was cast.
I have never seen a forged piston shatter. Deform, yes. Shatter... no.
I have never even HEARD of a forged piston shattering.
Frankly, I'm not sure it even CAN. Not without a liquid nitrogen bath, anyway.
Whatever else can or cannot be said about the failure of that engine, that piston shattered BECAUSE it was cast.
There were three events that occurred in that engine. One event was the piston shattering, one was the top separating from the bottom at the pin are and the other was the valve coming in contact with the piston.
We know the valve came in contact with the piston because the pushrod is bent.
We know the crown separated from the skirt because the pictures show it.
We know the piston shattered because, well... it's in multiple pieces.
It is in open question as to what order those events occurred in.
It is not, or rather SHOULD not be an open question as to whether or not the piston shattered because it was cast.
I have never seen a forged piston shatter. Deform, yes. Shatter... no.
I have never even HEARD of a forged piston shattering.
Frankly, I'm not sure it even CAN. Not without a liquid nitrogen bath, anyway.
Whatever else can or cannot be said about the failure of that engine, that piston shattered BECAUSE it was cast.
Registered User
Joined: Jan 2006
Posts: 230
From: Waterloo, Iowa
Re: Technical discussion on what would cause a piston to explode at idle
Originally Posted by 1racerdude
This is how things get screwed up.
People don't read or maybe they don't understand what they read.
I said 600 FWHP and have done it more than once Soooo.
I can STILL make 600FWHP with a set of angled plug 302 heads and they are cast iron.So don't be knocking something ya don't know about.
People don't read or maybe they don't understand what they read.
I said 600 FWHP and have done it more than once Soooo.
I can STILL make 600FWHP with a set of angled plug 302 heads and they are cast iron.So don't be knocking something ya don't know about.
Banned
Joined: May 2003
Posts: 6,661
From: LA (lower Alabama)
Re: Technical discussion on what would cause a piston to explode at idle
Originally Posted by IHI
Alright you win, I guess somebody is taking this a little too seriously LOL. Take pill to lower your blood pressure, taking things literally on any internet forum to heart is just showing how closed minded you really are. At least now we all know you'e got 40yrs building engines under your belt, know how to do math, hate hyperutectic slugs, and have no sense of humor...buot cover it??
I have a wonderful sense of humor
I just don't like BULL S*** taken as gospel and especially don't like BEING MISQUOTED.
IF ya gonna jump somebody's case make sure ya got the FACTS RIGHT or don't comment.
Banned
Joined: Oct 2002
Posts: 6,518
Re: Technical discussion on what would cause a piston to explode at idle
Originally Posted by Z28SORR
Experience without understanding is useless.
Nice side step. You aren't telling us that you have never rebuilt an engine using stock Chevy replacement pistons.
Nice side step. You aren't telling us that you have never rebuilt an engine using stock Chevy replacement pistons.
99% of the time I build motors with forged aftermarket pistons. Guess I'm lucky.
Registered User
Joined: Oct 2001
Posts: 2,684
Re: Technical discussion on what would cause a piston to explode at idle
I think all the engineers and builders need to get together for a week to do a Design FMEA, Process FMEA, and Root Cause Analysis and give the thread starter a legitimate answer to his question, then charge him a $25,000 consulting fee. Take that money, do some destructive testing, endurance testing, and accellerated stress & rattle testing to replicate the problem, cause it to fail, then punch it out to see who's right. If any money is left, buy beer.
Registered User
Joined: Aug 2005
Posts: 862
From: Columbus, IN
Re: Technical discussion on what would cause a piston to explode at idle
Originally Posted by LameRandomName
Oh, BTW...
It's OCCAM's razor. As in fr. William of Occam.
Numquam ponenda est pluritas sine necessitate.
It's OCCAM's razor. As in fr. William of Occam.
Numquam ponenda est pluritas sine necessitate.
Registered User
Joined: Mar 2005
Posts: 849
From: Shawnee Kansas
Re: Technical discussion on what would cause a piston to explode at idle
Originally Posted by oneslowz28
machine work
Select Hi Tin block 4 bolt main
Align bore and checked for run out. Full race clearancing
Mag Check -pressure check
Hot tank - jet wash
Bore Torque Plate honed to give a true finish.
Shotpeen rods
Dynamic balanced assembly
File fit rings - blue print clearance
press- pistons to rods
install cam berings and freeze plugs
port blue print cylender heads
Select Hi Tin block 4 bolt main
Align bore and checked for run out. Full race clearancing
Mag Check -pressure check
Hot tank - jet wash
Bore Torque Plate honed to give a true finish.
Shotpeen rods
Dynamic balanced assembly
File fit rings - blue print clearance
press- pistons to rods
install cam berings and freeze plugs
port blue print cylender heads
We have pictures of the tops of both pin bosses with substantial piston attached. The wrist pin bores look good to me with an even scratch pattern and no longitudinal markings. The machine work lists pressed rods, so if we can believe that then there were no pin retainers to fall out.The pistons do appear to be machined for round circlips. There is no mention of honing or bushing the X rods so let's assume the pins were pressed in.
If you look at the pictures that contain the pin bosses you will notice something very interesting. In one picture you can clearly see the ring lands and the piston doesn't look too bad in that area.
http://i2.tinypic.com/qyvf4j.jpg
In the other there is severe compression and stacking of the ring lands. In fact the rings are still captured by the piston. This is the opposite side.
http://i2.tinypic.com/qyvjwy.jpg
There must have been mechanical interference on that side of the piston to compress the ring lands in that way.
There are several parts of the original poster's account that don't add up. Not cutting him down at all but there is some weirdness to the "combination".
Race gas? "timing set at 0"
Small cam designed to run vacuum accessories and be streetable.
The engine was dynoed? Fairly expensive for a budget build.
The rod is mentioned to be relatively unscathed with pin attached.
The valves escaped harm by the grace of the engine gods, but the exhaust pushrod was bent.
The piston head land shows signs of runtime deposits.
The engine may have been built with high bleeddown lifters.
Some of the things the poster says sounds like what he may think somebody wants to hear.
If the engine was really run on an actual dyno the timing would be set and the carb dialed in. A rich mixture isn't good for cylinder walls and rings.
Surely a street engine wouldn't need or want race gas, though cylinder pressure would be through the roof with the small cam, high vac lifters and the 49cc combustion chambers regardless of the mystery piston configuration.
Are we hearing the whole story, or have we been given bogus info?
Did those piston remnants come out of an idling engine? The carnage is so great and every little piece appears to be beat to death with numerous contact markings and the rest of the piston is mentioned to be under the baffle in the oil pan. hmmm....
The bottom line of course is that cast (hypereutectic or not) pistons are stiffer than their forged counterparts and are subject to this kind of failure when interference occurs.
The forging process does not mean the pistons have a higher melting point, but they are elastic and can save the rest of an engine if something gets out of hand.
A valvetrain failure is something we should all worry about, and I am still confident that is to blame here, barring any new pertinent info.
It seems that over the internet people are fairly quick to go for the jugular behind their alias and pop off comments that are unnecessary. For those that do that over and over again ...why are you here on a performance board?
Hope everybody has an enjoyable weekend. I'm looking forward to a little one on one wrench time with my '69.
Peace.
Thread Starter
Registered User
Joined: Jan 2005
Posts: 1,139
From: Aiken, Sc
Re: Technical discussion on what would cause a piston to explode at idle
Originally Posted by oneslowz28
machine work
Select Hi Tin block 4 bolt main
Align bore and checked for run out. Full race clearancing
Mag Check -pressure check
Hot tank - jet wash
Bore Torque Plate honed to give a true finish.
Shotpeen rods
Dynamic balanced assembly
File fit rings - blue print clearance
press- pistons to rods
install cam berings and freeze plugs
port blue print cylender heads
Ok gentlemen, I've broke my promise and I'm back. Forgive me.
We have pictures of the tops of both pin bosses with substantial piston attached. The wrist pin bores look good to me with an even scratch pattern and no longitudinal markings. The machine work lists pressed rods, so if we can believe that then there were no pin retainers to fall out.The pistons do appear to be machined for round circlips. There is no mention of honing or bushing the X rods so let's assume the pins were pressed in.
If you look at the pictures that contain the pin bosses you will notice something very interesting. In one picture you can clearly see the ring lands and the piston doesn't look too bad in that area.
http://i2.tinypic.com/qyvf4j.jpg
In the other there is severe compression and stacking of the ring lands. In fact the rings are still captured by the piston. This is the opposite side.
http://i2.tinypic.com/qyvjwy.jpg
There must have been mechanical interference on that side of the piston to compress the ring lands in that way.
There are several parts of the original poster's account that don't add up. Not cutting him down at all but there is some weirdness to the "combination".
Race gas? "timing set at 0"
Small cam designed to run vacuum accessories and be streetable.
The engine was dynoed? Fairly expensive for a budget build.
The rod is mentioned to be relatively unscathed with pin attached.
The valves escaped harm by the grace of the engine gods, but the exhaust pushrod was bent.
The piston head land shows signs of runtime deposits.
The engine may have been built with high bleeddown lifters.
Some of the things the poster says sounds like what he may think somebody wants to hear.
If the engine was really run on an actual dyno the timing would be set and the carb dialed in. A rich mixture isn't good for cylinder walls and rings.
Surely a street engine wouldn't need or want race gas, though cylinder pressure would be through the roof with the small cam, high vac lifters and the 49cc combustion chambers regardless of the mystery piston configuration.
Are we hearing the whole story, or have we been given bogus info?
Did those piston remnants come out of an idling engine? The carnage is so great and every little piece appears to be beat to death with numerous contact markings and the rest of the piston is mentioned to be under the baffle in the oil pan. hmmm....
The bottom line of course is that cast (hypereutectic or not) pistons are stiffer than their forged counterparts and are subject to this kind of failure when interference occurs.
The forging process does not mean the pistons have a higher melting point, but they are elastic and can save the rest of an engine if something gets out of hand.
A valvetrain failure is something we should all worry about, and I am still confident that is to blame here, barring any new pertinent info.
It seems that over the internet people are fairly quick to go for the jugular behind their alias and pop off comments that are unnecessary. For those that do that over and over again ...why are you here on a performance board?
Hope everybody has an enjoyable weekend. I'm looking forward to a little one on one wrench time with my '69.
Peace.
machine work
Select Hi Tin block 4 bolt main
Align bore and checked for run out. Full race clearancing
Mag Check -pressure check
Hot tank - jet wash
Bore Torque Plate honed to give a true finish.
Shotpeen rods
Dynamic balanced assembly
File fit rings - blue print clearance
press- pistons to rods
install cam berings and freeze plugs
port blue print cylender heads
Ok gentlemen, I've broke my promise and I'm back. Forgive me.
We have pictures of the tops of both pin bosses with substantial piston attached. The wrist pin bores look good to me with an even scratch pattern and no longitudinal markings. The machine work lists pressed rods, so if we can believe that then there were no pin retainers to fall out.The pistons do appear to be machined for round circlips. There is no mention of honing or bushing the X rods so let's assume the pins were pressed in.
If you look at the pictures that contain the pin bosses you will notice something very interesting. In one picture you can clearly see the ring lands and the piston doesn't look too bad in that area.
http://i2.tinypic.com/qyvf4j.jpg
In the other there is severe compression and stacking of the ring lands. In fact the rings are still captured by the piston. This is the opposite side.
http://i2.tinypic.com/qyvjwy.jpg
There must have been mechanical interference on that side of the piston to compress the ring lands in that way.
There are several parts of the original poster's account that don't add up. Not cutting him down at all but there is some weirdness to the "combination".
Race gas? "timing set at 0"
Small cam designed to run vacuum accessories and be streetable.
The engine was dynoed? Fairly expensive for a budget build.
The rod is mentioned to be relatively unscathed with pin attached.
The valves escaped harm by the grace of the engine gods, but the exhaust pushrod was bent.
The piston head land shows signs of runtime deposits.
The engine may have been built with high bleeddown lifters.
Some of the things the poster says sounds like what he may think somebody wants to hear.
If the engine was really run on an actual dyno the timing would be set and the carb dialed in. A rich mixture isn't good for cylinder walls and rings.
Surely a street engine wouldn't need or want race gas, though cylinder pressure would be through the roof with the small cam, high vac lifters and the 49cc combustion chambers regardless of the mystery piston configuration.
Are we hearing the whole story, or have we been given bogus info?
Did those piston remnants come out of an idling engine? The carnage is so great and every little piece appears to be beat to death with numerous contact markings and the rest of the piston is mentioned to be under the baffle in the oil pan. hmmm....
The bottom line of course is that cast (hypereutectic or not) pistons are stiffer than their forged counterparts and are subject to this kind of failure when interference occurs.
The forging process does not mean the pistons have a higher melting point, but they are elastic and can save the rest of an engine if something gets out of hand.
A valvetrain failure is something we should all worry about, and I am still confident that is to blame here, barring any new pertinent info.
It seems that over the internet people are fairly quick to go for the jugular behind their alias and pop off comments that are unnecessary. For those that do that over and over again ...why are you here on a performance board?
Hope everybody has an enjoyable weekend. I'm looking forward to a little one on one wrench time with my '69.
Peace.
look man call bs on me all you want but everything i posted came straight from the builder. the only thing that was changed after the build was the fuel pump to a holly mechanical unit. here is the entire build sheet that he got from the builder. He paid 3500 for the engine i think.
This engine is a well balanced street performer. It will fit a wide varity of aplications and is the perfect muscle car replacement engine. Weighting in at 460 lbs this engine also would be good for a kit car or hotrod.
430 hp @ 5800 rpm 425 ft. lbs torque @ 5200 rpm
All new internals Profesionaly installed.
Prepaired block
Machine work and parts value this engine at $5795.00
Machine Work.
Select Hi Tin block 4 bolt main
Align bore and checked for run out. Full race clearancing
Mag Check -pressure check
Hot tank - jet wash
Bore Torque Plate honed to give a true finish.
Shotpeen rods
Dynamic balanced assembly
File fit rings - blue print clearance
press- pistons to rods
install cam berings and freeze plugs
port blue print cylender heads
Final assembly full rotating assembly and top end
Performance Internal Parts
Sealed power hyperutectic pistons 9.8:1
Race preped eagle steel crank with superior wear sized and indexed
Childs and Albert ZZ Gapdura file fit rings- The ultimate in ring sealing thus making more power
Durabond cam bearings
Gm Pink forged steel rods
Arp wavelock rod bolts
Clevite 77 tri metal main and rod berrings
Comp cams custom high output lifters
Cloytes true roller timing set
Comp cams valve locks
Comp cams XE chrom molly hardened push rods
Dyna gear race oil pump
Dyna gear pickup
Arp steel oil pump drive
After market oil pan baffeld 5 qt
Aftermarket timing cover
Arp head bolts
Fel Pro gasket set
Power making features
Dart heads 200cc Trick 49cc Chambers with power making features. Bowls blended
Features: Severe duty 2.02/1.60 valves. Comp cams 1.25 springs 7 degree super
locks. 3/8" studs, guide plates, p.c. seals , chrome molly retainers. Heads are
gasket port matched. 1.6:1 proform roller rockers.
Comp cams Custom series muscle car cam.
Features: 110 centerline 488-488 lift corrected 1.6:1 ratio = 530/530 lift.
228/228 duration @050. 100% streetable and will run vacume access.
Edelbrock performer rpm intake manifold.
Runs on high test pump gas without a problem.
Parts, machine work valued at $5795.00
Last edited by oneslowz28; Mar 11, 2006 at 04:45 AM.
Banned
Joined: May 2003
Posts: 6,661
From: LA (lower Alabama)
Re: Technical discussion on what would cause a piston to explode at idle
I was told i need to buy a set of $550 of mahle piston. that i would pull the top off KB, and manley pistons. i am just getting started and don't have alot of money to spend on just pistons. tring to find the best piston out there for $250 to $30
---------------------------------------------------
Here is a quote from another board.
Why do ya think he was told that.
---------------------------------------------------
Here is a quote from another board.
Why do ya think he was told that.
Registered User
Joined: Nov 1999
Posts: 363
From: spartanburg,sc usa
Re: Technical discussion on what would cause a piston to explode at idle
Originally Posted by 1racerdude
I was told i need to buy a set of $550 of mahle piston. that i would pull the top off KB, and manley pistons.
i have an LT1 and LS1 making 375-475rwhp and the pistons are fine so far. yes, the LS1 has nitrous too. both are stock shortblocks.