EPIC nuts/studs loosening thread (reposting stupid stuff without reading = warning)
#122
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If you're getting shearing and studs being ripped out, you've got something other than just normal clamping loads, vibration and heat going on, probably an exhaust that's not secured well enough. In that case v-bands will just move the failure point to the head flange or sections of the exhaust will start tearing.
Does anyone make cast iron hardware?
edit: The more I think about this, the more sense it makes. Every time I take a setup that's been behaving on the street to a track day, it's perfect for a single session, since the studs have stretched and expanded but they aren't actually loose. Then the car cools fully, the studs contract, but not to their original length. The hardware is all loose then. Then I take it back out for the 2nd session and **** is falling off.
Last edited by Savington; 06-23-2009 at 02:03 PM.
#124
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If it's really a temp expansion issue, you could also go with something like A286 Super Alloy caphead bolts.
McMaster-Carr
http://www.metalsuppliersonline.com/...etals/2090.asp
McMaster-Carr
http://www.metalsuppliersonline.com/...etals/2090.asp
#125
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So, Inconel it is then...? It's used in Formula One exhaust systems so if it doesn't work for us we have a major engineering error in BEGI/FM cast manifolds.
Inconel - Wikipedia, the free encyclopedia
Inconel 751: Increased aluminum content for improved rupture strength in the 1600 F range
http://www.specialmetals.com/documen...lloy%20751.pdf
BTW, the Resbond does sort of swell up when cured, so it should do pretty well as a thread sealant.
Inconel - Wikipedia, the free encyclopedia
Inconel 751: Increased aluminum content for improved rupture strength in the 1600 F range
http://www.specialmetals.com/documen...lloy%20751.pdf
BTW, the Resbond does sort of swell up when cured, so it should do pretty well as a thread sealant.
#128
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A286 can be found for $17 a piece, similar properties, used widely in aerospace turbines, and readily available.
High Temp Metals 800-500-2141 - Alloy A286 Technical Information
Looks like air power systems use A286 studs and copper lock nuts in their turbo kits.
Last edited by BenR; 06-23-2009 at 06:21 PM.
#131
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If your fastners are at 1300* F then you're going to be experiencing alot of failures in alot of other areas. Your inlet EGT shouldn't be the same as your outlet EGT, and your fastners shouldn't be anywhere near the inlet EGT.
Guessing the temp range that the fastners will need to live in, is like tuning without a wideband. Why doesn't someone that's having problems throw a thermocouple on the studs and tell us exactly how hot their **** really is?
Guessing the temp range that the fastners will need to live in, is like tuning without a wideband. Why doesn't someone that's having problems throw a thermocouple on the studs and tell us exactly how hot their **** really is?
#132
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If your fastners are at 1300* F then you're going to be experiencing alot of failures in alot of other areas. Your inlet EGT shouldn't be the same as your outlet EGT, and your fastners shouldn't be anywhere near the inlet EGT.
Guessing the temp range that the fastners will need to live in, is like tuning without a wideband. Why doesn't someone that's having problems throw a thermocouple on the studs and tell us exactly how hot their **** really is?
Guessing the temp range that the fastners will need to live in, is like tuning without a wideband. Why doesn't someone that's having problems throw a thermocouple on the studs and tell us exactly how hot their **** really is?
Does anyone make 1000*+ temp "sticker" thingies like what we've used on calipers and radiators?
#133
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^^ Check with Omega.com since they will most likely have it. I am guessing it will probably be permanent change paint at that temperature level. It exists in formulations hot enough for brake rotors. Omega is not the cheapest source, but usually has a ton of good information and products for any given measurement/instrumentation technology.
#134
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Temperature Indicating Rotor Paint - RaceShopper.com
http://www.truechoice.com/prodinfo.asp?number=GB 1000
Though it's more like tuning with a narrow band. At least you'll know it's getting above 1000* or 1250* but there's no way to tell the difference between 1250* and 1600*.
Get this.
http://cgi.ebay.com/ws/eBayISAPI.dll...%3D4%26ps%3D10
Measure temps.
Profit.
Another thing to keep in mind, aluminium's melting point is 1220.58*F. Sure the EGT's will be higher, but if the fastners are getting over 1300* I expect you to start having problems with the valves and head.
Last edited by BenR; 06-24-2009 at 06:51 PM.
#135
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Stage 8s dont hold up at Thunderhill @ 95* track temps either:
IMG_0519.jpg
IMG_0520.jpg
After looking at these pictures a few times I have noticed that the stud to the front of the car. Closest to us in the picture, is out a bit further than when i originally installed the studs. Also, note that the lower stud AND stage 8 locknut is missing. That fell off during the track event. Worked for 3 sessions, then fail.
I am guessing the stud actually backed out from vibration and eventually made the locknut fall off. This all happened in one session.
What next?
IMG_0519.jpg
IMG_0520.jpg
After looking at these pictures a few times I have noticed that the stud to the front of the car. Closest to us in the picture, is out a bit further than when i originally installed the studs. Also, note that the lower stud AND stage 8 locknut is missing. That fell off during the track event. Worked for 3 sessions, then fail.
I am guessing the stud actually backed out from vibration and eventually made the locknut fall off. This all happened in one session.
What next?