Slow Monster rebuild

[350TSS]

Today brings news of fresh disasters (meaning more work /time to completion).

First I made up two 6mm aluminium spacers to replace the 6mm plywood fitting in the cartridge gun. The pressure required to force the two part epoxy into the mixing nozzle was causing the plywood to bend/split. I used two x 100mm x 6mm coach bolts to act as the pistons threaded into some hole saw “washers” left over from some lightening holes.

Next I checked the solidity of the lower front mount which were left to cure overnight, both sides were secure but the second side I glued yesterday still had a globules of unset resin which I cleaned up as best as I could without removing the fly-screen. I did not want to disturb the position and jeopardise alignment of the top mount.

Then I set about glue-ing the top fly-screen mount in position. To ensure the maximum contact area between the inside of the screen and the steel bracket I had to move it forward which involved quite a lot of buggering about with spacers, trying different thicknesses and different length bolts, bolting them on and readjusting etc., etc. Eventually I worked out the best position which was 35mm forward of the instrument surround. The intention is to use 15mm x 15mm x 5mm male/female vibration mounts so I needed to make up some 19mm thick spacers.
I got about half way through forcing the glue between the steel and the CF when it was obvious that I had the same problem I had yesterday. The resin comprises a white element and a black one, the white is more viscous than the black, evidently the pressure was forcing the white resin past the plunger seal and only the black stuff was going down the nozzle. Also I have no idea how much properly mixed “good stuff” got deposited before the issue arose. What I do know is that the less viscous black stuff started dribbling onto the headlamp shell below. When I tried to wipe it off it took the paint off and not just the top coat either, so now the headlamp shell will have to be rubbed down and re-painted.

All I can do is hope that enough good stuff got deposited to secure the top bracket in place so that I can take the fly-screen off and apply a couple of laminations of CF over and around the bracket without it moving position.

Other issues are that with the rake of the screen I have got, the lower edges of the fly-screen will have to be cut to clear the fork legs and the pivoting bracket for the regulator rectifier which will be mounted on a bearing from the top yoke centre nut underneath the bottom yoke.

On a positive note I knocked up the required spacers from 7/8” aluminium bar machined down to 15.5mm, through drilled 4mm and tapped 5mm and then the circumference wasted to lighten them.



Also I think that the front mount and the top mount together will be strong enough without the need for the tubular steel one already made (but needing to be cut to length and the side plates brazed on at an angle). If so then no visible external fixings on the fly-screen

[350TSS]

Today I finally got round to fixing the holding brackets into the fly-screen. After the second failure of the special epoxy I went for enough JB Weld to hold the top bracket in place. It sets firmly after about 10 minutes and really hard after about 8 hours. To be sure I left it bolted in position for a day and then epoxied it in place using shredded glass mat as the CF mat just was not flexible enough to conform to the contours of the inside of the fly-screen and the angular edges of the brackets. I
I will leave this overnight now.

I am now reaching the stage where I am not sure what to do next, options are
1. continue with the bodywork, finish the seat upholstery and then prime base coat, colour and lacquer all that needs to be painted –
pros
a) gets it done (circa 50 hours off the ETTC) and then it can be put somewhere safe until needed for final assembly
b) having some major bits in colour would give a sense of achievement and encouragement for completion
cons
a) it is very cold in the garage so far from ideal painting conditions
b) setting up the spray tent in the garage will take over completely.

2. start work on the engine, heads off, check barrels/pistons/rings, replace cylinder head studs, lap valves and set clearances and fit new valve collets and valve stem seals, reassemble.

Pros
a) probably the most interesting/challenging bit for me as I have not worked on a Ducati engine before
b) gets rid of a lot of boxes of bits which are cluttering up the floor space and once done the frame can be re-united with the engine, forks in, wheels on so lots more (knock on) space quite quickly
c) there are still a number of interface issues that will require that the bodywork parts are fitted so I can check brake pipe runs, clutch pipe runs, loom routes particularly around the headstock and if these parts are painted there is always the possibility of damage, if I leave the final finishing until later, any accidental damage issues can be repaired/resolved before the paint goes on.
Cons
a) whilst I had a couple of days tidying up the garage a few weeks ago, quite a bit of cutting and rubbing down has been done since so I would need another couple of days getting the environment dust free
b) means the total number of partially completed jobs will double which I find frustrating.

Having written the above down decision is now taken – get on with the engine.

The first task was to replace the double fluorescent that caught fire a few weeks ago with a double LED which is brilliant. Before replacing the expired double I had 7 x 6’ fluorescents in the garage a mixture of 4 singles and 3 doubles (10 tubes) of which 1.5 doubles and 1 single did not work (40%). The single LED gives off so much light I might get away with replacing the 10 tubes with 4 or 5 LEDs with a much brighter and clearer light. Aside from the price (£50 each) the only downside is that when I installed all the fluorescents (second hand ones) I used plastic tubular conduit and if I say so myself did a pretty neat job of it. The fluorescents all have central cable entry whereas the LEDs are end connected so either I re-do all the conduit (means emptying the garage and spending a day or so re-doing the conduit) or I bodge it and leave the old luminaires frames as ornaments on the ceiling and have a 3 foot flying lead to the new LED.

Ornaments it is then.

[Luddite]

Originally Posted by 350TSS

The fluorescents all have central cable entry whereas the LEDs are end connected so either I re-do all the conduit (means emptying the garage and spending a day or so re-doing the conduit) or I bodge it and leave the old luminaires frames as ornaments on the ceiling and have a 3 foot flying lead to the new LED.

Ornaments it is then.

I don't know if you're aware that you can get LED tubes that are direct replacements for the old fluorescent ones and use the existing frames.

I swapped my old tubes for these and, like you, was surprised by how much brighter and lighter the illumination was. No flickering or buzzing and they light up instantly when you flick the switch, unlike the old fluorescents.

https://www.amazon.co.uk/gp/aw/d/B01N9F2AI7

[350TSS]

Thanks, I wasn't aware but if the LEDs use the tubes' twist and turn installation connection then I would not be interested as in my view that is half the reliability problem with a fluorescent. Anyway I bought the complete LEDs now as they were 15% off if you bought 3+ from Screwfix.

[350TSS]

Five LEDs installed in the garage today, 30,000 lumens in a space c 9m x 7m, much better than daylight when the switch is flicked.

From now on, no excuses are acceptable for mismeasurement, wrong position centre- punching or mis-reading the vernier caliper / micrometer.

It was actually a long hard day, standing all day and moving stuff to balance on the narrow rickety stool and fiddling with stripping wires and block connectors at the most awkward height (about 300mm above my head) mostly with no light and a hand held torch, whilst at the same time trying to keep the wires connected whilst screwing them tight to the connector blocks.

Not my finest hour in terms of neatness of installation, but it works. One day, when I have finished all the projects in the garage, I will go back and do it properly with repositioned conduit and I shall get rid of all the old luminaires which are now acting as over-blown connection blocks.

One day????

[350TSS]

Having vacuumed most every surface in the garage, I decided it was time to start on the engine, first the tape protecting the open alternator and clutch sides of the crankcase was removed, easier said than done. The masking tape glue had set like concrete in the time since the engine was painted.
Some while ago I bought a Laser (I think) cylinder head spanner and this was the opportunity to give it a try. Frankly it is not up to the job, the torque required to crack the cylinder head nuts caused the U section to twist. Fortunately I also had a 15mm crows foot spanner which did the job fine.

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I will do one head at a time as I could get in a right bugger’s muddle with shims etc.
This is what I saw when I took the vertical cylinder head off, piston remarkably clean top surface, heavily coked valve heads, some surface corrosion encroaching onto the milled surface, unlikely to have caused any pressure leak.





The engine has done about 25k miles and the bore looks nicely run in, some light polishing where the top ring stops and turns around, no ridges or longitudinal scoring or damage whatsoever. I was well pleased with that.
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The cylinder head studs are stainless and I was planning to replace them but using the two nuts locked together technique I tried to unscrew them but there was more danger of me breaking them than unscrewing them so I think I shall just leave them be. Given the condition of the bore and the remarkably little play on the top of the piston I do not think I will bother lifting this barrel as it will only lead to a possibility of broken rings when I put it back.

I cleaned the piston top surface of the carbon residue with a Scotchbrite pad but did not get time to have a go at the cylinder head itself.

[350TSS]

As I will be lapping the valves in and using some fancy American square section closer valve shim retainers all the valve clearances and the required shims will change when I come to re-assemble the head, nevertheless I thought before I disassembled it I ought to measure the valve clearances (and everything else that I have the equipment to measure) as it last ran.
As I disassembled it I was struck by what a clever design the head, camshaft and valve adjustment really is. I suspect doing valve adjustment on the bike would be an absolute pain and the thought of the valve dropping or the little wire clips dropping into the cam box would be a night mare. With the heads off and on the bench it is not difficult. All you need is a micrometer, a decent set of feeler gauges and a prong to hook the spring out with and a magnet to catch the valve retaining clips
Both the valve opener clearances were in tolerance (one bang in the middle and the other towards the upper limit) but both the closer clearances were much too large, (about the same as the opener clearances). Because of this, I was expecting the exhaust valves to show some sign of burned seats or pocked valves where they are supposed to touch the seat.
I was pleasantly surprised to find both inlet and exhaust in very good condition, very minor pocking, the valve stems were also bang on tolerance.
Not willing to take the barrel off so my measurement of piston clearance was only from the crown to the top piston ring and the gap was right at the close end of the tolerance in the Haynes manual (so virtually no wear).
The only component showing wear that I should probably do something about is the sleeve that runs inside the camshaft oil seal which has a discernible indentation where the lip of the seal runs. Easy I thought turn it round so the seal runs on a different part of the sleeve, but it only fits one way over the taper that holds the drive pulley. I will buy a new seal and when I replace it I shall put a o.5mm shim behind the seal so it moves the wear position to a new location on the sleeve.
Today was spent decarbonising the valves and the head and while I was at it I polished the exhaust port as best as I was able. I wanted to lap the valves in and start the process of getting the right shims in place. About 50 years ago I bought some valve grinding paste to lap the valves in on my 1948 G80 Matchless when I converted it to an aluminium head. I have used it maybe 10 times since and I have moved maybe 6 times and that pot has been faithfully transported to each new location. I know I have seen it where I live now but I could not find it. So that stumped further progress.

[Dukedesmo]

Originally Posted by 350TSS

Given the condition of the bore and the remarkably little play on the top of the piston I do not think I will bother lifting this barrel as it will only lead to a possibility of broken rings when I put it back.

Maybe but having released the clamping pressure on them, I'd be concerned about the possibility of oil leaks from the feed holes in the base of the cylinders (rear cylinder has an 'O' ring the front just the metal gasket).

It'd be a bit of an arse if you put it all back together only to have to open it again to sort it out...

[350TSS]

Good point - bugger

[350TSS]

I was only able to steal about 4 hours in the garage today, it was definitely a learning experience.
First, I ground in both valves (vertical cylinder head) with fine grinding paste. I managed to get a nice fine grey continuous ring on both the seat and the valve head less than 1mm wide, all pock marks eliminated. Then, I reduced the valve head diameter to not more than 0.35mm above the outside diameter of the light grey ring formed during the valve grinding. This probably reduced the valve head outside diameter by about 0.5mm and thus effectively increases the size of the port by reducing the restriction caused by the size of the valve head. It works across the entire rev range. Maybe only a single brake horse power or two but worth doing nevertheless as it costs nothing and is simply about efficiency of an existing design. This took about 45 minutes with lots of care taken to remove any valve grinding paste and carbon detritus from the de-coke from anything and everything that was going inside the engine. (3 applications of brake cleaner and about 10 minutes wiping everything down with paper towels)
The next job was to fit new oil control seals to the top of the valve guides. I compared the old fitted ones with the new ones supplied by Moto Rapido (and a set included in a gasket set supplied by Athena).
The old ones were definitely “latched” onto a groove at the base of the protruding valve guide in the cam box above the combustion chamber. All the new ones were about 0.025mm smaller in diameter where the groove was supposed to fit. The space for fitting these valve seals is extremely limited as the valve closing fork limits(read precludes) access to the inner side of the valve stem.
First, I tried to get the seal to seat with the valve not in situ, but when I did get it to seat (I think) and I pushed the valve into the guide it simply removed the stem seal. - Bugger!!!

[350TSS]

I then put the valve into the guide and pushed it into the completely closed position. I tried inserting an electrical screwdriver between the valve stem and the seal edge and then rotating the screwdriver (much like fitting a tyre) but with only about 120 degrees available to turn the screwdriver blade it never “caught” and never flopped into the groove. Eventually I had to resort to using the blade as a “snow plough” to force the outer edge downwards and to engage with the groove in the valve guide stem. The green seal on the inlet seems thinner and I managed to pierce the first one with the blade of the screwdriver, fortunately I had the gasket set additional spares.
I did the exhaust first, (the black seal) and after about an hour got it to seat properly.
The next job was to set the exhaust valve clearances.
First, I fitted the original opening and closing shims (valves had been ground which would have meant the stem was deeper in the cam box, whilst the fancy USA valve collets would in all probability move the top of the valve stem away from the cam box).
A long while ago I bought a complete set of valve shims in 0.10mm increments (0.039” in real money). With the old shims in place and the valves installed the valves clearances were in both cases exactly between the ideal setting and the next upper or lower size shim – double bugger!!!
Setting the opening shim was easy, with the retaining spring clip out of the way, the rocker could be pushed to one side, the camshaft jiggled to get the closed position and different size caps could be inserted and measured in a matter of seconds.
The closing shim was an entirely different matter, there are 2 methods of measurement, the handbook way and the CCW (California Cycle Works) way. The correct clearance on the closing shim is between 0.03mm and 0.05mm, (0.0015” in real money) basically sod all and shims that thick are a) extremely difficult to manipulate and b) virtually impossible to be accurate with when trying to insert them between the sides of a rotating shim collar and a forged fork with access to only one side which is subject to a moderate closing spring pressure.
I tried the Ducati manual method and got inconsistent results. The CCW way involves setting the opening shim and then measuring the opening shim gap with the closing shim fork pressed down with a screwdriver and subtracting the total clearance from the clearance with the closing rocker under closing spring pressure. I spent ages trying to get two results to add up - it was nevertheless more consistent than the Ducati manual method.
After 3 hours I had the opening clearance about 0.005 too tight and the closing clearance about 0,01 too loose. Much of this time was spent figure of eighting the shims on 600 grade wet and dry to reduce their thickness.
Part of the reason it took me three hours was I spent about an hour (on 3 separate occasions ) looking for my fancy USA collets which had ejected themselves past my face as they failed to engage properly as I released the tension on the closing shim.
All good fun- and I am sure I will get better at it with more practice.
PS I tested the exhaust valve by pouring methylated spirit down the exhaust port and it seals perfectly. – Result.

[350TSS]

Dukedesmo:
I thought a lot about your comment over night.
The cylinder barrel has definitely not moved, no paint cracking - nothing
If it has not moved then the seal should still be good between the crankcase and the barrel.
I have to balance the risk of a leak from the base of the barrel vs the risk of damaging the rings taking the barrel off and re-fitting it.
On balance I will take a chance with the barrel as it is, this view might be all buggered up if any one of the suspect studs fails when I torque down the de-coked head.
Thanks for the thought though (and in my case additional worry)

[350TSS]

I have received representations by pm - which could be summed up as "for god's sake change the studs" and by the way "you can take the barrels off and leave the pistons in the barrels by removing the gudgeon pins".
I know it makes sense so that is what I shall do with a certain amount of trepidation as the studs were very reluctant to come out with two lock nuts.

[Mossleymonster]

You could try one of these for removing the studs, best one I've ever used.
https://www.whitsales.co.uk/ocart/in...id=1328&page=3

[350TSS]

Mossleymonster - thanks for the suggestion - I think I need something beefier for the crankcase studs that will allow me to exert the force on the stud close to the crankcase. I think the above would be great for exhaust studs and has been put on my Christmas list.
I bought one of these:
https://www.cromwell.co.uk/checkout/...40292ee6f5562b