- High quality Stainless Steel head bolts for all 500cc Inter and SOHC Manx engines - Set of 4 sleevebolts, slightly cheaper than buying individually.

These 'Sleeve bolts' are threaded 7/16" for their lower part, where they tighten down the head, but are also threaded on their top part to take the cambox bolts, which is located on top of these sleeve bolts.

These are CNC machined from stainless steel and look lovely, they are just as per original.

Note:  these screw onto the barrel studs using 7/16" x 20tpi threads (as per original).  However it is no longer possible to get BSC taps in this size.  Therefore both our studs and sleeve bolts use 7/16" x 20 tpi UNF thread - these have the same teeth per inch but a fractionally different thread form.  We advise when fitting these you also fit our stainless steel barrel studs, which also have the same thread.  (If you are using original studs and really want to keep them you may find it possible to go over the original stud threads with a 7/16" UNF die if they have any tightness, but we really advise just replacing studs with our very pretty new ones!)

Not cheap due to their size and complexity of manufacture

- High quality Stainless Steel Sleeve Bolts (head bolts) for all 500cc Inter and SOHC Manx engines.  These 'Sleeve bolts' are threaded 7/16" for their lower part, where they tighten down the head, but are also threaded on their top part to take the cambox bolts

These are CNC machined from stainless steel and look lovely, they are just as per original.

Note:  these screw onto the barrel studs using 7/16" x 20tpi threads (as per original).  However it is no longer possible to get BSC taps in this size.  Therefore both our studs and sleeve bolts use 7/16" x 20 tpi UNF thread - these have the same teeth per inch but a fractionally different thread form.  We advise when fitting these you also fit our stainless steel barrel studs, which also have the same thread.  (If you are using original studs and really want to keep them you may find it possible to go over the original stud threads with a 7/16" UNF die if they have any tightness, but we really advise just replacing studs with our very pretty new ones!).

Not cheap due to their size and complexity of manufacture

Complete set of 4 x Sleeve Nuts and 4 x cambox bolts (two long and two short) as shown in the photos - and CNC machined in High quality Stainless Steel.  Slightly cheaper when purchased as a set as here, rather than buying individually.

CNC Machined by us to the original design and dimensions.  Cambox mounting bolts have correct lengths and deep Norton style head.

Sleeve Bolts are double ended for SOHC Barrel studs on the lower part and cambox bolts on the upper part.  They are manufacured from the correct imperial hex stainless steel and have correct lips and chamfers (not immediately visible until you look at one properly).

Not a cheap set, but very nicely made, they will not rust and means a decent spanner can be used to properly tighten down the cylinder head . . . when so many original sleeve bolts are 'mauled' or re-chromed, taking away the tolerances. 

- High Tensile Stainless Steel Cylinder Stud Set for 350cc engines (Set of 4).

These are the standard length for SOHC 350cc engines.

Note, sometimes 350cc engines are fitted with 500cc studs and different sleeves. Please email for length details if you are unsure which to order.

We normally sell these high quality engine studs as a set of 4, but we do occasionally sell them individually if required (slightly more, if bought as a single stud) - email us for availability of single studs

High Tensile Stainless Steel Cylinder Stud Set for 500cc (and some 350cc) engines (this for single stud).

These are CNC manufactured by us to the original dimensions and style and transform the look of your engine (particularly if you originals are rusty or losing their plating). 

Price here is for a single stud - note we also sell sets of 4 studs (Item 0050).  If replacing existing studs it is always better to replace the full set of 4 - to ensure all share the same tensile strength, but we offer these single studs, in case an owner has damaged one previously fitted.

These studs are manufactured to the original dimensions (and curved chamfer on each end) as original Norton SOHC studs, to the dimensions of the 500cc models.  However, I have also found some 350cc crankcases share the same dimensions - so please email me at paul.norman@racingvincent.co.uk if you wish to confirm dimensions for your bike before ordering.  

These studs have the standard BSW thread going into Norton cranckases, and the fine thread that fit our SOHC sleeve nuts (Item 0042 or 0043).  They are manufactured from a higher tensile grade of stainless steel than normal, to avoid stretching.

As you can see from the photos, replacing original rusty or pitted engine studs with a set of these stainless steel items will totally transform the look of your engine, as well as preventing rusting in the future.  They are a very popular item.

Note: these studs as standard come with the standard stainless steel bar 'satin' type finish, as shown in the photographs.  In the past I have occasionally linished these studs to give a semi-polished appearance.  If required - we can provide this finish as an optional extra (as of 2023 - expect this linishing to cost @12 per set of 4 studs, and requiest it in the 'comments' section when placing your order.  Turnaround to do this is normally at least 2 weeks - as I have to setup a manual lathe to mount the studs for linishing)

2024 Update:  A new batch of these popular studs are now back in stock.  Price of stainless steel has almost doubled since we last made them 3 years ago, we have only increased our retail cost by a fraction of that amount.

High Tensile Stainless Steel Cylinder Stud Set for 500cc (and some 350cc) engines (set of 4).

These are CNC manufactured by us to the original dimensions and style and transform the look of your engine (particularly if you originals are rusty or losing their plating). 

Price is for set of 4 studs

These studs are manufactured to the original dimensions (and curved chamfer on each end) as original Norton SOHC studs, to the dimensions of the 500cc models.  However, I have also found some 350cc crankcases share the same dimensions - so please email me at paul.norman@racingvincent.co.uk if you wish to confirm dimensions for your bike before ordering.  

These studs have the standard BSW thread going into Norton cranckases, and the fine thread that fit our SOHC sleeve nuts (Item 0042 or 0043).  They are manufactured from a higher tensile grade of stainless steel than normal, to avoid stretching.

As you can see from the photos, replacing original rusty or pitted engine studs with a set of these stainless steel items will totally transform the look of your engine, as well as preventing rusting in the future.  They are a very popular item.

Note: these studs as standard come with the standard stainless steel bar 'satin' type finish, as shown in the photographs.  In the past I have occasionally linished these studs to give a semi-polished appearance.  If required - we can provide this finish as an optional extra (as of 2023 - expect this linishing to cost @12 per set of 4 studs, and requiest it in the 'comments' section when placing your order.  Turnaround to do this is normally at least 2 weeks - as I have to setup a manual lathe to mount the studs for linishing)

2024 Update:  A new batch of these popular studs are now back in stock.  Price of stainless steel has almost doubled since we last made them 3 years ago, we have only increased our retail cost by a fraction of that amount.

High Tensile Stainless Steel Cylinder Stud Set for 600cc engines (set of 4).

The pattern for these was taken from a postwar (1949) Manx 600 engine, but they should also fit the pre-war 596 engines.

Footnote: you might not recognize the 'A15' designate, but '15' was the model number allocated to 600 OHC machines . . . it is not listed in any catalogs though!

We normally sell these high quality engine studs as a set of 4, but we do occasionally sell them individually if required (slightly more, if bought as a single stud) - email us for availability of single studs

Copper/Asbestos Type Washer used to seal exhaust pipe where it screws into cylinder head (normally requires replacement each time Union Nut is refitted). Fits all SOHC, OHV and Side Valve Norton models.

This washer is of the original Copper/Asbestos 'crushable' type construction, originally used by Norton, but in these modern times - it is now a much safer mineral type filling (i.e. not asbestos).  These washers are manufactured for us by a high quality UK gasket manufacturer to the original pattern.

Note this washer should fit all Norton single cylinder models - SOHC, DOHC, OHV and SV type motors.  Email us for dimensions if you are not sure - at sales@racingvincent.co.uk.

These washers should be replaced each time the exhaust is removed.  From past experience - I have always used a large 'C' spanner on the finned exhaust nut - and tighten when cold, but then carefully retighten for the first couple of runs - with the engine hot.  This I have found ensures the nut is fully tight and helps prevent any backfiring or rough running

Update March 2024: Unfortunately the manufacturing cost of this copper/mineral washer has doubled since last ordered 2 years ago!! (partily the material cost).  We have only increased the retail price by a fraction of this amount.

November 2021: A new batch of these popular pistons have now come in and are available again (and updated price is actually fractionally lower than was anticipating).

This is a 79.62mm (500cc) forged slipper piston to fit Norton International and Longstroke Manx (i.e. 79mm/79.62mm x 100mm) Longstroke singles. Manufactured by top performance piston manufacturer - Omega Pistons.

They are high quality forged 'slipper' type pistons from top quality manufacturer Omega Pistons, made specially for us - to the same vital dimensions of the pre-war International type Hepolite Ref 5288 piston form - one of these being supplied to Omega as a pattern (see picture for original piston alongside ours). This piston form was the standard higher compression piston suitable for petrol (rather than a 'dope' piston), as fitted to Norton International engines. Although I cannot be precise - the last time I fitted one of these original Hepolite pistons to an International engine it gave a compression ratio of approximately 9.5:1.

As you can see from the photos, the profile of the crown, and its position in relation to the gudgeon pin centre line is identical to the original - and as far as I am aware, this is the first time this pre-war type piston has been available for many years, so you can be confident it should be as per originally fitted. 

Fitting Information - Please Read:

Little End Width: This listing is for a piston to fit a Norton International engine - i.e. the piston is designed to take the International conrod which has a Little End width of 1.200"

if you are not sure - check the width of your conrod - original International engines (i.e. aluminium crankcase models) normally had a connecting rod with a width of 1.200" width, while Racing International/Manx (i.e. magnesium crankcase) conrods had a slimmer Little End width of 1.000",

Therefore, this item is for the wider conrod International SOHC engine, if you require the slimmer Manx width, see the seperate Item listing for the Manx type piston - (i.e. Item number 0398 or 0686).

Bore size: This piston is to fit a bore size of 79.62mm - which was the standard (STD) bore size for a SOHC Manx Norton (i.e 499cc rather than 490cc of the roadgoing International).  Norton's did this because for the racing models, they did not want to waste any available cc.  Because the cost of ordering pistons from Omega in all original bore sizes is prohibitive - we offer it in two variations - either the 79.62mm bore listed here, or 79.62mm + 20thou (i.e. 80.13mm), which is Item 0397. 

As a Norton International Model 30 (500cc) STD piston was originall 79.00mm - this 79.62mm is broadly equivelant to an originall 79mm STD + 0.025" piston on an International model (please check your original piston and bore), and the barrel should be bored to that 79.62mm dimension.  Email us if you require more information on this

Gudgeon Pin To Base of Barrel Height: It is important before ordering pistons for post-war SOHC (and early Longstroke DOHC) engines, to check the distance between the centre of the Gudgeon Pin and the base of the piston crown - as some later engines had a shallower barrel/cylinder head spigot - and to allow for this the piston was slightly different.  These pistons have a distance of 34.0mm between the Gudgeon Pin centre and base (i.e. circumference height) of the piston crown. Email us if you require more details.

Piston Weight: Weight of these pistons with rings/circlips etc is @465g (which is compatable with original pistons).  If you require information for 'balancing' your crank to this piston (or are just not sure if your crank is correctly balanced), then email us for details on how to do this.   

Compression Ratio:  The compression ratio we quote here is a guide only, as over the years the SOHC engine was manufactured there were many variations in barrel, head height, valve diameter etc, all of which can affect the compression ratio. However, the Hepolite Ref 5288 piston used as the pattern for our pistons is a good indicative dome for the most normal piston crown fitted to International Model 30 engines running on good quality pump petrol - similar to offered today (i.e. not post War 'Pool' petrol, which sometimes necessitated lowering compression ratio).

It was normal practice when fitting SOHC pistons to measure the swept volume (i.e. stroke and exact bore size) and the combustion chamber volume when the piston is at TDC - and then add or remove compression plates to get to a desired volume.  To help with this we can supply nice quality lasercut compression plates in two thicknesses (Items 0275 and 0275b) - but it should be remembered when changing the barrel/head height on SOHC (and DOHC) Norton engines, you also need to check the vertical coupling clearance is still within limits.  Email us if more information on this is required, and we also offer a useful MS Excel utility on our www.RacingVincent.co.uk Download page for calculating compression ratios for a given CC to swept volume.

November 2021: A new batch of these popular pistons have now come in and are available again (and updated price is actually fractionally lower than was anticipating).

This is a 80.13mm (or if you have an Inter with a standard bore of 79mm then this will equate to 79mm +44 thou oversize.

They are high quality forged 'slipper' type pistons from top quality manufacturer Omega Pistons, made specially for us - to the same vital dimensions of the pre-war International type Hepolite Ref 5288 piston form - one of these being supplied to Omega as a pattern (see picture for original piston alongside ours). This piston form was the standard higher compression piston suitable for petrol (rather than a 'dope' piston), as fitted to Norton International engines. Although I cannot be precise - the last time I fitted one of these original Hepolite pistons to an International engine it gave a compression ratio of approximately 9.5:1.

As you can see from the photos, the profile of the crown, and its position in relation to the gudgeon pin centre line is identical to the original - and as far as I am aware, this is the first time this pre-war type piston has been available for many years, so you can be confident it should be as per originally fitted. 

Fitting Information - Please Read:

Little End Width: This listing is for a piston to fit a Norton International engine - i.e. the piston is designed to take the International conrod which has a Little End width of 1.200"

if you are not sure - check the width of your conrod - original International engines (i.e. aluminium crankcase models) normally had a connecting rod with a width of 1.200" width, while Racing International/Manx (i.e. magnesium crankcase) conrods had a slimmer Little End width of 1.000",

Therefore, this item is for the wider conrod International SOHC engine, if you require the slimmer Manx width, see the seperate Item listing for the Manx type piston - (i.e. Item number 0398 or 0686).

Bore size: This piston is to fit a bore size of 80.13mm - which was the standard (STD) bore size for a SOHC Manx Norton (i.e 499cc rather than 490cc of the roadgoing International) + 20thou.  Norton's did this because for the racing models, they did not want to waste any available cc.  Because the cost of ordering pistons from Omega in all original bore sizes is prohibitive - we offer it in two variations - either the 79.62mm bore (Item 0396), or 79.62mm + 20thou (i.e. 80.13mm), shown here 

As a Norton International Model 30 (500cc) STD piston was originall 79.00mm - this 80.13mm is broadly equivelant to an original 79mm STD + 0.044"  thou piston on an International model (please check your original piston and bore), and the barrel should be bored to that 80.13mm dimension.  Email us if you require more information on this

Gudgeon Pin To Base of Barrel Height: It is important before ordering pistons for post-war SOHC (and early Longstroke DOHC) engines, to check the distance between the centre of the Gudgeon Pin and the base of the piston crown - as some later engines had a shallower barrel/cylinder head spigot - and to allow for this the piston was slightly different.  These pistons have a distance of 34.0mm between the Gudgeon Pin centre and base (i.e. circumference height) of the piston crown. Email us if you require more details.

Piston Weight: Weight of these pistons with rings/circlips etc is @465g (which is compatable with original pistons).  If you require information for 'balancing' your crank to this piston (or are just not sure if your crank is correctly balanced), then email us for details on how to do this.   

Compression Ratio:  The compression ratio we quote here is a guide only, as over the years the SOHC engine was manufactured there were many variations in barrel, head height, valve diameter etc, all of which can affect the compression ratio. However, the Hepolite Ref 5288 piston used as the pattern for our pistons is a good indicative dome for the most normal piston crown fitted to International Model 30 engines running on good quality pump petrol - similar to offered today (i.e. not post War 'Pool' petrol, which sometimes necessitated lowering compression ratio).

It was normal practice when fitting SOHC pistons to measure the swept volume (i.e. stroke and exact bore size) and the combustion chamber volume when the piston is at TDC - and then add or remove compression plates to get to a desired volume.  To help with this we can supply nice quality lasercut compression plates in two thicknesses (Items 0275 and 0275b) - but it should be remembered when changing the barrel/head height on SOHC (and DOHC) Norton engines, you also need to check the vertical coupling clearance is still within limits.  Email us if more information on this is required, and we also offer a useful MS Excel utility on our www.RacingVincent.co.uk Download page for calculating compression ratios for a given CC to swept volume.