drgnball34 Posted September 27, 2006 Share Posted September 27, 2006 Please take the time to read as it is long but very important As the mechanic proceded to bolt down the 2nd cam he heard a cracking sound. He took it off and checked to see if the cam had snaped but turned out it didnt. He placed it back down and continued bolting everything back 2getha. He then cranked the engine over to check if everything was ok but could hear snaping sounds. Thinking that he bent a valve he proceed to do a compression test. Thats when he heard a crunch sound. We took the head off and i nearly fainted. A valve snaped and with the cranking of the engine, must of dislodged itself and fell into the cylinder bore. As a result smashed head, damage piston and burred cylinder bore. He can not explain what he did wrong but suggested that the head had a crack valve seat prior to the cams getting bolted on. And this has not allowed the valve to close properly thus not only hitting the pistion, but on a angle which contributed to the valve snapping. But if it was cracked in the 1st place, then i would have suffered from miss fire in that cylinder. Not to mention under heavy engine load and with the constant high rpm, that valve would of crack long ago. My car has only 50k kms of which ive only put 5k kms and was runnig perfect when i gave it to him. He suggested that the cause of a crack valve seat was because i was runing too lean. But its only ever been boosted (AVCR) the last 2k kms and been below factory boost cut. My theory is that before placing down the cam, he either set the timing wrong or placed in dwn the wrng way. When he bolted it down the, the force would of pushed the valve onto the piston and snaped it. Could any tech people please give insight and feedback to what has actually happened to my engine? He is trying to shift the blame on me and wiggle himself out of any responsability. This has caused a great deal of stress upon myself. Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/ Share on other sites More sharing options...
Craved Posted September 27, 2006 Share Posted September 27, 2006 i bent 2 valves on cyl 6 when i bolted mine in .. i was later advised that the crank needs to be moved OFF TDC so that none of the pistons are at full extension, that way if the cams are not in the correct location the valves will not meet with the piston. cant see how it would be able to be that off that the valve would snap though Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2534310 Share on other sites More sharing options...
RB30-POWER Posted September 27, 2006 Share Posted September 27, 2006 sounds like the mechanic stuffed up with the installation. they don't just stuff by themself. i know who should be forking out the rebuild bill, not you... never good to hear stories like this... Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2534442 Share on other sites More sharing options...
drgnball34 Posted September 27, 2006 Author Share Posted September 27, 2006 dont do backyard jobs Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2534452 Share on other sites More sharing options...
Rolls Posted September 27, 2006 Share Posted September 27, 2006 Oh boy, this'll be fun. Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2534608 Share on other sites More sharing options...
R31Nismoid Posted September 27, 2006 Share Posted September 27, 2006 Did you and a mate do it? Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2534781 Share on other sites More sharing options...
SXR Posted September 27, 2006 Share Posted September 27, 2006 was it more then 1 valve? Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2534876 Share on other sites More sharing options...
grigor Posted September 27, 2006 Share Posted September 27, 2006 Did you just forget to mention timing belt or did he actually crank the engine without the belt fitted? Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2535355 Share on other sites More sharing options...
666DAN Posted September 27, 2006 Share Posted September 27, 2006 He broke it, he can fix it Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2535359 Share on other sites More sharing options...
GTRgeoff Posted September 27, 2006 Share Posted September 27, 2006 Which piston did the valve break in? 1 or 4? As mentioned before bolting the cam down at top dead centre (#1) can cause the valves to contact a high piston and bend or break as the cam may not be perfectly aligned for that timing. A valve seat would not do this at all unless dislodged. Was there part of a valve seat sitting loose in the cylinder? He is clearly not a good mechanic. Viewers may have already worked that out. He should have cranked the engine off TDC and put the cams in then retimed and fitted the timing belt. Then he should have cranked it over a couple of times using a ratchet off the harmonic balancer bolt to ensure there was no confliction of the moving parts. He should have stopped immediately there was noise as well, not continued on with a compression test. If he refuses to repair the damage he has caused take the head and valve piece to a place that does engineering materials analysis for a report on the cause of the failure. They will know if the seat or fatigue or sheer ham-fistedness caused the breakage. You can use the report in a small claims case for compensation. Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2535476 Share on other sites More sharing options...
satanic Posted September 27, 2006 Share Posted September 27, 2006 O U C H Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2535483 Share on other sites More sharing options...
blur Posted September 28, 2006 Share Posted September 28, 2006 maybe the cam was bolted down with no reference to tdc at all, and some of the valves opened and had piston contact which would be enough to bend/ crack a valve.. either way its not going to be nice, not exactly a common engine at the best of times. Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2535861 Share on other sites More sharing options...
Bass Junky Posted September 28, 2006 Share Posted September 28, 2006 This is bad. I just hope he's a registered mechanic, otherwise you are going to be a very angry person. But hey, look on the bright side. Broken RB25 = Fresh new RB30!!! Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2536024 Share on other sites More sharing options...
Craved Posted September 28, 2006 Share Posted September 28, 2006 r33 rb25 valves are $60 each from nissan, plus gasket .. so its not like he is up for much dosh anyway Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2537758 Share on other sites More sharing options...
R31Nismoid Posted September 28, 2006 Share Posted September 28, 2006 but the bore damage isnt $60 to fix Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2537796 Share on other sites More sharing options...
RB30-POWER Posted September 28, 2006 Share Posted September 28, 2006 Not to mention there could be hairline cracks or fractures in the pistons, valve guides are probably cactus and so on. Not sure what work was done but maybe the cheaper option is to buy a another motor for $1500 and dump it straight in. 24V head work will add up real quick. Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2537805 Share on other sites More sharing options...
StockyMcStock Posted September 28, 2006 Share Posted September 28, 2006 what an idiot. 1) put engine on TDC number 1 2) put exhaust cam in with cam gear dot lined up approximately towards where it will be when you put the rear timing cover on. torque it down. 3) do the same with inlet cam 4) fit timing belt and tension it up. how goddam hard is it? when your crank is at number 1 TDC, number 4 is there as well (i think it's number 4 anyway) so all you have to worry about is number 1 and number 4 valves hitting the pistons. visually check the lobes to see that they aren't at full extension when you install the cam. it is not a difficult concept. make him fix it. Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2537873 Share on other sites More sharing options...
Craved Posted September 28, 2006 Share Posted September 28, 2006 but the bore damage isnt $60 to fix oh yeah, forgot it did that Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2537919 Share on other sites More sharing options...
SLIMVLT Posted September 28, 2006 Share Posted September 28, 2006 owch vcat any 1 take him to vcat to get the cash then get some 1 else to fix it. ive seen plenty of this stuff recantly (im a tech/mechanic at a nissan/kia dealer) and ppl dont seam to think its worth changing timing belts, had about 7 instances in about 3 months all with major valve snapage and alot of busted cams,pistons heads ect, and usulay they break at highway speeds. ive also seen various aprentaces stuff up valve timing with predictable results. the best 1 was his own car (xf with ef motor, twin gt3070 ect) the work shop manual didnt have a crutial step in it for installing the timing gear (so he says anyway) resulting in the cam been about 40 degrees out. it wouldnt turn over so he put a big snap on bar on it. it would turn but not verry good. so he put it in his car cranked it over and not much happened. i gave his wolf 3d some tweaking thinking he hadnt set it corectly (it sounded suss at this stage. and when it cranked over and fired (well splutered) there where flames about 4 foot high out of the intake and the exhaust. it smashed every inlet valve and bent/broke every second exhaust valve. broke every piston and masacred the head. prity funny after the event not at the time http://i54.photobucket.com/albums/g81/slimvlt/Picture303.jpg http://i54.photobucket.com/albums/g81/slimvlt/Picture305.jpg http://i54.photobucket.com/albums/g81/slimvlt/Picture310.jpg http://i54.photobucket.com/albums/g81/slimvlt/Picture315.jpg http://i54.photobucket.com/albums/g81/slimvlt/Picture294.jpg http://i54.photobucket.com/albums/g81/slimvlt/Picture317.jpg pics of the mess Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2538087 Share on other sites More sharing options...
Adriano Posted September 28, 2006 Share Posted September 28, 2006 At least that was only a cheap ford motor Link to comment https://www.sau.com.au/forums/topic/136302-major-neo-rb25det-engine-damage/#findComment-2538154 Share on other sites More sharing options...
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