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glyph posted:Ho buddy, have I got bad news for you. Them aint allen heads. gently caress that's nothing but laughable, who the gently caress would think those could hold down combustion pressures?
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Aug 19, 2018 12:06
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DiggityDoink posted:gently caress that's nothing but laughable, who the gently caress would think those could hold down combustion pressures? ZE GERMANS
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Aug 19, 2018 12:07
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glyph posted:Ho buddy, have I got bad news for you. Them ain’t allen heads. Hahahahaa
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Aug 19, 2018 12:54
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Olympic Mathlete posted:Look at the depth of the part you put the torx in. Then note the part it's sheered at has very little metal between it and the bit where you put your torx bit. Oh i got why I was confused, I was thinking about it failing on disassembly from torsional stress, but they were popping under use from pulling forces on the head. Makes sense that it fails there as the head flexes into an inverted cone and peels off the shank from the outside in.
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Aug 19, 2018 14:13
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Kafouille posted:Oh i got why I was confused, I was thinking about it failing on disassembly from torsional stress, but they were popping under use from pulling forces on the head. Makes sense that it fails there as the head flexes into an inverted cone and peels off the shank from the outside in. I'll bet the root cause analysis is over-torquing at the factory. Whether it's a tooling, training, or design issue who knows.
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Aug 19, 2018 14:41
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I think it's purely the head design, the socket hole and thin socket floor allows the head to collapse inwards when the engine head pulls the outside bits upward. The flex allows uneven loading on the bolt shank and it gets defeated in detail, even if it was theoretically strong enough when you assumed an even loading. But then again I'm not an engineer and am probably talking out of my rear end, I just find root cause analysis fascinating.
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Aug 19, 2018 15:03
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Normally I'd say probably poor grain flow in the underhead fillet (or poor cold rolling of the fillet radius) that's the root (hah!) cause, assuming they're using them properly. You'd have to test some to be sure. In this case, I suspect the forging of the Torx form has punched down the material immediately below it more than it should (not enough heat in the blank when they hit it with the die?) and given a nice path to propogate cracks across. If you look, the failure is parallel to the bottom of the recess, not up into it.
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Aug 19, 2018 15:07
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Those look like the R63 head bolts that someone had fail and cost like $50,000 to rebuild the engine.
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Aug 19, 2018 18:02
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DJ Commie posted:Those look like the R63 head bolts that someone had fail and cost like $50,000 to rebuild the engine. Yeah, the AMG tax.
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Aug 19, 2018 18:19
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C-Bangin' it 
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InitialDave posted:Normally I'd say probably poor grain flow in the underhead fillet (or poor cold rolling of the fillet radius) that's the root (hah!) cause, assuming they're using them properly. You'd have to test some to be sure. In this case, I suspect the forging of the Torx form has punched down the material immediately below it more than it should (not enough heat in the blank when they hit it with the die?) and given a nice path to propogate cracks across. If you look, the failure is parallel to the bottom of the recess, not up into it. Could totally be a manufacturing defect in a bolt batch, but once it's caught I'd think you'd see a manufacturing line cut in where they started using new bolts that passed QA and it stops being a problem for everything manufactured after. Maybe you do see that, I don't know the data.
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Aug 19, 2018 19:09
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Finger Prince posted:Could totally be a manufacturing defect in a bolt batch, but once it's caught I'd think you'd see a manufacturing line cut in where they started using new bolts that passed QA and it stops being a problem for everything manufactured after. Maybe you do see that, I don't know the data. I'd be interested in getting hold of some and seeing if I can persuade one of my lab guys to give them a pull, see if they fail in the underhead area then. Maybe section one for micro. They did change the design of them though: 
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Aug 19, 2018 20:22
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They changed them sometime in late 2010, early 2011 IIRC. In production, I mean.
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Aug 19, 2018 20:25
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InitialDave posted:Depends how many they make and what the in-process testing regime required is, along with how long it takes the problem to present in service. If you have a stock of 10,000 of the loving things, and you didn't test them in a manner that shows up the defect, then welp, you've got an expensive problem on your hands if it crops up after 3 years of engine building. If it would matter for your theoretical testing, those bolts are torque-to-yield. Video with torque specs
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Aug 19, 2018 20:51
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MrYenko posted:If it would matter for your theoretical testing, those bolts are torque-to-yield.
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Aug 19, 2018 21:09
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DJ Commie posted:Those look like the R63 head bolts that someone had fail and cost like $50,000 to rebuild the engine. Yep, I got those pics from the “unicorn of something something” GRM thread.
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Aug 20, 2018 02:20
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Mr-Spain posted:Vehicle mount? Pretty sure it's also considered a machinegun the way the guy did it. If it was a momentary switch where it fired 1 round per press of the button it would not be considered a machine gun.
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Aug 20, 2018 03:46
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otaku69 posted:If it was a momentary switch where it fired 1 round per press of the button it would not be considered a machine gun. Yeah, but it would probably fall afoul of the "easily converted" clause though.
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Aug 20, 2018 04:29
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n0tqu1tesane posted:Yeah, but it would probably fall afoul of the "easily converted" clause though. I can use a paperclip to convert a glock to full auto, should I be charged with a felony because I have a paper clip on me? Also that is the second stupidest thing I have seen, next to lets attach a gun to a drone.
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Aug 20, 2018 04:54
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Lmao at digging up a 12 day old post for a gun well actually
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Aug 20, 2018 05:01
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12 days is the new one day. I love my dead gay forums.
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Aug 20, 2018 05:24
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I prefer my gay alive 
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Aug 20, 2018 15:44
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Memento posted:Look how little meat there is in the shaft of the bolt. Please don’t share my dick pic
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Aug 20, 2018 15:47
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Screw you?
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Aug 20, 2018 15:49
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DJ Commie posted:Those look like the R63 head bolts that someone had fail and cost like $50,000 to rebuild the engine. It wasn't 50K to rebuild the engine. Mercedes dealers don't touch the headers apparently and the 50K was for a brand new crate M156. Olivil fucked around with this message at 15:57 on Aug 20, 2018 |
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Aug 20, 2018 15:54
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Also, they won't replace the engine or the head bolts, thus saving the engine, UNTIL THEY FAIL, because they refuse to acknowledge that there was a problem. Or at least last I heard via the Unicorn Of My edit: found the thread: https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/r63-amg-the-unicorn-of-my-destruction/110824/page1/
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Aug 20, 2018 21:54
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Darchangel posted:Also, they won't replace the engine or the head bolts, thus saving the engine, UNTIL THEY FAIL, because they refuse to acknowledge that there was a problem. Or at least last I heard via the Unicorn Of My There's externally acknowledging the problem, and there's internally acknowledging the problem. The new bolts are a pretty clear indication of the latter.
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Aug 20, 2018 22:18
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True enough. Kind of like Apple (and probably many others) in that regard. "There was nothing wrong - we just decided to change it for reasons" and the issue stops occurring magically, coincidentally.
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Aug 20, 2018 23:50
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Seems like they could at least sell you a new crate engine for less than $50k
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Aug 21, 2018 00:37
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MomJeans420 posted:Seems like they could at least sell you a new crate engine for less than $50k Hand built That engine really is something else; It’s only distantly related to anything else they build/built.
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Aug 21, 2018 03:05
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 Rev in peace, D16-swapped EH hatch.
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Aug 21, 2018 14:25
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Dagen H posted:
Uh, were you driving that?
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Aug 21, 2018 14:36
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#1 Son was. He was doing ~60 up a state highway when someone pulled out in front of him. Roof is buckled, driver's door is jammed up against the quarter panel, LF wheel shows weird camber. Car is toast. He's got a hairline fracture in his left ankle, but it could have been a lot worse without the airbag.
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Aug 21, 2018 14:41
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drat. Glad he's okay.
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Aug 21, 2018 14:42
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Yeah holy poo poo, glad he's okay. Sidenote: do you have more than one son and do you refer to them as #1 and #2 to their faces?
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Aug 21, 2018 14:49
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I refer to them as #1, Middle, and #3 Sons, but only online.
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Aug 21, 2018 14:52
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Dagen H posted:#1 Son was. He was doing ~60 up a state highway when someone pulled out in front of him. Roof is buckled, driver's door is jammed up against the quarter panel, LF wheel shows weird camber. Car is toast. He's got a hairline fracture in his left ankle, but it could have been a lot worse without the airbag. Impressive. Pretty sure that if that had happened to me at that age, I'd have been in a real mess.
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Aug 21, 2018 15:08
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Dagen H posted:I refer to them as #1, Middle, and #3 Sons, but only online. https://www.youtube.com/watch?v=aaI4xalOJsU
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Aug 21, 2018 15:08
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Dagen H posted:I refer to them as #1, Middle, and #3 Sons, but only online. Dad, why are you doing this to me, the #3 son!
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Aug 21, 2018 15:16
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Glad your boy's alright but I'm sad another cool little Civic is toast :/
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Aug 21, 2018 15:29
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So is he, only had it a week. 
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Aug 21, 2018 15:31
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