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Worn Cams and/or tappets

 
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V8GPC



Joined: 03 Apr 2016
Posts: 256
Location: Manchester

PostPosted: Thu Apr 14, 2016 6:38 am    Post subject: Worn Cams and/or tappets Reply with quote

Has anyone had any experience of worn cams and/or tappets? I’ve been reading the following on RPi’s website.

http://www.v8engines.com/engine-4.htm#v8gen
http://www.v8engines.com/engine-4.htm#worncams

Quote:
“Almost all used Rover V8 engines that have covered in excess of 70,000 miles will be suffering, or beginning to suffer, from worn camshaft, lifters and a stretched timing chain. This is normal with the V8 because these engines are amongst the most forgiving.”


Quote:
“The result is a gradual decrease of engine efficiency and economy that goes quite unnoticed to start with, this is due to the fact that although you have eight cylinders, the major loss of efficiency, in only in one or two of them (typical of a worn camshaft), may not be apparent until they have perhaps failed completely, as the remaining good cylinders will mask the power loss effectively until severe enough to make replacement unavoidable. However, if left this long, many other engine components will have suffered due to this, and can lead to an engine's condition being far too bad for an inexpensive overhaul.”


Quote:
"As an engine's internal parts start to wear out (cam, tappets and timing gear first), metal particles (swarf) are created and set loose to run around with the oil in your engine. Although your filter will trap most of the larger particles, oil filters (especially cheap or old ones) will not stop this swarf from reaching the vital soft metal components (cam bearings, main bearings, big end bearings and alloy rockers) where it soon permanently embeds itself into the soft surface of the alloy and white-metal bearings, turning them into a very effective abrasive surface (the end is nigh).”


Even though most of the 50th Defenders are low mileage for their age; many are now coming up to this mileage range.

As a potential buyer; Prices range from (£15K to £30K) and some 50th Defenders being offered for sale by dealers at £25K will little information about engine maintenance; I wouldn’t like to part with this kind of money to find out that an expensive engine rebuild is around the corner.
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jimblowscash



Joined: 14 Dec 2010
Posts: 252
Location: kent

PostPosted: Thu Apr 14, 2016 10:27 am    Post subject: Reply with quote

I used to be the sales manager at piper cams.. if you have a V8 rover engine the chances are your cams worn, and if not the cam then it will be the followers.. however how worn they are will depend on a variety of factors from how you drive your defender to the quality of oil you have used. when the OE cam came out of mine i had done 74k and the defender ran well however on inspection almost all the followers were worn and 4 cam lobes were on the verge of disintegrating.
camshafts are typically made from cast iorn and then case hardened. The lobes themselves are ground to a suitable profile. Usually the case hardening goes to a depth of a couple of thou on the cam and will be a couple of rockwell harder than the follower material, the reason for this is the follower ( being a smaller cheaper and easier to replace component ) is designed to wear to the cam. After time the cam will wear the hardened material away and the softer metal is exposed, at this point the follower will start to strip material from the cam at a higher rate until the profile is significantly diminished.

DO NOT UNDERESTIMATE the difference a decent cam profile makes to the V8, it will totally transform the engine!


Regular servicing and decent oil will prolong the life of your cam & followers but if your knocking on the door of 70k miles + then I would strongly recommend you consider it.
_________________
im allways in the muck... its just the depth that differs..

ex owner GB165
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gilmore



Joined: 01 Feb 2012
Posts: 139

PostPosted: Tue Oct 29, 2019 11:14 am    Post subject: Reply with quote

This is interesting. Mines coming up to around the 74k miles mark and my mechanic has suggested that the engine feels a little down on power and could be the cam/timing chain wear.
Has anyone had these replaced? Costs? How much did it improve performance?
Thanks
Rob
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