Scott Posted February 7, 2010 Share Posted February 7, 2010 Sorry to read this J, hope you manage to keep your head up and you dont find anymore more issues. boom boom Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 7, 2010 Author Share Posted February 7, 2010 Sorry Nic, HKS cams for the 2JZ are cast. If caps were left loose they would probably snap, same if the head was warped. Chris, the caps were loose but I have good confidence that when they were installed they would have been torqued upto the correct torque, the engine has been running for quite a while & survived TOTB & VMax What reasons could the cap bolts loosen over time? Quote Link to comment Share on other sites More sharing options...
JamieP Posted February 7, 2010 Share Posted February 7, 2010 What reasons could the cap bolts loosen over time? Stretched bolts? Quote Link to comment Share on other sites More sharing options...
Scott Posted February 7, 2010 Share Posted February 7, 2010 Chris, the caps were loose but I have good confidence that when they were installed they would have been torqued upto the correct torque, the engine has been running for quite a while & survived TOTB & VMax What reasons could the cap bolts loosen over time? Of course an engine might be completely different but in my experience the main culprits are wrong torque or vibration. Are they meant to be held in with loctite or another variant? Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 7, 2010 Author Share Posted February 7, 2010 (edited) The last place to install the cams was Motoscope. I recall when they pulled them out they said that everything was not 100%. The caps themselves are numbered from Toyota, all my caps were in a random order, they tried putting them in the correct order but they said somthing wasn't right, in the end the installed them in the positions that they removed them from. I'll be glad to get rid of this head, never liked it, never had any confidence in it This is the 3rd cam this head has destroyed Edited February 7, 2010 by jevansio (see edit history) Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 7, 2010 Author Share Posted February 7, 2010 I don't believe the wrong torque explaination. The guy who put it in last wasn't an idiot. I don't believe he would torque up 95% of them correctly & not do a couple. I might be wrong, but I just don't see it. Do I recall Chris saying that there was a possibility the head may have become soft? My exhaust manifold studs kept pulling out & the alloy around them was soft. Something to do with an overheat in a previous life, could that affect the caps in some way? Quote Link to comment Share on other sites More sharing options...
Scott Posted February 7, 2010 Share Posted February 7, 2010 I don't believe the wrong torque explaination. The guy who put it in last wasn't an idiot. I don't believe he would torque up 95% of them correctly & not do a couple. I might be wrong, but I just don't see it. Do I recall Chris saying that there was a possibility the head may have become soft? My exhaust manifold studs kept pulling out & the alloy around them was soft. Something to do with an overheat in a previous life, could that affect the caps in some way? The history of your trouble regarding the head seems to point to the material of the head itself so it would seem that has a lot to do with it. If the exhaust manifold studs were pulling out then I guess it is very possible that the caps were doing the same... maybe not to the same extent hence the longevity. Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 7, 2010 Author Share Posted February 7, 2010 The history of your trouble regarding the head seems to point to the material of the head itself so it would seem that has a lot to do with it. If the exhaust manifold studs were pulling out then I guess it is very possible that the caps were doing the same... maybe not to the same extent hence the longevity. Does sound plausable doesn't it, never really thought about it that way but if studs are coming out on the side I guess it's possible a couple cm away bolts could be pulling slowly out Quote Link to comment Share on other sites More sharing options...
Scott Posted February 7, 2010 Share Posted February 7, 2010 Well the closer to the exhaust side things are the more fatigue the material is going to suffer. Has it always been the exhaust side? Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 7, 2010 Author Share Posted February 7, 2010 I wish I'd gone with my gut instinct in post 1 here http://www.mkivsupra.net/vbb/showthread.php?t=201828 Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 7, 2010 Author Share Posted February 7, 2010 Well the closer to the exhaust side things are the more fatigue the material is going to suffer. Has it always been the exhaust side? Yip, never had a problem on the intake side. Quote Link to comment Share on other sites More sharing options...
Scott Posted February 7, 2010 Share Posted February 7, 2010 Could get it tested if you really wanted closure on it? Alarm bells are ringing though. Quote Link to comment Share on other sites More sharing options...
Kirk Posted February 7, 2010 Share Posted February 7, 2010 Id just scrap the head right now as you pretty much said all that need be said mate Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 7, 2010 Author Share Posted February 7, 2010 Id just scrap the head right now as you pretty much said all that need be said mate The head is already scrap, the quesition now is hows the block Just going back over some of my previous head threads, found an interesting post by CW http://www.mkivsupra.net/vbb/showpost.php?p=2236765&postcount=14 Quote Link to comment Share on other sites More sharing options...
Scott Posted February 7, 2010 Share Posted February 7, 2010 Again thinking out loud but could the RLTC pulling the fuel while you were going at full bore have added the final nail to the coffin? Just wondering if the immediate temp rise from no fuel would have let them pull? Quote Link to comment Share on other sites More sharing options...
Kirk Posted February 7, 2010 Share Posted February 7, 2010 Ahh yes so it is! Just read the carnage report Im sure the block should be alright Quote Link to comment Share on other sites More sharing options...
JamieP Posted February 7, 2010 Share Posted February 7, 2010 Im sure the block should be alright Id not take the risk, any metal shavings or fragments from the broken cam could kill the block and the new head at a later date, even if the block appears to be good id give a complete strip down and chuck away any oil coolers, clean everything and flush all pipes for the engine rebuild. Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 7, 2010 Author Share Posted February 7, 2010 Id not take the risk, any metal shavings or fragments from the broken cam could kill the block and the new head at a later date, even if the block appears to be good id give a complete strip down and chuck away any oil coolers, clean everything and flush all pipes for the engine rebuild. If we assume that the block is gone too, & I went for a low mile stock engine, apart from me fitting some cams, what would be wise to do to it, should I not even crack it open & see how far it gets me? Maybe just get the stem oil seals done? Or should I be opening it up & changing a few essentials and a new HG? Quote Link to comment Share on other sites More sharing options...
JamieP Posted February 7, 2010 Share Posted February 7, 2010 If we assume that the block is gone too, & I went for a low mile stock engine, apart from me fitting some cams, what would be wise to do to it, should I not even crack it open & see how far it gets me? Maybe just get the stem oil seals done? Or should I be opening it up & changing a few essentials and a new HG? Id probably leave new engine untouched, you could fit arp rod bolts if you fancy taking the sump off but i doubt id bother. My car is still on the original stem seals and never a drop of smoke on startup, bit pot luck on that one id guess. Key is finding a good used engine. Quote Link to comment Share on other sites More sharing options...
Kirk Posted February 7, 2010 Share Posted February 7, 2010 If we assume that the block is gone too, & I went for a low mile stock engine, apart from me fitting some cams, what would be wise to do to it, should I not even crack it open & see how far it gets me? Maybe just get the stem oil seals done? Or should I be opening it up & changing a few essentials and a new HG? Suppose you could do the HG and if you do that then you may aswel do the stem seals whilst your there Id not take the risk, any metal shavings or fragments from the broken cam could kill the block and the new head at a later date, even if the block appears to be good id give a complete strip down and chuck away any oil coolers, clean everything and flush all pipes for the engine rebuild. That pretty much what i was getting at Quote Link to comment Share on other sites More sharing options...
Scott Posted February 7, 2010 Share Posted February 7, 2010 The only reason I would want to take the head off would be to put ARP head bolts on there. I would go for the rod bolts too but that can be done from underneath. Is it the rod bolts that were pointed out to be the weak point or the piston pins? Quote Link to comment Share on other sites More sharing options...
jevansio Posted February 7, 2010 Author Share Posted February 7, 2010 Can't you do the stem seals without removing the head? Quote Link to comment Share on other sites More sharing options...
JamieP Posted February 7, 2010 Share Posted February 7, 2010 Is it the rod bolts that were pointed out to be the weak point or the piston pins? Possibly but mine are ok so dont think id bother unless you want to raise the rpm limit. Quote Link to comment Share on other sites More sharing options...
Scott Posted February 7, 2010 Share Posted February 7, 2010 Yeah but if it aint broke Quote Link to comment Share on other sites More sharing options...
Kirk Posted February 7, 2010 Share Posted February 7, 2010 The only reason I would want to take the head off would be to put ARP head bolts on there. I would go for the rod bolts too but that can be done from underneath. Is it the rod bolts that were pointed out to be the weak point or the piston pins? There techically studs not bolts From what i know its the wrist pins that are the weak point Quote Link to comment Share on other sites More sharing options...
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