Asciidv Posted November 22, 2012 Share Posted November 22, 2012 "Dave was not happy with the method of Tony’s manufacture of the Valve Guides"..... I have just been longing for someone to ask 'What did Tony do wrong'?!, but everyone has been polite enough not to ask. Were the outer diameters turned first and then the guides drilled and reamed rather than the other way round? Barry. Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted November 22, 2012 Share Posted November 22, 2012 "Dave was not happy with the method of Tony’s manufacture of the Valve Guides".....I have just been longing for someone to ask 'What did Tony do wrong'?!, but everyone has been polite enough not to ask. Were the outer diameters turned first and then the guides drilled and reamed rather than the other way round? Barry. You have it in one! I should have known better! Tony Quote Link to comment Share on other sites More sharing options...
Great War truck Posted November 23, 2012 Author Share Posted November 23, 2012 Started to replace the 3/8” diam shafts in the Cam Followers today – one of the originals is still sound leaving seven to replace. The first three completed successfully – but then found that the centre hole in the next Roller was well over 3/8” Diam at something like 13/32”. No sign of wear in it and it looks as if a Roller with a larger hole has been fitted at some time to the originally designed 3/8” fitting. This must be replaced as it would leave much too much play if it was re-fitted to a 3/8” shaft with that amount of slop. We do still have the eight Cam Followers from the other engine and provided that we can find a suitable one from those, we will substitute the Roller. Quote Link to comment Share on other sites More sharing options...
Redherring Posted November 24, 2012 Share Posted November 24, 2012 What effect would this 1/32 slop have on the operation of the valve? Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted November 24, 2012 Share Posted November 24, 2012 What effect would this 1/32 slop have on the operation of the valve? Others may want to comment more fully - but to me it means that it will not be possible to obtain a fixed and precise adjustment to the Cam Follower - and also, only one small part of the circumferance of the pin will be taking the "hit" each time the valve is opened and closed instead of the whole , causing more concentrated hammer blow on the pin - and thus excessive wear. Tony Quote Link to comment Share on other sites More sharing options...
Great War truck Posted November 24, 2012 Author Share Posted November 24, 2012 Our great friend and highly experienced motor engineer, Dave H called as arranged to make a trial cut on the well-corroded Exhaust Valve Seat to see if his Cutter would work on it and to see if Tony’s work on the Valve Guide was accurate enough for its designated purpose. And it was nothing but good news! The Valve Seat was wide enough for the Cutter to work on it very easily and it quickly left a re-cut seat which will only require the new valve to be lapped in later – we do not have the new valves yet – delivery promised for January. The diameter of the valve head must be checked when received as the new seat is in a “well” and we must ensure that the diameter of the well is large enough to take the valve. The first of this sequence of four pictures shows the seat before being re-cut. The second shows the Cutter in position, The third shows Dave (who is 80) eyeing up progress and the fourth showing the re-cut seat with the Cutter Guide still in position. With the quick and easy success in cutting the first seat, we decided to carry on with the remaining seven. The remaining three new Valve Guides previously made were pressed into the Blocks and re-cutting commenced. These two pictures show the first of the Inlet Valve seats – before and after. Corrosion here was not nearly so bad on this one and it proved to be an easy job. These two pictures show another Inlet Valve Seat being cut – with the Cutter in position. I have got plenty more to add tonight. I will just have to upload them in groups. Quote Link to comment Share on other sites More sharing options...
Great War truck Posted November 24, 2012 Author Share Posted November 24, 2012 These three pictures show two of the Exhaust Valve Seats and one Inlet Valve Seat after re-cutting. They are rather dirty in the pictures as they have been smeared with oil to stop rusting. These two pictures show the one Valve Seat which caused a problem. This is an Exhaust Valve Seat and there is extensive corrosion in about a third of the seat which the Cutter could not touch. The first of the two pictures show the Seat after some preliminary work on it, and the second shows it after some further cutting – but with extensive corrosion still apparent in the one segment. The corrosion is deep and Dave will return with Cutting Stones to try again to get under the corrosion. Three more pictures of Valve Seat after re-cutting – again smeared with oil. And to finish – two further pictures of the very poor valve seat which will have to be “stoned”! All in all, a successful day with far more accomplished than what was envisaged when we started, this morning. Dave will be back during the week to finish the job. We heard yesterday that the Cylinder Liners have been completed and will be with us this week. At last, things are starting to move! The Christmas Break is usually a good period of progress for us and a lot is planned for this time and I hope that we can make significant progress. Quote Link to comment Share on other sites More sharing options...
Redherring Posted November 24, 2012 Share Posted November 24, 2012 How smooth does the finish have to be after cutting? and is the cutter adjustable for angle or do you specify the angle when you order the valves? How do you measure the angle on the valve if you have to? Your challenges here are my challenges in the very near future! Cheers. Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted November 24, 2012 Share Posted November 24, 2012 How smooth does the finish have to be after cutting? andis the cutter adjustable for angle or do you specify the angle when you order the valves? How do you measure the angle on the valve if you have to? Having used the Neway cutters as seen here, in the past, I can tell you a bit about them. They make an excellent job and are for set angles. The engines we work on are mainly 30 and 45 degree valves, that means that the seats are cut one degree different, ie cutters are 31 and 46 degrees. The cutter as two angles, just turn it over for the other one, you will see this in the photos. The diameter of the cutter can be adjusted by releasing the locking screws and sliding the cutters out. Whatever you do, you must have unworn guides as the cutter cannot centralise on the seat. Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted November 24, 2012 Share Posted November 24, 2012 (edited) Really nothing to add to Richard's comprehensive reply - ours are 45 degrees! With previous engines, we have lapped in new valves to give the nice final smooth surface on the valve seat. When we recently ordered the new valves, we did send one of the old ones to the manufacturers so that they a pattern to work from. Tony Edited November 24, 2012 by Minesweeper Quote Link to comment Share on other sites More sharing options...
paul.norton Posted November 25, 2012 Share Posted November 25, 2012 Hi Tony Good to see Dave is still fettling Please give him my regards when he returns during the week. Keep up the good work. Paul Quote Link to comment Share on other sites More sharing options...
Great War truck Posted November 25, 2012 Author Share Posted November 25, 2012 These are the Cam Followers from the other engine – we were optimistic that we could salvage one Roller from one of these – with the right size hole in it! The remaining seven that we are working on from the other engine are all OK. However this was the best Roller from the other set of Cam Followers – you will see that it is corroded in one part and I guess we will have to make one. Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted November 25, 2012 Share Posted November 25, 2012 None suitable there - they are all heavily pitted - so an alternative is to "bush" the original one with the over-size hole in it! Tony Quote Link to comment Share on other sites More sharing options...
Great War truck Posted November 26, 2012 Author Share Posted November 26, 2012 We have opted to put a 3/8” internal diameter bronze bush in the Roller with the over-large hole in it. Quote Link to comment Share on other sites More sharing options...
Great War truck Posted November 27, 2012 Author Share Posted November 27, 2012 The Cylinder Liners have arrived – now just the new Valves to come! Quote Link to comment Share on other sites More sharing options...
Asciidv Posted November 27, 2012 Share Posted November 27, 2012 Did you consider boring the roller out further so you could fit a thicker wall bush? I know you consider the load on these parts to be negligible but on my Dennis the roller shaft pins have to be nitrided or they last no time at all. Barry. Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted November 27, 2012 Share Posted November 27, 2012 Did you consider boring the roller out further so you could fit a thicker wall bush? I know you consider the load on these parts to be negligible but on my Dennis the roller shaft pins have to be nitrided or they last no time at all. Barry. Well, you saw the state of the pins that I removed, and I certainly agree that they did show signs of heavy wear! The ones that I am putting in now are EN8 and i thought that they would be tough enough to do the job. We shall see on that one. I did not consider a thicker walled bush, and again I guess time will tell. Steve might want to have "two pennyworth" on this - but his computer is down at the moment. Tony Quote Link to comment Share on other sites More sharing options...
Great War truck Posted November 28, 2012 Author Share Posted November 28, 2012 David returned this morning with additional Valve Seat Cutters and stones and had another go at the two poor Exhaust Valve Seats. One in particular was very deeply pitted and he has had to cut as much as an 1/8” lower than the original valve face to establish a new good face.. All successful and we now have eight good faces. However, as he has had to cut so deeply, two of the faces at least are in “wells” so we must ensure that the diameter of the new valves when they are received are not greater than the diameter of the “wells” as obviously they will not be able to seat on the valve faces. Similarly, with the valves likely to be running lower down than before, there is a danger of the undersides of the valve faces if they are tapered – or mushroom shaped, then hitting the tops of the valve guides – so if there is any interference there, the tops of the valve guides will have to be lowered by cutting. This would have to be done in situ as the Guides cannot be removed for that purpose and then re-fitted as accuracy would be lost. Quote Link to comment Share on other sites More sharing options...
mtskull Posted November 29, 2012 Share Posted November 29, 2012 (edited) Presumably it is possible to cut or grind back a little of the material surrounding the valve seat in order to minimise the "well"? Looking closely at the last photo, I hate to say this but isn't that a crack in the valve seat, at about 11 O'Clock? Just in case that sounds a little negative, may I just say that I think you are doing magnificent work with this restoration and I very much enjoy following this thread. Edited November 29, 2012 by mtskull Quote Link to comment Share on other sites More sharing options...
TOM MODEL T Posted November 29, 2012 Share Posted November 29, 2012 Will it be too risky fitting a valve seat insert ? How much "meat" is there to play with? I fitted hardened inserts (custom made) in my 14 Ford T and used stainless valves. We were worried about cutting into the water jackets, but it worked out fine. The original in-situ seats were badly pitted, cracked, oversized and recessed. At least the valve heads now protrude slightly above the seats, minimising the risk of burnt valves. Quote Link to comment Share on other sites More sharing options...
Minesweeper Posted November 29, 2012 Share Posted November 29, 2012 Presumably it is possible to cut or grind back a little of the material surrounding the valve seat in order to minimise the "well"? Looking closely at the last photo, I hate to say this but isn't that a crack in the valve seat, at about 11 O'Clock? Just in case that sounds a little negative, may I just say that I think you are doing magnificent work with this restoration and I very much enjoy following this thread. Well, I hadn't spotted that - and I just have not been able to look at it again today - will go ouside in the morning to have another look! If it is a crack - then it is yet another challenge to take on - but I am quite sure that we will get there! We will keep you posted! Tony Quote Link to comment Share on other sites More sharing options...
Old Bill Posted November 30, 2012 Share Posted November 30, 2012 I'm down in Devon again with a chance to see what Father has been up to! I have had a look at the valve seat and I suspect that you are right and it is a crack. it is very fine so my current plan is to lap the valve in and leave it alone. What risks will we be running if we just ignore it? This lorry, like our others, will see very little use and I don't really want to risk major surgery to our fragile and irreplaceable block if we don't have to. Steve Quote Link to comment Share on other sites More sharing options...
8_10 Brass Cleaner Posted December 2, 2012 Share Posted December 2, 2012 I'm down in Devon again with a chance to see what Father has been up to! I have had a look at the valve seat and I suspect that you are right and it is a crack. it is very fine so my current plan is to lap the valve in and leave it alone. What risks will we be running if we just ignore it? This lorry, like our others, will see very little use and I don't really want to risk major surgery to our fragile and irreplaceable block if we don't have to. Steve Steve, you will not be risking anything, considering there are other cracks in the cylinder casting. Just fill the bugger with K seal and run it. Quote Link to comment Share on other sites More sharing options...
Old Bill Posted December 2, 2012 Share Posted December 2, 2012 Truly a man after my own heart! Thanks Hedd. I have been in Devon again to take the Dennis out for some friends. I think it has done 86 miles now. I took the opportunity to see what Father has been up to, keeping the ball rolling whilst I have been doing other things. With the valve caps finished, the cam followers coming on, cleaning and painting is nicely under control and various bits on order or in stock, we have set ourselves the target of getting the crank and camshafts fitted over Christmas. Something to shake that lunch down! Steve Quote Link to comment Share on other sites More sharing options...
Great War truck Posted December 3, 2012 Author Share Posted December 3, 2012 are now all finished and ready to fit! Quote Link to comment Share on other sites More sharing options...
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