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2013-14 Shelby GT500
2014 GT 500 Catastrophic Engine Failure: Next Steps? Thoughts?
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<blockquote data-quote="Catmonkey" data-source="post: 16474606" data-attributes="member: 124025"><p>How big a loss are you willing to accept if you just walk away from it? Problem with rebuilding it is you may not come out ahead if you end up selling it when it's done. Modded cars might command a small premium, but generally you simply won't recoup the cost of the parts you put into it. Even removing and reselling you're not going to come out that well, but are likely to yield a little bit more than leaving the parts on the car. And I'm talking parts cost alone. You just have to write off the cost of installation. Frankly, if you could get more than $25k out of it with a blown engine, I'd be somewhat amazed. I'm not saying it's not worth that, but I don't think there's a long list of buyers wanting to take on that headache. These engines are just damned expensive to rebuild. I think your market will be someone that's looking to get it back on the road as cheaply as possible and flip it. You sort of have to look at it as what's the biggest loss to you and how much of your personal time is it going to take going either route.</p><p></p><p>If it were me, I'd yank the engine and tear it down, but I'm capable of doing the work myself. I blew a head gasket with less than 3,000 miles on my car, so I just built a 5.8 shortblock to put it back together, so I've been down this road. If you're relying on others to do the work for you, I'd do a bit of research on a good reputable shop to pull the engine and reinstall it. I would then work with an engine builder to do whatever needs to be done to get the engine back on the road. Talk to them before hand and let them know you're not looking for a 1,500 hp short block that's looking to set records. I've seen too many situations go bad when the mechanic has the work done with a different engine builder. I'm sure we only hear about the guys that paid for one thing and got another, when the shit blew up again, but I think if you deal with two reputable shops you lessen the chances of getting taken. And by "you", I mean you. Mechanic and engine builder should not have to deal with one another on specs or payment. </p><p></p><p>The logistics of doing a rebuild could present problems. Reputable engine builders have back logs. It may take weeks or months to build your engine. Mechanic is not likely to store your engineless car in his shop waiting on the motor. Think that one out ahead of time. I'd rather have my car sitting at home in the garage without an engine, then sitting in a yard where it's not being monitored. It'd be pretty easy to lose the whole car to someone with a flatbed.</p><p></p><p>So, someone needs to pull the engine. You don't have to do that much disassembly to find out what happened. If the engine is seized, it should be apparent trying to turn the crankshaft. If it is seized, you would need to drop the pan to see what happened. If there's no visible damage, like rod(s) broken in two, it either ran without any oil, or you have piston/cylinder failure. Rings can butt together if they get too hot and are capable causing enough friction to pop the crown off the top of the piston. That will typically produce cylinder and/or head damage. You may not be able to see that sort of damage with the pan off. If the damage is not evident from the bottom side, you're going to have to pull the heads. </p><p></p><p>However, if you've decided to rebuild it, I'd let the engine builder do the autopsy. Parts are too easy to misplace if an engine is torn down by one guy and rebuilt by another. The fact that you were down on compression leads me to believe, you'd need the block to be sleeved at a minimum. If the block is windowed, buying a new aluminum block will only end up being a little more expensive. At this point you need to decide if you're upgrading any internals or not. Good rods aren't cheap, but at a minimum I'd put H-beam rods in it because it's a good selling point, especially on a modified engine. Now if a piston came apart and damaged one or both of the heads, your cost could increase dramatically. If that's what you find, I'd try to find a complete engine assembly out of a parted car and skip the rebuild altogether. </p><p></p><p>I'd explain to the misses upfront that you're not getting your money out of this deal anyway you slice it, so you're just going to drive it to get your money's worth out of it. </p><p></p><p>Now as to rev limiters. If you look at the hundreds of dyno charts in the 5.8 and 5.4 forums, you will notice that these engine are all done by 6,000 rpm with the stock cams. You might pick up few hp wringing it beyond that, but you really do compound the risk of breaking a rod. You'll make more power with an aggressive cam above that, but you have to weigh the price of a possible rebuild going beyond the redline. The stroke on these engines is over 4". That's a lot of stroke and capable of producing some really fast piston speeds. That long stoke is intended for mid-range torque, not high revving horsepower. Many hear the term sintered forged rods and think their rods are forged. Sinter forged powdered metal rods are not the same thing as hammer forged steel. They're strong up to a point, but are brittle and unforgiving. The fact they can take what we dish at them is rather amazing, but they have their limitations. Leave the 7,500 rpm redlines to the Coyotes or get some real forged rods.</p></blockquote><p></p>
[QUOTE="Catmonkey, post: 16474606, member: 124025"] How big a loss are you willing to accept if you just walk away from it? Problem with rebuilding it is you may not come out ahead if you end up selling it when it's done. Modded cars might command a small premium, but generally you simply won't recoup the cost of the parts you put into it. Even removing and reselling you're not going to come out that well, but are likely to yield a little bit more than leaving the parts on the car. And I'm talking parts cost alone. You just have to write off the cost of installation. Frankly, if you could get more than $25k out of it with a blown engine, I'd be somewhat amazed. I'm not saying it's not worth that, but I don't think there's a long list of buyers wanting to take on that headache. These engines are just damned expensive to rebuild. I think your market will be someone that's looking to get it back on the road as cheaply as possible and flip it. You sort of have to look at it as what's the biggest loss to you and how much of your personal time is it going to take going either route. If it were me, I'd yank the engine and tear it down, but I'm capable of doing the work myself. I blew a head gasket with less than 3,000 miles on my car, so I just built a 5.8 shortblock to put it back together, so I've been down this road. If you're relying on others to do the work for you, I'd do a bit of research on a good reputable shop to pull the engine and reinstall it. I would then work with an engine builder to do whatever needs to be done to get the engine back on the road. Talk to them before hand and let them know you're not looking for a 1,500 hp short block that's looking to set records. I've seen too many situations go bad when the mechanic has the work done with a different engine builder. I'm sure we only hear about the guys that paid for one thing and got another, when the shit blew up again, but I think if you deal with two reputable shops you lessen the chances of getting taken. And by "you", I mean you. Mechanic and engine builder should not have to deal with one another on specs or payment. The logistics of doing a rebuild could present problems. Reputable engine builders have back logs. It may take weeks or months to build your engine. Mechanic is not likely to store your engineless car in his shop waiting on the motor. Think that one out ahead of time. I'd rather have my car sitting at home in the garage without an engine, then sitting in a yard where it's not being monitored. It'd be pretty easy to lose the whole car to someone with a flatbed. So, someone needs to pull the engine. You don't have to do that much disassembly to find out what happened. If the engine is seized, it should be apparent trying to turn the crankshaft. If it is seized, you would need to drop the pan to see what happened. If there's no visible damage, like rod(s) broken in two, it either ran without any oil, or you have piston/cylinder failure. Rings can butt together if they get too hot and are capable causing enough friction to pop the crown off the top of the piston. That will typically produce cylinder and/or head damage. You may not be able to see that sort of damage with the pan off. If the damage is not evident from the bottom side, you're going to have to pull the heads. However, if you've decided to rebuild it, I'd let the engine builder do the autopsy. Parts are too easy to misplace if an engine is torn down by one guy and rebuilt by another. The fact that you were down on compression leads me to believe, you'd need the block to be sleeved at a minimum. If the block is windowed, buying a new aluminum block will only end up being a little more expensive. At this point you need to decide if you're upgrading any internals or not. Good rods aren't cheap, but at a minimum I'd put H-beam rods in it because it's a good selling point, especially on a modified engine. Now if a piston came apart and damaged one or both of the heads, your cost could increase dramatically. If that's what you find, I'd try to find a complete engine assembly out of a parted car and skip the rebuild altogether. I'd explain to the misses upfront that you're not getting your money out of this deal anyway you slice it, so you're just going to drive it to get your money's worth out of it. Now as to rev limiters. If you look at the hundreds of dyno charts in the 5.8 and 5.4 forums, you will notice that these engine are all done by 6,000 rpm with the stock cams. You might pick up few hp wringing it beyond that, but you really do compound the risk of breaking a rod. You'll make more power with an aggressive cam above that, but you have to weigh the price of a possible rebuild going beyond the redline. The stroke on these engines is over 4". That's a lot of stroke and capable of producing some really fast piston speeds. That long stoke is intended for mid-range torque, not high revving horsepower. Many hear the term sintered forged rods and think their rods are forged. Sinter forged powdered metal rods are not the same thing as hammer forged steel. They're strong up to a point, but are brittle and unforgiving. The fact they can take what we dish at them is rather amazing, but they have their limitations. Leave the 7,500 rpm redlines to the Coyotes or get some real forged rods. [/QUOTE]
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2014 GT 500 Catastrophic Engine Failure: Next Steps? Thoughts?
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