Chris59 Posted July 15, 2016 Report Share Posted July 15, 2016 Thanks Stan, I've modified the settings (t'was easy !), so I should have emails to notify new PMs now. Quote Link to post Share on other sites
Ian Vincent Posted July 20, 2016 Author Report Share Posted July 20, 2016 The car is now back in my garage. We were in London last week, so I got my wife to drop me at Portsmouth on the way back to Devon. DAS arranged a ferry to Caen on the Sunday afternoon plus a hotel in Caen for the Sunday night and a taxi to take me to the hotel and pick me up on the Monday morning to take me to the garage that had repaired it. The garage charged me 62€ for replacing the rocker (I supplied the part via Moss UK) and I caught the pm ferry from Caen back to Portsmouth - again courtesy of DAS. So apart from their initial slowness in booking a hire car on the day we broke down (in the end I located and booked it and they picked up my booking), the service after that was excellent. I arrived in Portsmouth and cleared customs at about 10pm on Monday and it took me until 2:15am including stops to drive home to West Devon. It was a fabulous drive, at that time of night the traffic was light and there was a cloudless sky with a nearly full moon all the way. The only annoying part was the profusion of 4X4s on the M27 that insist on driving right up behind you. Their headlights are about at the same level as my mirror which makes them pretty dazzling (and big), makes you realise how small a sidescreen car is. I have sent pictures of the broken rocker to Moss and will see what they say. I will also send a report to the PQI team. Rgds Ian Quote Link to post Share on other sites
mike3739 Posted July 20, 2016 Report Share Posted July 20, 2016 Good to hear it went quite smoothly. Cheers Mike. Quote Link to post Share on other sites
john.r.davies Posted July 20, 2016 Report Share Posted July 20, 2016 I'm no metallurgist, Ian, but that broken surface looks to have rapidly propagated from a defect on the left hand side (as you look at the broken end) and towards the back of the engine. JOhn Quote Link to post Share on other sites
RogerH Posted July 21, 2016 Report Share Posted July 21, 2016 Hi Ian, as John mentions the top left corner has two odd depressions where the metal started to fail. These are casting defects of some sort and would have left a rough/sharp edge on the surface. The slow crack propagated down and towards the right. You can see a brown line (old oil) that possibly sat there for a while and cooked a little. Then suddenly it snapped. The rough surface texture below the brown line shows how it just simply broke away. On the lefthand side immediately below where the brown line would be there is a raised very sharp edge - this is typical of a tensile failure The edge across the top does not have this. The plain edge developed as the crack slowly propagated. Nice picture. Roger Quote Link to post Share on other sites
Ian Vincent Posted July 21, 2016 Author Report Share Posted July 21, 2016 Thks Roger, The broken bits are on their way back to Moss along with an email and copies of the photos. Rgds Ian PS The photos were taken by my son who was the passenger and is a semi professional photographer. For more of his photos you can visit his website http://www.jamesianvincent.com Quote Link to post Share on other sites
mike3739 Posted July 21, 2016 Report Share Posted July 21, 2016 Ian Bit off topic, had a look at your son's website some great pictures there looks talented. Cheers Mike Quote Link to post Share on other sites
Ian Vincent Posted July 21, 2016 Author Report Share Posted July 21, 2016 Thks Mike, I think he is but I would say that wouldn't I? Rgds Ian Quote Link to post Share on other sites
Don H. Posted July 22, 2016 Report Share Posted July 22, 2016 Hi Ian, as John mentions the top left corner has two odd depressions where the metal started to fail. These are casting defects of some sort and would have left a rough/sharp edge on the surface. The slow crack propagated down and towards the right. You can see a brown line (old oil) that possibly sat there for a while and cooked a little. Then suddenly it snapped. The rough surface texture below the brown line shows how it just simply broke away. On the lefthand side immediately below where the brown line would be there is a raised very sharp edge - this is typical of a tensile failure The edge across the top does not have this. The plain edge developed as the crack slowly propagated. Nice picture. Roger I was looking forward to your inputs to this, Roger. Nothing like the analysis from a guy who's spent a career looking at material failures! Are rockers cast? I'd have guessed forged, but that might be optimistic... Quote Link to post Share on other sites
Allan Jezzard Posted July 22, 2016 Report Share Posted July 22, 2016 Only just spotted this thread and would certainly confirm that Chris was invaluable a couple of years back when I had a U J give up the ghost as I left the ferry in Boulogne. Not only did he lend me a complete shaft but he also corrected damage caused by the French mechanic (who in all honesty was trying his best). Good bloke! Allan Quote Link to post Share on other sites
RogerH Posted July 22, 2016 Report Share Posted July 22, 2016 Hi Done, I spent most of my working life looking for cracks and other strange things. I know very little about metallurgy but somethings are always there. I would guess that the rockers are cast. Forging used to be the way to get strong shapes - keeping the grain flow in one direction. That all changed many moons ago when (I think Ford) developed a way to produce excellent casting. The steel billet cranks are machined (lots of cut grain flow) not forged and are stronger than ever. The above rocker may have had a deformity on the surface where the cracking started - cracks like any irregularity, sharp edges etc. (Comet square windows) Roger Quote Link to post Share on other sites
Waldi Posted July 23, 2016 Report Share Posted July 23, 2016 By the appearance of the fracture I would in this case say it is a casting. A forging would have the same appearance as say normal steel fracture, with more plastic deformation. For normal steels, in general the following applies: The higher the grade steel (tensile stress), the less plastic deformation before final fracture. Compare the fracture of say a 10.9 class bolt with a lower strength 4.6 bolt. The lower strenght bolt is more ductile. Quote Link to post Share on other sites
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