I am having a 16H head gasket template made right now for solid copper gaskets. If anyone is interested in one, please let me know so I can have an idea how many he should produce. Unsure of the price right now, will know more shortly and I will post it here. They will be made in the USA, but he posts worldwide.
Sam

Sam,
please count me in.
can you confirm what thickness they will be?
thanks
iain.

I'll get back to you on thickness.

O.k. got some more info. The original NOS one I supplied him was 1.6mm thick. This is pretty much mid range of the thicknesses he can offer. He can supply .40mm to 3mm thick. For my own purposes, stock 1.6 mm is what I will get. Here we go with the price now. 24.00$ USD each plus shipping overseas which he has guesstimated at 12.00 USD. In the US they will be 28.00 shipped. He says his biggest expense is copper at 7.00 a pound.
I will wait a couple days before giving him an idea as to how many to produce.

Thanks Sam,
i will try to check my bike today but my thinking is a thinner one - probably 0.6mm if that is available.
iain.

Could the BSA chaps advise what thickness they use with solid copper ?

1.6mm seems about the thickness of an unused composition gasket but presumably they compress much more than solid copper when fitting ?

I'm interested.

The one I sent him, which I believe was WD NOS surplus, had a hard fiber core with copper lining on one side, it did not seem to compress much at all which is why I assumed that thickness to be good, however if consensus is reached that thinner would be better, I'd certainly go with that. As I say he can go .4mm and up.

I don't know, Sam. I don't use copper on the Commando as they leak round the pushrod tunnels and the compositions for those are Halite or something and they don't compress too much but the modern versions of the 16H copper /asbestos (I hope they've found a substitute) are a different story.
Tightening one of those is like biting into a particularly extravagant cream slice...The more pressure that's applied, the messier it gets.

The spare M20 gasket I have from TT John measures 1.06mm and the Triumph 5SW gaskets that Lani just made for me are 1.6mm. He lists these in imperial as .042" and .063". Based on the compressibility of the modern composhite gaskets. I'd say anything between 1mm - 1.5mm would be fine. I find once the head is torqued down and re torqued when hot is usually all that's needed with solid copper. Ron

email (option): ronpier@talk21.com

I have checked a used composite gasket i have on the shelf (well it might come in handy) and it comes in at around 1.7mm thick. My guess is it would be a decade or two old from the look of the engine it came out of.
The reason i am looking at a thinner copper gasket is that i have a spare head which is currently at a workshop to be planed so that i can play with increased comp ratio. A thinner gasket, if still effective, will mean less machining.

Sam if possible i would be interested in one at 0.6mm and a second at 1.6mm
thanks
Iain

Ok, am interested in one or two too, have just measured an Original(?) composite copper/asbestos 16H one, and that is 1/16" and an unused new composite one, and that is also 1/16" or .0625" or 1,6mm.

Would not go any thinner, as heads and or barrels get skimmed, after 70 years who knows what has happened, and valves/piston could touch the head when gasket is too thin.

Cheers,

Lex

ps, Ron love the "composhite" wording!!

email (option): welbike(at)welbike.net

Here is a copy of an e mail I sent to Rik on the subject which may be relevant....Ian

'Hi Rik,..It's about clearance under the head....I can't say I'm familiar with the Norton set up but I would imagine it incorporates a 'squish area' somewhere....With the flat piston of the BSA the squish is created under the flat part of the head.....The principle is that the gases are squeezed out of the squish area into the remainder of the combustion chamber which obviously includes the area for the valves..This makes for effectively a smaller combustion chamber and a smaller flame front at combustion which reduces the tendency for pre ignition or pinking.
The principles were established by Ricardo quite early on.....
Alternatively squish can be over the top of a domed piston.....The critical feature is the clearance between the piston head and the cylinder head face in both cases....Once clearance exceeds .040" in the squish area it no longer functions as intended.
Taking the example of the M20 however, this has some 'flex' in the crank assembly when the engine is running, which reduces the squish...So, in that case if the squish is too tight when measured statically and then the crank flexes when running, there will be piston/head contact...Trust me...I've experimented with this and it does happen.
I wouldn't imagine the Norton is unaffected by this 'flex' as the crank pin assembly isn't as heavy as the BSA one.
In practice therefore I recommend a squish clearance measured with the engine static of .040"....This will reduce once the engine is running but won't result in contact between head and piston and guarantees the clearance is within the accepted range for squish (up to .040" maximum....)
The M20 piston comes to the top of the cylinder at TDC and is flat, as is the underside of the head...So in that case the fitting of a .040" thick copper gasket sorts out the clearances simply....(Copper gaskets, effectively, don't 'settle' and more or less retain their full thickness....)
Some consideration should be given to how all this applies to the 16H with the clearances I have mentioned and the particulars of the 16Hs layout in mind..best regards...Ian'

email (option): ian@wright52.plus.com

I have also just measured an original unused 16H copper asbestos gasket and it measures 2.1mm. Allowing for compressing and based on Lex and Ian's comments. I would also agree that 1.6mm is a saver option.I doubt that by raising the compression by say .5mm will have much affect on the performance and at the risk of the 'pop up piston' hitting the head.
Sam can you put me down for a 1.6mm to hang on a nail as a spare please.

Ron

PS. I suppose it would be simple to put some plastiguage on the piston crown and turn the engine over by hand with the head lightly fitted with out a gasket to determine the thickness of gasket required to obtain the optimum squish......Or am I getting to anal?

email (option): ronpier@talk21.com

At the risk of highjacking the thread.
I was inspired to look at the engine after a fellow NZ club member rode his WD16H (accompanied by a friend on a 1929 CS1) from north of Auckland to our rally in Collingwood (South Island) earlier this year. It was a stealth machine - larger inlet valve, relieved head over the inlet, increased compression, machined a radius on the edge of the bore to improve flow, smaller diameter exhaust also allegedly helped.
A while ago i had a play - a dob of bluetack on top the piston, gently turn the engine over. (did someone say anal?) There was way more that 40 thou clearance over the piston.
So the plan is up the comp via planed head and have the bore edge radiused. Way too technical for me so when i said the spare head was at a workshop i didn't mention that the rest of the bike was there too. From earlier discussions on this topic we (they) are working to 40 thou clearance.
The aim is better grunt on the hills rather than top speed.

The sidevalve combustion chamber layout is pretty poor and needs all the help it can get...Whilst not everyone wants to get into these sort of modifications ensuring the squish is operating correctly is pretty fundamental to the engines design and I believe is best regarded as a requirement rather than an option...Ian

email (option): ian@wright52.plus.com

Sam, please put me down for 1.6mm if that is the consensus. Cheers, Rik

O.K. Sounds like the 1.6 mm is the way to go. He stocks the 1.6mm copper. lain, he doesn't stock 0.6mm, he has 0.66mm, is this satisfactory? If so I'll tell him to make one of this thickness. He says the thinner gasket will be more like 20.00 USD. My gasket is at his programmer right now, so still a bit before he makes them, It will give a chance for others to reserve one if they wish.
Also, this is not a one time deal, he will have the gasket on file and will be able to make them on demand, I just figured if anyone else needed one, it would be good to have him make a few while he was at it. I will let you know when they are ready and you can order them directly from him. His site is www.coppergaskets.us.

Thanks Sam, 0.66 will be fine.

Hi guys, the gaskets are being made this weekend and he will be ready to ship on Tuesday at the latest.
Here is what I gave him for numbers.
Mine 1
Ron 1
Iain 2 (1 @ 1.6mm and 1 at 0.66mm)
Rik 1
Lex 2 ( You had written 1 or 2, I told him 2, if you don't want the second one, I'll buy it, just let me know)

Please get in contact with him, his email address is gasketman@cox.net this is also his Paypal address. His name is Lani and he just quoted me 22.00 USD plus your postage, so a bit better than originally quoted.

A friend of mine has just been given a 16h that is a basket case. The engine was loosely thrown together with a domed piston fitted which of course hits the head. I presumed it was an ES2 piston because everything else about looks like a Norton piston including the grooves around the skirt?

I just looked up a piston on Ebay and it also seems to be domed? What's going on? When did a sidevalve engine havs domed pistons??? http://www.ebay.com.au/itm/Original-Norton-16H-Motorcycle-Piston-1931-1948-60-Hepolite-/121158913948?pt=UK_Motorcycle_Parts_13&hash=item1c35a24f9c

Quite right Douglas. Here is a standard 16H piston. It doesn't work like an M20 and has been discussed earlier in this thread. Ron

email (option): ronpier@talk21.com

Sam if it's ok with others I will email Lani and get the best price for 4 to me. As I will see Rik /Lex in a couple of weeks. Ron

email (option): ronpier@talk21.com

Now i've got to re learn sidevalve stuff again? I think we'll look for a more efficient flat top piston if we can find one.Seems a stupid idea when the top of the head is flat anyway.

Douglas,
I run a 1935 16h and have built a few WD type 16hs. All 79mm bore side valve norton pistons are slightly domed as Rons pic. 1930 to 50s 79mm OHV standard Norton pistons have flat tops with cut outs for the valves. You could try one of these but i think you are waisting your time.
The piston will hit the head if no gasket it fitted as they run close. I have a NOS soild copper head gasket hanging in the shed it's an original item from the 30s, if you want i will measure the thickness.
A good well put together 16h with good cams and followers and non recessed valves will be as good as any M20, maybe not as mechanically quite as the M20s also the 16h is a bit more agricultural than the M20.
I have both and i like each one as they are, totaly diffrent bikes but both bring smiles.

Tim W

email (option): t.j.walker@btinternet.com

No way! You will have to justify that! The wd16H was always the more expensive, slightly more civilised machine (although admittedly it is based on the 1936 engine)
Just look at the forks, a work of art.
Regards
Keith H

The 16H was more expensive primarily because BSA benefitted (and their customers did) from the economies of mass production...It wasn't that the Norton was a far better product overall..
When considering the 16H you have to forget the Manx, much as you don't think about Gold Stars when you look at an M20...This is 'base' model stuff built to a price as a utility machine...
The Norton engine was a 1935 design which itself had evolved from an earlier design..it was not 'fresh off the drawing board' even at that time.

Grease lubricated valve guides for instance were a 'vintage period' feature along with the 'splash fed' big end, 'parallel' pattern cylinder finning, 18mm plug, and the extended exhaust port..
Lack of valve timing marks and less well designed valve gear are also negative features of the design IMHO..
Likewise, the gearbox was old fashioned with a very long 'movement' that came from its hand change background...
Saying that, the bike also had some nice features such as the forks and they have a nice robust frame..

However, as both machines produce similar power and are in a chassis of similar weight their performance is compatible and it could fairly be argued they represent two different ways of doing the same job....

From a purely design point of view though, when looking at the engine and gearbox logically, the M20 does have the more 'modern' design features that reflect the thinking prevalent by 1938.. and I think it is easier to assemble and has a superior valve gear layout ...
None of this was intended to produce a faster machine though...that wasn't the point of it, so there is little to choose between them in practice 'on the road'...
I don't really think either is entirely 'better' than the other...
They are different though and both have good and bad features, so it's really down to how you perceive the overall picture in making your choice.....

Regarding the 'domed' or 'non domed' piston discussion...The point is that there should be a working squish area that, effectively, reduces head volume and size at TDC. This aids better combustion by reducing the flame front into a more compact chamber and thus reduces the tendency to pre ignition (pinking) present in 'non squish' sidevalves....
This principle was established in the very early years by Ricardo and the practice was adopted by most manufacturers, though to achieve this, the correct head to piston clearances are required...
Whether that is done with a flat or domed piston makes no difference to the squish itself as long as the clearances and piston/head shapes are correct....
I run a domed piston in my M20 but the head has been altered to match it to maintain squish...
This set up ('pop up' or 'semi pop up' piston) also improves breathing as it increases the size of the throat between the top of the barrel and the bottom of the head without compromising the compression ratio....Ian

email (option): ian@wright52.plus.com

Hello Ian
I agree with what you say about the engine and gearbox, but I did admit the engine was to 1936 spec. Not Norton's fault tho' the army didn't want the better 1939 spec engine which was available before the war. The big end is positively lubricated though.
Also there is the undeniably superior wet clutch, I haven't needed to look at mine in 20 years, touch wood, also the interchangeable wheels and better brakes.
I didn't mean to start a, mine is better than yours debate, but I had to stick up for the Old Girl!
Regards
Keith H

That debate has been had before Keith...and will continue as long as there are different makes of bikes...and it will always be debated with conviction...
However, as machine selection is far more than a forensic analysis of the particular design features and is also based partially on far more subjective features such as styling, handling, machine dimensions, company history etc. etc. there is no resolution to it...
Me?...I'd take the BSA every time over the Norton and have no doubts I had made the right decision...
The right decision for me that is...Ian

email (option): ian@wright52.plus.com

Hi Ron, Yes, I'm sure he'd love to package once instead of 4 times, set it up with him! Save on shipping, that's for sure.
Sam

I have ordered 6 with Lani to get a bit of discount. Ron

email (option): ronpier@talk21.com

No way was i knocking the 16H as i said i have both and like them both but they are completely diffrent machines. The M20 is a bit more civilized and quiter but it does not matter to me, as Ian says they do the same thing.
The pre war 16H with a chrome panel petrol tank and chrome oil tank would have looked very smart in its day. Norton's were always expensive compared to other makes of similar design, think they held the high price tag due to the pre war racers and the well known Norton riders. If you have ever seen one of the pre war Norton sales brochure called the Roadholder you can see why they sold well. These brochures ran from around 1933 till the war and had around 40 pages with all the new models and the previous years competition success.
Don't lets get into a discussion of which is best of the 2 bike as it's 6 for one and half dozen for the other.

Tim Walker

email (option): t.j.walker@btinternet.com

Funny how the 16H - v - the M20 debate surfaces with regularity.......you can almost rely upon it, along with tax and death.....:o)

For my tuppence worth, I've done many, many miles on both.......and they are both very different to ride and maintain........I like the M20's weight, solidarity and grunt, but also like the 16H's sleekness, one-piece frame and vintage "feel".........

Finer details....personally I prefer the 16H's ground clearance compared to the M20, the forks are arguably far better, 'though a pain to initially assemble (damn check springs !!) and are not bushed (so a maintenance menace).......and the gearbox (originally intended for hand-change) does mean that you need to move your leg to effect changes but those changes are very sweet and precise without the clunking you get with a Burman.......closest I've found to this sweetness is the Albion fitted to Enfield's.........and the clutch, beautifully light and trouble-free.........but having also used two M20's as daily transport for several years they were comfortable, reliable and never let me down......neither has the Norton........

In many ways, it's a bit like cars.....you eventually settle for something you are comfortable with, and for me it was the 16H over the M20, despite the various peculiarities........I'm lucky to have more than one WD bike, all reliable and individual in their own way, but if I am ever given an option I generally plumb for the Norton..........

Those exposed valves have never needed any attention other than occasional adjustment, the exhaust valve and seats never seem to display any wear, and my cylinder head fitted with a NOS WD copper/asbestos gasket has never given any trouble nor leaked..........yes, it's been rebuilt any maintained properly, and perhaps isn't serviced as often as she should be, but she is reliable enough to be almost trouble-free..........I think the designers got this one just about right....(though she probably wasn't built on a Friday afternoon...lol !).....

email (option): sjmwdbikemad@aol.co.uk