Roger

Thanks Dan, that is my plan. I already bought a second dial gauge a week ago. Doesn't have to be an expensive one since the actual value does not have to be accurate as you mention. I removed the cylinder head not long ago, I really regret not checking this then. Learning the hard way as usual...

This forum topic is dedicated to all errors you might find in Triumph Workshop Manuals, or things they did not explain properly in the workshop manual (missing information). I put this under "Forum help and suggestions" since I could not find any better place for it. Admin, feel free to move it. First topic: Fig. 57 In the red GT6 Mk 1,2,3 & Vitesse 2-Litre manual (Part No 512947, ISBN 0 907073 90 5) on page 1.126. This drawing shows the camshaft lobe 1 & 2 looking at the engine from behind the car. Also, missing information: The point of balance shown in Fig 57 and Fig. 59 can be found at TDC for cylinder 1 on the end of exhaust stroke when the distributor rotor arm is pointing at cylinder 6. The reason for opening up clearance to 1 mm is that otherwise valve 1 & 2 would be slightly open at this point of balance, hence no clearance to be measured with standard 0,25 mm clearance. This was discussed in this thread:

I agree 100%! As Pete said "bit of Triumph daftizum". This is what Triumph engineers forgot to add in WSM on page 1.126 and 1.127: 1) Always turn engine and camshaft clock-wise (looking at engine from the front of the car) during the valve timing. 2) The point of balance is at TDC on the exhaust stroke. 3) The reason for opening up the clearance on rocker 1 & 2 to 1 mm is that these valves would otherwise be slightly open at the point of balance and there is no clearance to be measured. Hence, the balance / imbalance can not be measured with standard 0,25 mm clearance. 4) Drawing 57 on page 1.126 is incorrect. It shows the camshaft lobe 1 & 2 looking from behind the car. It's of course %&¤# obvious now after cranking the engine 500 turns observing lobes, debating here, looking at (incorrect) drawings etc, but sometimes the information in WSM can be really misleading. We should write a new edition and include all missing info and correct all errors! Might be a new topic for the forum.

None! The inlet valve opens way before the point of balance at exhaust TDC so there is no clearance to be measured. I would probably have to increase clearance from WSM 1 mm to 3 mm (or more) in order to be able to measure and define the difference which does not make sense. This is what made me so worried that I did something wrong. Happy new year everyone!

No worries, I learned a lot about valve timing when cranking my engine by hand looking at the lobes, and I'm quite sure that my valve timing is not correct. It will be interesting to start the engine after re-adjusting the valve timing and see if I have found my missing horses!

Thanks, I have to make one. The endoscope camera works fine as a "sanity check" to see if the mark is way out, but I will need one of those tools when I do the valve timing.

Unless you increase rocker clearance to 1 mm, then none of the lobes will operating the valves even if you turn the cam 180 degrees. I think this is the point that creates confusion!

Thank you Graham, this was vey helpful and correlates with my interpretion of the WSM. I had to go to the garage and test your statement above and for me it seems to be correct when turing my engine. The only thing that does not seems to be correct is the fact that my inlet seems to open too early when doing this.

Ok, on the picture below I Have turned the camshaft 180 degrees. So if the exhaust is just about to open here, and the inlet is just about to close: Which stroke has just been completed, and which stroke begins at this point? Where is the poston at this point of balance?

Well, to add some confusion: Drawing 57 seems to be incorrect on page 1.126 in WSM (Alternative, it is a drawing that shows the camshaft looking from behind the car). The pictures below shows the camshaft looking from the front of the car and the camshaft is here turned so that the point of balance is upwards. On the drawing it looks as lobe #1 (exhaust) is pointing to the left, but in reality it is lobe #2 (inlet) that points to the left. Hence, exhaust is about to be closed and inlet valve is about to open if the camshaft goes CW. Still not convinced.

I must be daft, but this do not make sense to me for two reasons: 1) You mention that exhaust valve is just beginning to open. That does not happen with piston at TDC. The exhaust valve opens when the piston is at the bottom (BDC, or actually just before BDC) so that the piston can push out exhaust gases on its way up. 2) The sequence of events does not make sense to me either. If the inlet has just been closed (inductions stroke just completed) then the piston is also at (or close at) BDC after just completing the induction stroke, and the piston has sucked petrol/air into the cylinder on its way down. The sequence of the strokes are induction-compression-power and exhaust, and I just cant see that happening in that order as you describe it. Maybe some champagne will make me see the light, this is confusing… Thanks for your patience Johny.

We interprete this drawing differently. To me it shows the position of the cam lobes (no 1 cylinder) when the exhaust is about to close and inlet is about to open. This happens at TDC at the end of exhaust stroke and the induction stroke begins. Not at TDC before power stroke (after compression).

Yes, but my thinking was that increasing the clearance to 1 mm will prevent (delay) them from opening / closing at TDC on the exhaust stroke hence a clearance can be measured also at this point. They should open close 18 degrees before / after TDC on this stroke, but the increased clearance delays this from happening? Uncle Pete? John? Anyone else who can elaborate on this subject?

I beg to differ Johny! No one really answered my question whether the 1 mm clearance should be measured at no 1 cylinder on TDC on the compression stroke or at TDC on end of the exhaust stroke. When the piston reach TDC on the compression stroke then both valves are closed both when the piston is going up, and also when the piston starts to descend on the power stroke. Hence, at this TDC I can rotate the crankshaft & camshaft +/- 10 degrees and I still have 1 mm rocker clearance on valve 1 & 2. At this TDC position the clearance do not show the position of the camshaft since I obviously can turn the camshaft many degrees in both directions without any change in clearance. However, when #1 cylinder is at TDC on the exhaust stroke then the camshaft reach the “point of balance” hence the clearance in mm can be converted to degrees on the camshaft and the position can be established. I’m daft at these things, first time I do it. I had to put a camshaft from another engine on top of the rockers, turn the engine and look at the lobes at both TDC to get the picture. So, please correct me if I’m wrong: The 1 mm rocker clearance should be measured when no 1 cylinder is at TDC at the end of the exhaust stroke (?)

Thank you John for your detailed explanation. I did check that TDC match the mark on the pulley by looking into the cylinder with an endoscope camera. I know the accuracy is very poor with this method, but the camera has quite high magnification and very small movements of the piston can be detected. It is not a perfect method, but at least is should give me an indication if the mark is completey wrong.

Short status report from The Åland Island after much engine turning 😊 I have adjusted rocker clearance to 1 mm for valve 1 & 2 when pushrods 11 & 12 are at their highest points by the book. After that I do have 1 mm clearance for both valve 1 & 2 when cylinder 1 is at TDC between the compression and power stroke. However, when #1 is at TDC between exhaust and inlet stroke I do NOT have 1 mm clearance for valve 1 & 2. In fact, inlet valve is partly open at this point. I’m confused, should it not be the other way around?! The inlet valve should open 18 degrees before TDC between exhaust and induction stroke, and exhaust valve should close 18 degres after TDC. I assume the extra clearance 1 mm is there to be able to detect that there are same number of degrees (18) before / after TDC but in mm instead. My gut feeling is that inlet valve opens way too early during exhaust stroke (hence carbs spitting petrol fumes) and severe loss of power. Brain trust, help me out here…

I have read the text in the WSM above many many times by now, and things that confuse me is that there are a lot of instructions to turn things, but no information in which direction. I just assume they mean to always turn both crankshaft and camshaft clock-wise looking at the engine from the front of the car (as the crankshaft rotates when the engine is running). Also, it would help if they would relate this point of balance to the engine strokes in writing, not only with Fig. 58. The point of balance is at TDC at the end of the exhaust stroke and when the induction stroke just begins. If I get it right...

No hight lift cam, but the head was slightly warped which has been corrected. I do not know how much material that had to be removed in order to get a flat surface. Should I be worried?

Someone should write a new edition of the WSM and clarify things and fill in all the missing information... Thanks Pete.

I should have mentioned this in my first post: I checked this with one of those fancy USB endoscope cameras you can put through the spark plug hole. The mark has not moved, it is at TDC.

My 2000 Mk I engine has a sever loss of power, and I'm trying to establish if the root cause could be that the camshaft is not properly aligned with the crankshaft so that the valves open and closes too early or too late. After all, the PO had installed the dizzy 180 degrees out, so he might as well made mistakes when he asembled the camshaft and chain. So far I have only done a quick and dirty check according to the “point of balance” method described in WSM. If I understand the instructions correctly then piston #1 should be at TDC when valves 1 & 2 are at the point of balance (one going up, one down). It is not at TDC, far from it. Either I’m doing something completely wrong, or my camshaft is indeed at least 3, 4 or more (!) teeth (tooth?) out. I wish I had checked this when I had the cylinder head off, it would have been so much easier and more accurate. Now my question. Before I remove the timing chain and start to correct this I would like to know if our six pot is a so called interference engine or not. Does anyone here know? I assume it is a non-interference engine, but it would be nice to know for sure before I start fiddling with the cam chain. I have invested in new valves and I would like to keep them stright and shiny. Thanks in advance /Roger.

Brilliant! That was exactly the information I was looking for. I have said it before and I say it again: The knowledge and support on this forum is excellent. Thank you Ed!

Frustrating! I found one issue of Practical Classics (November 2013) that covered the rebuild of a TR6 engine. I'm quite sure that they removed that lead blob in one of the issues in 2013 (it was a serie) but I can only find November 2013. I even spent 99p trying to get access to the archive of PDF versions, but no joy. So, those of you who collect magazines and have all issues 2013 can see what is behind that lead blob... Well well, I'm sure I can clean it properly anyway, I'm just curious! (and stubborn).

Definitely! I was so eager to get those studs off the block that I completely forgot that. I did not even notice that. I also have some spray that will prevent this thing from happening, I should at least have used that. Yes, as you mention it will be rebored so hopefully no damage done. If I can use the block, but it looks promising so far.

I have to find that issue of Practical Classic where they removed that thing. I remember that he used a hammer and it looked like "from factory" after he had replaced it