# The Silver Hawk Again.



## Silver Hawk

Why did I ever buy it back in 2003?  Because one came up for sale, that's why...and its been a constant drain on my bank balance ever since.

I last rode it in September last year and it was such a bad ride, I threw it into the back of the garage and vowed to either 1) sell it or 2) try and sort it out once-and-for-all. At the beginning of Feb, I decided to give option 2) yet another chance.

The problem is the barrels...everything else has been replaced ( or at least feels like it  )...but the barrels are as rare as rocking horse manure. At some point in its life, shot blasting grit has left vertical score in all 4 bores ....not very deep but enough to reduce compression and lead to very heavy oil consumption (do not follow close behind me!). Mine are already +60 (the max) and no-one dares sleeve them.

Speaking to a friend on the Silver Arrow / Silver Hawk Yahoo group --- yes, there is one but a very small membership, since only 40 or so are known to survive out of 500 made --- he has decided to use BSA Bantam D1 +20 pistons in his +60 barrel. The gudgeon pin to crown height is the same, BSA gudgeon pin is smaller but that's not a problem since we can turn up some small ends with correct I/D to suit and the +20 BSA pistons means only a honing of the +60 Hawk bores are needed.

Thought I'd do the same...but who would I trust with my barrel? Well, there is only one person and he lives in Latvia; his name is Juris and he runs the Ramoto Engineering Company. So I was resigned to getting the barrel shipped over there and waiting a good 6 months plus.

But it hasn't worked out like that; I had an email about 2 weeks ago, on a Wednesday, saying that his friend was flying into London on Saturday to hire a van and would be driving it back to Latvia the same w/e....so if I could get my barrel up to him in the next two days, he'd take it with him. Q: Mad rush to dismantle bike & engine in a 1 degree C garage but I did managed to get it to the driver in time :thumbup:.

And it arrived safely in Latvia on the Monday. I then had real problems finding someone who had 4 of these +20 D1 Bantam pistons in stock but eventually bought them from Rex Caunt Racing (very helpful people!). The intention was then to email the accurate dimensions (nearest half a thou) of each piston to Juris...except all my digital calipers gave slightly different reading taz. Called up Mike / Seadog1408...asked him to come round with his digital calipers and got yet another set of readings taz: :taz...so we ended up going down to one of his diving engineering companies and borrowed a 2-to-3 inch micrometer and took another set of readings. Got there in the end.

Barrel was honed on a DELAPENA programmable honing machine in Latvia last Tuesday and it made it onto the weekly Riga-to-London coach on Thursday night, arrived in Essex on Friday night and I collected yesterday.

Phew! Can't believe it has all happened so quickly. Beautifully honed; scores all gone, pistons fit a treat, been to Latvia and back, no damage, all done in less than 2 weeks and all for Â£120.

Of course, I now have to do my bit: make the new small end bushes, make slight modifications to the pistons (drill oil holes), size the rings, re-built the head, re-assemble engine, re-build the bike etc, etc. Just wish it would get warmer. I'll post an update and tell you whether it has been worth it...or it will be in the Sales Forum :lol: :

A few pictures ...

The barrel is a 4 bore single block in a two V-twins configuration...hence most re-borers have no idea how to deal with it. Juris owns one of these bikes...and he's a superb engineer:










Some of the scoring:



















And the bike:


----------



## BlueKnight

She's a beauty!







Funny...I look at the front and rear suspension set-up which is almost identical in execution as my R1200RT.


----------



## JonW

Wow! great work Paul. Sounds like a mad dash but 120quid for that work is superb value. Fill us in when you have her back together, pics would be good


----------



## oubaas56

Love the looks of them old Brit bikes. Wouldn't have one if you gave me it as a present though. Bought a Matchless 500cc single in 1967 ( 1950's model ), nothing but grief. This after a BSA Bantam which was even worse. Then an AJS 650 twin, more heartache. Sunbeam 600cc twin, crap!

BSA Gold Flash? Â£120 in the showroom, totally reconditioned. Couldn't resist. The tray of sawdust under the crankcase to catch the oil leaks ( with a cold engine? ) should have been a warning sign. More grief. Honda CB750. Utter biking bliss. Subsequent bikes ( after 20 year break, marriage, mortgage, kids ): GPZ900, Z1000 chop, multiple CX500's ( courier in London ), CBX1000, GS850, GSX1100G, FJ1200 (current).

Am actually considering one of the new Triumphs. Only considering mind.

Best of luck with the rebuild.


----------



## mach 0.0013137

Great stuff Paul :thumbup:

BTW this Latvian gentleman, he wouldn`t happen to be Juris Ramba, one time chairman of the Latvian Antique Car Club, Motorcycle Section would he?


----------



## dombox40

That,s a work of art Paul and a great project, I had a couple of Bantams in my younger days first bike I learnt to ride, if my memory serve,s me correctly the bantam was a 125cc so i assume your bike is 500cc, but it is worth it so keep going until you fix it as it must be a very rare collectable bike.


----------



## Silver Hawk

mach 0.0013137 said:


> Great stuff Paul :thumbup:
> 
> BTW this Latvian gentleman, he wouldn`t happen to be Juris Ramba, one time chairman of the Latvian Antique Car Club, Motorcycle Section would he?


He is indeed Mac!

He often rides in the London-to-Brighton Pioneer Motorcycle Run which takes place in March...so had thought about giving him my barrel then...but he's not riding this year due to building work on his workshop extension.

How do you know him?


----------



## mach 0.0013137

Silver Hawk said:


> mach 0.0013137 said:
> 
> 
> 
> Great stuff Paul :thumbup:
> 
> BTW this Latvian gentleman, he wouldn`t happen to be Juris Ramba, one time chairman of the Latvian Antique Car Club, Motorcycle Section would he?
> 
> 
> 
> He is indeed Mac!
> 
> He often rides in the London-to-Brighton Pioneer Motorcycle Run which takes place in March...so had thought about giving him my barrel then...but he's not riding this year due to building work on his workshop extension.
> 
> How do you know him?
Click to expand...

I got to know him in the `80s while doing research on the Soviet motorcycle industry with the aim in collaboration of a man called Maurice Kelly (who lived in Worthing BTW) of publishing a book on the subject. Juris came over with his daughter in `88 (I think) & stayed for a few days with me & my then wife.I seem to remember he owned a 1903 "Rossiya" motorcycle which had been made by Alexander Leutner & Co. in Riga, I`ve got a photo of it somewhere.


----------



## MarkF

Â£120!! :thumbup: Should be getting warmer in 8-10 days, hope the re-build goes well and your next ride is spot on.


----------



## pg tips

massive respect mate :notworthy:


----------



## Griff

Blimey Paul, that's a job well sorted no mistake. Congrats.

Just reading your account made me feel I needed a lie down

It must be very rewarding though :thumbsup:


----------



## Philz

Wow you have a great commitment to take on this and all your watch work. You must have longer days downs south to cram all this in. Well done.


----------



## Silver Hawk

Thanks for all your comments guys.



Philz said:


> You must have longer days downs south to cram all this in.


I wish that was true...I think I have two kids, two cats and a wife, but not seen them recently. To be fair, I've not touched this bike in the last 6 months, but summer is approaching and watches usually take a back seat in the summer, so time to pull my finger out and get this one back on the road.

A few more photos..mainly for my records, but for JonW as well.

Barrel after its trip to Latvia:




























BSA Bantam D1 +20 pistons and a nice fit:










Matchless +60 pistons alongside the BSA ones.










[more]


----------



## Silver Hawk

Originals are three rings (2 compression, 1 oil control) and oil holes below 3rd while BSA are only 2 compression (because the Bantam is a 2 stroke). This shouldn't be a problem since early Matchless pistons were also 2 ring. The plan is to drill oil holes in second groove but keep compression ring and also turn a shallow groove with holes below the second ring (as per original pistons). These bikes are known for over oiling.










Another decision to make. 2 stroke pistons come with a pin to stop the rings turning in their groove. Leave or remove? Decided to remove, or rather grind flat since I couldn't pull them out even with the piston at Gas Mark 9. It will be much easier to assemble without the pin.



















More to follow in a few weeks time...I hope.


----------



## Griff

This guy is staggering down the pavement from the pub when he sees a man at the kerb attending to his bike.

He asks.............you broke down mate?

Man says..............yeah, piston broke

Guy replies.........that makes two of us!!! :bag:


----------



## JonW

Superb photos from Paul, and terrible joke from Griff... yep im on RLt all right! :lol:

Paul, the new parts look yummy!  But then all new engine parts do, dont they! 

Agree with removing the ring pin on the pistons and reckon if they dont shift with gas mark 9 they wont shift with the heat in the bore. My only worry is the expansion of the stub grabbing the ring and pushing it out if the steel expands more than the alloy, which is unlikely and also even then would be less of a hassle. So weighing up pros n cons I think you did right. not that it helps but in case you wanted my view.

New pistons look to have smaller small ends as well, or is that just the picture angle?

Spend a bit of special time with one of the kids or the wife or maybe even the cat, and get one of them to photo the rebuild of the engine in stages... I want a running project, and for now will have to live vicariously through yours and Marmisto's work. Sigh... LOL


----------



## pg tips

> BSA gudgeon pin is smaller but that's not a problem since we can turn up some small ends with correct I/D to suit and the +20 BSA pistons


Superb work, I must say I don't miss doing that sort of work!


----------



## JonW

pg tips said:


> BSA gudgeon pin is smaller but that's not a problem since we can turn up some small ends with correct I/D to suit and the +20 BSA pistons
> 
> 
> 
> Superb work, I must say I don't miss doing that sort of work!
Click to expand...

Ooops, cheers PG, I missed that when I was reading, I was drooling over the shiny bits in the photos... :inlove:


----------



## mjolnir

Just a fantastic looking bike Paul.

I'm always jealous of the mechanical skills some people have. I keep eyeing up a BMW R80 in a shop around the corner and thinking that it would make a perfect project bike to play around with. The only problem is that i haven't got a clue where to start and it would end up in bits, never to be put back together again.


----------



## MarkF

mjolnir said:


> Just a fantastic looking bike Paul.
> 
> I'm always jealous of the mechanical skills some people have. I keep eyeing up a BMW R80 in a shop around the corner and thinking that it would make a perfect project bike to play around with. The only problem is that i haven't got a clue where to start and it would end up in bits, never to be put back together again.


Buy it and then worry about it. There are loads of resources on the net, somebody will always be able to help, R80's are ace, especially the pre-cast wheel ones, go for it. :thumbsup:

Mac, what happened to the proposed Russian bike book?


----------



## seadog1408

glad to be of help paul, now all you need to do is let me borrow the ariel !!!!!

cheers

mike


----------



## mjolnir

MarkF said:


> Buy it and then worry about it.


You don't know how many times i've thought that. I might wander over on Saturday for another look.

If I bought it Trace would kill me... twice.


----------



## jasonm

Great post Paul, Im looking forward to this one being updated regularly


----------



## BondandBigM

Good stuff, look forward to some more pictures as you progress but I'm genuinely surprised you had to send the barrels away and weren't able to get it done in the UK.


----------



## Boxbrownie

I think I might be tempted to machine the third ring groove in the new pistons, provided of course there is enough material to do so.....I like the idea of two comp rings rather than just the one, and also then you can machine the oiling ports in the third groove and leave the second well alone.

I wish I had known about you needing those pistons measured....I could have had them checked within a nanoknats here at work, did you use a digital micrometer or calipers?


----------



## Silver Hawk

Boxbrownie said:


> I think I might be tempted to machine the third ring groove in the new pistons, provided of course there is enough material to do so.


There isn't 

But I am changing my mind about drilling oil holes in the second groove and rather just leave it as a compression ring. I still plan to have a slightly depressed ring under the second ring and drill the oils holes here...as per original

What do you think? Good compression but too much oil getting into the bores??


----------



## BondandBigM

Boxbrownie said:


> I could have had them checked within a nanoknats


What sort of micrometer do you use for that :lol:


----------



## Boxbrownie

BondandBigM said:


> Boxbrownie said:
> 
> 
> 
> I could have had them checked within a nanoknats
> 
> 
> 
> What sort of micrometer do you use for that :lol:
Click to expand...

F  K knows ....but its about 6 feet square made of superman steel and hums a lot....I'll nip down inspection tomorrow and find out!

Not so sure about mixing the comp ring and control ring in the same groove, it might work or the comp ring might blatter the control ring to pieces...theres a good reason the comp rings are solid little buggers!  I am sure in the dim and distant past there was a combination compression and oil control ring used on some vehicle.....buggered if I can remeber now though, sorry


----------



## Silver Hawk

Boxbrownie said:


> Not so sure about mixing the comp ring and control ring in the same groove,


I was never planning to do that.

The plan was to keep compression rings in both grooves but drill oil holes in the second groove and then also cut a shallow recess (25 thou deep) under the second groove with more oil holes i.e. as per orig pistons.

But now I'm thinking not to drill oils holes in the second groove...


----------



## mach 0.0013137

Sorry to go off topic Paul but to answer Mark`s question...



MarkF said:


> Mac, what happened to the proposed Russian bike book?


Basically despite the fact that Maurice had already had books published, had worked in publishing himself & knew the right people, they weren`t interested. Not supprising I suppose as they`d only recently branched out into books on non-British manufacturers. Still it had been fun, eight years of work with most of the research matterial coming through me from contacts I had in the former Eastern Europe.

My main source was a guy ( I won`t mention his name in the admittedly unlikely event there is any come back on him) who worked as a photographer in a rather well known motorcycle factory with speedway connections :wink2:

Every month he`d send me a parcel containing Russian, Czech, Polish, Hungarian, Latvian, etc books, magazine articles, factory documents & reports plus blue prints (there seemed to be quite a lot of information exchange between the various communist motorcycle factories) including some Soviet ones such as full size Russian side on plans of the Vostok OHC racers. He also sent loads of photographs of prototypes such as a Jawa shaft driven 500cc water cooled flat twin ( I suspect they got the idea from the Honda CX500 V-Twin), I gather the main reason it was not put into production was that the Czech government decided to allocate the money to Skoda for the development of the Favorit.

For years I thought my arrangement with this man was done with the knowledge of his bosses but when I asked him about it he told me he had a friend in the company`s postal department who intercepted my mail to him & processed his parcels to me and he said he would be in serious trouble if his firm found out 

BTW all the guy wanted off me was photographic accessories which he wasn`t able to get himself oh & a book on the British Royal Family for his wife 

About the time the publishers turned down the book things started getting `interesting` in Eastern Europe & I was going through my divorce so lost contact with the various people. After a few years I decided to get rid of the majority of the material I`d gathered (which filled a set of shelves six foot high by eight foot wide). I offered to donate it to the National Motor Museum Beaulieu but after some intial interest they appeared to change their minds so it fell through. Eventually a guy in California called Wallace (I can`t remember his last name) got to hear of the stuff via someone in the VMCC & offered me Â£1000 for it which I accepted, he flew over & picked it up but only had Â£900 on him promising to pay me the reminder later, he never did pay the rest <_<

Maybe this is why I`m always on at our man in Florida :bangin: :lol:

Maurice & I did have a couple of articles published in one of the British motorycle mags at the time & I still have a few items including an early short draft of the book & I occasionally notice information we uncovered appear in articles on Russian motorcycles but that`s it, oh well it was fun while it lasted


----------



## mach 0.0013137

double post


----------



## johnbaz

Crikey Paul- she's a stunner and no mistake B) B) B) B) B)

When you're riding through the country lanes in the blazing sunshine (that we *WILL* get this year  ) it will have all been worth it unk: unk:

Keep up the good work :good:

John


----------



## Silver Hawk

I suppose I should be bidding on this....but the current price is already nuts  ....but I guess the chicken is pushing up the price :thumbsup: .


----------



## PhilM

Dam that is going for some, the bloke will also see the number of times it's been viewed shoot up 

BTW As for this Chicken, I think it's justified as it's free range :grin:


----------



## Guest

Silver Hawk said:


> Boxbrownie said:
> 
> 
> 
> Not so sure about mixing the comp ring and control ring in the same groove,
> 
> 
> 
> I was never planning to do that.
> 
> The plan was to keep compression rings in both grooves but drill oil holes in the second groove and then also cut a shallow recess (25 thou deep) under the second groove with more oil holes i.e. as per orig pistons.
> 
> But now I'm thinking not to drill oils holes in the second groove...
Click to expand...

When i first started tinkering with engines i was introduced to the world famous ''Cords'' company in Park Royal.They had just moved to a new premises in the same area after decades [i understand] at the original.

Having not used them myself for years,a Google search shows adresses in Tunbridge Wells and Merthyr Tidfil.The old Park Royal plant would undertake machining and give the necessary advice on modifications,The trade counter staffed by knowledgeable old-school engineers.

Try also Len patterson at the Cylinder Head Shop for advice,But bear in mind that you will need someone with cam griding kit for piston mods.Simple turning not being sufficient as you need to reproduce the [slight] ovality that a piston is given due to expansion concerns.


----------



## Guest

littlealex said:


> Silver Hawk said:
> 
> 
> 
> 
> 
> Boxbrownie said:
> 
> 
> 
> Not so sure about mixing the comp ring and control ring in the same groove,
> 
> 
> 
> I was never planning to do that.
> 
> The plan was to keep compression rings in both grooves but drill oil holes in the second groove and then also cut a shallow recess (25 thou deep) under the second groove with more oil holes i.e. as per orig pistons.
> 
> But now I'm thinking not to drill oils holes in the second groove...
> 
> Click to expand...
> 
> When i first started tinkering with engines i was introduced to the world famous ''Cords'' company in Park Royal.They had just moved to a new premises in the same area after decades [i understand] at the original.
> 
> Having not used them myself for years,a Google search shows adresses in Tunbridge Wells and Merthyr Tidfil.The old Park Royal plant would undertake machining and give the necessary advice on modifications,The trade counter staffed by knowledgeable old-school engineers.
> 
> Try also Len patterson at the Cylinder Head Shop for advice,But bear in mind that you will need someone with cam griding kit for piston mods.Simple turning not being sufficient as you need to reproduce the [slight] ovality that a piston is given due to expansion concerns.
Click to expand...

Cords Piston Ring Co Ltd,Tunbridge Wells


----------



## broken guzzi

Thats a beautiful bike, ive been waiting a year for cam pulleys for my guzzi engine to be re-manufactured so i appreciate all the work you have done, hope she is on the road for you to enjoy the summer with, regards, jim :kewlpics: :thumbsup:


----------



## bry1975

Sounds like you have one of those multi axis QA stations very posh? :thumbsup:


----------



## BondandBigM

bry1975 said:


> Sounds like you have one of those multi axis QA stations very posh? :thumbsup:


I have a feeling that FORD will have something a bit bigger, throw in a couple of James Bond lasers and think more along the lines of measuring a whole car 










I used to use Renishaw kit on our machines.

http://www.renishaw.com/en/1030.aspx


----------



## bry1975

Is that Dagenham Ford I suppose? :cool2:

I remember the last time I delivered to the Ford Southampton Transit plant they were using forklifts to move the Van shells around site, found it quite an interesting place along with the now shut Ford foundry at Leamington!


----------



## Guest

Silver Hawk said:


> The plan is to drill oil holes in second groove but keep compression ring and also turn a shallow groove with holes below the second ring (as per original pistons). These bikes are known for over oiling.
> 
> :


Have just had a look over the pictures of the pistons more closely.

I seems that this design provides too much oil to the cylinders.Plumstead have then tried to curb this by using the slightly unusual [And what would be considered over the top otherwise]arrangement what with a control ring and then the shallow drilled groove below this.I say stick with the original plan you proposed here.

What you are doing here is a compromise anyway.The motor will run set up as such,But i would suggest keeping an eye on revs and temp,and ensuring a good supply of clean oil at all times.This bearing in mind the reduced size small ends which will need attention more frequently what with the increased load placed on them.

I did think about trying to reduce the pressure coming off the oil pump,But of course,this reduces pressure to everywhere else [big ends Etc] and not just the problematic cylinders.Seems you can't win here,and that the best will be a compromise.



JonW said:


> My only worry is the expansion of the stub grabbing the ring and pushing it out if the steel expands more than the alloy


It's always a good idea to slightly round off the innner ends of piston rings with a stone to prevent them catching anywhere.

Did you or the chap who did the hone get around to chamfering any sharp edge left over on the top of the bore ?.Doing this with a chip of silicone carbide or slipstone dipped in oil will take of a sharp enough edge [DO'NT CUT YOURSELF !!] which will glow at high combustion chamber temperatures.This produces [Damaging] pre-ignition or ''Pinking'' problems.Check for,and take off any sharp edges at the bottom of the cylinders also,This will make the later handling i describe safe.

Let me know how you get on,and i will give you a necessary [You will see why when you understand how it works] but seldom practiced,step by step method of cylinder preparation as practiced by top tuners and restorers.


----------



## SharkBike

Silver Hawk said:


> And the bike:


Know I've said it before, but ... :notworthy: :wub:


----------



## Silver Hawk

An update...the thought of riding around all year on the new Kawasaki with the Silver Hawk languishing in a cardboard box was too sad to contemplate. So spent the day in the garage yesterday and will do so again today.

Small end bushes now made from phosphor bronze (PB102) and safely in the rods:




























And BSA Bantam pistons modified. A 20 thou deep relief under the second ring and 10 oil drain holes / pistons around the periphery. The holes are deliberately stepped: 2 mm drill all the way through with 2.5 mm on outside. In addition, couple of oil holes for the gudgeon pin. And all X 4 of course



























Back into the garage to gap the rings and then we can start re-assembly. h34r:


----------



## JonW

littlealex said:


> Let me know how you get on,and i will give you a necessary [You will see why when you understand how it works] but seldom practiced,step by step method of cylinder preparation as practiced by top tuners and restorers.


Im all ears/eyes for any guide Alex, Im doing my RD350 engine rebuild soon. Ive done loads of engines, but am always keen to learn more.


----------



## nolsj

Griff said:


> This guy is staggering down the pavement from the pub when he sees a man at the kerb attending to his bike.
> 
> He asks.............you broke down mate?
> 
> Man says..............yeah, piston broke
> 
> Guy replies.........that makes two of us!!! :bag:


Dreadful.


----------



## JonW

Silver Hawk said:


> An update...the thought of riding around all year on the new Kawasaki with the Silver Hawk languishing in a cardboard box was too sad to contemplate. So spent the day in the garage yesterday and will do so again today.
> 
> Small end bushes now made from phosphor bronze (PB102) and safely in the rods:
> 
> .
> 
> .
> 
> .
> 
> .
> 
> .
> 
> Back into the garage to gap the rings and then we can start re-assembly. h34r:


Paul, loving the pics etc. I will do the same when I do my RD engine to repay the favour


----------



## Guest

Silver Hawk said:


> Small end bushes now made from phosphor bronze (PB102) and safely in the rods:


Saw the pictures.Way To Go Paul,Well Done !



JonW said:


> littlealex said:
> 
> 
> 
> Let me know how you get on,and i will give you a necessary [You will see why when you understand how it works] but seldom practiced,step by step method of cylinder preparation as practiced by top tuners and restorers.
> 
> 
> 
> Im all ears/eyes for any guide Alex, Im doing my RD350 engine rebuild soon. Ive done loads of engines, but am always keen to learn more.
Click to expand...

Bearing in mind the point at which the Matchless build is sitting now,Two points firstly come to mind.

As for as the piston circlips are concerned i would say this.There are those that wont entertain standard stamped clips and will modify a piston to take the round wire type.Alternatively there are those that will choose to Loctite in flat clips [WHATEVER you do,Make absolutely sure that the clips used are properly seated.A tip being,to use one of the plier ends to rotate the clip in the opposite direction to one of it's ends as a check].This would obviously be a good time to machine new grooves into the pistons while the motor is in bits ...Providing you have the kit to do it.But is your own call,depending on the proposed use of the motor [High RPM racing Etc].

Also,I would check at this point that any bevelled edge or ''Lead'' given to the bottom inner of the cylinders,is checked at this point to aid assembly.Any roughness or nicks here can make for a frustrating time when trying to fit the cylinders to bore.Check this edge for smooothness,And if necessary go over this with some worn/oily emery cloth.Do this now.


----------



## Silver Hawk

A small update...I've come to a grinding halt for the time being.

Put the supplied rings into the bore to gap them: 3 thou per inch bore diameter, so about 7 thou on this barrel. Only to find the gap was already 32 thou  . Not due to the bores being too large...so a call to the suppliers and they've dispatched some others for me to try; they should arrive early next week.

Alex, circlips on the new pistons are round style; on the old pistons they are flat style. Matchless altered the piston design several times during the Silver Hawk's 5 year production run...and Hepolite also had different designs for the Hawk. My old pistons are actually Hepolite ones...and are considerable heavier than the Matchless version.

Juris is a distributor for Flexhone...and highly recommends the tool:

http://www.brushresearch.com/index.php


----------



## Guest

Silver Hawk said:


> A small update...I've come to a grinding halt for the time being.
> 
> Put the supplied rings into the bore to gap them: 3 thou per inch bore diameter, so about 7 thou on this barrel. Only to find the gap was already 32 thou  . Not due to the bores being too large...so a call to the suppliers and they've dispatched some others for me to try; they should arrive early next week.
> 
> Alex, circlips on the new pistons are round style; on the old pistons they are flat style. Matchless altered the piston design several times during the Silver Hawk's 5 year production run...and Hepolite also had different designs for the Hawk. My old pistons are actually Hepolite ones...and are considerable heavier than the Matchless version.
> 
> Juris is a distributor for Flexhone...and highly recommends the tool:
> 
> http://www.brushresearch.com/index.php


Handy about the clips,Seems that round may be becoming an industry standard.

But though,Looks like you've been supplied the wrong rings with these pistons here :angry2:.

Bearing in mind that you will be aiming to achieve best cleanliness with each stage before moving to the next,here is something you could do in the meantime.

1/Clean the bores with [Clean] rag/Blue roll and something like WD40.

2/Using warm water and washing up liquid,Scrub the bores with a nylon [Nail] brush.I guessed that if these particular bores are not too wide,a bottle brush may prove handy for this.Dry the cylinder.

3/Using clean and lint free WHITE cloth.Wipe the bores with solvent,Changing the cloth or turning frequently and only moving on to the next bore when the cloth stops showing dark [Honing grit] smears.

4/Give the bores a coating with the same WD40.Put the block in a plastic bag i'd say,and lay safely to on side.

For a modest displacement,you have multi [small by most standards] bores here,Making this method surely applicable i feel [Rare and valuable bike also].This method helps preserve these components here,And gives you as good a start for starting up and running in as you will get.


----------



## Silver Hawk

Time for an update...since I finished rebuilding the engine a few days ago and I'm now riding the bike h34r: . Thanks to Seadog Mike for helping me put the barrel on :thumbsup: ...a really difficult task on a double V-twin without breaking a ring.

When I say "riding the bike", I mean I have done 2 miles at 10 mph. So far so good, and I'm encouraged; there are not clouds of oily smoke coming out the exhaust system despite no oil control ring. It nipped up once but freed off immediately...a common occurrence in my experience with vintage bikes and nothing to worry about...yet.

It just needs careful running in but I'm surrounded by hills which is a real problem...I need to find an open flat road when I can potter along at 25mph for several hours in top gear. The A23 is the nearest but no way am I travelling at 25mph on that race track :down: .

Last set of photos I took:


----------



## BondandBigM

Good job, the first fire up after a rebuild is always a bit nerve racking


----------



## Boxbrownie

Excellent news there, glad its all come together now....tell the truth I forgot all about this thread









I remember towing my Cooper S with a 1293 Longman engine for about 4 miles before the bloody thing would free up enough to fire on its own.....had about a 13:1 comp ratio and a super sprint cam, not good for ticking over at anything below 1500rpm  Scared a few Escort Twin Cams in her time though :boxing:


----------



## Silver Hawk

An update....

Put the Hawk away for the winter in Oct 2010 after clocking up 660 miles since this major work. The last nip-up* was at 630 miles. (*not really a seizure; by the time you've pulled in the clutch, stopped the bike, put it on its stand, the offending piston has free off and we're on our way again.)

Got the Hawk out last week, dusted off the cobwebs, and have now completed 900 trouble-free miles and with no more nip-ups thumbsup.

Actually, not quite trouble free (  ). I've been chasing an HT related problem since last year. Symptoms are very straight forward: huge 20mm spark when cold from plug lead to earth which reduces to almost nothing when the bike is hot and sometimes resulting in me limping home on 3 cylinders instead of the normal 4. Checked all the usual suspects: tried 3 different coils, many condensers, new HT leads, rotor arms, points, good earth in distributor, several batteries, charging.

It was the distributor cap! Which was a new pattern one :taz:. Now looking for a good original Lucas one; shouldn't be too hard since they are the same as an Austin 7.


----------



## ketiljo

Silver Hawk said:


> It was the distributor cap! Which was a new pattern one :taz:. Now looking for a good original Lucas one; shouldn't be too hard since they are the same as an Austin 7.


That was a new one, the words Lucas and good used in the same sentence 

"A gentleman does not motor about after dark", Joseph Lucas, 1923


----------



## Silver Hawk

ketiljo said:


> Silver Hawk said:
> 
> 
> 
> It was the distributor cap! Which was a new pattern one :taz:. Now looking for a good original Lucas one; shouldn't be too hard since they are the same as an Austin 7.
> 
> 
> 
> That was a new one, the words Lucas and good used in the same sentence
> 
> "A gentleman does not motor about after dark", Joseph Lucas, 1923
Click to expand...

People are unfair about Lucas....Prince of Darkness :no:

BTH and Miller produced far worse electrics in the 1930s.


----------



## pauluspaolo

Fantastic work Paul - puts me to shame with the SS1! All I've done with that is bung another engine in it over the course of 3 years & I still haven't finished it !!

Enjoy the bike - it's got soul which is sadly lacking in many modern machines (though they'll probably develop it as the internal combustion engine makes way for new technology) - & here's to another 70/80 years of motoring :thumbup:


----------



## mach 0.0013137

I have a lot of respect for people with mechanical ability :thumbsup:

Unfortunately, apart from very simple stuff, I`m more like Ogri`s friend Malcom when it comes to fixing things :hammer: :duh:


----------

