ant802 Posted September 26, 2012 Report Share Posted September 26, 2012 Hi everyone, i've encountered a problem with my zx636 c1h engine and wondered if any of you guys can come up with an opinion to what it might be. i've recently re-build my zx6r engine after a blow up, no4 piston holed at high rpm, the engine did not lock up and was still runnable in the pit garage afterwards, although totally knackered with bits of piston everywhere inside the motor. So...........i completely rebuilt the motor as follows: Stripped and fully cleaned the crank cases, inspected, removed all traces of ally etc Full bottom end rebuild - mains/big ends - all plastiguaged etc Crank checked for trueness and balanced Rods balanced New pistons (matched), rings, pins, ring gap set, piston to bore checked etc Barrels de-glazed, could still see the cross hatch hone marks from previous build. New valves and collets New oil pump rotor, and sump filter. Head ported, new plugs New Cam chain Gear box inspected, clutch inspected (usual wear, but not unserviceable) Timed up correctly and checked so many times, i can now do it blindfolded!!, valve clearances double checked. On initially running the motor after rebuild, cam chain noise was heard, and an inconsistent rattle, sounds like a marble around the clutch side of the motor, i though this was maybe the cct as i'd used the old one, so bought a manual ape cct - this has not solved the problem. I can only describe the sound as very much like a cam chain wurr on over run, as if the chain is trying to catch itself up, also the rattle at idle is still there, the noise does not go away when the engine is under load either or when it is fully up to temp, it doesnt seem to be clutch related as pulling the clutch lever in does'nt help. Today ive had the motor out of the bike and apart again, thinking that i'm bound to see a problem, but low and behold...........nothing obvious found. we checked, big ends, small ends, bore diameter (piston slap?), crank movement, inspected pistons, rings, gudgeon pins, all valves show no signs of contact with the pistons, they shouldn't anyway as i'd not skimmed the head, its looking like the motor is going to go back again, not sure if it will sound the same though!, what a waste of brand new gaskets, the motor has only been run for 20 mins max upto around 7k rpm. Its had 2 oil changes in this time also, no debris found, came out like new each time. So 3 of us stood around today scratching our heads, and wondered if any you might think of something different, over to you people! thanks for reading Ant Link to comment Share on other sites More sharing options...
BudgetBoy Posted September 26, 2012 Report Share Posted September 26, 2012 have you checked the clutch area? Could be the bearing.. bits of that alloy would have gone everywhere inside the engine,this includes bearings.You have a needle bearing in the clutch area also one on the casing like this..Also think that No 4 piston is the closest to the clutch.. so i would be inspecting the clutch basket,bearings basically everything in that area. Link to comment Share on other sites More sharing options...
ant802 Posted September 26, 2012 Author Report Share Posted September 26, 2012 have you checked the clutch area? Could be the bearing.. bits of that alloy would have gone everywhere inside the engine,this includes bearings.You have a needle bearing in the clutch area also one on the casing like this..Also think that No 4 piston is the closest to the clutch.. so i would be inspecting the clutch basket,bearings basically everything in that area. hi, thanks for the reply and pic, yes had a look at the clutch housing, the bearing appears to be fine, smooth etc, but i'll check it again tomorrow, we also checked the springs on the back of the clutch housing, these can sometimes break up, but mine look good, 2 are maybe a little loose, but nothing untoward, doesnt explain the weird cam chainy noise though would it? Link to comment Share on other sites More sharing options...
BudgetBoy Posted September 27, 2012 Report Share Posted September 27, 2012 If you had some of these (see piccy) you would be able to pinpoint the noise and where its coming from. Let me just say that these are worth every penny mate, i have used mine many times over the years.. The fact that you have replaced everything major in the engine but left the bearings would leave me to go with those.If it was me i would have replaced the internal bearings whilst it was apart as these are pretty cheap. Also check the needle bearing on the clutch. I would also be inclined to put the normal CCT back on and let the new cam chain settle in and then put the manual one on at a later date. Some other people on here might give more better advice than me but thats how i would go about it. Link to comment Share on other sites More sharing options...
ant802 Posted September 27, 2012 Author Report Share Posted September 27, 2012 thanks for the reply budget, yes we used the stethascope few times on the engine but couldn't really pinpoint it, although saying that, today we've had the rods off and crank out, mains and big ends appear to have major wear, no1 has a deep score, so all in all we think we've found what the problem is, i think oil starvation on the first run of the engine has caused this, or i've measured up wrong. Clutch bearing and needle bearing are fine, checked those today, going to start measuring up again tomorrow to find out why this has happened. Link to comment Share on other sites More sharing options...
BudgetBoy Posted September 27, 2012 Report Share Posted September 27, 2012 thanks for the reply budget, yes we used the stethascope few times on the engine but couldn't really pinpoint it, although saying that, today we've had the rods off and crank out, mains and big ends appear to have major wear, no1 has a deep score, so all in all we think we've found what the problem is, i think oil starvation on the first run of the engine has caused this, or i've measured up wrong. Clutch bearing and needle bearing are fine, checked those today, going to start measuring up again tomorrow to find out why this has happened. Oil starvation? you fitted a new pump though..And are you 100% sure you have every bit of the old alloy out of the engine? And not being funny but when you rebuilt the engine you did apply fresh oil to all the main/big end bearings.. Did you turn the engine over first with NO spark connected to lube the engine fully before the main start procedure. Is your new oil pump working correctly,, what bar are you getting?Should be 1,3-1,6 bar @ 4k rpm Check ALL of the oil gallery's to make sure these are completely clear.IMO i would think you still have traces of the old piston remain in the engine..And it's this that has caused the score on your bearing. Only down side to alloy is you cant pick it up with a magnet.. Any engine rebuild like you have done needs to be done in a clean environment and everything MUST be 100% clean. All you can do is Check check and recheck..take your time as well.. Link to comment Share on other sites More sharing options...
ant802 Posted September 27, 2012 Author Report Share Posted September 27, 2012 Oil starvation? you fitted a new pump though..And are you 100% sure you have every bit of the old alloy out of the engine? And not being funny but when you rebuilt the engine you did apply fresh oil to all the main/big end bearings.. Did you turn the engine over first with NO spark connected to lube the engine fully before the main start procedure. Is your new oil pump working correctly,, what bar are you getting?Should be 1,3-1,6 bar @ 4k rpm Check ALL of the oil gallery's to make sure these are completely clear.IMO i would think you still have traces of the old piston remain in the engine..And it's this that has caused the score on your bearing. Only down side to alloy is you cant pick it up with a magnet.. Any engine rebuild like you have done needs to be done in a clean environment and everything MUST be 100% clean. All you can do is Check check and recheck..take your time as well.. I do reckon it was oil starvation on initial startup, zx6's tend to be awful at getting initial oil pressure after a full rebuild, not sure if other models etc do this, lots of fresh oil was used on all bearing surfaces as the engine went together, but when i ran it for the first time, getting oil pressure was difficult, loosened filter to gain oil pressure etc and i guess this is where i did the damage, i'm pretty new to building engines, but done a few with good results, cleanliness is not the problem (ocd!), but inexperience may have been, i usually tend to learn the hard way, and i'm sure lots of reputable engine builders have ruined engines in there early days of learning. When it goes together again, it'll be checked about 50 times!, heres a pic anyway, you'll see its no bodge job hopefully, and thanks for the input mate. Ant http://i453.photobucket.com/albums/qq259/ant802/SDC10533-1.jpg http://i453.photobucket.com/albums/qq259/ant802/SDC105283.jpg http://i453.photobucket.com/albums/qq259/ant802/SDC105313.jpg http://i453.photobucket.com/albums/qq259/ant802/SDC105293.jpg http://i453.photobucket.com/albums/qq259/ant802/SDC105142.jpg http://i453.photobucket.com/albums/qq259/ant802/SDC105382.jpg http://i453.photobucket.com/albums/qq259/ant802/SDC105392.jpg http://i453.photobucket.com/albums/qq259/ant802/SDC10534-1.jpg http://i453.photobucket.com/albums/qq259/ant802/SDC10540.jpg Link to comment Share on other sites More sharing options...
BudgetBoy Posted September 27, 2012 Report Share Posted September 27, 2012 Looks good mate.. All you can do IMO is clean it all again double check everything and start the bike. Just disconnect the spark so if dont fire up. you will see if the oil light goes out and that you are getting pressure.if not check the oil pressure switch or just fit a new one anyway. As i say take your time and im sure you will get there.. Any problems and im sure someone with more knowledge than me will help out. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.