dandan Posted December 12, 2007 Share Posted December 12, 2007 Have we had some rpm related rod (or rod bolt failures) on this board then? Quote Link to comment Share on other sites More sharing options...
Thorin Posted December 12, 2007 Share Posted December 12, 2007 Have we had some rpm related rod (or rod bolt failures) on this board then? I've certainly read of rod bolt failures on here yes, but generally we don't go stupid with rev limits over here. Plenty of destroyed engined over on Supra forums though, and plenty more that you never hear about. They tend to keep things quiet over there sometimes when things go wrong I've noticed. Quote Link to comment Share on other sites More sharing options...
b_have Posted December 12, 2007 Share Posted December 12, 2007 Common sense. You've not been looking very hard then have you? I know of several engines letting go at much less revs. Are you just trying to get a rise or are you really that naive? How many 2JZ-GTE's have you seen revving to 9000+ RPM over there then? Well I've been looking pretty hard, struggling to find many engine failures like Chris's. Most failures on here are det related (due to poor mapping or build) or just plain worn out. Whos engines were these that failed due to excessive rpm? Quote Link to comment Share on other sites More sharing options...
b_have Posted December 12, 2007 Share Posted December 12, 2007 I've certainly read of rod bolt failures on here yes, Where did you read this? Quote Link to comment Share on other sites More sharing options...
Thorin Posted December 12, 2007 Share Posted December 12, 2007 Whos engines were these that failed due to excessive rpm? Well I don't make note of everyone's engine failures, but I recall Usmann's (http://www.mkivsupra.net/vbb/member.php?u=777) old engine having a rod bolt go at higher RPM. Quote Link to comment Share on other sites More sharing options...
b_have Posted December 12, 2007 Share Posted December 12, 2007 Well I don't make note of everyone's engine failures, but I recall Usmann's (http://www.mkivsupra.net/vbb/member.php?u=777) old engine having a rod bolt go at higher RPM. Yep, thats one, but many many years ago and he did push the boundaries (remember his sig 'life begins at 30 [psi]. Quote Link to comment Share on other sites More sharing options...
Thorin Posted December 12, 2007 Share Posted December 12, 2007 Go search on supraforums then. Quote Link to comment Share on other sites More sharing options...
Guest KDW Posted December 12, 2007 Share Posted December 12, 2007 I have searched very hard, both on here and SF. There seem to be very few threads regarding failure due to high revs. You are more than welcome to post up links if you find any though, I would love to read more tangible facts related to this topic. Quote Link to comment Share on other sites More sharing options...
Thorin Posted December 12, 2007 Share Posted December 12, 2007 I have searched very hard, both on here and SF. There seem to be very few threads regarding failure due to high revs. You are more than welcome to post up links if you find any though, I would love to read more tangible facts related to this topic. Well you seem convinced that running 9500+ RPM on a long stroke engine like the 2JZ is a good thing, why not try it and let us all know your findings? Quote Link to comment Share on other sites More sharing options...
Wez Posted December 12, 2007 Share Posted December 12, 2007 Why are we discussing rev limits in a thread called turbos turbos turbos when there is another dedicated thread discussing exactly this? Quote Link to comment Share on other sites More sharing options...
Wez Posted December 12, 2007 Share Posted December 12, 2007 Here is the thread http://www.mkivsupra.net/vbb/showthread.php?t=128695 Quote Link to comment Share on other sites More sharing options...
Thorin Posted December 12, 2007 Share Posted December 12, 2007 Why are we discussing rev limits in a thread called turbos turbos turbos when there is another dedicated thread discussing exactly this? Because it got brought up in this thread and a link already posted to that other thread which is what started that one back up again. Quote Link to comment Share on other sites More sharing options...
Chiefgroover Posted December 12, 2007 Share Posted December 12, 2007 Rev limit reliability may actually be boost and mapping related? 9K @ 2 bar vs 9K @ 1.2bar has got to make a serious difference. I know a chap runs twins @ 1.17bar and regular does 9K and has covered 20K Km so far and the engine is still crisp. An agressive timing curve would surely stress thing a bit too? Quote Link to comment Share on other sites More sharing options...
Ian C Posted December 12, 2007 Share Posted December 12, 2007 The crippling moment is the exhaust stroke to intake stroke where the piston stops going up suddenly and starts going down, with nothing going on in the combustion chamber. During the firing event cycle, though, the expanding gases produce an opposing compression force against the tensile (I think, might have my terms mixed up) force of the piston changing direction, so the more power at that point the better, especially ignition advance as it means the mix starts burning earlier. The power production from the firing event is a compressive force spread across most of the downstroke, which is why light pressure charging of normal NA engines works ok - the extra force there is nothing compared the the rattling the conrod gets under maximum revs when it changes direction. So you might bend a conrod with a lot of power but it shouldn't affect the rev limit capabilities. -Ian Quote Link to comment Share on other sites More sharing options...
dandan Posted December 12, 2007 Share Posted December 12, 2007 So you might bend a conrod with a lot of power but it shouldn't affect the rev limit capabilities. -Ian You won't bend a Pauter rod in a 2JZ Quote Link to comment Share on other sites More sharing options...
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