Fish13 Posted March 6, 2008 Share Posted March 6, 2008 Stripping V8 for a new camshaft as it was running like a bag of spanners and this is what I found! On lobes/lifters for cylinders 5 and 7. I've seen wear before but this is impressive! Could people let me know how this could happen so bad on just two? The others have dished a little but nothing like this! Worried that if I put in new cam and lifters same will happen? Any ideas? The dished lifters are shorter than the rest because they have not been lifted up and have scored the cam (see pics) and begun to wear the lifter base away! Quote Link to comment Share on other sites More sharing options...
teslo Posted March 6, 2008 Share Posted March 6, 2008 and valves are OK? Quote Link to comment Share on other sites More sharing options...
paintman Posted March 6, 2008 Share Posted March 6, 2008 What's the mileage? You will find some more pics at http://www.v8engines.com/engine-4.htm#worncams Quote Link to comment Share on other sites More sharing options...
Fish13 Posted March 6, 2008 Author Share Posted March 6, 2008 135,000 miles - haven't checked the valves yet. Heads were done a few years ago, will wear this bad have damaged the valves? Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted March 6, 2008 Share Posted March 6, 2008 Yep thats not unusual 7 is the 1st to wear away, then 5, so 7 & 5 means a engine that hasn't been loved. Basically 7 wears out due to the oil control system and flow etc, 7 seems to be the runt "oil" wise, followed by 5 Poor qulaity Oil / infrequent oil changes / sludged up engine / High Mileage ...........are the ingredients - select as needed and mix - result = cam gone Bin the lifters too, and most prob the pushrods, at least check the pushrods haven't gained a nipple on the end (ooer) if you plan to even think of reusing Valves sghould be fine as they are operated from the rocker arm so differwent part, they just won't have been opening (much) Nige Quote Link to comment Share on other sites More sharing options...
bazza Posted March 6, 2008 Share Posted March 6, 2008 Stripping V8 for a new camshaft as it was running like a bag of spanners and this is what I found! On lobes/lifters for cylinders 5 and 7.I've seen wear before but this is impressive! Could people let me know how this could happen so bad on just two? The others have dished a little but nothing like this! Worried that if I put in new cam and lifters same will happen? Any ideas? The dished lifters are shorter than the rest because they have not been lifted up and have scored the cam (see pics) and begun to wear the lifter base away! Thats a familiar site! i rebuilt a V8 in a series 1 that ran fine but popped back through the carbs when you floored it, turned out the last two cam profiles were near on perfectly round!!! Love em! Quote Link to comment Share on other sites More sharing options...
steve_d Posted March 6, 2008 Share Posted March 6, 2008 Once the oil supply is compromised the case hardening on the lifter fails and rips the cam up pretty fast after that. I had a cam like that once. Steve Quote Link to comment Share on other sites More sharing options...
Fish13 Posted March 8, 2008 Author Share Posted March 8, 2008 Thanks guys, Have hada look at the push rods and they aren't nippled so that's all good. I guess I was in shock when I saw how badly worn these two lifters and their corresponding lobes were, but I guess it's quite normal after all! Will let you know how new cam does! Cheers. Quote Link to comment Share on other sites More sharing options...
steve_d Posted March 8, 2008 Share Posted March 8, 2008 Sure you already know but worth reminding. Your new cam and the lifters must be coated with the best cam lube you can get. Start the engine and run it at 2000rpm minimum for 20 minutes. You can vary the revs a little but don't drop below 2000. If you have to stop the engine just cut it without letting it come back to tick-over. Steve Quote Link to comment Share on other sites More sharing options...
Fish13 Posted March 8, 2008 Author Share Posted March 8, 2008 Thanks Steve, will do. Start putting it all back together tomorrow so will give an update. Quote Link to comment Share on other sites More sharing options...
V8david Posted March 9, 2008 Share Posted March 9, 2008 Thanks Steve, will do. Start putting it all back together tomorrow so will give an update. Definitely keep this updated. Really interesting. I'm starting the same job on mine soon so I'd be really interested to see it going back together. Keep up the good work Cheers David Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted March 10, 2008 Share Posted March 10, 2008 Make sure you 'break in' the cam correctly when you first run the engine ............ with flat tappet cams its very important to get it right. There plenty of info here on cams, lifters, timing gear, and anything V8..............http://forums.lr4x4.com/index.php?showtopic=14006&st=20 Ian Quote Link to comment Share on other sites More sharing options...
Fish13 Posted March 10, 2008 Author Share Posted March 10, 2008 Thanks Ian, have read your thread with interest! Unbelieveable amount of time and effort, nicely done! I got the cam in today, with the lifters, pushrods and rockers in too (all cleaned up and freshly lubed/oiled). Then front cover, crank pulley and waterpump with respective belts to AC and Crank put on. Seems simple, but going slowly and methodically taking notes and photos, that took me 8 hours! Just as well I am not a garage! Oh, got the AC radiator and fans bolted back in - I didn't de-gas the aircon and just draped it over the wing when removing/installing the camshaft. Next (tomorrow hopefully) is power steering pump back on, then I need a set of rocker gaskets and they can go on, along with valley gasket. After that, it's more cleaning if the inlet manifold as well as replacing vacuum hoses that were well and truly perished on the t-piece at the back. Will keep you posted as I go along. Need to keep taking photos as I took loads during disassembly, but have been slack when doing the reassembly. Quote Link to comment Share on other sites More sharing options...
Fish13 Posted March 24, 2008 Author Share Posted March 24, 2008 Hi, Got my cam replacement finished and ran it in for 20 mins at just over 2,000rpm and it is running very well indeed - very happy! It went back together pretty smoothly, main thing being sure that everything was clean and there was gasket sealant in all the places it should be. Also replaced perished hoses and knackered screws/bolts etc where required. Still needs timing done properly, but it can't be far off because it's running very nicely! Mind you, if anyone looks at the last cam and tappets that may give a clue as to why! Here is a pic of it going back together - I painted the rockers with red engine paint as I thought it made it look smart - and I had a can of red in the garage! Quote Link to comment Share on other sites More sharing options...
Fish13 Posted March 24, 2008 Author Share Posted March 24, 2008 Hmm, don't know why the pic loaded twice - my error I guess! Apologies. Quote Link to comment Share on other sites More sharing options...
willfromsussex Posted March 29, 2008 Share Posted March 29, 2008 good heavens, I bet that's what went wrong with my 1993 3.9. Never found out as I sold it on. Similar mileage. Quote Link to comment Share on other sites More sharing options...
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