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Post by enigmas on Feb 24, 2022 12:31:56 GMT
From what you stated David, I assume that the rocker shaft was rotated 180° to reorient the oil feed holes to the bottom of the shaft (or 6 o'clock position) from the top (12 o'clock.)
Shouldn't this have been the way the factory originally fitted the shaft...for obvious reasons?
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Post by djm16 on Feb 25, 2022 13:07:33 GMT
engine number: sorry car is locked up right now, but I know for a fact that the engine has the smaller sized crank journals (1963).
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Post by djm16 on Feb 25, 2022 13:13:45 GMT
Hi enigmas,
Yes I rotated the rocker shaft so that the lubrication holes were at 6 pm, which is where it would make sense for them to be, directly under the point of maximum load.
They started out at approximately 3:30, so needed rotating a little more than 90 degrees.
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Post by enigmas on Feb 25, 2022 13:36:54 GMT
Sounds like the Factory screwed up on the shaft oil feed orientation David.
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Post by djm16 on Mar 2, 2022 5:30:59 GMT
Sounds like the Factory screwed up on the shaft oil feed orientation David. I am relieved to hear you say it, because all three of my Rovers (6c IOE) are the same - P3, P4, P5. Weird or what. I would like to believe that the oily exhaust smoke is reduced, but it is not gone. After a prolonged coast downhill, killing the engine, and pulling the plugs, number 6 is wet with oil. The rest are mostly dry. So my choices now are: 1) wait and see 2) pull off the new oil seal on number 6 inlet valve guide and re-install with anaerobic sealant.
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Post by enigmas on Mar 2, 2022 10:16:04 GMT
You're a very patient man David.
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Post by djm16 on Mar 6, 2022 23:10:53 GMT
Minor update.
If you recall, I am getting oily smoke after a downhill run on closed throttle. Stopping the engine immediately and pulling all the plugs revealed a wet number 6 plug (despite having fitted a new valve guide oil seal).
I removed the rocker shaft (again) and removed all the seals and refitted them with a trace of anaerobic sealant. The result is mixed. I still get some oily smoke after a long downhill run on closed throttle. It is hard to say if this is less. However, when I pull the plugs, they are all dry, including number 6, and number 4 that I was not previously sure about.
That probably concludes as much as I am prepared to go into for a long while.
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Post by MK IA Norway Viking on Mar 7, 2022 8:56:52 GMT
Hello David,
It has been very interesting to see your various posts about the oil issue. Being a positive-minded person I would say it is great that five cylinders work as they should.
After all this work on the cylinder head, I should think the oil is being sucked up from the crankcase for there is tremendous vacuum inside the combustion chamber when you coast downhill with the ignition off.
It could be as simple as a minor uneavenness on the cylinder wall.
As you say, you've put in enough energy into this project and it's been worthwhile as you have both eliminated many culprits and you have made five cylinders operate as they should.
I've had an engine project too in that I have replaced the camshaft, both sets of rocker shafts, new camfollowers and new rockerbushes. I have been dogged with noise from the valves. I ran the engine yesterday and it's still noisy however I believe this can be reduced or eliminated after tuning the tappet clearance.
Kudos to you, and hoping the car will give you satisfaction for many years to come ! It's posts like yours that inspire the rest of us ...
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Post by 3litrekiwi on Mar 7, 2022 20:25:39 GMT
Hi David When you say you removed the seals and refitted them, does this mean the new seals are able to be removed without damaging them? The type I fitted are a tight fit to the valve guide that I think would make them a single fitting sort of thing. If mine were to be removed I would think they would need replacing. When I machined the guides, I aimed for a size of 0.5300" to 0.5305" as the bore of the seals was 0.530". This meant that they were a tap fit using an aluminium punch.
I expect the adhesive will eliminate any leakage but wonder whether the machine shop got the size a bit small.
cheers Martin
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Post by djm16 on Mar 8, 2022 22:44:01 GMT
Any residual smoke is going to be coming either up the bores or in the exhaust valve guides. I purposely did not replace the exhaust valve guides as they felt pretty good to me on checking. My P4 where I replaced the valve guides also smoked like this, but the exhaust valve guides were pretty sloppy in comparison.
You are likely right about the inlet valve stems being a little on the small side. Yes, the seals came off pretty easily with a copy of screwdrivers.
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Post by djm16 on Jul 26, 2022 1:40:41 GMT
The long silence has been in part due to frustration over the problem, but also being very busy playing music (car work wrecks my hands for music playing).
I have come to a plausible hypothesis for my oily smoke on over-run problem.
When I first removed the inlet valve guide seals, I noticed there was a collection of machining swarf under each seal. I laid the car up for a couple of months before looking further. This time, when I looked more carefully at the oiliest cyclinder (number 6), scoring of the visible end of the valve stem was both visible and palpable. The scored valve stem is probably what is leading to rapid deterioration of the seals.
I wasn't going to post this before as I had given the head to an acquaintance to do the inlet valve guide seals, but I have since learned that he farmed it out to a.n.other. So I feel less constrained in stating that an un-caring job was done. The cut surface of the valve guide was pretty ragged (blunt tool, cutting too fast, no lubricant etc) and as I already said, swarf left in the valve guide.
I have already ordered a set of new guides and valves, and have someone else that I trust to do the job (he has done good work for me before).
There is a moral to this tale somewhere, along the lines of giving work to someone you can look in the eye first.
I will update this post when (if) the smoking is gone after the guides and valves are done.
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Post by MK IA Norway Viking on Jul 26, 2022 16:08:24 GMT
Very interesting video - gives food for thought when the holes to lubricate the inlet rockers is not providing oil in the critical places AND to note that the rocker shaft is soft.
Where did you get those rocker shafts ?
I just replaced mine and have the ever-irritating noise from valve gear, without suspecting lack of lubrication. BUT, it could be an essential factor to my lasting problem.
Tappet noise improves when setting the tappet clearance - my car is at the garage now for repairing various damages to the paint so curing the engine noise will be a winter-project.
I have obtained a tool for rapid setting the tappet-clearance - the infamous Gunson Clik-adjust - which is said to be very handy for worn tappets (mine aren't, for I did a big overhaul last winter). I hope accurate setting of tappet clearance will help to cure the problem.
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Post by enigmas on Jul 26, 2022 22:53:50 GMT
Interesting post but I wonder at times how many of these types of repairs are self inflicted. Quality cylinder head repair work is generally best carried out by professional engine builders who specialize in this type of work exclusively, not generalist mechanics. I'm not trying to rain on any individial's desire to do it all themselves, but as in most professional fields, none of us have every skill set required to restore an engine or perhaps some other complex component to "better than new" factory standards. It's not just the specialised equipment required, but the years of practical experience/knowledge acquired by a truly skilled specialist in this field.
I have a friend, an engineer of advancing years, who specifically focuses on all types of cylinder head repair and refurbishment, from veteran to modern engines and to observe the precision of his skill set is truly a wonder.
Considering an engine's cylinder head is one of the primary components that can either enable or hamper an engine's reliabilty (from overall power output to general operational quality) then why allow anything that maybe substandard on your cherished classic.
As stated previously, I'm not trying to rain on anyone's parade or DIY aspirations, these are purely my personal views based on past experiences.
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Post by MK IA Norway Viking on Jul 27, 2022 6:57:46 GMT
Good morning, and good point which I share entirely. This engine has been sorted by a professional engineer of the old-school - meaning he is not the replace-components type of engineer. He did sort many things out, but not the irritating noise of one tappet. As his wife is sick with cancer, his current focus is not on my engine so to say ... but, the noise has been reduced with minor changes in setting tappet clearance.
I was intrigued with the video showing a part from what I perceive to be a reliable parts supplier did not provide adequate lubrication. Perhaps the same is the case with my engine... We shall live to find out :-)
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Post by Phil Nottingham on Jul 27, 2022 8:50:16 GMT
Have you checked all the roller tappets are truly round (even if brand new) as they do wear flats on the running faces or are not true to start with
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Post by enigmas on Jul 27, 2022 9:49:05 GMT
I'm acutely aware these days of potentially expensive screw-ups. During the 1970s, an engineer assembled a reconditioned engine of mine (a major expense at the time), obviously unfocused he fitted undersized crankshaft thrust bearings. Subsequently, after a short period of use they fell out and ruined both the crankshaft and block. Lesson learned.
Consider the many tasks in properly reconditioning a cylinder head. Some of which never get due attention. For example, refacing every rocker or tappet surface that comes in contact with a valve stem or lobe. A pitted rocker face will never adjust correctly or ride smoothly across the valve stem with correct geometry. But who ever bothers to check this? Similarly roller rockers or roller tappets don't last forever, so careful inspection is required.
Who bothers to check valve tip heights to ensure they're equal across the length of the cylinder head. Differing heights cause the geometry of the rocker action to vary. This varies valve lift cyl to cyl.
Belting valves guides in and out of cylinder heads (not always the best idea) causes distortion within the ID of the guide. Accurately honing or reaming a guide to size and knowing the required size takes expertise and skill.
Adding modern top hat seals (to end constant smoke trails) because O rings are a band aid that may last two minutes also requires both the tooling and skills.
None of this should obviate proper inspection of the camshaft and each lobe in particular.
As the 3 litre engines are an older IOE design, they seat the exhaust valve in the block. As with all SV engines, similarly, this positioning of an exhaust valve further heats the block causing cylinder wall distortion, this then compromises the piston's ring seal resulting in blow-by.
All of these parameters need to be taken into account and configured as best as possible when refurbishing both the cylinder head and the exhaust valves sited within the block of a 3 litre IOE engine.
So if the reconditioner's knowledge base is limited to OHV and OHC cylinder heads of modern engine design, I'd hazard there's reason for concern.
Once again, just my 2 cents worth.
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Post by MK IA Norway Viking on Jul 28, 2022 8:45:16 GMT
Good morning Phil, the camfollowers were all replaced and they were new and round and fine.
The cam was replaced too, albeit a used one it was in good condition.
Bearings etc. are also in good condition.
The rocker shafts both inlet and outlet were replaced as were the bushes, for play had developed.
I believe the tappet clearance is the key to smooth running, for when cold the engine runs well but hot it develops noise from one or two tappets.
It could be that there is lack of lubrication, as we've seen on a fellow members engine.
I have started to put lead replacement in the petrol and believe this has improved the noise issue.
Note I have switched to hardened seats and valves, which I got a very long time ago from the Rover parts supplier in Whiteheart Lane. Think it was Roverpart in South Croydon.
Of course, I have the DG automatic box and was amazed to see how friskier the other MK IA I have (with manual gearbox) is. Much improved accelleration and pull when overtaking. But, I suppose autoboxes of old did soak up a lot of the engine output so it will be wrong to say that my engine is weak. It is perfectly adequate for town-use.
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Post by MK IA Norway Viking on Jul 28, 2022 8:53:00 GMT
Excellent points - most engineers are content with replacing worn parts with new and assembling it all well together.
I believe the Gunton tappet clearance adjuster tool will compensate for uneven wear between each tappet when tuning.
That said, the points you mention with pitted rockers, lips and tolerances etc. were not likely to be measured.
I will ask the engineer when in the autumn after I get the car returned from repairs to the paint. I have great confidence in him, for he is old-school and have the proper attitude and clever touch to his work. Akin to "warm hands" in the "medical trade" :-)
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Post by enigmas on Jul 28, 2022 13:33:47 GMT
New "flat tappets" are not truly flat, they should have a slightly convex base (approx .003") The convex base causes the tappets to rotate on the camshaft lobes as the lobes have a fractionally high side when ground correctly. These 2 aspects of tappet and camshaft design ensure that the flat tappets rotate whilst running. If they don't rotate the camshaft lobe will slowly gouge a hollow into the base of the lifter.
If hardened valve seat inserts have been fitted, this should have been done to the engine block where the exhaust valves seat. There's no obvious need of specially hardened seats for the inlet valves, as these are effectively cooled by the wet incoming mixture and by heat transference to the alloy cylinder head. The exhaust valves live in an extremely hostile environment.
Just out of interest, what viscosity oil are you running in the engine?
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Post by MK IA Norway Viking on Jul 28, 2022 13:51:42 GMT
Good afternoon - the oil that I use is 20-50 mineral oil since I found the oil pressure to low at idle when using 10-40 or (even worse) 5-40 synthetic.
I fitted hardened seats (and valves) both to the cylinder head and to the engine block. They have been ground recently, to ensure a tight fit.
Interesting that you mention the rotation, for prior to the latest overhaul the noise I heard sounded as if something was turning in the sense that the noise was varying, giving me hte sensation that the valve was twisting - that cannot be, of course; I mention it to shed light on how my engine has been behaving.
I also suffered (until the lates overhaul) shaking/high vibration of the engine at low rpm and even shuddering despite all engine mounts (and gearbox mount) having intact rubber.
I think the shuddering came from poor firing at one of the spark plugs.
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Post by enigmas on Jul 29, 2022 8:51:35 GMT
The juddering and shaking could also be due to a suspect ignition system Norway Viking, * Is your ignition system based on points or an electronic module? * Are the high tension leads, solid core, carbon core or spiral core? * Have you bundled the ignition leads together? (Not a good idea as cross firing can occur) * Do you know how to check spark plugs for: high resistance or open circuit. * Similarly so for the high tension leads. * Is the distributor cap clean internally? If not, electrical tracking may occur causing cylinder misfires. * Is the Ignition coil wired correctly and not back to front?
PS. If you have a garage try the "Midnight Test" Do this test at night. Block out or turn off all the light sources in your garage. Start the engine then observe: * if any leads are glowing, or * if there is any shorting or visible sparking occuring at the coil or any high tension components. If any of the leads are glowing the insulation is suspect.
You just might be surprised what you find.
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Post by MK IA Norway Viking on Jul 29, 2022 9:17:25 GMT
Good morning, and thanks for the great support.
The juddering and shaking could also be due to a suspect ignition system Norway Viking - indeed it was, the distributor rotor had broken plastic, and did not sit properly on its base. I found at least one spark plug that did not get proper charge so the engine was running on 4 or 5 cylinders only, with weak pull up a steep hill. Now rectified BUT the valve train is noisy (one valve in particular) and the engine note is rougher than the two other 3 litre engines I have witnessed. The power is OK but not great, which I attribute to the DG box.
Another point I suspect is the ignition advance. I have not been able to test the mechanism for vacuum advance.
To your points:
* Yes, I have Lumenition for 6 cyl engine courtesy of JR Wadhams. This was fitted long time ago to eliminate / reduce number of weak points - Is your ignition system based on points or an electronic module?
* Not sure, these are leads that came from JR Wadhams and are fairly fresh - Are the high tension leads, solid core, carbon core or spiral core?
* Yes I have, as they run through the "distribution pipe" - Have you bundled the ignition leads together? (Not a good idea as cross firing can occur)
* No, these two categories of spark plugs is unknown to me. The spark plugs are new of quality brand; NGK probably - Do you know how to check spark plugs for: high resistance or open circuit.
* No, these two categories of HT leads is unknown to me - Similarly so for the high tension leads.
* Yes - the cap is clean - Is the distributor cap clean internally? If not, electrical tracking may occur causing cylinder misfires.
* I believe it is wired correctly, however will check this with my mechanic in September, when I hae the car back from the paint shop - Is the Ignition coil wired correctly and not back to front?
The "Midnight Test" is a splendid idea. I shall certainly do that test and observe what I find. I shall also observe the flow of oil from the rockers / rocker shaft to be certain that the valve train gets proper lubrication
Do this test at night. Block out or turn off all the light sources in your garage.
Start the engine then observe:
* if any leads are glowing, or
* if there is any shorting or visible sparking occuring at the coil or any high tension components.
If any of the leads are glowing the insulation is suspect.
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Post by 3litrekiwi on Sept 9, 2022 7:08:31 GMT
Slightly tangential to the way this thread has moved, I have done a bit more work on my replacement engine. I have been a bit distracted from Rovering over the past few months, replacing my mill with a better one and more recently replacing the 1990 Nissan ute with a much more recent Toyota.
Anyway, I had a piece of suitable steel so thought that since the lower rocker shafts on both of my spare engines were horribly worn I would make a couple of new ones from AISI4140 and have them nitrided so the surface would be really hard. This process is also good in that the steel doesn't need to be heated as much and there is no quenching so the longer one should stay straight.
Drilling the oil gallery was a bit daunting through the longer shaft at 350mm but went surprisingly well. Similarly turning such a long skinny shaft parallel, but the lathe was only 1 thou out from end to end so a bit of emery on a board polished that true.
The rocker bores were surprisingly good which is really the point of this post. Once I had polished the shafts it is remarkable how the bronze rocker bore has taken the surface off with just a few semi dry passes up ànd down the steel which is about 32HRC in hardness as supplied. The hardness will pretty much double after nitriding.
It seems to me that the bronze has absorbed hard carbon particles from the oil over the years and is almost like a lapping surface. I fear that in the long run even a really hard steel shaft is going to wear with these rockers but any others will likely be the same. Fortunately the car is unlikely to do high mileage with this engine. I suppose if one were really keen, boring and bushing might be a solution but it would be a lot of extra work especially when the white metal under the rollers seems to be a temporary thing.
I have already resurfaced all 12 rollers, using the best of five sets. The case on these seems quite thick and once dressed, the diameter is a match to the rocker that it has worn to. The cam on my most worn engine had nice grooves on the lobes matching the rollers. The cam I intend using has no visible damage.
Once again, interested in any thoughts.
Martin
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Post by enigmas on Sept 9, 2022 10:22:16 GMT
Your a legend Martin. 👍 All kudos to you and your engineering skills. Why not bush those rockers though with fresh material and not have them chew into your hard won/fabricated rocker shaft.
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Post by 3litrekiwi on Sept 9, 2022 20:47:14 GMT
Thanks Vince, I probably will bore the rockers, it would be good if there are some suitable off the shelf bushes. The size is 0.592" or 15.04mm id so there might be a metric option out there. A 19/32 bore would be too loose at 0.594". It should be possible to make a fixture to hold the rockers. If my theory is correct re the carbon, it really demonstrates the value of a good quality oil filter.
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