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MG MGB Technical - Cam follower wear
| My engine seems to eat cam followers (tappets). Its done over 120,000 miles. It used to chew up the old bottle shaped tappets. So I fitted a new Indian standard camshaft, which I have to say looked to be well made and of good quality. It appeared to be induction hardened rather than nitrided steel. At the same time I converted to the smaller A series followers and long push rods. I thought that these followers were common with A series and were suposed to have a small drilling to aid lubrication. Anyway the ones I bought didn't have the drilling but were phosphated and appeared to be chilled cast iron. Curously the phospate was cleaned off the bottom wear surface. Does antone know whether these parts are OEM quality. The engine has done just 5000 miles since the re-build and the valvegear became noisey again, so I checked the followers again to find that 3 of them, all exhausts had pitted again. I have just replaced them again, but with what appears to be the same type of follower. The wear initiated at the outside diameter which indicates that lubrication was the problem rater than contact stress. I hope That I have caught it before it damaged the cam. I'm sure that the inlet and exhaust cams are common at 252 deg period, so why only the problem on the exhaust valves. It also had a tendency to be worst at the front of the engine. |
| Paul Hollingworth |
| This has always been a problem with B series tappets. Using new cams helps because the lobes are larger and gentler on the tappet. There are several suppliers of these tappets ranging from £2 ones that don't last long to £4 ones supplied by Piper which are much better quality IMHO. All cams and tappets will benefit from the use of engine oil designed for use in diesel engines which have an additive package that protects them better. |
| Chris at Octarine Services |
| Chris, If you are talking about zddp as part of the additive package, I believe that it has now been removed from the diesel engine oils as well. That may not be true in the UK, but I understand that it is here in the States. The zddp can still be found in some specialty oils for classics, some competition oils, and some motorcycle oils. Charley |
| C R Huff |
| I run Castrol 4T which is designed for 4 cycle motorcycles which are hard on oil. It still has the zddp package as it is primarally designed for offroad use. The zddp has been removed from most oils because it clogs catalitic converters which manufacturers are required to warranty for 100,000 miles. RAY |
| RAY |
| Paul, New cams and followers must be bed in during the first initial run after their insatallation! If it was not done right, severe wear on loops and followers can occure soon. Just surf to piper cams and read about this process! Ralph |
| Ralph |
| Hi Ralph - couldn't find the page to which you refer at Piper Cams. Don't really know how you would run a cam and tappet in because the slower you run the worse the contact stress and lubrication (oil film thickness). I did soak the the tappets to ensure the phosphate obsorbed oil and I smothered everything when I reassembled. When you think about it what happens with a new engine or a recon - no special precautions are taken. The combination of chilled cast iron (phosphated) and hardened steel is the best from a tribological point of view. I will look into a ZDDP adative. |
| Paul Hollingworth |
| Ex Peter Burgess's site (saves me typing it all! Firing up an engine for the first time. • The battery / ies must be fully charged. • Fill the engine to the maximum mark with running in oil. • With the spark plugs removed, crank the engine until the oil light goes out or the pressure gauge reads at least half normal pressure. • Check the oil level and refill as necessary. • Fit the spark plugs. • Start the engine. • Hold the engine at 2000 rpm for 10-15 minutes to bed in the camshaft. • If you have a problem....switch the engine off, do not let the engine idle as this may damage the camshaft and followers( lifters). • After bedding in the camshaft, reset the tappets ( valve lash)...remember you need a hot clearance. • Set the ignition to the required setting. • Set the carburetion. • Check for oil and water leaks. • Check for loose nuts and bolts. |
| Chris at Octarine Services |
| Dear all, Please see the Q&A I've had with Texaco Havolene regarding oils aand their aditives. I haven't been able to find a contact at Duckhams to ask them the same question. Hello, I recently used your 20W/50 oil when I changed the oil in my 1971 MGB. I had previously been running on Duckhams Q20/50. I have been suffering from cam follower wear and have been told that this could be due to the lack of ZDDP additive in more modern oils. I notice that this particular grade of oil is no longer shown in your product line up. Could you please reassure me that this oils has adequate levels of additives to prevent the re occurrence of my wear problems. If not could you suggest a suitable additive that I could put in myself. Many thanks Paul Hollingworth Dear Paul, The product you are using, Havoline Motor Oil 20W-50, contains ZDDP and the levels present are typical for an engine oil based on older technology. The more modern oils to which you refer are the latest 'Low SAPS' engine oils, which are necessary for emission control (Diesel Particulate Filters-DPF's and Three Way Catalysts-TWC's) on the latest vehicles, these have alternative additive packages to provide lower Sulphated Ash, Phosphorous and Sulphur limits which enables the treatment devices to function correctly. A few of the more recent specialised engine oils can also have a slightly lower ZDDP content, but as mentioned this is not the case for Havoline Motor Oil 20W-50. Unfortunately, this particular grade has now been removed from the UK product slate as there has been falling demand for a number of years, hence its disappearance from the product line-up. If I were asked to recommend an oil for your particular vehicle it would have been the Havoline 20W-50. We do not recommend the use of oil additives as our engine oils are developed to provide adequate protection/performance and the addition of supplementary additives could possibly have a damaging effect. I trust this answers your queries, however if you need any further information just drop me a line. Best regards Andy. Andrew Moseley Technical Support Analyst Global Lubricants Chevron Limited |
| Paul Hollingworth |
| Since seeing Castrol XL 20W-50 on offer from the MGOC this month claiming better ZDDP than modern oils, and having seen the Americans banging on about this for a year or more I have just done some digging. If you look at the specifications on the containers amongst other things you will see an API spec followed by a series of letter, S* for petrol and C* for diesel. Most petrol engine oils these days are to API SL or SM. Our engines were originally designed when SB was in force, and produced through SC, SD and SE, with SF, SG, SH and SJ for more recent engines (there is no SI or SK). Up to and including SJ they were backwards compatible, i.e. earlier engines got the benefits of the later ratings from improved formulation (as long as you stuck to the original viscosity, the modern very low viscosity oils are *not* suitable for our engines but that is another bone of contention). But after SJ the environmentalists got the proportions of ZDDP, phosphorus and other additives reduced, partly for environmental reasons, and partly because they tend to poison the catalyst over time and reduce its life. Therefore you should stick to API SJ or earlier, but the later the better. Castrol XL 20W-50 is API SE so is suitable, as is Halfords Classic 20W-50. Castrol GTX 20W-50 is said to contain about half the original amount of ZDDP, but you don't seem to be able to get it in the UK anymore. Lower viscosities don't contain enough, Castrol GTX High Mileage 15W-40 is API SL for example. However because of the pressures in diesel engines particularly on the little-ends they have been allowed to keep the additives, as have 4-stroke motor-cycle oils as they are relatively high revving and have small sumps i.e. rapid recirculation and little time to cool down so greater stress on the oil in both cases. If you look at many oils they show both petrol and diesel API codes, for example Castrol XL 20W-50 is API SE/CC, which means they are suitable for both petrol and diesel engines of the appropriate eras. It doesn't always follow, Castrol Magnatec 15W-40 only specifies API SL, so isn't suitable for diesel engines. If you look at diesel engine oils you will see the same thing in many cases, although the diesel rating will be shown before the petrol in that case. The crux of the matter is that if you look at Halfords 15W-40 Enhanced Diesel Oil you will see it is rated 'API CF-4 CF SJ'. The 'SJ' is the important bit, it means it has the right amount of ZDDP for our engines. Yes, it says 'Diesel' on the tin but because it includes the SJ rating it means it is suitable. I'm sure there are others. No connection with MGOC, Castrol, Halfords etc. etc. except for being a paying member/customer. More info at http://www.mgb-stuff.org.uk/wn_engineframe.htm and click on 'Oils and ZDDP'. |
| Paul Hunt |
| Anyone tried comma classic oil its 20-50 se Mike |
| m j slater |
| The Havolene I have in now is SF where as the Duckhams I had in before was SH |
| Paul Hollingworth |
| Hello, For this year and may be the next, motorcycle oil 20w50 is still suitable. cheers, |
| Jean Guy Catford |
| Hi Paul As you know the cam lobes are splash fed on Bs and the max loading is at idle/low revs when horrible wear can set in. We always smear the cam and followers with a moly disulphide thick grease/paste such as graphogen, we use billet Piper cams and have only lost one B lobe prematurely on a race engine that had suspect initial break in procedure.We have lost 2 A series cams due to gearbox debris finding it's way betwixt cam and follower on FWD A series applications. Once bedded the oil used seems to make little difference.We have been using billet cams for over 10 years. One reason we find that people are getting 'premature' wear is when engines are left over winter with old oil or run up and not driven properly to warm the engine. The old oil and the hardly used luke warm oil harbour nasty acids which attack areas under pressure, prime areas of attack are cam followers/lobes and piston rings against bores. Peter |
| peter burgess |
| FWIW Comma is said to produce Halfords oils. Peter - I feel a discussion coming on about whether to change the oil in the autumn so the engine isn't left with old oil in it, spring to get rid of any nasties from limited 'garage running' over winter, or both. Personally I change mine in the spring, but then I do use them when conditions are suiitable in the winter as well. If I haven't been able to use them for a month or so I run them at a fast idle (wedge under the throttle pedal stop, not from the choke) for about 20 mins to get them thoroughly warm on the gauge. I can't really see the problem of leaving them with old oil over winter, they would have that oil if you were using them. Running them for very short periods *is* to be avoided I agree, and running them on the road in cold weather probably won't get them as hot as running them in the garage (exhaust vented outside of course). |
| Paul Hunt |
| Hi paul I cannot help but feel your 20 minutes is bad for your engine, it isn't enough time to thoroughly warm the oil and get rid of those nasty contaminants from cold start combustion. remember the engine only makes enough bhp to fast idle..not enough to heat it up properly, that is why we say to people who don't drive the cars over winter to change oil, put a little oil in bores, spin it over to get the pressure up then leave well alone and don't fire the engine up with the new oil until spring. The problem with old oil is that it is quite often acidic and the prolonged standstill time is when the acid attacks the rings, bores, cam and followers. Peter |
| peter burgess |
| Peter, it's not so much of a problem down here where I am as it doesn't get so cold in Winter you can't drive at all. But what is the proper way to drive the car to warm it up after letting the car sit for a while? I guess you want to let it rev to build up some heat? Thanks! Simon |
| Simon Jansen |
| Simon, Our winters here can commonly go down to -6C overnight, rarer extreme nights round -9C. Daytime anything from 2/3C up to 12/15, though the chill factor can take ambient temps well below those depending on winds. Uninsulated brick garage. I start with necessary choke, get it on the road as soon as possible - reducing choke as you are able - gentle running with gear changes as needed until temp is near normal. If left unrun for a period of days and/or temperature really cold I bring up oil pressure on the starter, set it to idle on the starting choke level, reducing that as is possible till temp starts to climb, then on the road as above. Seems to work for me. What is your temp range over there and your strategy? Regards Roger |
| Roger T |
| Hi Roger, Hi Simon You both seem to know what to do to look after the engines. You don't need to bring up the pressure before starting it unless it has been stored for a considerable time. Just start 'em and go and use 'em. The father of a close friend of mine worked on agricultural plant until he retired, always a problem was farmers who had purchased a new tractor and only used it to show friends how sweet it was and never worked the tractor....caused bore glaze and accompanying smoke. Remedied 9/10 by the addition of scouring cream into the bores, turn the motor over and then flush bores/engine, refill with good oil and away you go, or not. I know it isn't over winter problems but it has the same root cause, not using the engines. The opposite of the fire pump problems with Coventry Climax engines, no time to warm up, full bore instantly as the fire doesn't wait, very rapid wear and seizure too if the bore clearances hadn't been huge (from experience)! Peter |
| peter burgess |
| Peter - I can only say that the temp gauge is significantly higher when garage running than when winter driving. I put that down to there being no cold blast over the sump and crankcase, which gives a significant amount of surface cooling in addition to the radiator. In fact the radiator will be very hot when garage running, cool or only slightly warm immediately after driving. |
| Paul Hunt |
| Hi Paul What is needed is the time to burn off the crap from cold starts with good oil. Old oil will never be any good if it is acidic, no matter how hot it gets. B engines are dirty old things with lots of blow by etc etc. Peter |
| peter burgess |
| About Comma oil: I have used Comma Sonic 20w50 for some years now, no trouble so far. When they upgraded the oil to SL specification I asked and was informed that both the Zinc and Phosphorus content is 0.15%, which I believe to be well above the limit? Tore |
| Tore |
| I've seen claims for other oils as well that even though they are to SL and SM spec they contain the earlier levels of ZDDP. I don't see how that can be, surely the later specs require very little or no ZDDP, that being the point of them. |
| Paul Hunt |
| I have wondered about that too. But I believe there is a big difference between SL and SM specification? Tore |
| Tore |
| Here is a link with some discussion about the API service classes. http://www.le-international.com/uploads/documents/051_Current%20API-SAE%20Engine%20Oil%20Service.pdf Wayne |
| Wayne Pearson |
| That link works if copied and pasted but not clicked (for me anyway). The biggest difference between SL and SM is that the latter is low-friction for the most modern engines, giving lower consumption and CO2. There are warnings that SM oils may not be suitable for earlier engines, including even recent engines i.e. way more mdoern than ours. But it also says SL is suitable for earlier engines including those using SJ, even though many other sources say SL is *not* suitable for engines of our era that require ZDDP and SJ is the latest you should use. A very confusing subject all round. |
| Paul Hunt |
This thread was discussed between 16/02/2009 and 13/03/2009
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