Ted RobinsonHi, Dave, when I said the number for a 1951 registered engine should be DPY53XX I was replying to efr215. I think he is probably correct that all postwar Shipleys were not fitted with a spacer. I would think that only the coil ignition ones had it fitted to allow room for the nice cover under the carb. all the best Ted.
Ted RobinsonHi, if your bike was registered in 1951 the engine number should be
DPY53–. best wishes Ted.
Ted RobinsonHi, I think all postwar Scotts had a spacer fitted, my 1949 has ,I don’t think the carb will fit without it. best wishes Ted
Ted RobinsonHi, I think all postwar Scotts had a spacer fitted, my 1949 has ,I don’t think the carb will fit without it. best wishes Ted
Ted Robinson@efr215 wrote:
These fittings are something of a bastard child. The only thing that these 7/16in. x 19tpi fittings really have to do with the BSP series is the 19tpi. pitch and that their function is to hold bits of tubing together! It is easy enough then to see why they all get lumped under the general heading of “plumbing”!
The 19tpi pitch, (1/4 & 3/8 BSP), is as far as I am aware unique to the BSP series. Certainly the 7/16in. O.D. has nothing to do with BSP based as it is on the bore of the pipe plus the wall thickness and thus none of the threads in the BSP family finish up with nice round numbers.
The real difference between BSP and these fittings is that the thread is not made on the pipe but on the parts fitted to the pipe. That shift coupled with thin walled solid drawn tube permits of much lighter section parts and that in turn requires different threads.
My guess is that what we have is an historical adaptation; companies making iron fittings would have had tooling to hand so when they branched out into the lighter, mostly nonferrous fittings, they made use of what they had. After all if you have a capstan set up for 19tpi threads why change it?
And if you have a spare moment over Christmas ponder on this: Small stuff is called tube, big stuff is called pipe. So then the question is at what point does a tube become a pipe?
If small stuff is called a tube why do we refer to petrol and oil pipes?
‘Appy Christmas all!
Ted RobinsonIf it is still a rigid rear end I would stick with the single sprung saddle.Much more comfortable.
Ted RobinsonA 1/4 inch is ample movement for the adjustment, if my memory is correct the chain is 69 links long including the spring link. there is nothing wrong having a Cranked link (or as you refer to a half link) in the chain so long as it is fitted correctly ie. no tightness on the plates. The weak point is the spring link,on some inferior ones the spring clip is a loose fit on the rivets and due to the movement will eventually fatigue. The use of cranked links is common practice in engineering, if you check a Renolds chain catalogue all manufacturers British and foreign have at least one or more models that use a cranked link.
Ted Robinson@Ted Robinson wrote:
1933 Scott Special on Ebay No.250297792249.
Silk Block and Pistons No.270278147775.
This seller also has other SILK spares for sale.
Pilgrim Pump Ebay No. 190253305383 also other Scott spares for sale.
Ted RobinsonHello Roger,
The order of assembly starting from the knob with the threaded spindle,
– star washer with the open ends of the star facing down, – the domed cup with the dome facing down, the steering head nut (1/58”long). Now the bottom end- plate welded to the bottom fork yoke with slot to locate tag on bottom plate – then the ferodo disc – then the steel plate fixed to frame stud by strap – then the bottom domed plate with threaded boss for spindle and tag to locate in fixed plate. I hope you can understand this,
Best wishes Ted.
Ted Robinson@Brian Rowe wrote:
Good day once again. As suggested I removed the head and barrel together to fascilitate removal of head to replace head gasket. Very simple operation to do that and I was singing the praises of Mr Scott.
However trying to drift off the head from barrel is proving to be quite a chore. Several applications of penetrating fluid and considerable amounts of heat via a rosebud have failed to dislodge it in the slightest. I had made a drift of hardwood slightly smaller than bore and with a 5 lb hammer failed miserably to achieve the slightest famount of movement. I am reluctant to use anything larger as am afraid of doing damage to the head, not sure how much force itcan take. It is at present immerssed completely in a penetrating solution.
A friend of mine who has a collection of Rolls- Royces mentioned how some of their models had aluminum heads and the same thing occurs at times with them. He mentioned a special type of metal drill bit that is hollow that is slid over the stud and material removed(including corrosion) down to the iron block. This is rather drastic I think and once again am asking for suggestions. Another friend suggested simply immersing it in water for a week or so. Another mentioned the electrical process of removing rust from steel and iron with a battery charger. I have done this with great success on small steel bits but not sure what it might do to the aluminum. I am assuming what is happening here is the electrolisis of the two dissimilar metals and the resultant corrosion.
Any further ideas or processes I should try. I would think it is a very common problem to the model. Also when re-assembling what precautions should be taken to prevent re-occurence.
Once again many thanks for the help provided on this forum. Might get her on the road this year yet.
Regards
Brian[/Hi,Brian, I think I would tackle the studs one at a time. After immersing in diesel I would screw a standard 5/16 BSF nut on the stud until it was just flush with the top, tack the stud to the nut with an arc welder then try and rock it back and forth with a suitable wrench. I think you would have more chance of breaking the bond than trying to release all sixteen plus the water pipes in one go. You could still use the studs if you wanted to by grinding off the weld or even skimming in a lathe.I dont know how long you would need to let it pickle in diesel I would not have the patience to leave it for three months I don’t think.
Ted RobinsonI am sure this has come up on the forum before but I have looked through all the posts to no avail. One method I remember was the welding rod on an industrial welder was replaced by a 5/16” diameter rod,it was applied to each stud in turn which heated up and expanded thus cracking the corrosion. I remember Jim Best had to cut a head off once and had to make new brass water tubes. When he refitted the head he enlarged the stud holes to give more clearance. I once made some new head studs and had them parkerised and they never corroded a process they used on shafts to prevent fretting. Unfortunately the factory where I spent most of my working life and was able to do this is now a large housing estate. Best wishes Ted.
Ted Robinson@dave bushell wrote:
Hi Brian
Very difficult with everything in situ. You could try heating the head with a small propane torch to break the corrosion bond between the studs and the head.
One trick that I employed many years ago, was to feed some window sash cord down the spark plug holes and out through the transfer ports (you will have to do one cylinder at a time), I then threaded each cord through a thick washer of suitable size, tied a knot so that the cord would not pull through the washer and pulled the washers up to under the plug holes. Tie the cords to a suitable bar above the head, and with the aid of a friend, you may be able to lift the head. If you are on your own, use a long bar, block it up at one end and lever up from the other end.
Be careful not to pull the bike off it’s stand!
Dave
Hi, Brian, If the head is just weeping a bit on the outside I would live with it, or seal it with a smear of LSX or silicone sealant it will probably seal itself when you have used the bike for a while. If it is leaking on the inside
obviously you will have to replace the gasket. I never remove the cylinder head just the barrels with the head attached.
Ted.
Ted Robinson@dave bushell wrote:
Hi Lewis.
I’ve always understood that the term Pigrim “Pump” is a mis-nomer, and it is in fact, no more than a metering device. The supply of oil still depends on crankcase depression to draw the oil into the engine. I may be wrong and no doubt some-one more knowlegible than I will put me right! So converting a pump to the pure dripper version should make no difference. The oil in the petrol is a “belt and braces” move.
Dave
Hi, Dave, A Pilgrim Pump is definately a Pump. I had a chat to David Brierley some years ago and he told me he had put a pressure gauge on one and if I remember correctly he got a reading of 30psi plus.
When I worked at the BTH in the 1950s we had large compressors fitted with Pilgrim Duplex Pumps, there was an oil feed that went to the top of the cylinder which I can remember breaking and it spewed oil all down the side in spits. The difference with a dripper you will get the same number of drips regardless of speed whereas with a pump it will be variable with engine speed. There is nothing wrong with a Pilgrim just the wrong application on a Scott running at engine speed.
Best wishes Ted.
Ted Robinson@eyeguy wrote:
that’s interesting Erik, I might have known that you’d be onto it! I wonder if it’s worth talking to Tony Haywood, I might give him a call, what sort of width do we have to play with?
ATG
Paul
Hi, Paul, I was always adjusting the primary chain on my 1949 scott and it was wearing them out about every thousand miles. It gets so hot in between the crankcase that the lube just got flung off. Then I started using Castrol Chain wax and have’nt had to touch it for over two thousand miles it stands high temperatures and stays on the chain. Best wishes Ted.
Ted RobinsonHi, Graham. new clutch plates are available from Ian Pearce.
Unit 5, Stanley Lane, Bridgenorth, Shropshire. Tel. 01746 762743.
Best wishes Ted.
