High quality (UK manufactured) coil valve springs to fit the first Norton OHV models manufactured 1924 - circa 1929, and also the first Walter Moore CS1 models 1927 - circa 1928.  These models identifiable by having a smaller and more deeply conical type top spring cup than the type that followed in 1929. They have a smaller outer diameter than the next generation of springs that followed in 1928-29 (and there may have been a short period of overlap - possibly the new type being fitted to just the CS1 models and the smaller type still fitted to some OHV models).

They are identifiable from the larger springs thats superceded these (on OHV and CS1 models) in approximately 1929 - by having an outer spring OD of 37.3mm and an inner spring OD of 23.5mm.  the 1929 onwards springs are wider than these

Spring Length: The length of the Outer Spring is 45.7mm and the inner spring length is 35.4mm.  Please satisfy yourself this length is correct for your engine and valves - as I am told by 1920's experts there may have been a longer type, and regardless of that - some owners may have also fitted slightly longer valves than the original valves these springs were intended for (but we know these are original Springs for Norton OHV engines from their packaging, and they have been fitted to original genuine early type cups - so they will have been fitted to some OHV models of that era!!).

PLEASE NOTE BEFORE ORDERING: These springs are intended for the first 'conical' type cups made from 1924-@29.  We do not currently manufacture the cups for this early type.  The cups we offer (Item 1029) are for the 2nd generation type introduced circa 1928.  Do not order those cups if intending to fit with these springs.  Email us if you require more information

Price is for a set of 4 springs (i.e. enough for one engine)

Update February 2023:  Please note that the length of the outer springs of this spring set are @44mm long.  We mention this because we have had feedback from a customer with an early 1928 Walter Moore CS1, which was fitted with this early 'small' type spring (as supposedlly the first CS1 models were) but his engine may have been fitted with later (ES2) valves - and these springs were too short for that particular bike.  It is difficult to be definitive about if the early CS1 models fitted with this smaller diameter 1920's type spring also had shorter valves - but please bear this in mind.  If you do have a CS1 (or 1929 ES2) fitted with this early type of valve - and the length of the outer spring is longer than 44mm we would be interested to hear from you - on sales@racingvincent.co.uk.  Thx.

Hard to believe - but to make these springs, we were able to borrow from a collector friend a 100 year old, 'New Old Stock' genuine set of Terry's valve springs - still in the remains of their orgiinal box! - see accompanyning photos.  As an aside, we have many original sets of Terry's valve springs we use for patterns - but I have never seen Terry's packaging as old as this type, and with different colouring and branding to the later types that followed.  However, it is just possible to confirm they are indeed for OHV Norton models of the earliest design, and alongside them you can see original 1924-29 type top cups.  As always, we have had these valve springs replicated to the original dimensions and design by our top quality UK spring manufacturer.

This design of valve springs (with very small inner spring, when compared to most OHV and CS1 coil springs that followed) was fitted to the very first design of 'Flat Tank' OHV Norton models from 1924 to approximately 1929 (it is hard to tell exactly which year they swopped over to the later and larger spring - as Spare Parts lists for circa 1928-29 were seperate for SV/OHV and ES2/CS1 and supplements were later added - it may be some Model 18's continued to be fitted with the earlier spring types, while ES2 moved to the later design first.

This first design of valve spring and deep conical cup were also fitted to the earliest Walter Moore CS1 models - probably 1927 and 1928.  But if you have a CS1 model - please enquire with us if you are not sure - sales@racingvincent.co.uk, as we have spoken to CS1 owners with both types fitted - and we gather many owners of earlier machines may have switched to the later design at some point in the distant past!

Please Note:  This type of spring - and the conical top valve cups that were used with them, are of smaller diameter and length than the later type of spring/conical cup that followed in approximately 1929 (see Item 1029 for the the 1929 onwards conical cups and Item 0966 for the valve springs that were fitted to that later design) - so although this distinctive 'Conical' style top cup is a good identifier - it should be noted that there were two types ftited between 1924-1932  . . .  when ordering it is important to ensure your engine is fitted with this earlier type, as I am told it was not unusual for earlier Pre-1930 OHV and CS1 models to have been retrospectively fitted with the later and 'beefier' valve springs and larger conical valve springs cups.

We are pleased to be able to offer this spring, particularly as it was patterned on genuine period valve springs - and as I write this listing in November 2022 - I can say that these have the earliest Norton Part Number we have ever referenced - that being Part Number 1074-1075, as listed in the 1925 Norton Spare Parts List!  (and picture of a Model 18 from the factory photograph of that 1925 year is shown)

Final Note on these springs:  We do not currently have plans for making the distinctive cups for these early type springs (although we do nmanufacture the 1929 onwards type) .. . but if you do require them, contact us, we may consider making them in the future if enough demand

This item is for a pair of the distinctive 'conical' shaped valve spring cups, of the type that were fitted on OHV and Walter Moore CS1 Norton engines trom approximately 1928 up to 1931.  CNC machined from an original pattern, including radial holes (for the top valve cup) - these are designed to fit the early spring type (which we can also supply - Item 0966 or 0967). 

Note: sold as a top and bottom cup pair - 2 sets required per engine.

PLEASE NOTE BEFORE ORDERING:  There were 2 types of Conical cups (not commonly known) made by Norton - an earlier type fitted from 1924 - @1928, of smaller diameter, THEN THIS TYPE: made from approximately 1928/29, but I am told - sometimes retrospectively fitted to earlier models.  If ordering this type, they are intended for our Valve Springs Item 0966 or 0967.  We only sell the valve springs for the earlier type, not the conical cups - they are Item 1135 (see the listing for this spring for more information).  The earlier type valve spring will not fit these cups. See photo.

This type of valve cap are now extremely hard to find, this is possibly the first batch made since Norton Motors last made them  . . . probably about 1931! 

They are the second design of Conical Valve Spring cups - and look to have been fitted from approximately 1928 onwards.  Prior to this date, a smaller diameter set of springs were fitted, with much smaller diameter cups and springs.  That initial design was first fitted from 1924 with the first OHV design - and carried through to the earliest Walter Moore CS1 models in 1927.  It was almost certainly found at the time that those smaller diameter valve springs were too flimsy for the power and revs of the CS1 engine and it looks like they were changed for this second type of spring and the cups shown here in approximately 1928.  However, talking to those in the know - it would seem that a number of owners retrospectively changed earlier models (both CS1 and OHV) from the early small springs (our Item 1135) to the later spring (our Item 0966), and at the same time fitted these 1929 onwards type conical caps.

If you are unsure which type of cups and springs are fitted to your model - email us for dimensions before ordering on sales@racingvincent.co. uk

(Note: as I update this listing in November 2022 - although we can offer the Pre 29 valve springs, Item 1135, we do not manufature that very early type conical cups - but if you do want them, email us - I may consider a small batch if enough interest)

Sold as a matching top and bottom cup (they are sold as a pair as they cannot be used with any other type of Norton spring - they are specific to this earlier design), each pair of cups has been CNC machined to the original specifications (originals used as patterns), from similar material to original, and come with a black rust preventive finish applied.  2 Pairs are required per engine.

We can also supply the correct 1920's type coil valve springs - both the 500cc OHV/SOHC type (our Item no 0966) and the even rarer 596cc OHV spring (our Item no 0977), of which both types were copied from original patterns.

These are CNC manufactured to fine tolerance in EN8 steel, then black chemical dipped to protect from rust.  Price is for a single matched pair (i.e. 2 pairs required per engine).  As you can see - these are not cheap, but hope you will appreciate that the setup costs for a quite complex design, and small volumes means they are as competitively priced as we can make them (in reality - I doubt we will ever sell enough to get back the setup costs!).  

Background and Fitting Information:

These conical type valve spring cups are designed to take the 1920's Norton valve spring design - where the inner spring was substantially smaller than the outer spring, both in outer diameter and length.  Therefore it was necessary to design a top spring retaining plate which was conical in outer shape, to allow seating of both springs at very different points.  Because of that spring design, it also necessitated that the inner section of the top valve cup is heavily concave and curved - and has 6 radial holes drilled in them to reduce the overall weight of the top valve cup.  By the early 1930's (sometime in 1931 I believe), this design was replaced on both OHV and SOHC design by a pair of springs were the inner spring was taller and closer in diameter to the inner - I am told this could be because it was realised that having valve springs that touched was a better design.

As far as I can tell, these conical type valve spring cups were fitted to the following models:

- 1920's OHV Models up to 1931 :  They are listed in late 1920's Spare Parts Catalogs as either part numbers 4060/4061 (top/bottom) or parts numbers 5131 (top).  I cannot guarantee if this design was used on the very first OHV models (1922) - but assume they were, and would be glad to have that confirmed by any owner lucky enough to own one this early or thereabouts

- 1927 - 1930 Walter Moore SOHC CS1: Known as the 'Cricket Bat' engine because of its distinctive timing cover and bevel tube shape, this design of valve caps (in conjunction with our 0966 valve springs), were used on that engine - part number 4060/4061.

- 1930 1931 Arthur Carroll SOHC CS1: As far as we are aware, the very first Arthur Carroll SOHC engines (i.e. pre-cursor to the Interanational) also used this type of valve cup design, up until sometime in 1931.  Although surviving engines may have been restrospectively fitted with the later design 'flat cup' to valve spring cup - we would be interested to hear from any owners of an original pre-31 Arthur Carroll engine fitted with this type of conical cups

Fitting information and parts interchangability:  These valve spring cups, and our matching valve springs - 0966 and 0977 were all copied from original Norton patterns.  Looking at the Spare Parts catalogs for the late 1920's, it is possible to see that the valve design for most of the engines had a pronounced 'Tulip' type valve head design.  I have a drawing of one of these valves, and can see they are very similar in dimensions to the later Norton ES2 OHV valve which we stock - Item 0678.  

You will see that in one of the accompanyning photographs we have assembled the top and bottom conical cups, along with valve spring 0966, our OHV collets (0675). G&S ES2 Valve (0678) and our ES2 Valve guide (0696).  Unfortunately I do not have an original valve guide from a 1920's cylinder head, so I cannot confirm that the valve guide (0696) that we sell would have exactly the same chamfer for the bottom valve sring cup as an original 1920s valve guide - but it looks very close.  If anyone has an original valve guide, I would be interested to confirm the chamfer - but please email us if you are ordering any of the parts above for your 1920s model and happy to confirm dimensions of our listed part's shown here - sales@racingvincent.co.uk.

We may consider making a batch of the tulip headed valves in the near future if enough interest - but I know of other owners that have fitted ES2 valves (our item number 0678) to their CS1.

High quality (UK manufactured) coil valve springs to fit 1920's OHV models up to 1933, early (Walter Moore) type CS1 models and the first Arthur Carrol SOHC CS1 engines up to 1932/33 - see detail listing for more information and if your machine requires this type of spring.  Price is for a set of 4 springs (i.e. enough for one engine) 

These springs were fitted to the 1920's models and are easily identified by the valve cap that were fitted to these OHV/CS1 models of the 1920's - which as can be seen in the accompanyning photographs were deeply recessed and conical in the centre, so that the inner spring fitted in the recess of the central recessed part of the conical top cup.

They have been manufactured by a well established UK spring manufacturer, who makes all our valve springs.  An original set of 1920's Norton valve springs were used as patterns, and they are shown in the photographs, next to ours, along with a pair of original top and bottom valve spring cups of the same era - where the top valve spring cup has an easily identifiable conical shape with radial drill holes.

It is hard to be precise about years - but according to most information availble it seems this type of valve spring was fitted to both OHV and CS1 SOHC models up to the end of 1932 or possibly 1933, at which time the spring design and valve cups was changed so that the inner spring was a greater diameter than this early type (although the outer spring seems to be identical). 

Looking at different Norton Spare Parts catalogs - this type of spring cup and springs were shown listed in 1928/29 for CS1 and all OHV models (although the Model 19 springs may have been different - see Item 0967) - at which time the Walter Moore 'Cricket Bat' type CS1 engine was current.  At this time the part numbers for these springs were 4058/59

However, the same style of valve cups and springs were still shown listed as fitting OHV and CS1 models in the 1931/32 Spare Parts catalog, by which time the Walter Moore CS1 had been superceded by the better known Arthur Carroll SOHC design (that later became the International).  It seems this earlier valve spring design carried over first of the later type CS1 engines, before being superceded in approx 1932/33 - but by then the part numbers for the springs were referred to as 3X60/61 (the '3X' being a common way of identifying part numbers in the early 1930's). 

I believe the Terry's numbers for these springs were: VS114 (1920's OHV) or VS109 (pre 34 SOHC).

By the time of the 1934 Norton Spare Parts Catalog came out - the valve springs and cups had changed to the later design (the springs being type 3076/7, our Item number 0889). We also sell spring sets of that later design which replaced this early type - Item 0889, but although they are similar, the later type used very different valve spring cups (see Item 0673 which is the later type 1930's valve cap) - if your engine uses that later type of valve cap, rather than the type shown in these photographs, then you will require valve springs 0889 rather than this type. If unsure, please email for detail.

Talking to some knowledgable Norton people about this spring design - I have heard a view that it is good coil valve spring design to have the inner spring touching the outer spring on compression - and the later (Item 0889) design shows an inner spring much closer to the outer spring, which may be why Norton's changed the outer spring only on the Post 1932 design.  However, if you have an earlier type engine (i.e. 1920's or early 1930's), but fitted with the later flatter (i.e. not conical) top spring cups - this may because previous owner's had changed over to the later spring design later in the motorcycle's life.

If you are unsure - then email us with your engine details and we will try and help identify the correct spring for your engine.

Note we also offer a very similar spring to these - Item 0967, of which were listed by Terry's as being fitted to the 596cc OHV model (presumably late 1920's), which look to use the same valve cups, but are of a different length again.

IMPORTANT UPDATE MAY 2022:  Please note that we are currently checking with some owners of early flat tank and 1928 CS1 owners - it is looking likely that very early Walter Moore CS1 models (i.e. 1928) and pre-1929 OHV machines may have been fitted with smaller diameter valves spring cups and springs - that although looking very similar to these, are actually of a lesser diameter.  As soon as we have verified this, I will update this listing . . . but please contact us before purchasing if you intend to fit these (or valve spring cups - Item 1029 that fit with these springs) to a pre 1929 CS1 mode or OHV model - as earlier springs and cups may have slightly different diameters.  FYI - the outer diameter of these Item 0966 outer springs are @42.5mm OD.  If we verify a smaller/earlier type was used - if someone is able to supply a pattern, we will manufacture a batch. I have an original Norton spare parts supplement showing this type fitted in at least 1929, so maybe they changed the diameter some way in the middle of the Walter Moore CS1 production run, realising they needed to be stronger?

High quality (UK manufactured) coil valve springs to fit 1920's 596 OHV models up to 1933, although they may also fit others models fitted with early conical type top valve caps - email us for details if you are unsure on sales@racingvincent.co.uk

Similar to Item 0966 - These springs were fitted to the 1920's models and are easily identified by the valve cap that were fitted to these OHV/CS1 models of the 1920's - which as can be seen in the accompanyning photographs were deeply recessed and conical in the centre, so that the inner spring fitted in the recess of the central recessed part of the conical top cup.

They have been manufactured by a well established UK spring manufacturer, who makes all our valve springs.  An original set of 1920's/30's Terry valve springs were used as patterns - which are shown in the photographs, next to ours, along with a pair of original top and bottom valve spring cups of the same era - where the top valve spring cup has an easily identifiable conical shape with radial drill holes.

It is hard to be precise about years and models (as some Norton Spare Parts catalogs list the Model 19 valve spring being the same as fitted to the 500cc Model 18) - but the writing on the box that these Terry's springs came in clearly state they are pattern VS110 (which indicates 596cc OHV in their reference charts) and says they are 596cc OHV type on the packet.  It is difficult to say which years this type of spring were fitted up until, but as they fit the earlier conical type valve caps - it seems evident they are pre 1933.

The Terry's numbers for these springs were: VS110.

If you are unsure if these are correct for your engine - then email us with your engine details and we will try and help identify the correct spring for your engine and confirm dimensions of these springs.

Note we also offer a very similar spring to these - Item 0966, which are for the 500cc OHV/CS1 pre-33 engines, again we can confirm spring dimensions and differences if you are unsure

Final Note: As I update this listing in Dec 2020, we are looking to manufacture a small batch of the earlier valve sping conical type valve caps in early 2021.  We will only make limited numbers of these - if you wish to reserve a set, please email at sales@racingvincent.co.uk

Hardened Valve Cap to fit 3/8" Stem Diameter valves.  These have been CNC machined using original period 'Terry' valve caps as the pattern.  These are available in two thicknesses - state thickness when ordering. 

Price is per valve cap

These valve caps are CNC machined to the original 'Terry' valve cap design, they are in case hardened EN32B.

We supply them in two thicknesses - the thickness being the amount they will sit proud of the top of the valve once fitted - the two sizes we offer are:

- 1127_1 :  0130"-0.135" Thickness - this will be sent as default if customer does not make a request when ordering

- 1127_2 :  0185"-0.190" Thickness 

The 1127_1 (0.130" thickness) item is one of the thicknesses originally offered by Terry in their Valve Cap boxes (see accompanyning photo of original Terry Valve caps)

Background and Fitment:

First of all - let me say, that I do not normally fit valve caps to my own SOHC engine builds.  Not because there is a problem with doing so - but I suppose I have always had the luxery of being able to machine valves to the length I require.

However, I have been asked various times over the years by SOHC engine builders if I can supply them - so, we have now manufactured a small initial batch (as at time of writing this - October 2022), and will make more in the future if popular.

I have heard various stories in the past, as to if Norton themselves supplied valve caps for SOHC engine builds - I have not seen them listed in the main Norton Spare Parts lists cambox sections - but I know they are considered useful if you are building a SOHC engine and cannot get the cambox rocker arms to sit correctly over the valves.  They are also useful if you have one valve that is longer than the other, in relation to the cambox, for bringing both valves to a similar height (i.e. fitting a valve cap on the shorter valve only).

And finally, with earlier OHV Norton engines, using 3/8" valves and exposed valves (i.e. earlier non enclosed rocker box) - the same applies, I know of some customers who have engines where the gap between valve and rockers would benefit from valve caps.

In all these instances - it the engine builder's responsibility to decide if they wish to use valve caps - but if they do, these are modelled on the original Terry valve cap design.

Useful tip if fitting valve caps:  Remember you have them fitted! .. . i.e. they are normally used on engines with exposed valve tops, and sit on top of the valve, with the rocker pad making direct contact on them - with minimum tappet clearance, which stops them flying off.  But they are very easy to forget about and loose when stripping the engine . . . good idea to keep them safe in a bag as soon as you strip engine!

See also Item 1128 - for 11/32" (i.e. SOHC Inlet Valve standard stem diameter) equivelant valve caps

This item is for a spare spring - of the type that were fitted into the distinctive 'Clack Valve' breathers in 1920's OHV and Walter Moore CS1 breathers - an original dismantled clack valve (shown in photo) providing the spring pattern.  We will shortly be manufacturing the complete breather/clack valve unit. 

Price is per spring

Backgound:  This distinctive breather/clack valve unit was normally fitted to both OHV and early Walter Moore CS1 engines in the 1920's through to the early 1930's.  Sorry, but I cannot be definitive about which year they were first fitted, and which year they stopped using them - but the accompanyning photos of engines shows them fitted to the crankcase of CS1 Walter Moore engines (normally either behind or in front of the barrel), and in the timing case of 1920's OHV models.

The pattern we are using came from an original 1928'ish Walter Moore CS1 engine and looked to be complete and untouched for many years (lent to me by a close friend Norton collector).  It has a small steel disc that sits in the chamber of the main bottom banjo union, and is held against the breather hole by a spring that sits in a similar receptor/chamber of the top union connection.  The spring keeps the disc flat against the hole - the idea being that gasses can escape out, but outside air cannot be sucked in.

This design was replaced by the 'normal' Norton 1/4" BSP 'One Way Valve' (our Item 0248) with a ball valve, screwed into the crankcase above the driveside mains housing - from approximately 1933 ownwards.

Although it is very difficult to be definitive about 1920's components still being original (so often they got worn out and replaced), the spring that was fitted to this breather looked to fit perfectly in this breather - and the wear marks on the top of the steel disc corresponded to the spring - so we took this spring as being original - and have now had it replicated.

We are selling it seperately, for those that might have an original breather - with insides missing or worn, but at a later date (hopefully later in 2022) - we will be manufacturing the other parts of the breather assembly.  For the moment - the spring is available seperately (apologies not cheap - but we had to pay setup costs for manufacture of a spring which we are only expecting to sell very small numbers of).

For those trying to find more information on this type of breather assembly - you can email us on sales@racingvincent.co.uk.  Something worth noting about this type of assembly - although the actual circular banjo looks like later 'normal' oil fitting banjo's - on this earlier type - it had conical top and bottom faces, with corresponding conical faces on each union - rather than relying on red fibre washes to seal the banjo.  We are looking at having a small number of these banjos cast and machined.

These Cylinder Head nuts are perfect copies of the design used by Norton's on 16H and Big4 Side Valve models, from the 1930's through to the end of Side Valve production in approximately 1957 - they have a distinctive deep hex and a gradual curve to the top of the nut - which was a Norton feature on many of their engine bolts. 

Price is per nut.  Normally 9 are required for a complete SV Cylinder Head.

We have CNC machined these, using an original 'New Old Stock' Post War 16H nut - ours are identical, other than being manufactured from stainless steel, so they do not rust and will transform the look of your SV engines cylinder head! However, as you can see from the factory picture of a 1937 WD 16H engine - the same design of Side Valve cylinder head nut was also used pre-war (sorry, I am not sure when this nut design was first used - but providing your cylinder head studs are 3/8" x 26tpi BSC, then these should fit).

We inclujde a picture of the 'New Old Stock' cylinder head nut in the picture (which is normal steel, satin nickel plated), and as you can see we have emulated all the features of the original nut, including the chamfers and shoulders.

Normally - seven of these were fitted per cylinder head, and as they are in a very visible location (and most Side Valve engines I see have original nuts which look a bit sorry for themselves) - hopefully you will agree, fitting a set of these should transform the looks - as well as making removing the cylinder head a much simpler chore if your original nuts are chewed. 

As always, the hex bar we use is the correct Imperial spanner size of the original nut - now even more difficult and expensive to find in stainless steel.

Note: We also sell the corresponding cylinder head studs for these Side Valve engines, in two varieties, both also in stainless steel: Item 1131 - for Pre War type, as per WD16H in photo, and Item 1132 whcih is the type used on Post 1948 Side Valve engines. 

These Cylinder Head studs are of the type fitted to pre-war WD16H and Big4 Side Valve engines through to 1947 - an original 1937 WD16H cylinder head stud being used as a pattern. 

Price is per stud.  Normally 9 are required for a complete SV Cylinder Head.

We have CNC machined these from stainless steel, using an original 1937 WD16H cylinder head stud to ensure we got the lengths of thread going into the barrel, and protruding from the cylinder head, as per the original Norton stud.

When used in conjunctions with our SV Cylinder Head Nuts (Item 1130), they transform the look of your cylinder head, and if your originals are chewed, make working on this part of the engine far easier.

This cylinder head stud was originally Part Number 9136, shown as that in the 1937 WD16H Norton Spare Parts List, but most importantly - also shown as that in the 1934, 1937 and 1939 normal road models Norton Spare Parts List - indicating it was the definitive stud used for all 16H and Model 1 (Big4) models from the indtroduction of the seperate Side Valve cylinder head in the 1930's - through to the final Side Valve 1947 Civil engine (the 1939 Norton Spare Parts is list is very rare - but shows the 1938-47 engine design, which for the Side Valve engine was slightly different to the WD design manufactured for Army use through the war - but the 39 list also shows this part 9136 still being used - proving it was used through to 1947).

Email us on sales@racingvincent.co.uk if you require more information to confirm these are correct for your engine.

If you have a 1948 onwards Side Valve model, then see Item 1132 instead, for the stud design fitted to that later engine 

These Cylinder Head studs are of the type fitted to 16H and Big4 Side Valve engines from 1948 through to 1957 - an original Post War WD16H cylinder head stud being used as a pattern. 

Price is per stud.  Normally 9 are required for a complete SV Cylinder Head.

We have CNC machined these from stainless steel, using an original Post War 'New Old Stock 16H cylinder head stud to ensure we got the lengths of thread going into the barrel, and protruding from the cylinder head, as per the original Norton stud.

When used in conjunctions with our SV Cylinder Head Nuts (Item 1130), they transform the look of your cylinder head, and if your originals are chewed, make working on this part of the engine far easier.

This cylinder head stud differs from the Pre-War type (Item 1131) fitted up to 1947 models, as for 1948 both the OHV and SV engines received a complete make-over, which included the Side Valve models getting a re-designed alloy cylinder head, which required longer (deeper) studs.  See in the accompanying pictures - line drawing fromt the 1948 Spare Parts list, showing this type of stud, and the photograph of our stud and cylinder head nut (Item 1130) alongside 'New Old Stock' originals.

Email us on sales@racingvincent.co.uk if you require more information to confirm these are correct for your engine.

If you have a  Pre-1948 Side Valve model, then see Item 1131 instead, for the stud design fitted to that later engine 

If you have looked at this listing before (i.e. prior to October 2021) you will have seen that we were able to offer a modern reproduction of the original spec KLG ML50 - which had the correct (and now very difficult to find) 18mm 'Long Type' thread, which was 0.750" in length, as was originally fitted to some Norton models (i.e. WD16H Norton and the early Douglas 2 34hp and 3.5hp models).  Unfortunately, these have now all sold and our manufacturer supplier tells us that (partly due to Covid impact) they are not likely to have another batch made, so are now unavailable - sorry.

However, having talked to this spark plug specialist, I am told that there are modern 18mm 'Short Length' spark plugs available (i.e. 0.5" length thread), and these will still work in a cylinder head with 0.750" thread length - and in fact it was quite common for this length plug to be fitted even in period times.  Therefore, we now offer two modern Champion alternatives in this listing - both in 0.5" thread length and will continue to add if other types come available.

We are also looking at the possibility of converting a quantity of 'New Old Stock' KLG WW2 18mm WD aircraft spark plugs (with 0.750" threads) to a suitable motorcycle spec - as they currently have the aircraft style suppression tops.  Email us on sales@racingvincent.co.uk, if interested, we will update this listing at a later date if successful  

Finally, this listing also offers both 14mm and 18mm modern copper/asbestos type crushable washers for spark plugs

Spark Plug Types:

0896_5 Champion D14 - 0.5" Thread Length.  Normal Running for Side Valve Engines:

These are modern 18mm 0.5" reach plugs, made by reputable manufacturer Champion - and the D14 variant is considered the best choice of grades for a Side Valve engine in normal running condition. As 0.750" reach plugs are now unobtainable - these provide a suitable alternative, and according to our supplier - were often fitted to those engines with an 0.750" length spark plug hole even in period times.  

0896_6 Champion D16 - 0.5" Thread Length.  Oily or Rich Running for Side Valve Engines:

These are modern 18mm 0.5" reach plugs, made by reputable manufacturer Champion - and the D16 variant is considered the best choice of grades for a Side Valve engine if your engine runs rich or often oils plugs. As 0.750" reach plugs are now unobtainable - these provide a suitable alternative, and according to our supplier - were often fitted to those engines with an 0.750" length spark plug hole even in period times.  

 For the two plug types above (the same type of plug - but with a fractionally different heat settings - it may be prudent to take one of each type and find which is best for your own engine, if you are not sure which you require.

0896_1 KLG ML50 - 0.75" Thread Length. (Sorry now unobtainable):

For anyone that has searched for the 'Long Reach' (0.750") type 18mm plugs that were fitted to some older (pre-WWII) motorcycles or cars, they will know this longer reach type are now extremely hard to find - most 18mm types now available being a shorter 0.5" inch length - which although can be fitted, can upset the combustion and timing slightly. This type of long reach 18mm plug was of the type fitted to both Douglas 2 3/4hp models (if fitted with 18mm plugs) and some early Norton single cylinder models.   I know this type was fitted to Norton WD16H models - and in the accompanying photographs you can see one of these plugs fitted to an original 1938 manufactured Norton WD16H cylinder head.  I do not have any other earlier Norton 18mm heads myself - but would expect this type of 18mm/0.750" spark plug hole was likely to have been used on earlier Side Valve models and maybe some 1920’s OHV models? . . I expect if you own of these you will know yourself if it requires this type of plug.

Update September 2021 - Very sorry, but our suppliier has now ran out of this plug - and is not expecting to have another batch manufactured (partly due to cost increases post Covid).  I have kept the listing here, in case this changes in the future - and will update it if a new batch are to be manufactured in the future

0896_7 KLG RML 60 - 0.75" Thread Length. (Oct 2021 Enquiry Only - but possible special order):

As at October 2021 - we are looking at the option of converting a quantity of 'New Old Stock' WW2 military aircraft KLG spark plugs - which also have the longer 0.750" length spark plug thread, as fitted to the models described above.  As can be seen in the photograph - as originally manufactured they have a special 'aircraft type' suppressor fitting - and will not accept a standard motor cycle style HT Cap.  We are currently looking at re-manufacturing the top of these to fit a motor vehicle style insulator and central core, so they will accept a standard HT Cap or screw on knurled top.  If interested - please email sales@racingvincent.co.uk - but expect the price to reflect the work required to re-manufacture these, and their rarity

0896_2/3/4 - Crushable Spark Plug Washers:

If like me, you have numerous 'New Old Stock' spark plugs - but they have lost their original 'copper/asbestos' type washer (with the distinctive copper colour), we can now supply them in both 14mm and 18mm sizes - in packs of six.  The 18mm size have two thicknesses - the wider type being slightly more expensive (and sold as a pair) - but the slimmer 18mm type are still usable and worth keeping some in your toolbox in case you lose one on a run.  You would normally replace these washers each time you remove the spark plug (unlike modern steel spark plug washers) – so it is worth keeping some in your toolkit

Note: Originally these heat resistant 'crushable' type washers were copper with asbestos filling - these modern ones no longer use asbestos - but instead a modern safer filling!

If we find any other modern reproductions of the older style veteran 18mm or 14mm plugs we will add them to this listing - please email us on sales@racingvincent.co.uk if you know of anyone manufacturing them, thanks.