Blew Piston rebuilt forged engine
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it could have also been a bad batch of fuel, what are you using?... do you have a meth kit as well and if so are you positive it's working?... do you have any idea what your target afr was and how lean it went?
Team Owner
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From: Dear Karma, I have a list of people you missed.
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Since the head is off, have it pressure tested. If the spring pockets were ever machined (for larger springs, etc) it's very possible the seat cutter cut into the coolant passageway in the head.
The wall thicknesses of the cylinder head coolant passageways can vary from head to head, mainly due to "core shift" when the head was cast during the manufacturing process.
I have personally seen this happen and it's easy to miss. Even a small hole is all it takes.
HTH
The wall thicknesses of the cylinder head coolant passageways can vary from head to head, mainly due to "core shift" when the head was cast during the manufacturing process.
I have personally seen this happen and it's easy to miss. Even a small hole is all it takes.
HTH
Thread Starter
Racer
Joined: Nov 2015
Posts: 408
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From: New York
The same guy did a valve job and cleaned my heads before I put that engine on. He said they looked good. But before I put it back together I'm gonna bring them back to him to look at. I'm gonna get that piston out tomorrow. I'll let u all know how it looks.
Since the head is off, have it pressure tested. If the spring pockets were ever machined (for larger springs, etc) it's very possible the seat cutter cut into the coolant passageway in the head.
The wall thicknesses of the cylinder head coolant passageways can vary from head to head, mainly due to "core shift" when the head was cast during the manufacturing process.
I have personally seen this happen and it's easy to miss. Even a small hole is all it takes.
HTH
The wall thicknesses of the cylinder head coolant passageways can vary from head to head, mainly due to "core shift" when the head was cast during the manufacturing process.
I have personally seen this happen and it's easy to miss. Even a small hole is all it takes.
HTH
Thread Starter
Racer
Joined: Nov 2015
Posts: 408
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From: New York
So just got the piston out. The rings aren't busted. The cylinder walls are smoothe as they were brand new. Not a single scratch. Hopefully I can just buy another piston and get new injectors and hopefully this is the end of it.
Still wondering how coolant got in with oil. Could the big detonation have pushed up my heads? The head gasket isn't broken. Might have warped the head.
Still wondering how coolant got in with oil. Could the big detonation have pushed up my heads? The head gasket isn't broken. Might have warped the head.
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the first pic above, what is that line going down the cylinder?... looks like a cracked sleeve to me, but the camera could be playing tricks
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Thread Starter
Racer
Joined: Nov 2015
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From: New York
Its either bore markings or oil and coolant from me rubbing my fingers all around in there. I ran my fingernail around the whole cylinder and didn't get caught anywhere.
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Racer
Joined: Nov 2015
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From: New York
Well now now that you pointed it out I just checked it again and it is indeed a crack. I don't know how I didn't feel it before. Maybe too much grease on my hands. But my fingernail def gets caught in it. Is that fixable? Or is the block shot?
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you could resleeve it but not worth the cost in my opinion so a new block would be your best bet... did they not check it out before building it?... that was most definitely the cause of all your issues and not the injectors... sorry for all the troubles you have had
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Racer
Joined: Nov 2015
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From: New York
The sleeve must have just cracked. It was just bored. He would have noticed that. I'm sending the injectors out Monday to have tested so I'll know then.
Since I have a brand new rotating assembly with 3.908 bore pistons should I just get an ls1 block and have a shop bore it to 3.908. Or does anyone sell pre bored blocks?
Since I have a brand new rotating assembly with 3.908 bore pistons should I just get an ls1 block and have a shop bore it to 3.908. Or does anyone sell pre bored blocks?
Le Mans Master
Joined: Sep 2013
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From: near the thumb in the mitten
The coolant deal is puzzling however the leak does not have to come the effected cylinder. If you fully disassemble engine and have block and heads pressure tested cause may be found. Oil cooler? You may get away with just one piston. IMO when you get it back together no playing until tuned. I think the one run with boost may have caused the piston failure. I doubt hydro lock since rod didn't fail.
Thread Starter
Racer
Joined: Nov 2015
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From: New York
Yeah now that I found the crack in the cylinder wall I'm probably going to buy a new bare block and one new piston. Then bore block out to fir my pistons.
The coolant deal is puzzling however the leak does not have to come the effected cylinder. If you fully disassemble engine and have block and heads pressure tested cause may be found. Oil cooler? You may get away with just one piston. IMO when you get it back together no playing until tuned. I think the one run with boost may have caused the piston failure. I doubt hydro lock since rod didn't fail.
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that sounds like the best option in my opinion... you already have a good rotating assembly and a bare block shouldn't cost too much if you can find one already bare and just have the machine work done... just make sure they go over it really good and maybe look for a better tuner
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Racer
Joined: Nov 2015
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From: New York
Nope. The piston before was on the other side. And that did have a scratch which the boring fixed. I was searching all night for a new aluminum ls1/6. All I find are the 5.3L engines. Seems like they can be bored out to 3.908 like I need. Would everything else move over to a 5.3 properly? Thanks
Safety Car
Joined: Mar 2016
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From: Atlantic Beach FL.
^I want to say yes but since I haven't personally done it I would ask the machine shop. I would imagine that not all 5.3's are alike.
Normally I am not a fan of the added weight of a cast iron engine in a Corvette but you may be making too much HP for the aluminum block. It might be a good solid choice.
I might put in a stiffer Z06/51 leaf spring on the front end to balance out the added weight on the suspension.
Normally I am not a fan of the added weight of a cast iron engine in a Corvette but you may be making too much HP for the aluminum block. It might be a good solid choice.
I might put in a stiffer Z06/51 leaf spring on the front end to balance out the added weight on the suspension.
Last edited by Rob 02; Sep 24, 2017 at 07:12 AM.
Thread Starter
Racer
Joined: Nov 2015
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From: New York
Thanks. They do make aluminum 5.3s. I actually just found A site with 5.7s.
Yeah I really would rather aluminum but I too am worried about the strength.
https://www.superchevyperformance.com/LS1_LS6_Block_p/12561166.htm
Yeah I really would rather aluminum but I too am worried about the strength.
https://www.superchevyperformance.com/LS1_LS6_Block_p/12561166.htm
^I want to say yes but since I haven't personally done it I would ask the machine shop. I would imagine that not all 5.3's are alike.
Normally I am not a fan of the added weight of a cast iron engine in a Corvette but you may be making too much HP for the aluminum block. It might be a good solid choice.
I might put in a stiffer Z06/51 leaf spring on the front end to balance out the added weight on the suspension.
Normally I am not a fan of the added weight of a cast iron engine in a Corvette but you may be making too much HP for the aluminum block. It might be a good solid choice.
I might put in a stiffer Z06/51 leaf spring on the front end to balance out the added weight on the suspension.
Last edited by CharlieC5Z06; Sep 24, 2017 at 08:12 AM.
Safety Car
Joined: Mar 2016
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From: Atlantic Beach FL.
Sorry, I thought you meant iron. It should work. I never feel good about reusing bearings and piston rings.
I would be wondering what is causing all these problems. You have had enough trouble.
I would be wondering what is causing all these problems. You have had enough trouble.