Hamish Posted January 7, 2018 Report Share Posted January 7, 2018 Roger well done for getting this far and what looks like the rhythm section of your in engine steel band. Very disappointing to find that damage after only 2 years. I hope your new parts fit and work. ???? H Quote Link to post Share on other sites
Paul J Posted January 7, 2018 Report Share Posted January 7, 2018 They look impressive Roger, whats the reasoning behind that after 20000 miles, other lobs look really good. Perhaps the manufacturer should be made aware. Paul Quote Link to post Share on other sites
RogerH Posted January 7, 2018 Author Report Share Posted January 7, 2018 Hi Paul, don't know who the manufacturer is. I'll mention it to the shop. It is a bog standard cam so quality was probably bottom of the list when being made. Roger Quote Link to post Share on other sites
Lebro Posted January 7, 2018 Report Share Posted January 7, 2018 Hi Folks Looking at the present wear/damage you would think that the rocker gaps were moving (getting bigger with wear) BUT they were not. Could it be that the damage on the cam lobe is after the max lift position !! daft idea. Roger The wear is at the top of the lobe, when the valve is being pushed down. Only get rocker clearance off the lobe , where it was not worn. Bob. Quote Link to post Share on other sites
RogerH Posted January 7, 2018 Author Report Share Posted January 7, 2018 Hi Bob, spot on. What was I thinking of - panic setting. Roger Quote Link to post Share on other sites
Nigel C Posted January 7, 2018 Report Share Posted January 7, 2018 so I guess a simple dial gauge set up would have "raised" the difference in 1=2 and the rest after a full rotation/lift....... Quote Link to post Share on other sites
graeme Posted January 7, 2018 Report Share Posted January 7, 2018 Hi Roger, The damage is very similar to what I witnessed with my engine, however, the bad news for you, I didn't have any 'musical' indication of the damage! Cheers Graeme Quote Link to post Share on other sites
john.r.davies Posted January 7, 2018 Report Share Posted January 7, 2018 Ouch! Painful! No.2 looks the worse, almost as if it has beem hammered out of shape, not just worn. John Quote Link to post Share on other sites
RogerH Posted January 7, 2018 Author Report Share Posted January 7, 2018 Hi Graeme, I am hoping all the problems/issues are in the cam/followers. That is where the noise was coming from. So tomorrow - clean/tidy everything in and around the front of the engine. Re-assemble as much as possible. Set the timing. Probably will not get it all together tomorrow - but hey, I have the whole year to play with. Roger Quote Link to post Share on other sites
iain Posted January 7, 2018 Report Share Posted January 7, 2018 (edited) Hi Roger. I think you have had the same problem I reported a year ago. http://www.tr-register.co.uk/forums/index.php?/topic/60277-tappet-noise-or-is-it-a-cam-follower-issue/?hl=follower When hot the followers are sticking in the guide. The result being the follower loses contact with the cam. . The lobe then comes round again and wack you have your musical Tympany. After my initial debacle.....i was told to soak the new followers in meths for 24 hrs. Clean thoroughly and then hand finish each one with wet and dry to each guide. Ensure each will rotate and drop on to the cam lobe with no resistance. They will have to be numbered 1...8 and fitted accordingly. Then use your cam lube of choice and reassemble. Hope this helps Iain Edited January 7, 2018 by iain Quote Link to post Share on other sites
RogerH Posted January 7, 2018 Author Report Share Posted January 7, 2018 Hi Iain, Your observations and John comment about hammer appear to be at one with each other. The followers do not appear to be tight but that is at cold. perhaps a little heat cause some tightness. I'll attempt your cleaning process. Roger Quote Link to post Share on other sites
iain Posted January 7, 2018 Report Share Posted January 7, 2018 Roger On first install the followers were I thought ok....... they weren't,that drop test and free rotation is critical. My engine was quiet on start up......noisy as per the videos in the thread when hot. When sorted it's normal for a TR with 0.018/0.016" clearances. Good luck Iain Quote Link to post Share on other sites
RogerH Posted January 7, 2018 Author Report Share Posted January 7, 2018 Hi Iain, thanks for that. Tomorrow I shall Mic up the old followers ti see if the front pair are bigger than the others. Then I shall Mic up the new followers and see if there is a difference. Roger Quote Link to post Share on other sites
Lebro Posted January 8, 2018 Report Share Posted January 8, 2018 Some random thoughts: Given that we set a clearance between rockers & valves, unless the followers drop down to the cam instantly as the lobe retreats, (under gravity only) then there will always be a hammering effect. The oil feed to the rockers, and therefore to the push rods & followers comes from the rear of the shaft, so the front followers may get less oil poured into them from above. Bob. Quote Link to post Share on other sites
RogerH Posted January 8, 2018 Author Report Share Posted January 8, 2018 (edited) Hi Bob, good thoughts. The followers firstly are pushed down along the lobe trailing edge. It is only the last 0.010" where it may hang. With the very hot/thin oil and its momentum to follower should end up sitting on the back face of the cam oil film. If it gets tight the the last 0.010" travel may not happen. This gap would produce hammer blow on the leading slope of the lobe (I think) I have serious wear on the lobe tip. I'm not 100% sure that the followers are/were to blame but the cam may have had a bad profile on #1 & 2 lobes (it is only a cheap tatty cam) as it was tapping from day one hot or cold. Iain had done a lot of strip down and head scratching to get where he did. I will heed his advice. I did consider the oil feed but on strip down my first port of call was the rocker arm bushes. These are in very good condition as is the shaft. The cam lobe gets most of its lubrication from below. So the top end oil feed should not kill the cam. Today I will be cleaning up all the gasket faces, doing a visual/boroscope inspection of the cam bearings (they should never wear out), getting some spares and then start the leap into rebuild land. Roger Edited January 8, 2018 by RogerH Quote Link to post Share on other sites
RogerH Posted January 8, 2018 Author Report Share Posted January 8, 2018 Hi Folks, just measured the old and new followers The max diameter for the followers is 0.9371. All the old ones are round about 0.9369 The new expensive followers have 6 at 0.9369 with 2 in excess at 0.9375 The two very bad old ones were on the small side, so I don't think the were jamming. So, back to the shop for a discussion. Roger Quote Link to post Share on other sites
Nigel C Posted January 8, 2018 Report Share Posted January 8, 2018 interestingly when I got my black coated ones from source there was no mention of cleaning and polishing and there was no packaging or printed guidance .......... Quote Link to post Share on other sites
ChrisR-4A Posted January 8, 2018 Report Share Posted January 8, 2018 Just checked the info on my engine rebuild in 2011 and against cam followers it says Phosphated and drilled. I think the drilled had something to do with oil drainage and promoting rotation.? We're yours drilled Roger Chris Quote Link to post Share on other sites
RogerH Posted January 8, 2018 Author Report Share Posted January 8, 2018 Hi Chris, mine are phosphated (black/dark matte surface) and drilled. The drill hole allows oil to run down onto the cam lobe when it is not running. Mine are also lightened. Not sure if this is a good thing as this may allow the follower to go out of round at the open end. !!! However they Mic' up pretty concentric so far. Roger Quote Link to post Share on other sites
ChrisR-4A Posted January 8, 2018 Report Share Posted January 8, 2018 In that case Roger my money's on a dodgy camshaft. I'm asking because I have no idea but at this stage is it possible to check the hardness of the cam on unworn areas. Chris Quote Link to post Share on other sites
RogerH Posted January 8, 2018 Author Report Share Posted January 8, 2018 Hi Chris, I can do a crude hardness test (file and edge etc). I'm coming to the conclusion that the cam was dodgy from the start as there was metallic tapping sound from day one. Roger Quote Link to post Share on other sites
iain Posted January 9, 2018 Report Share Posted January 9, 2018 (edited) Roger have the followers got gall marks on their sides? Mine had and they some very obviously had stopped rotating. The wear pattern on the can follower head is also a give away....an oblong pattern indicates a constant patch in contact with the cam lobe. ie no rotation. Healthy rotation leaves the cam follower head with radial lines almost like a section through a tree....not the growth rings but the radial lines, centre to outside edge. Probably teaching you to suck eggs but worth a mention. Number 5 has the oblong witness mark, clearly not rotating and No4 shows what happens when the follower is not rotating, can not follow the cam, due to sticking and is repeatedly hit! Iain Edited January 9, 2018 by iain Quote Link to post Share on other sites
RogerH Posted January 9, 2018 Author Report Share Posted January 9, 2018 Hi Iain, all my followers have wear patterns on the sides but no sign of seizing/sticking. The flat end does not show the rectangle pattern like yours. Although a couple can not be recognised due to the serious wear. The wear shows it being all over the face. I have had a look down the follower bores in the block and they are mark free and clean Roger Quote Link to post Share on other sites
iain Posted January 9, 2018 Report Share Posted January 9, 2018 Hi Roger I know we discussed this a year ago and your engine was slightly musical then. Perhaps you have just driven through the period of galling and sticking and knocked the lobes off the cam? Anyway whats done is done.....new cam and followers time. Good luck with this one Iain Quote Link to post Share on other sites
Paul J Posted January 9, 2018 Report Share Posted January 9, 2018 Roger if you had an original follower at hand it maybe worthwhile warming both an original and one that you have just removed to engine temp then measure the diameter of both, it would prove if the expansion rates are the same and the integrity of the material used. Just a thought. Paul Quote Link to post Share on other sites
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