Garage Diary : Sunbeam Motorcycle resto's..

[Bfg]

^ yes indeed, it'll definitely be worth dropping the sump sometime soon to see what's in there.  I have no experience of testing any particles but aluminium is very much harder than white metal and so I think the way each crumbles might be distinctive.  Of course that's easier gauged when you have two known substances as particles side-by-side as a datum.   Aluminium I believe burns as a white flash. I'd have to look up white-metal, which I guess is mainly lead, to see what colour that burns. I think it's bluish but then so are various other metals so it is difficult to assess with any certainty.  Let's see if I find anything..

Pete

[martc]

17 hours ago, Bfg said:

Dunlop Tyres made in Japan, what is this world coming to ! ?  ..I do hope it has better traction than the old Bridestone tyres ..made in Japan in the 1970's !

It's complicated but Dunlop have been owned/part owned by Sumitomo Rubber for a few decades/over a centaury. Sumitomo have owned an interest in  Dunlop Japan since 1909 and bought them out completely in the 60's. Dunlop in the UK was owned by several combines over the years, but went to Sumitomo in the late 1990's. Sumitomo are now in a joint venture with Goodyear, and some Goodyear tyres are branded as Dunlops (and vice versa).

[Bfg]

^ If I'm not mistaken at one time the Dunlop TT100 tyre was unavailable .. credit where due to Sumitomo, to have maintained old product lines like the TT100 and indeed to have now re-introduced it in two or three guises ; TT100 Classic, TT100 GT, and perhaps another.  Furthermore credit to that tyre's original design engineers who must have got the pattern pretty darn good as the new ones are very much the same but with different rubber composites and construction. 

I rode 65 miles today and, apart from a brief pause to take a photo, that was non-stop.   The new front tyre behaved just as it should, ie., unnoticed ! That is to say that there was nothing detrimental in its grip, steering or comfort at all, indeed the bike's usual ridge-riding and white-line tracking appear to have gone altogether, and aside from that - the tyre was comfortable and seemingly sure-footed.  

 

^ my piccie of the day (again sorry for my camera phone's lack of quality).

Mostly today I was riding B-class roads at 30 - 45 mph, but at one turning I found myself on the, busy with heavy lorries, A14 dual-carriageway  ..and so i needed to maintain a minimum of 50 - 55mph.  And as it was a steady incline between junctions - I was concerned that the engine would seize again, not least because the hard shoulder was just 2ft wide (most likely really intended for road drainage rather than a panting old Sunbeam motorcycle.  Other sections of today's route included narrow unclassified, with subsidence, country lanes with passing places, pot holes, wet in the shadows, and mulched leaves on corners. 

I'm pleased to report that, in contrast to Tuesday's record breaking, the engine didn't seize at all today..  Mind you when I got back at 4pm the air temperature was 44 degrees F  / about 6 degrees C.  I'll let you guess what the wind-chill factor was ! ..I don't need to because I felt it first hand.  Indeed I was in quite a cold shaky dither as I put Nudge  away for the night. 

Keen to get home and into the warmth of the apartment I quickly raised the bike on blocks and pulled the plug out . . .

^ Following the very timely prompt from Asimo, and while the oil was hot from the run - I decided to drain it today, in readiness of dropping the sump tomorrow.

As an aside., the speedo now reads 08569 miles,  and on the 2nd November it was 08152.  So in the past 17 days we've done 417 miles.  I'd only had time to do 26 miles before I moved house - so the total since engine rebuilt is now 443 miles  .. just a little further than driving London to Edinburgh (..or vice versa as a Scotsman might say).

Bidding you a pleasant and warm evening,

Pete

[Bfg]

. . just a quick update . . .

On 11/19/2020 at 5:21 PM, Bfg said:

^ Following the very timely prompt from Asimo, and while the oil was hot from the run - I decided to drain it today, in readiness of dropping the sump tomorrow.

I didn't do this on Friday, as it had been a heavy frost and it also happened that I was in a grumpy mood from being woken each morning around 5:15am (to the sound of someone having a pee, directly into the water of the toilet bowl located immediately above the bed-alcove of this studio apartment) ..and thereafter cannot get back to sleep.

As someone who considers "mornings are wonderful ..but they start too early" - my loosing three hours of sleep every day is a trial.  Anyhows that's not what we are here to discuss, so let's get on with the findings in the sump... 

Not at all good, but then it could have been far worse. . .

 

^ After 443 running-in miles this is what I found.  The dirty colour of the oil reflects the amount of carbon deposit (soot) from the combustion chambers before the piston rings have bedded in (..there's more blow-by than there will be ..once that running-in is complete).  You can see here lumps of metal withing the folds of the paper element filter and also two pieces laying in the bottom (just under the filter). There's also a couple of flakes, one may be seen at the end of the central rib) which look like a flake of varnish or shellak.  

NB. replacing the original wire-mesh gauze filter with the paper-element is a modification I do to my engines.  All have been done but for Katie which had a new finer gauze fitted. I did however give the bike's new owner the special parts to convert it should he so choose.

^ nothing amiss can be seen up inside there.

^ in close up this is what I found (..after being rinsed in petrol / laid out on a piece of kitchen paper-towel). 

The shellak-like flakes I've never seen before ; they're brittle/hard and transparently thin.  First thought was - it must surely be a smear of gasket sealant that's flaked off somewhere.  But where it could have come from is a mystery, particularly as there are no signs of gasket-card fibres nor of cork. They are too large to have gone through any of the oil-ways,  and in any case - I'm really careful not to apply too much gasket sealant ..in avoidance of creating squeezed out beads.  I was using Wellseal  gasket sealant but have recently been trying a similar product in tube form, it's of thicker consistency and from Loctite.  Wellseal doesn't go hard and the tubed stuff is only supposed to go tacky.  Whatever they are must have flaked off a relatively flat almost-shiny surface.  But what and where.?  

After sleeping on the question, I think I might have an answer : Loctite yes, but not the gasket sealant.   No, I'm thinking it must be the wicking Loctite I used to seal around the leaky cylinder sleeve (as fitted by aforementioned said professional) < here >.  And in the process some of it has run through the crack, and all the way down the outside of the sleeve.  It has then hardened, not in the crack but around the bottom rim of the cylinder liner where it projects just a little into the crankcase.  The engine-running splash of oil from the crankshaft has in effect jet-washed it loose, and it's then been washed into the sump with the returning oil. 

 

I'm happy with that explanation so let's now look at the metal bits ; they are non-ferrous and judging by their hardness and sheen are more likely to be aluminium than white-metal (from the rear-main bearing).  The almost 4mm long piece is a turn-and-a-half scroll, or thought of another way - like a shaving.  Other pieces of the metal found are also very thin shaving with torn edges.  Again in context of a running engine, it seizing and otherwise vibrating far more that it should, I was bewildered - where on earth have they come from ? 

If they are indeed white-metal from the rear-main bearing - well., there's nothing there to scrape or shave the metal.   If it were the aluminium of the piston seizing, then.., I've never seen one which has been 'shaved into a scroll '  nor can I envisage how a 4mm length of metal shaving can get passed the piston's skirt and its bottom ring..?  

There are actually very few moving parts within these engines that are aluminium.  The pistons & con-rods are, but with a chain-driven overhead-camshaft design .. that's about it.  Still, I had two scenarios to consider.,  1. is that moving aluminium parts have scrapes along an edge of steel, or 2. moving steel parts have scraped along the insides of the aluminium cases or a cover.  In time, I considered the fact that I hadn't replaced the cylinder liner myself, and perhaps that the skirt of it is shaped to clear the con-rod as it swings around to 90 degrees ??  The scraping then would be off the side of the aluminium con-rod.  

Surely not., no I think., the sleeves are flat bottomed and although there may be an inside chamfer, that is ..I'm sure is all the way around, so there's no 'right orientation' to fit the sleeves ..but for the cutouts in their top rim which to clear opened valves.  I would have seen and noted such clearances when I had the engine inverted on the bench. 

Hang on.. The sleeve fitted to the rear cylinder of this engine was replaced (..by aforementioned said professional) and its dowel hole didn't align  and had to be re-drilled.  Judging by its original dowel location - the sleeve was probably from a front cylinder and so is rotated.  Well perhaps then., those dowels also locate the rotation of the sleeve ..whereby cutout / scallops in its skirt are there to clear the con-rod's throw.?  

I couldn't think of anything else that might scrape, so I left the matter to be further investigated.  I could do that by visually inspecting up the sump more closely, or perhaps from previous rebuild and assembly photos.  After sleeping on it, or rather waking early and thinking about it - I might now have realised the source of those metal bits.. 

Aluminium ? yes.  Engine case ?  possibly yes.  From < here > doing this ..after the engine was rebuilt and during installation . . 

Moments before this photo was taken ; the hole was drilled. Being non-ferrous I couldn't use a magnet to catch any bits, so instead I had layers of sticky gaffer and masking tape with plastic packed-in behind the hole.  Still, at the time, I suspected some bits might find their way into the sump but knowing that I was using a fine oil-filter, which is situated before the pump and/or bearings - I accepted the risk (..rather than dismantling everything) ..baring in mind that this was my own bike's engine and not a customers.

Drilling and tapping the aluminium case might well have created the scroll like shaving and other particles.  And even if they had been caught in the stickiness of the layers of tape, they might have easily been dropped again just as I pulled that tape out of the timing chain's chimney. 

Shoddy workmanship on my part, but I think that is the mystery solved. 

I don't know about the black round ball seen in the photo, either what it is nor where it came from, perhaps it's a bit of shot used to blast this engine's cases that had hidden away in some dark corner until washed out by the engine oil ?  ( NB.. I did extensively jet wash these cases inside and out, and also washed out the cases with petrol, but one cannot be 101% be sure that a piece might have been tucked away withing a rough sand casting).        

In conclusion, the bits found in the sump and filter are a sad reflection on my skills &/or carelessness in rebuilding this engine.  But my choosing to modify / replace the original gauze oil-filter with a very much finer paper element type has proven its worth. 

Regarding this engine repeatedly seizing - I'm still assuming it is the end-float against the rear-main bearing being too tight.  In the future I'll use the recommended 0.004" as the very minimum. David Holyoaks - Engineer and experience re-builder of these bikes ..and who once own Stewart Engineering, had advised me that it wasn't critical if a little too tight, but perhaps this engine demonstrates the old adage "if it possibly can go wrong - it will".

 

Moving on., the sump and magnets was cleaned out, and is back now on again, with a new filter of course.  The oil was a little dirty but I didn't think too bad for the next five hundred miles - when it and the filter will be changed again.. subject of course to no great disaster happening in the meantime.  At least with dirty oil I can see, and therefore address, any oil leaks !

 

Yesterday, I also changed the engine's leaky front crankshaft oil-seal.   I don't know what happened there, because the dynamo's journal (that the seal works against is fine, and there's no way without being totally ham-fisted I could have damaged it, but still it didn't seal 100%.  It's easy to change, simply by removing the dynamo, prising the old seal out with a couple of screwdrivers and then gently and squarely tapping the new one into place.

^ the new NAK replacement seal.  The one previously fitted was a different brand and is much harder ..Perhaps it was old stock and the rubber had gone hard.  Anyway it was consigned to the bin.

^ weepy oil dribbling down and being blown back along the engine fins is just a mess which possibly conceals any other places that may also have an oil weep.  Wiped clean so that I can monitor anywhere that doesn't remain dry.  As before, I added a smear of silicon grease to the seal's lips before fitting it. 

Fortunately the drain hole in the bottom of dynamo's casing had been cleared before I fitted it, and so any oil drained well enough away and no damage was done to the windings or contacts.  However., with mud on the road and the bike being 'garaged' in a farmer's yard that hole was all but blocked again. Good job I checked it now and cleaned it out again. as a flood of oil in the dynamo will cause it to short out.   I used to have a rubber mud flap on the mudguard of this bike.  I can't remember taking it off but there's no sign of it so I guess I must have.  Time again to fit one &/or else a local cover over the dynamo's hole, so it might still drain, but the mud from the front tyre cannot splatter over and block it. 

Well that's it for yet another day. I have a couple more jobs to do before I ride very far including a recently failed headlamp-dip bulb.  Hey ho., the riding is good. 

Bidding you a pleasant Sunday.

Pete.    

 

[Bfg]

On 11/16/2020 at 5:47 PM, Bfg said:

Also ordered today < here > off ebay @ £9.99 for 1/2 metre which ought be enough for both the silencer on the bike and a spare which I'll clean up and sell. 

The exhaust silencer's pipe diameter is 1-1/2" OD with an inside diameter of +/- 35 mm, so dare I risk buying 35mm DO perforated tube because it'll be a good fit.?   Nope.. the possibility of having to reduce this perforated stainless steel tube's diameter by a few thousands of an inch - to get it to fit into the pipes in the silencer was not something I wanted to consider - so just to play safe I've ordered 32.5mm OD and a tube of silicon sealant to glue it in with.!  Yes horribly crude.  And anyone who wants to look up my exhaust and nick-pick is welcome to do so. I'll just start the bike while they are peeping up the pipe !  

      

 

Having got the baffle tube and a tube of black silicon in stock, I took the opportunity this afternoon to test the ideas I have.  Here's a pictorial report . . .

1/2 metre of 32.5mm OD perforated tube in stainless steel.  

32.5mm was actually closer to 31.5mm and the ID of the stainless tube fitted into this silencer is perhaps 35.5mm ..so the baffle's fit was a little slack. Nevertheless - better than being too tight to go in !

^ The felt pen mark on the silencer is to where its end pipe extends into the casting.  And the felt pen marks on the perforated tube are at 100, 150, and 200mm. The baffle tube pushed into the silencer to just short of the 200mm mark, before its end fouled on the inside curvature of the aluminium casting.  That doesn't leave a whole lot of length of baffle to do its job.  But as that was expected - I had an idea to improve on that. . .

^ four slots cut into the end ..each at approximately 90 degrees to the next

 

^ the top and bottom quadrants (between the slots) was biffed in ..and then the two sides were similarly formed around those to shape its end into an almost-closed (..aside from the perforations of course) cone shape.  The now tapered baffle pushes into the silencer by another 50mm.  

The concept being ; the pulses of exhaust gasses will be forced through the perforations, and although a very short length of baffle - this re direction of their high-pressure wave-fronts will happen progressively  ..as the cone gets tighter.  Likewise the sound's wave-front will progressively dissipate and loose its bark ..which (previously) uncurbed resonated around in the cast-metal chamber.   Silencer baffle theory talks about sound waves cancelling each other out, whereas I tend to think of this baffle as progressively shaving the magnitude from each shock wave.  

I took this experiment one stage further. . .

^ the blue felt pen mark indicates where the inside end of the silencer's front end-pipe finishes.  The 'flutes' I've shaped (one from either side) are from the hacksaw cuts made at 3/4" and 1-1/2" from that mark. 

^ Having cut across the pipe (across just three perforations) I used a solid round bar, hammered at an angle into the tube - to invert the curved shape of the perforated tube.

Again my understanding of the theory is ; the exhaust gasses will have to snake passed these indentations which will induce swirl and turbulence ..and in doing so the sound's wave-front is part reflected and part deflected, so broken up.  An analogy might be the energy of a seaside ocean wave being progressively dissipated as it crosses and is part reflected, part deflected by diagonal breakers ..rather than the wave crashing hard and square against a sea wall.   

^ The perforated tube within the end pipe does nothing as a baffle, so it was cut short ..leaving just enough for the baffle to be glued in place. 

^ cleaning the inside of the end pipe took just as long as making the baffle.  Fitting the baffle inside was then a sticky job.

^ Job done.  The silencer will now sit undisturbed for a day or two to allow the silicon goo to set (during this cold weather).

I've never made silencer baffles before - so it will be interesting to see if it works, and of course how effectively.?  I'll refit the silencer and try it as it is now ..which ought to give me a clue as to whether I ought to do similar with the rear end pipe. 

 

That's it..  lots of pictures, not too many words. But I hope it has been of interest.  Your feedback is welcomed. 

Pete.

[Mally]

Looking at it, I feel the baffle may be too restrictive.

It's only a gut feeling, I  used to jam old tin cans in mine, which usually blew out again.

You will soon tell with loss of performance and/or overheating.

May well be fine. Your engineering expertise easily surpasses mine.

[Bfg]

Interesting gut feeling.. and that is not  a criticism  as I often rely on the same myself ..so I'll listen to yours.  In these circumstance I do a quick check to see if I'm making a right ass of myself.  Similarly, I'll do the same now (,, a quick check that is, not make an ass of myself ) . . .

 

The inside diameter of the silencer's end pipe I measured at 35.5mm, so that has a cross sectional area of 990 sq.mm.  

I don't recall seeing a spec., nor have I actually measured them - but let's say the holes in the baffle are 3mm dia.   There are 12 holes spaced around the perimeter, and counting to the end ..there are twenty holes in the line from my felt pen mark (where the end-pipe finishes) to the end. 

Now., for the sake of convenience in maths and also to allow a little for turbulence / friction of the air passing through the perforations - let's say those holes are just 2.765mm in diameter.  Therefore the cross sectional area of each is 6 sq.mm.  

So ..,

6 x 12 x 20 = 1440 sq. mm  area of holes for the exhaust gasses to disperse through.   And that is the best part of 1-1/2 times the area of the end pipe.

It's true that the 1440 sq.mm area calculation hasn't excluded the overlapping metal within the shaped cone (where holes are covered or part covered, or where one is directly over another),  but then similarly that area doesn't include the hole I've left in the end of the cone, the open cracks between the overlapping plates, nor the two bigger holes created by the indented flutes.  As I say - it's only a quick check I'm doing here.

 

For sake of further comparison ; the chromed exhaust silencer I presently have fitted to the bike now is the right one for Pudge, the bike this engine is out of.  ie., it is the correct type for the S7-deluxe ..even though the engine and carburation are the same as the S8 (which was said to be the sports model).  My observation when I fitted this silencer were . . .

" Inside this chromed (S7-d) silencer are two plates, welded across-wise like bulkheads, each with a relatively small central hole .. I didn't measure them but I'd guess they'd be about 7/8" diameter (hole size), and they have a perforated metal tube spanning inbetween them. The exhaust gasses are therefore part restricted - to give back pressure, but otherwise the narrowed diameter is straight through.

. . . The bike felt a little more gutsy at lower-medium revs., but flatter at higher speeds. Whether that is real and perhaps attributed it its state of tune or just an impression of the noise - I cannot be certain, but it does tie in with my limited-understanding of exhaust back-pressure and the surprisingly (to me) amount of constraint / reduction (small diameter hole) through the S7's internal baffle-bulkheads.

Something else I was hoping for, but couldn't be certain of, was that it has now stopped the engine popping on over-run.  The notes are a little more abrupt ..but I attribute that to the engine's new camshaft, whereas on the previous engine the camshaft was worn and so the bike's performance was a little more subdued. " 

 

Going back to this quick check ;  The cross sectional area of a 7/8" diameter hole is just 388 sq.mm  ..a little more than one-quarter  of the holes I have in this short length of perforated tube.  And even if it were an inch diameter hole through those plates - their cross sectional area would still only be 507 sq.mm.  This amount of constriction supports my riding impression that it was flatter at higher (albeit still running-in) speeds,  ie., that this silencer is too  constrictive.  Perhaps this is not the case with each of these chromed S7-deluxe silencers, as I have personally ridden an S7-deluxe in excess of 80mph. (..that's not quick on a modern bike but it is a fair pace for a 1940's design of gentleman's motorcycle) ..so I might only assume great variation between different manufacturer's silencers.

Thank you Mally, it's been interesting to do the sums and this comparison . . .  

My expectation is that the 1440 sq.mm of perforated holes through the baffle will in fact be somewhat more  restrictive than the straight through 990 sq.mm of the silencer's end pipe / baffle-less silencer.  And that would be because of the forced change of air/gasses direction, the splitting up of the air-stream = turbulence, and of course friction (..those numerous holes total a far greater length of sharp edge (2084mm) than a straight through pipe (just 111 mm in circumference).  And I hope  this constriction will generate the back-pressure needed for the inlet/exhaust valve overlap to work better than it does without baffles, or indeed better than it does when over constricted by this particular S7-deluxe's silencer.   

In truth ;  I can hope but I cannot even hazard a guess to how well it will perform at one engine speed or another. The calculations are far too complex for me.  Best I can do is make a stab in the dark and hope !  ..that it will be much quieter than it was and also not detrimental to the bike's performance.   If not I can always try again !   

Pete.

[Mally]

Sounds good to me.

Will likely sound good when you start it up.

[Bfg]

On 11/24/2020 at 7:49 PM, Bfg said:

^ The perforated tube within the end pipe does nothing as a baffle, so it was cut short ..leaving just enough for the baffle to be glued in place. 

Well I tried, and I'm sorry to report the new baffle didn't work.   

I haven't yet ridden the bike with it in but I have started it and rev'd the engine, and although a just little better than having no baffle (in respect to noise level) it is no better than the chromed S7-deluxe silencer.  In short it is still too loud.  Worse still is that the engine pops quite a bit more on overrun than it did with no baffle ..and as I've said previously.. using the chromed S7-d silencer had got rid of popping that altogether.  

I'm having difficulty trying to mentally visualize what is happening inside there ..and why this baffle appears to have lessened the back pressure.!  I know of 'extractor manifolds' designs (which these Sunbeams already have) and I can understand how they work, but have I inadvertently made myself an 'extractor silencer' ??  

While the engine was running I tried the off-cut length of baffle up the tail pipe.  Interestingly that made a huge amount of difference to the noise level. Indeed it was very easy to adjust the noise output by simply pushing the perforated tube further in.  Pushed in so that the length of perforation projecting inside the silencer, beyond the tail-pipe, was about 4" (100mm) it became almost as quiet as a Japanese four-stroke twin of this capacity.  ie. sufficiently quiet that, with the Sunbeam, it really drew ones attention to the noise of the engine rather than exhaust.!      

I have one other* rectification task to do, and then I'll ride the bike to see if I can feel any difference on-the-road, with and without that perforated tube crudely poked up its tailpipe.  Then, I guess, I'll need to pull out the front / conical baffle and try the bike again with just the tube up the tailpipe.  My conclusions will be totally subjective, but at the end of the day that's what matters most.. how the bike feels and how I hear it rather than the 30 - 60mph acceleration time or a number being read off a decibel meter.   

So cold, misty, damp weather or not ..I've got to go.

Catch you later.

Pete.  

* the wiring at the bulb connection of the headlamp's dip beam 6v 45w H4 halogen has melted. The bulb itself is fine.  I've never seen that before but I guess there must have been corrosion and that increased the electrical resistance - which in turn generates heat.  I'm surprised that 6v 45w created enough heat to melt the insulation off the wire. But it did. 

 

Edit ;  Failure to proceed .. the car wouldn't start !  Today is postponed by 24 hours.

NB. the car's battery is OK but for the past month I've only been driving a few miles, to and from the container / workshop, with the headlamps, screen demist and wipers on - so there's been more starting and stopping than running to charge the battery.  Having been on (slow) charge for just two hours the car started fine.  I'll nevertheless leave the charger on overnight to top-up the battery's energy levels. 

[Bfg]

Today ;  4 degrees this morning and too flipping cold for me to work in the Tardis.  It took 2 hours to heat up it upto 10 degrees, using a single burner camping cooker, by which time it was just as warm outside  ..so I opened the door for some decent light.!  At least in that time I got some sorting and tidying done of my electrical odds n' sods drawers.  And then ..finally, I got down to replacing the headlamp bulb's wire and connector.  In doing so, I used a 12v soldering Iron for the first time today. I've no idea what its wattage is., but its wires to the battery are pretty skinny.  Anyway, and very much to my surprise - it worked fine, even for this large core wire.  

Another job was to remove some of the engine oil I had added.. Like a twit I had over filled it the other day. Oddly I've never done that before ..but this time I managed to add about a 1/3rd of litre too much.  A large syringe drew it out slowly but easily enough.  And then I donned my gear and went for a ride in the damp-misty sort of weather.  I thought it would be too cold to go far, but although damp the temperature wasn't as cold as a clear day we had last week.  I did another 42 miles and on the whole thoroughly enjoyed it.  With just the new conical baffle in (ie., without the perforated tube pushed into the tail pipe) the exhaust note was fine. The bark that had previously resonated around inside my helmet has gone, but there's still a good old British bike sound.  At times she still sounds like a big single, but the magnitude and pitch has been altered to a very acceptable level throughout those 40 plus miles.  Perhaps if I were riding down to Devon, which I did a few years ago, then I might stuff the perforated tube up her tailpipe for some long-distance peace & quite (I sound like a married man ) ..but for normal use - I like it as it is.  Success !  

Regarding the popping on overrun.. well that's odd because it only seems to happen when I quickly close the throttle for the gear change, and not on overrun. ! ?  I don't understand it - but I'm happy to live it it.  It is after all only a pop or two rather than a bang. 

Then of course is the question as to whether it has effected the engine's running ? To which I'm making reference to the effect of exhaust back-pressure.  And yes it does have an effect.. quite a positive one it seems.  Of course it could have been the extra humidity in the air changing the 'test' conditions ..but from the outset the bike pulled better - that is the engine's torque seemed noticeable improved.  From when I first pulled out of the farm-yard and onto an uphill stretch of A-class road, and similarly when accelerating (from 30mph village restrictions to open country) in third and top gear, and again when pulling up hills.   Very quickly I'd find myself up at 55+mph ..which is the upper limit I've been taking this engine to, these passed 200 miles of running-in.  Although I've dared play a little bit as I run the engine in, today I really quite enjoyed myself.  

It was dismal light today for a nice piccie of the day,  so here's one I took a week ago. . .

Pete

[Bfg]

Piccie of the day . . .

it was just six or seven degrees temperature today, so a tad cooler than yesterday and the back roads were also very damp..  Nevertheless another 35 miles of running in, over to Elmslett and around the countryside.

Bidding you all a good Sunday evening.

Pete.  

[Zelandeth]

My guess is that what you've done is slow down the exhaust gasses departing the silencer, therefore it's acting as a large (relative to engine size) expansion box.  It's taken the edge off the pulses so made it less harsh.  The original arrangement was protruding into the box so lessening the effective volume of the chamber.  Think you'd have needed far smaller holes in the tube to really have worked well in that arrangement.

As for the overrun/off throttle popping.  My understanding is that this is unburnt fuel that leaves the cylinders igniting in the exhaust - when you come off the throttle quickly the fuel delivery from the carb takes a moment to adjust to the new throttle position, so the mixture momentarily will be very rich - cue a bit of extra fuel ending up in the exhaust.  When the throttle stays closed the fuelling catches up accordingly so the pops and bangs don't continue.

That's my theory at least!

[Bfg]

^ Thanks, I'll think about what you've suggested.

in the meantime, here's my bike's piccie of the day ..taken yesterday . . .

^ Elmsett Airfield.. which is a grass strip. The white dots along the field in the background are the markers.  I flew into there many years ago when learning to fly a light aircraft ..and I can tell you - a grass strip, even with a row of tiny white dots, is really difficult to spot from 3000 ft.  And it is even worse when you've just taken off, are climbing and turning, and then travelling at 120 knots - you look back to check your bearings ..and you can't see where you've just come from !

 

p.s. you might just spot the front mudguard rubber flap to help prevent mud n' road spray from blasting the underside of the dynamo.  It just a piece of sticky back neoprene I had, but it works.  The front face of the sump extension has a pile of mud stuck to it now ..but above that the engine's pretty clean. 

 

[Bfg]

Today, the weather here is raining and glum ..and I'm tired - so I'm having a day off.  But, waste not want not - I'll use this time to very quickly fill in a gap in this bike's rebuild story. And to do that, we need to run back in time

 

On 10/31/2020 at 11:39 AM, Bfg said:

And Pudge 's forks and rear suspension were hurriedly rebuilt and refitted, so that she was at least a rolling cycle and therefore easier to move . . .

^ Pudge,  also from 1953, is a Sunbeam S7-deluxe (with fat tyres) and so is big sister bike to Nudge.  She was first registered in the same borough of London just five weeks before Nudge, indeed it was on the day after the Queen's Coronation which probably accounts for both being painted the silver metallic colour.  This colour was standard on the S8 but is almost unheard of on an S7-deluxe ..which were usually a light pea-green colour, or black by special order.  Subsequent to the above photo I've now also reassembled her cantilever saddle mechanism.   

Amazingly it was just two months ago I was busting my 'alls to move house to a deadline (1st October) ..the house has been empty since.!  Back in mid-September though - I needed to get Pudge back onto her wheels so that she would be very much easier to move. . .  on the 17th of September things looked like this . . .

^ restored and then stored, but not reassembled.  And I'd pretty much forgotten how things were meant to be assembled.

I find the best thing to do in these circumstance is to lay things out all in order ..as if they were an exploded diagram . .  .

^ the parts of just one fork assembly, and only the top (steering) yoke.  This is the right-hand fork's lower-leg, with its threaded screw  for the axle-spindle and the (cast aluminium) upper shroud / headlamp bracket without the tax disc holder. The lower shroud has holes for where it is screwed to that upper, and the alignment of those holes determine this one to also be for the right hand side.  The three tiny screws can just be seen just above that shroud. Those and the tapped holes in in the upper shroud have all been cleaned, checked, and the two parts of the shroud dry assembled to ensure the screws go back in, now that the parts have been repainted.  The fork's other parts including the stanchion itself are common to LH & RH sides, however I had them marked - so they go back together as they were originally.

The bronze sliding bushes were a good fit and didn't need replacing. The stanchions themselves were similarly hardly worn and not scored, so again they are to be re-used. Aside from the paint and the chrome - only the seals are new.    NB. again this bike is almost unique because it was painted monochromatic-silver. And for that to have been done before, as well as they were, would likewise have necessitated their complete strip down. 

 

So onto the forks reassembly. . .

^ the order of assembly of parts onto the fork stanchion is to be noted. . .  Fed on from the bottom ; the chromed shroud goes on first with the seal holder facing downwards.  This had already been fitted with its double-lipped fork seal, with its open bottom also facing downwards. Next is the circlip and then the upper sliding bush ..with its rim at the top.  And then finally the bottom bush and the screw-on end.  

Before assembly though., the inside of the chrome shroud had been painted with cold-galvanising (zinc) spray paint and thereafter smeared inside with waterproof grease - to help avoid it rusting from the inside (..as indeed were the other shrouds). The lips of the seal were smeared with silicon grease so they might not stick to the stanchion.  These seals must be double lipped because the oil has to be contained within the fork leg, and as importantly dust and grit has to be prevented from getting in from above.   Stewart Engineering had sent me single lip seals for this task and I sent them back ..as being wholly-unsuitable for the task.  Had I used them - the stanchion would be scored and scratched by road grit that finds its way into such places. 

The bottom screw end, which retains the lower fork bush, is refitted and firmly tightened.   I use soft jaws (aluminium) in the vice to hold the stanchion, and afterwards quickly retouch my zinc paint.  I don't like rust inside these places at the best of times, and I like it even less when a speck of that rust comes off and falls down inside moving parts.

    

^ the bushes are oiled and lower fork leg reassembled onto the stanchion. The lip around the top of the upper (sliding) bush sits into a recess in its end, and the circlip then fitted to hold it in place. . .

^ circlip securely in its own recess, which in turn holds the upper bush in place. Sometimes there are steel shims which go under the circlip, and they may help with the retention, but apparently none were fitted to these forks.   Btw., the end of that circlip is just by the shadow, ie., its end is very close to the 'v' cut into the recess ..where a small screwdriver or hooked wire can be used to lift the circlip out.

And., around the fork leg's screw-thread is not rust but Coppaslip. It's from where I had dry assembled the individual parts before final assembly. It is very much easier to be able to screw the chrome shroud on freely by hand ..as there is no other provision for gripping it.  So I worked it on and off half a dozen times to ensure it was free all the way.  But first, before final assembly . . .

    

^  waxed (or in my case - greased) cord is fitted around the fork leg and cut to length.  Then when the chromed shroud is screwed tight onto the fork leg (which retains the fork's seal) its paint nor the chrome is chipped.  Simple, cheap, perhaps even a little crude, but very effective. So why is so often left out ? 

.. with ten photos already - I'll stop here and have some lunch, and then I'll come back to the fitting of the fork springs and the legs reassembly onto the yokes.

Later..  Pete

[Bfg]

OK., part two . . .

^ my first task was to cut out the middle of some felt washers I have (they're probably from wheel bearings) to fit over the stanchion.

^ greased and fitted into the top of the chrome shroud / seal holder. These serve a dual purpose. The first is as first line of defence to protect the fork seal from grit and dust. And the secondly to sit the spring on, rather than turning metal on metal (as the spring is compressed - the length of its wire has to go somewhere and so its ends turn). Similarly greased fibre washers are also used in these bikes rear suspension plungers.  For the top of these springs I happened to use robust plastic washers (see piccie below) . . .  

^ ^ You'll note the taper which fits into the yoke and the very fine screw thread are both clean. Grease on these doesn't hurt as there is a locking tab-washer to prevent the nut from coming undone.  

The spring and stanchion are coated in CV joint Lith-moly grease (intended for high pressure loading where access would be infrequent). It's a filthy bit of stuff ..but I like it   You'll note the lower (painted) shroud is in place (although if I recall it does just about come up from the bottom passed the front mudguard studs) and the now-resized red plastic (nylon ?) washer .. which if I remember correctly once adorned gas bottles.  This will seat the spring off the underside of the bottom (steering) yoke, so as the spring's end turns it'll not squeak or groan. 

^  ..and then for the locking tab-washer and nut to be fitted down onto the yoke - the stanchion is pulled upwards as the yoke, tab-washer and nut are pushed down and the first turn on the thread made.  You can see, on the left hand side of this yoke, where the the tab washer sits into an indent. Once that washer's tab is correctly positioned and the nut pinched up more securely it can be put aside ..ready for the other leg's reassembly in the same way. And likewise it to be fitted into the bottom yoke. 

In retrospect., a job I might have done, but which I missed  was to remove the paint around the top of the yoke's holes - so the tab-washer and nut would tighten hard against the steel ..rather than having layers of primer + paint sandwiched in there.  As it would be hidden under the shroud - I could have locally painted it afterwards (to keep out moisture / rust).  Alas in the haste of the moment I didn't. 

Similarly., a job to clean off some paint that shouldn't have been in there - was done . . .

^ with that paint cleaned out, the wheel's axle / spindle fitted and the spacer tube slid correctly (again with a smear of Coppaslip to ease its way) and the pinch bolt could be tightened without cracking the paint. 

So then to tighten things up. . .

^ the bottom end of the fork legs is on cloth to avoid scuffing the paint and the top on a block to save damaging the shrouds as the nuts are pinched up tight (while ensuring the tab washer's indent is in place).  The sharp eyed observer might have noticed that the adjustable spanner is broken (actually its adjustment is also rusted up !)

^ yep, it's one I saved from the skip and has been up-cycled for just this job.  It was actually a very good quality tool but, above its screw adjuster, it was broken and so wouldn't lock. I opened it to the size (1-5/8") of the fork's nuts and welded it there. 

As you can see by the extension lever used - These nuts do need to be very tight if the forks are to feel secure.  That welded up adjustable spanner was perfect for the job.  Soft jaws on the vice wouldn't hold the stanchion tight enough so they were removed and the stanchion did then get imprinted. I subsequently filed the worst of those off and repainted their zinc protective 'cold-galvanising' layer.

With the locking tabs bent up - the job was done ..and ready for reassembly of the forks to the steering head.

 

But.., enthralling though it may be - that'll be enough for today. 

Have a good evening.

Pete.

[Bfg]

Piccie of the day . . .

Seeing as it is now December and it's a balmy summers day ( ..in Australia) ..or something along those lines according to Jimmy Buffet - I thought I'd go to the beach 

Anyhows., a good run of 88 miles today, and I think I've finally managed to cure almost all of the oil weeps (..and yes there is  oil in the engine !)

Pete.

[Bfg]

Piccie of the (yester)day . . .

^ on the way back from the sun drenched beach I came across a chap thatching a cottage.  A wonderful example of craftsmanship.  Is that 'typically British' ..and Irish or are thatched cottages commonplace in other countries ?  (I sort of expect them to be in Grimms fairy tale's Germany, although of a slightly different style and possibly not pig's blood pink.

A friendly chap to talk to (..on the scaffolding between the windows). He was saying that this year was a good harvest for the long straw they need, which I believe is wheat. Most farmers now use a grain which produces a short stem (straw) but with a good yield of wheat ..which is of no use to a thatcher.  Shame the work wasn't closer to where I live otherwise I would have liked to see and learn more.

Bidding you suitably trim haircut yourself - now that some of the lock-down restrictions are being eased (..so I'm told but tbh I haven't really been following the news and the government's efforts to either terrify or baffle us).  

Pete.

[Bfg]

piccie of the (Tues)day :

^ next door to the being-re-thatched cottage

This weekend's rain, snow ..and fog today - the weather around here was barely conducive to my getting out of bed ..let alone to my riding a motorcycle. 

 

 

[Bradders59]

Barely car driving weather today, never mind biking.

The Sunbeam Im interested in isnt going to happen at the moment. I spoke to the old chap about it and he still thinks he is going to rebuild it himself.

In all honesty, its very obvious thats not going to happen unfortunately, but I shall have to leave him to realise that for himself in his own good time.

Poor old fella. 

[Bfg]

Not to worry, I've decided that next springtime I'll probably sell one of my last two Sunbeams ..simply because I'm buying another classic car, already have the other Sunbeam and a boat to put back together and, being in my mid-sixties - I'm running out of years for projects so I want to consolidate what I have and to get on and enjoy them while I can. Very likely it'll be the S8  Nudge  I'll be letting go of first.  I would of course love to find an enthusiast who would in time like to buy both my sister bikes, but I guess in reality that's unlikely to happen.

Pete

[Bfg]

My piccie of the day  ..from last Tuesday but the computer server here at the apartment has been AWOL since then. 

As you can see the weather turned nice but the roads were still wet from sequential downpours !

 

Now the bike is in bits again.. The engine hasn't seized over the passed couple of hundred miles but the engine's vibration (30 mph in third and 40mph in top and then again above 55 mph) is wrong. I don't really have much idea what it is - but I do know the flywheel was mistakenly over-machined when it was lightened.  It was supposed to be reduced to 18mm thick but I guess someone couldn't read their own handwriting because it was reduced to 15mm thick.   As a consequence, I had to space the clutch mounting studs out with washers to avoid the springs being coil bound.  I've now taken the engine out (it has been 'interesting' working within the confines of an unheated container with only 12v lighting).  I've also pulled the clutch and swapped the flywheel and then reassembled it again and remounted the gearbox.  All in all it was a right sod to put together, at every stage, which I largely put down to my not being in an affable frame of mind, and not at all helped by my taking 3 hours to find the spare thrust bearings - which were in the correct place ..in a specific parts box that I had looked in twice previously ! 

Fortunately, despite all - I had the good sense to check its operation before dropping the engine back in the frame.. and thankfully I did..  because the clutch didn't work properly.  So I went home home tired, cold and hungry, not to mention a tad grizly. 

Today I came back to it, in a better state of mind, and pulled the gearbox off again, pulled the clutch off ..only to find the pressure-plate binding tightly on the flywheels studs. . .

^ even with the clutch removed and the posts having had Coppaslip liberally applied - the pressure plate is bound onto its studs ..despite the clutch springs behind it trying to push it off.  Even clouting it with a block of wood didn't shift it - I had to prise it off.  I have never seen this before, and so I had no idea the parts varied that much between one flywheel + clutch and another.  Never-the-less, after also swapping the pressure plate - things reassembled easily, the gearbox was again refitted, and the clutch's operation tested yet again.  Now we have a beautifully smooth clutch operation. 

This afternoon the engine with its gearbox were dropped back into the frame, and so tomorrow or Monday I can get down to resetting the engine mounts correctly.  Unusually the engine & gearbox are rubber mounted on these post-war Sunbeams.  Then next week I'll refit the exhaust, dynamo and distributor, the electrical box and petrol tank.  I don't know if this flywheel will make that much difference to the vibration,  but I needed to try it - if only to eliminate it from the inquiry.  Unfortunately, if it is not wholly successful, the next course of action is another total engine strip down - to have the crankshaft balance checked. Hopefully before Christmas (pending weather etc.,) I'll be able to report on whether it made any difference.

When I bought this bike I only drove it around the car-park and private lane, and not up to 30mph ..so I have no Idea whether it vibrated badly then.

That's it for this evening, so I'll bid you a good weekend,

Pete.

[Bfg]

 

Putting pandemic & Brexit news aside for a moment . . .

I wish you all a Very Merry Christmas / seasonal greetings.

Best Regards,

Pete.

[Bfg]

piccie of the day . .

This afternoon, I pulled myself out to the container ..I've been 'demotivated' so pretty much by the shirt tails ! ..to recheck the bike's ignition timing, which I like to set to 3 deg in advance of TDC (standard is 0 deg ie., TDC).  It was correct, but clearly the engine wasn't happy, hunting around all over the place.  So I advanced it by another 3 degrees and things have settled down a lot.  I tweaked the carb's idle jet and tickover to suit and then went out for a ride.   She now feels to have noticeably better pick up in performance and sounded fine. Still popping on overrun but I can live with that.  

I took her up to 70mph between junctions on the A14, and decided that was sufficient for my needs, so backed off ..bearing in mind that last time I rode her she seized.  My usual riding on these old bikes is to play my way through the gearbox and ride upto 60 to 65mph around the country lanes - so, for the time being at least, it'll do.  I think it's best for me to leave this engine in Nudge for the time being, and to take her out for a ride as and when the weather invites us to do so.  It's time I think to get on with other projects.

It was wet roads and a bit slippery out today but I enjoyed another 30 miles with no seizure .  Stopped to take a piccie and then rode home as it was turning chilly.   Visibility was seriously compromised the low sun and even more so when I smudged the fine road spray on my visor (unfortunately I didn't have my chamois pad with me to wipe things clean).    ..nevertheless it was nice weather.

It was 1 deg c. inside the container when I left to ride, and then ice on the windscreen of the car by the time I'd stripped off my riding gear and picked up some LED lamps that I bought recently, which I need to extend the wiring on.  I was glad to get home and have a hot cuppa tea. !

If you do go out - remember it's both slippery along the curbs & inbetween the usual tyre tracks (ie., when using the width of the road) and possibly also icy in the shadows.  Be safe.

Pete.

[Jonwawa]

On 20/03/2019 at 15:15, Mally said:

 

If you would like to buy this one for your collection, I'll take you for a spin.

I see rear footrests, have we got a pillion seat?

What was the thinking behind tank sealant? The surface rust you scoured out would tell me it’s not flaking rust. Acslosh of diesel and good to go…🤔

[Mally]

25 minutes ago, Jonwawa said:

What was the thinking behind tank sealant? The surface rust you scoured out would tell me it’s not flaking rust. Acslosh of diesel and good to go…🤔

Welcome to the forum.

Be careful quoting me from so far back it's very fortunate I'm still alive😀

It's @Bfg you really need. He's the man with Sunbeam knowledge.

Closest I ever got to a Sunbeam was riding in a box attached to the side of one.

Stick around it's good on here.

[Bfg]

On 07/11/2024 at 21:13, Jonwawa said:

What was the thinking behind tank sealant? The surface rust you scoured out would tell me it’s not flaking rust. Acslosh of diesel and good to go…🤔

The rust I cleaned out was surface rust, but the question always is how deep is the pitting ?  Clearly I couldn't see inside very well.  I'd used POR-15 before and had absolutely no issues with it.  I think it is reassuring to know that the tank is thoroughly clean inside and well painted (chemical & and moisture proof) ..to avoid future rusting, or bits in the fuel filter. 

Proof of the pudding ?  Five and a half years later . . . I sold the bike to Andrew, who lives near Wattisham Flying Station (British Army airfield), and we became friends. The photo (below) was taken this September, at the Coffee & Classics meeting we go to.  The dual seat has been swapped for an original style saddle, but the tank is still good to go.

 

Pete

[Jonwawa]

On 10/11/2024 at 16:33, Bfg said:

The rust I cleaned out was surface rust, but the question always is how deep is the pitting ?  Clearly I couldn't see inside very well.  I'd used POR-15 before and had absolutely no issues with it.  I think it is reassuring to know that the tank is thoroughly clean inside and well painted (chemical & and moisture proof) ..to avoid future rusting, or bits in the fuel filter. 

Proof of the pudding ?  Five and a half years later . . . I sold the bike to Andrew, who lives near Wattisham Flying Station (British Army airfield), and we became friends. The photo (below) was taken this September, at the Coffee & Classics meeting we go to.  The dual seat has been swapped for an original style saddle, but the tank is still good to go.

 

Pete

Looks beautiful, I was just curious as I recently bought an S8 which is good mechanically but the paint work was Rough.  Whilst stripping the tank it was evident that it had been sealed.  I let it soak in acetone and it all came out, but the tank looks fine inside.  Thanks for your great advice, I’ve read all till here.  You could make a book of it!! Very best wishes

[rustdevil]

How are you getting on with these beams and hope everything is good with you.

[Bfg]

On 12/11/2024 at 17:59, Jonwawa said:

Looks beautiful, I was just curious as I recently bought an S8 which is good mechanically but the paint work was Rough.  Whilst stripping the tank it was evident that it had been sealed.  I let it soak in acetone and it all came out, but the tank looks fine inside.  Thanks for your great advice, I’ve read all till here.  You could make a book of it!! Very best wishes

Be aware that the captive nuts that go into the tank ..for both the knee pads (x2 on either side) and for the tank mounting brackets (x4 underneath) can be the root cause of a leak or two.  It is not at all uncommon that too long a bolt has been used, in one place or another, and when bottomed-out it's been further over-zealously tightened ..enough to crack through the wall of the tank. 

Unfortunately, this is generally not discovered until after a fuel tank has been freshly repainted, and again filled with petrol.  Trust me.. It's rather upsetting when this happens.   It's also a pain-in-the-arse to repair.  Please., if you are not using tank sealant, then do pressure test your tank ..before you paint it.

. . . . .

" You could make a book of it !! "    Please feel free to do so, and I'll split the profits with you.    

As it happens I have just been reading through the restoration of an Jaguar XK120  by Canadian (home restoration) enthusiast - Bob Exelby.  It's a nicely presented hardback book, with lots of colour photos and useful advice.  c.2016  Porterpress Publishing with US price $69.95.   Alternatively if you are an IT website developer you could help put my old website back on line.  There was a host more stuff on that, than I ever blogged on this 'ere forum..

Pete

 

[Bfg]

On 13/11/2024 at 20:56, rustdevil said:

How are you getting on with these beams and hope everything is good with you.

There's been too many other projects, and summer outings this year with TR Katie + quirky little trailer tent ..but plans are already in motion to consolidate those other projects.  And if said plan comes to fruition ..as I sincerely hope it will (perhaps even this coming weekend) then my two (very special) Sunbeams will be in the garage and treated to a hive of winter activity.    

All is very well thanks, so very much better than last year. !

Pete