Guest catweazle (Banned Member) Posted October 1, 2008 Share Posted October 1, 2008 How do you get under the engine,with great difficulty. first you sit with your back to the engine then you put your feet under the centre bilge. then you try and lay on your side without smashing your head on the crank damper. Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 1, 2008 Share Posted October 1, 2008 then pull yourself under. getting out is worse i really am getting to old for this,whilst under there i thought if i have a problem and cant get out ,it would make good tv on the helicopter rescue program,i could just see the cable coming thro the hatch,only problem not enough room for two.:shake::shake::shake: Quote Link to comment Share on other sites More sharing options...
younggun Posted October 1, 2008 Share Posted October 1, 2008 reading this thread is like waching the film DAS BOOT there is a strikeing resemblace between catweazle and the cheif of the boat dous eny one else agree keep up the good work catweazle Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 2, 2008 Share Posted October 2, 2008 I dont like the ariel shots ,i could of sworn i had more hair than that.More like DAS RUDDY BOOT:banghead: Quote Link to comment Share on other sites More sharing options...
Tony B Posted October 2, 2008 Share Posted October 2, 2008 Cor! Ain't he supple for his age! :-D Any idea how long the job will take? Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 2, 2008 Share Posted October 2, 2008 Cor! Ain't he supple for his age! :-D Any idea how long the job will take? A couple of days non stop. Quote Link to comment Share on other sites More sharing options...
Tony B Posted October 2, 2008 Share Posted October 2, 2008 Ouch! Not plesaent, best of luck. Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 11, 2008 Share Posted October 11, 2008 Not another ash tray. Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 11, 2008 Share Posted October 11, 2008 Lets have your thoughts on the cause please gents. Quote Link to comment Share on other sites More sharing options...
chevpol Posted October 11, 2008 Share Posted October 11, 2008 not a pretty site, I aint no engineer, but oversize piston in liner? Mark Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 11, 2008 Share Posted October 11, 2008 not a pretty site, I aint no engineer, but oversize piston in liner? Mark Hi Mark,this was an original piston in a new liner,new rings,it all fitted perfect and measured up ok,done about 100 hours maybe. Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted October 11, 2008 Share Posted October 11, 2008 Hi Mark,this was an original piston in a new liner,new rings,it all fitted perfect and measured up ok,done about 100 hours maybe. Hi CW, That is a mess, judging by the extent of the sieze, could it be a fault in manufacture, ie, expansion rate more than the clearance allowed? When you give these engines full power, is it considered to be neccessary to give the pistons more clearance, as you might do with racing engines? I cannot see it is lack of oil as others would be effected. Quote Link to comment Share on other sites More sharing options...
chevpol Posted October 11, 2008 Share Posted October 11, 2008 Hi Mark,this was an original piston in a new liner,new rings,it all fitted perfect and measured up ok,done about 100 hours maybe. Hi cw, like I said, I aint no engineer!!!! Mark Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 11, 2008 Share Posted October 11, 2008 Hi Richard,it is an original 1968 piston and would of thought it would of shown before now,at the time of failure allthough we had equaled our best speed it was probably under less stress than before due to the belzona props being more efiecent.I now think the rise in coolant temp was due to this piston seizing,rather than the otherway around. The liner cream crackered as well. Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 11, 2008 Share Posted October 11, 2008 Hi cw, like I said, I aint no engineer!!!! Mark Begining to wonder if i am after this feasco.:shake: Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 11, 2008 Share Posted October 11, 2008 Just out of interest i weighed the piston assy,its 20lb,thats a fair old weight to be going at 2200rpm i would love to know what the accelerating/decelerating speeds are.:shake::shake::shake: Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted October 11, 2008 Share Posted October 11, 2008 Begining to wonder if i am after this feasco.:shake: No signs of siezing on the other bores? Maybe it was an obstruction to the cooling as first thought, and this one siezed first, for some reason. Perhaps we are looking at this the wrong way around, it could be not so much the piston expanding but the block / liner distorting due to overheating? Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 11, 2008 Share Posted October 11, 2008 Sounds logical Mr Spock,no signs on the other bores,never thought of it that way cheers.CW Quote Link to comment Share on other sites More sharing options...
Degsy Posted October 11, 2008 Share Posted October 11, 2008 Could it have been a blockage in the oil feed to this one piston? Have you asked for an opinion from Cat? Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 11, 2008 Share Posted October 11, 2008 Could it have been a blockage in the oil feed to this one piston?Have you asked for an opinion from Cat? Oil feed is ok. The official responce was change the injector even if it bench tests ok.they were all new at time of rebuild,will be forwarding pics to them for there opinion,one of there engineers now in his 60s was engineer on the boat during the original sea trials so is very familier with it all. Quote Link to comment Share on other sites More sharing options...
Degsy Posted October 11, 2008 Share Posted October 11, 2008 The damage seems a bit extreme even if it was over injecting but I suppose Cat know a lot more about it than I do. Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 11, 2008 Share Posted October 11, 2008 The damage seems a bit extreme even if it was over injecting but I suppose Cat know a lot more about it than I do. I agree,The pump also had a billion dollar rebuild at the time,we even some months later made special tools to check the pump ourselves,We were suspicious of this cylinder as at idle removing the fuel made little difference,that turned out to be the sea water damage which started the first rebuild off,Andys now worried we introduced a problem to the pump,either quantity or timing just on that cylinder,i cant see that myself we went over it a million times. Quote Link to comment Share on other sites More sharing options...
radiomike7 Posted October 11, 2008 Share Posted October 11, 2008 Cat, you did gap all the rings to the recommended setting?? Some years ago we had several VW diesels fail due to single faulty injectors not closing and leaking, this generated huge amounts of heat which in most cases melted the head rather than pistons. As in your case, the only outward signs were smokey exhaust on part throttle and a slight roughness. Quote Link to comment Share on other sites More sharing options...
Stormin Posted October 12, 2008 Share Posted October 12, 2008 Lets have your thoughts on the cause please gents. Third picture down bottom leff corner, looks like a piece has been taken out in a large chip, no melting. Are you sure you've not had valve to piston contact? The chipped piece may then have migrated round and done the rest of the damage. The rest of the top of the piston doesn't look too badly overheated. The only other way that large chip could have been removed is on the last few downward strokes of the piston as it overheated due to some other cause. Looking how clean the area is at the fracture point I would expect to still see this large chip on top of the piston once stripped down. You've not mentioned seeing it anywhere so my guess is the first scenario sticky valve! Quote Link to comment Share on other sites More sharing options...
Guest catweazle (Banned Member) Posted October 12, 2008 Share Posted October 12, 2008 Cat, you did gap all the rings to the recommended setting?? Some years ago we had several VW diesels fail due to single faulty injectors not closing and leaking, this generated huge amounts of heat which in most cases melted the head rather than pistons. As in your case, the only outward signs were smokey exhaust on part throttle and a slight roughness. Hi Mike ,yes we did check everything more than once,we couldnt believe it all matched up to the book,We still need to check the fuel delivery side but its not easy,we will measure the output of the others for quantity per so many strokes,the problem is this engine needs to make oil pressure before it will grant fuel.no oil,no sump one rod missing,guess we have to put it back together again before we can do a test,Bugger. Quote Link to comment Share on other sites More sharing options...
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