This is a high quality facsimile of the original Norton 1928-29 Spare Parts Catalog for OHV (excluding ES2) and SV Models, but printed in A4 format. The main spare parts list covers the roadgoing Model 18, 19, 21 and 24 OHV models and Model 1, 2, 14 and 16H SV models.  It also includes a rare 4 page supplement for final (post 1929) changes to the  'magneto forward of engine' OHV and SV models.  

This particular catalog covers the roadgoing/non-sports OHV and Side Valve models for 1928 - 29, but also includes a rare 4 page supplement which includes all the final changes made to the 'magneto forward of crankcase' OHV/SV models subsequent to 1929 (which was shortly superceded by the magneto behind crankcase models that followed into the 1930's).  Just like the original catalog, this 4 page supplement is supplied slipped into the main catalog seperately.

For anyone interested in Norton single cylinder models of the late 1920's into the early 1930's this is an excellent catalog and makes good reading in its own right, with nice clear pictures of every part (expanded to be legible in A4 format) as well as every part number included.  In many years of hunting for rare Norton catalogs, this is the only copy of this particular year/model format I have seen - and if like me, you like looking at the detail of part changes by year for originality purposes, then this particular catalog is fascinating at it seems to cover that transition from the Norton 'flat tank' 1920's era, into the first pannier tank models, in some ways straddling both.

It has clear pictures of all OHV (excluding ES2 - see note below) and Side Valve model parts for that year, but is unusual in that it is the only spare parts catalog I have seen that gives detailed pictures (with all parts shown) of both the Norton Webb forks fitted into the early 1930s and the earlier Druid type forks fitted through the 1920's.  Another interesting feature of this catalog as the frames shown are those fitted to the non-sports models which were still of the type fitted through the 1920's - they being the open cradle type with a casting that held the gearbox by two vertical studs.

The catalog is 24 pages (with picture plates) + 4 additional supplement pages. The card cover is a beige/grey similar to the original cover for this year (the original being a bit grubby) with red lettering.  

Note: it seems that Norton produced two Spare Parts Catalogs for this period - this version covering the 'Standard' type OHV and SV machines, and a second catalog covering the 'Sports/Racing' CS1 (Walter Moore) SOHC engine and ES2 (sports type) OHV moels - the SOHC model having just been introduced at the time. 

I am fortunate to have original copies for each catalogs and have reproduced both.  the CS1/ES2 catalog is Item 0892.  If you do not wish to purchase both - but are not sure which catalog will cover your own machine:  The CS1/ES2 catalog covers mainly the sports/racing parts of that period - i.e. SOHC Walter Moore engine in full detail, Webb Forks only, 3 tube full cradle frame and sportier tanks and fittings for the CS1/ES2 models.  This listing covers the standard roadgoing OHV/SV models, i.e. open frame and slightly different oil tanks, carbs, magnetos, leg shields etc.

Having compared both catalogs back to back, there is a small amount of overlap - but overall it is suprising how many parts (including part numbers) are different between the two model ranges.

As an incentive to anyone unsure which to order - if both catalogs are ordered at the same time we will offer a £3 discount on the total price of both catalogs - please remind Steph of this at the time you place the order!

Pre-War Facsimile Catalogs: Additional Information

We print these pre-war catalogs in larger format as they did not use 'Exploded' diagrams - therefore A4 format makes the pictures much easier to see.  All else as per original - see detail information for more information. 

 As with all the facsimile catalogs we produce, much effort has been taken to remove any defects from the original copy - i.e. smudge marks, finger prints etc, and as you can see from the photographs, the overall yellow fading that is prevelent in most original pre-war catalogs has been removed - resulting in a high quality reproduction with all the original parts numbers, artwork and descriptions easily legible.

However, while the original Spare Parts Catalogs were printed in an approximate A5 format (i.e. 8 3/4" tall by 5 3/4" wide) format, we produce these facsimile's in A4 format (i.e. 11 3/4" tall by 8 1/4" wide).  We do this because pre-war catalogs had not started to use the now common concept of an 'exploded' diagram.  Instead every item was shown as a very small picture on its own (see pictures listed with this item to see what we mean).  We have found that from a restorer's perspective - enlarging these diagrams to A4 format makes them much clearer to identify than looking at the picture in the original format with a magnifying glass!

It is printed on high quality 100gm branded Xerox paper/card on a commercial quality printer. The cover is card, of similar quality to the original - with the colour also similar to the original year.  You may find other cheaper reproductions on Ebay, but I doubt they will be the same quality as ours and have the time spent cleaning them up from the originals as ours have - which is reflected in the price 

This is a high quality facsimile of the original Norton 1928-29 Spare Parts Catalog, but printed in A4 format. The main spare parts list covers CS1 (Walter Moore design) SOHC and ES2 OHV models, but includes the rare 4 page supplement for Model 18, 19, 21 and 24 (OHV) and 1,2,14 and 16H (SV) models.

Catalogs of these early models are very rare, but this is a particularly nice reproduction - with all marks and wear from the original carefully removed from the original Norton catalog, which was used as the basis for this reproduction (and can be seen in the listing photographs). This reproduction also includes the even more hard to find 4 page supplement provided with later copies, that covers OHV models subsequent to 1929 - Models 18.19,21 and 24 for OHV and 1, 2, 14 and 16H for SV.  This supplement is normally missing or was not supplied with the main catalog (in fact I bought a second and expensive copy of the original some years after the first - just to check, as my first version did not have it).

The supplement is provided as a sepeate 4 page pullout, just as the original was, but again in A4 and with any wear and oily marks to it carefully removed.

The catalog is 31 pages (with picture plates) + 4 additional supplement pages, and as an aside, is an interesting read in its own right - particularly as it shows good quality pictures of these early models, including variations, which allows you to compare parts with the later models and see how the single cylinder machines evolved.

Note: it seems that Norton produced two Spare Parts Catalogs for this period - one version covering the 'Standard' type OHV and SV machines, and a second catalog covering the 'Sports/Racing' CS1 (Walter Moore) SOHC engine and ES2 (sports type) OHV moels - the SOHC model having just been introduced at the time - this catalog is the one covering the CS1/ES2 models. 

I am fortunate to have original copies for each catalogs and have reproduced both.  the SV/OHV catalog is Item 0893.  If you do not wish to purchase both - but are not sure which catalog will cover your own machine:  The CS1/ES2 catalog covers mainly the sports/racing parts of that period - i.e. SOHC Walter Moore engine in full detail, Webb Forks only, 3 tube full cradle frame and sportier tanks and fittings for the CS1/ES2 models.  The tandard roadgoing OHV/SV models, i.e. open frame and slightly different oil tanks, carbs, magnetos, leg shields etc.

Having compared both catalogs back to back, there is a small amount of overlap - but overall it is suprising how many parts (including part numbers) are different between the two model ranges.

As an incentive to anyone unsure which to order - if both catalogs are ordered at the same time we will offer a £3 discount on the total price of both catalogs - please remind Steph of this at the time you place the order!

Pre-War Facsimile Catalogs: Additional Information

We print these pre-war catalogs in larger format as they did not use 'Exploded' diagrams - therefore A4 format makes the pictures much easier to see.  All else as per original - see detail information for more information. 

 As with all the facsimile catalogs we produce, much effort has been taken to remove any defects from the original copy - i.e. smudge marks, finger prints etc, and as you can see from the photographs, the overall yellow fading that is prevelent in most original pre-war catalogs has been removed - resulting in a high quality reproduction with all the original parts numbers, artwork and descriptions easily legible.

However, while the original Spare Parts Catalogs were printed in an approximate A5 format (i.e. 8 3/4" tall by 5 3/4" wide) format, we produce these facsimile's in A4 format (i.e. 11 3/4" tall by 8 1/4" wide).  We do this because pre-war catalogs had not started to use the now common concept of an 'exploded' diagram.  Instead every item was shown as a very small picture on its own (see pictures listed with this item to see what we mean).  We have found that from a restorer's perspective - enlarging these diagrams to A4 format makes them much clearer to identify than looking at the picture in the original format with a magnifying glass!

It is printed on high quality 100gm branded Xerox paper/card on a commercial quality printer. The cover is card, of similar quality to the original - with the colour also similar to the original year.  You may find other cheaper reproductions on Ebay, but I doubt they will be the same quality as ours and have the time spent cleaning them up from the originals as ours have - which is reflected in the price 

This is a high quality facsimile of the original Norton 1931-32 Spare Parts Catalog, but printed in A4 format. The main spare parts list covers SOHC (Arthur Carroll design) and OHV ES2 models, but many cycle parts listed are the same for all models (see listing for more detail on this).

We print these pre-war catalogs in larger format as they did not use 'Exploded' diagrams - therefore A4 format makes the pictures much easier to see.  All else as per original - see detail information for more information. 

This is a particularly rare catalog - and to my knowledge is the very first catalog to show details of the 'Arthur Carroll' type SOHC engine design - which went on in later years to become the Norton International and eventually Manx Norton.  What makes this catalog so interesting is that it details the very earliest SOHC cambox design, identifiable by having a more 'rounded' front bevel cover design than the later cambox design that replaced it the following year.

To my knowledge, this is also the last Norton Spare PArts Catalog that showed the '3 tube' Rear stay frame, and of course, Sturmey Archer gearbox fitted to SOHC and ES2 models (prior to the Norton design that followed in 1934).

This facsimile has been faithfully coped from a genuine 1931-32 Norton Spare Parts List, that can be seen in the picture - and as you can see, we have even replicated the cover of the cover, as well as smaller details like the original phone lines of that period and printer details on rear cover!.  This is then only original copy of this rare edition I have ever seen, and although it was in very good original condition (and fetch premium prices at auction) - as we do with all our facsimile Norton literature - we have gone to great efforts to remove any defects (i.e. thumb prints or staining) before printing the final copy.

Also, as with all our Pre-War facimile Spart Parts Lists - we have produced these on high quality paper/card, in duplex, as per original - but we have produced them in a larger 'A4' format.  We do this because pre-war, Norton's had not started using 'exploded' diagrams, instead showing all parts as a tiny picture.  By magnifying these pictures to A4 size it makes those pictures far easier to read.

As a final point - I personally find these early Spare Parts Lists fascinating and a good read in themselves.  As well as showing rare optional features such as legshields or original mudguard profiles - comparing the pictures and part numbers with later editions of the parts lists give a great insight in to how the single cylinder models evolved.

Note that this spare parts calalog says on the cover it covers 'CS1 and ES2 models.  However on the inner front page it also mentions Model 30 and Model 40 models.  It does not however cover the Side Valve models (and although it covers ES2 OHV, it does not specifically mention differces between that and the Model 18).  It is worth pointing out though that for this year I have never seen a Spare Parts List for the SV/Mod 18 models (unlike the earlier 1928/29 editions, where there were definitely 2 different catalogs).  By the time of the next spare parts catalog I am aware of (1934), Norton's had amalgameted all single cylinder models into a single Spare Parts catalog (see our Facsimile section for all types we offer - although we have some pre-war mainitenance and Roadholder editions we are yet to offer) 

Catalogs of these early models are very rare, but this is a particularly nice reproduction - with all marks and wear from the original carefully removed from the original Norton catalog, which was used as the basis for this reproduction (and can be seen in the listing photographs). This reproduction also includes the even more hard to find 4 page supplement provided with later copies, that covers OHV models subsequent to 1929 - Models 18.19,21 and 24 for OHV and 1, 2, 14 and 16H for SV.  This supplement is normally missing or was not supplied with the main catalog (in fact I bought a second and expensive copy of the original some years after the first - just to check, as my first version did not have it).

The supplement is provided as a sepeate 4 page pullout, just as the original was, but again in A4 and with any wear and oily marks to it carefully removed.

The catalog is 31 pages (with picture plates) + 4 additional supplement pages, and as an aside, is an interesting read in its own right - particularly as it shows good quality pictures of these early models, including variations, which allows you to compare parts with the later models and see how the single cylinder machines evolved.

Note: it seems that Norton produced two Spare Parts Catalogs for this period - one version covering the 'Standard' type OHV and SV machines, and a second catalog covering the 'Sports/Racing' CS1 (Walter Moore) SOHC engine and ES2 (sports type) OHV moels - the SOHC model having just been introduced at the time - this catalog is the one covering the CS1/ES2 models. 

I am fortunate to have original copies for each catalogs and have reproduced both.  the SV/OHV catalog is Item 0893.  If you do not wish to purchase both - but are not sure which catalog will cover your own machine:  The CS1/ES2 catalog covers mainly the sports/racing parts of that period - i.e. SOHC Walter Moore engine in full detail, Webb Forks only, 3 tube full cradle frame and sportier tanks and fittings for the CS1/ES2 models.  The tandard roadgoing OHV/SV models, i.e. open frame and slightly different oil tanks, carbs, magnetos, leg shields etc.

Having compared both catalogs back to back, there is a small amount of overlap - but overall it is suprising how many parts (including part numbers) are different between the two model ranges.

As an incentive to anyone unsure which to order - if both catalogs are ordered at the same time we will offer a £3 discount on the total price of both catalogs - please remind Steph of this at the time you place the order!

Pre-War Facsimile Catalogs: Additional Information

We print these pre-war catalogs in larger format as they did not use 'Exploded' diagrams - therefore A4 format makes the pictures much easier to see.  All else as per original - see detail information for more information. 

 As with all the facsimile catalogs we produce, much effort has been taken to remove any defects from the original copy - i.e. smudge marks, finger prints etc, and as you can see from the photographs, the overall yellow fading that is prevelent in most original pre-war catalogs has been removed - resulting in a high quality reproduction with all the original parts numbers, artwork and descriptions easily legible.

However, while the original Spare Parts Catalogs were printed in an approximate A5 format (i.e. 8 3/4" tall by 5 3/4" wide) format, we produce these facsimile's in A4 format (i.e. 11 3/4" tall by 8 1/4" wide).  We do this because pre-war catalogs had not started to use the now common concept of an 'exploded' diagram.  Instead every item was shown as a very small picture on its own (see pictures listed with this item to see what we mean).  We have found that from a restorer's perspective - enlarging these diagrams to A4 format makes them much clearer to identify than looking at the picture in the original format with a magnifying glass!

It is printed on high quality 100gm branded Xerox paper/card on a commercial quality printer. The cover is card, of similar quality to the original - with the colour also similar to the original year.  You may find other cheaper reproductions on Ebay, but I doubt they will be the same quality as ours and have the time spent cleaning them up from the originals as ours have - which is reflected in the price 

This is the single row roller bearing as fitted to both sides of the SOHC Walter Moore CS1 and CSJ 1927 - 1930 engines.  It was also fitted to Model 18 engines of the same period. These are the correct original 'C3' looser fit bearings - but are from a slightly lesser quality NKE brand (i.e. not RHP Brand).  See listing for more detail

Update Jan 2022 -  In previous years, we have been able to obtain this bearing in UK quality RHP brand.  However, RHP are no longer manufacturing the C3 fit version of this bearing - therefore as an alternative - we are now able to offer NKE Brand 'C3' Fit alternatives.  These are an offhshore brand - and not of quite the same high quality as original RHP . . . but is ultimately how it will go with all the main Norton bearings, as original RHP brand run out.  These bearings are still of a reaonable quality, and unless you are still riding your bike 20k miles a year . . . should be fine!  (and are of course much cheaper than any 'new old stock' RHP brand versions we are still able to find.

Backround Information on C3 or Standard Fit bearings:

These 'standard fit' bearings are exactly the same manufacture as the C3 versions, except when fitted they have a less loose tolerance - so if you decide to fit them, bear this in mind and allow for it when first running them in (however, many people historically did not realise there were different fit bearings - so you may find your engine has already been fitted with standard bearings by a previous owner.  Original C3 bearings will normally have either C3 stamped after the main bearing designate on the outer race, or 3 dots (i.e. '. . .'), which was often the old way of showing them as C3 fit. 

Final point on ball and roller main bearings fitted to 1930's/50's OHV and SV engines: Unusually, Norton's showed a roller bearing being fitted on both sides of the crankcases on OHV/SV engines (i.e. 1948 catalog), with a ball bearing fitted just on the outer drive side.  However, I have stripped OHV engines down in the past where a ball bearing is fitted both sides, with just the drive side inner being a roller bearing (as was the case with all SOHC engines).  Not sure if it makes a great deal of difference - as like the SOHC engine, the OHV/SV engine was locked to the timing side bearing - but worth noting if you are struggling to find two roller bearings (and once ours have inevitably ran out)

This is the large single ball bearing that was fitted on the top vertical bevel gear housing on the SOHC Walter Moore CS1 or CSJ engine, manufactured from 1927 - 30.  This is a high quality SKF brand bearing.  

The second picture of this listing shows the Norton Spare Parts List for the 1927-30 CS1 Model, showing the bearing listed here - as Part No 4130.  

This bearing is a high quality SKF bearing.

If you have a requirement for other bearings to fit CS1/CSJ or other 1920's Norton models - we may be able to obtain them - email us at sales@racingvincent.co.uk

This is a 79.62mm (500cc) forged slipper piston which copies the same vital dimensions as the original 1940's-50's Norton Heplex 572 OHV (Model 18 and ES2) piston, other than having a slightly raised crown - which on most OHV models should relate to an estimated circa 8:1  compression ratio.  As with our SOHC slipper pistons - these are the highest quality forged slipper pistons made by top manufactuer Omega.  

Price is per piston - piston includes rings, Gudgeon Pin and circlips

Background Information:

As can be seen in the accompanyning photographs - original post war (Heplex) OHV Model 18 and ES2 pistons were most often of the full skirt and flat dome variety - as per the original Norton OHV piston in the photo (taken from a late 1940's standard ES2 many years ago).

The most importand dimensions which we have copied into these Omega pistons are the correct Gudgeon Pin Diameter, the width of the OHV/SV con rod Little End distance and most importantly - height from the centre of the gudgeon pin to the base of the piston crown, and with this, the same base piston crown chamfer as the original Heplex Model 18/ES2 piston. 

However, we have had these pistons made with a slightly raised crown in the centre -  raised by 10mm at the centre, which should provide a compression ratio of approximately 8:1 (as original pistons and motor specifications in the 1940's were more suited for the lower quality petrol available at the time).  As can be seen - the valve cutaways have also been enlarged slightly to allow for this.

Norton Side Valve 16H piston usage: It should be noted that the WD side valve 16H Norton, and the later Postward 16H models, all used a piston similar to the ES2, but this piston also had a raised crown, to achieve a similar compression ratio to the OHV model in the larger SV combustion space (but of course, original 16H pistons did not have the need for valve cutaways and were normally of a more heavyweight skirt construction for long life.  The construction of these Omega pistons may make them lighter than original 16H pre-war pistons (although post-war type were lighter and comparable) - but are a viable alternative to be considered for 500cc 16H sidevalve models.  A picture of an original WD sidevalve piston is shown in the accmpnanying photos for comparison

Norton CS1 (SOHC) Usage:  These pistons are similar to the higher compression 'International' pistons we also offer (Item 0396 and 0397), but with slightly different dome dimensions (and of course, a lower compression ratio than the International type).  If you have either a Walter Moore or Arthur Carroll type CS1, and are looking for a lower compression version of our International piston, then email us on sales@racingvincent.co.uk to confirm if these will fit your engine 

Norton Late SOHC Inter/Manx 500cc (Early 50's) Usage:  It should be noted that our main SOHC pistons (Item 0396-0398) are intended for the 'deep barrel spigot' type Inter/SOHC Manx engine, which was used on most SOHC engines until sometime in the late '40's/early 50's.  At some point around this time a shallower barrel spigot and combustion chamber seems to have been adopted.  We do not offer a piston specifically for that later 'shallow barrel spigot' type 500cc SOHC engine, but if you have an engine of that later type - this piston may turn out to be more suitable to adopt.  It is important to measure the height between the centre point of the gudgeon pin and the top lip of the barrel to confirm the type of piston required - if unsure - please email us and we can confirm the important dimensions of this piston. It is important to check this beforehand - as unfortunately we cannot accept returns once a piston has been removed from its packaging and trial fitted.

As a final point - although most people associate 'Slipper' type pistons with racing engines - but for all uses, they are a high quality forged piston that have a steady and reliable expansion rate and are very stiff and rigid in construction.  And surprisingly - the total 'touching' side wall of the thrust face of these Omega pistons is actually fractionally more than the original Heplex 572 Norton piston shown in the photograph.

Fitting Pistons: As with the fitting of all pistons to older engines (which may have been previously modified) - we strongly advise you satisfy yourself there is sufficient piston to head/clearance in your own engine when fitting one of these pistons - I always put a thin layer of plasticine on the top of a piston crown - then slowy turn the assembled engine over by hand first - there should be at least 60 thou of clearance on valve cutaways and to ensure the piston is not touching the head at any point.  a Digital caliper, using the depth gauge prong into the plasticine is ideal for this.  

Piston Weight: These pistons weigh 450grams complete with Gudgeon Pi, rings and circlips - which is within a couple of grams of the weight of the original Norton Heplex 572 piston (unlike other non forged modern OHV substitutes, which are considerably heavier).  Therefore the balance charateristics when using these pistons should be comparable to original specification 

Little End Width: This listing is for a piston to fit a Norton OHV/SV or CS1 specification engine - i.e. the piston is designed to take the Norton conrod which has a Little End width of 1.200"

Bore Size Information: 

Original OHV and SV Norton (Longstroke) 500cc pistons had a standard bore of 79mm, and were then offered in standard oversizes of +20, +40 and +60 thousandths of an inch.  Occasionally +30 thou oversize can also be found.

We can currently only offer these pistons in two bore sizes - 79.62mm (which is this Item listing) or 80.13mm (Item 1062)

79.62mm in OHV/SV oversize parlance can be converted to 79mm + 24thou, while the 80.13mm version can be converted to 79mm + 44thou.  Hopefully one of these two 79mm oversizes will be suitable for your engine (or of course you can consider re-lining your cylinder if already out at +60.  If based in the UK we can recommend people we have used for this in the past).

When taking your barrel to be bored/honed, ask for the barrel to be honed to the exact size shown on here (79.62mm or 80.13mm), Omega will have worked out the correct clearances for these pistons for that bore.

In case you are wondering why we have chosen these two bore sizes for our pistons - our original Omega forge patterns were made for the Manx Norton piston size of 79.62mm and one oversize of this - as original Manx Longstroke pistons were a slightly larger bore, to allow the full 499cc capacity to be used for Grand Prix racing.  These two sizes also allowed a useful 'oversize' piston for standard 79mm engines.

This is a 79.62mm (i.e. 79.62mm +20thou oversize) 500cc forged slipper piston which copies the same vital dimensions as the original 1940's-50's Norton Heplex 572 OHV (Model 18 and ES2) piston, other than having a slightly raised crown - which on most OHV models should relate to an estimated circa 8:1  compression ratio.  As with our SOHC slipper pistons - these are the highest quality forged slipper pistons made by top manufactuer Omega.  

Price is per piston - piston includes rings, Gudgeon Pin and circlips

Background Information:

As can be seen in the accompanyning photographs - original post war (Heplex) OHV Model 18 and ES2 pistons were most often of the full skirt and flat dome variety - as per the original Norton OHV piston in the photo (taken from a late 1940's standard ES2 many years ago).

The most importand dimensions which we have copied into these Omega pistons are the correct Gudgeon Pin Diameter, the width of the OHV/SV con rod Little End distance and most importantly - height from the centre of the gudgeon pin to the base of the piston crown, and with this, the same base piston crown chamfer as the original Heplex Model 18/ES2 piston. 

However, we have had these pistons made with a slightly raised crown in the centre -  raised by 10mm at the centre, which should provide a compression ratio of approximately 8:1 (as original pistons and motor specifications in the 1940's were more suited for the lower quality petrol available at the time).  As can be seen - the valve cutaways have also been enlarged slightly to allow for this.

Norton Side Valve 16H piston usage: It should be noted that the WD side valve 16H Norton, and the later Postward 16H models, all used a piston similar to the ES2, but this piston also had a raised crown, to achieve a similar compression ratio to the OHV model in the larger SV combustion space (but of course, original 16H pistons did not have the need for valve cutaways and were normally of a more heavyweight skirt construction for long life.  The construction of these Omega pistons may make them lighter than original 16H pre-war pistons (although post-war type were lighter and comparable) - but are a viable alternative to be considered for 500cc 16H sidevalve models.  A picture of an original WD sidevalve piston is shown in the accmpnanying photos for comparison

Norton CS1 (SOHC) Usage:  These pistons are similar to the higher compression 'International' pistons we also offer (Item 0396 and 0397), but with slightly different dome dimensions (and of course, a lower compression ratio than the International type).  If you have either a Walter Moore or Arthur Carroll type CS1, and are looking for a lower compression version of our International piston, then email us on sales@racingvincent.co.uk to confirm if these will fit your engine 

Norton Late SOHC Inter/Manx 500cc (Early 50's) Usage:  It should be noted that our main SOHC pistons (Item 0396-0398) are intended for the 'deep barrel spigot' type Inter/SOHC Manx engine, which was used on most SOHC engines until sometime in the late '40's/early 50's.  At some point around this time a shallower barrel spigot and combustion chamber seems to have been adopted.  We do not offer a piston specifically for that later 'shallow barrel spigot' type 500cc SOHC engine, but if you have an engine of that later type - this piston may turn out to be more suitable to adopt.  It is important to measure the height between the centre point of the gudgeon pin and the top lip of the barrel to confirm the type of piston required - if unsure - please email us and we can confirm the important dimensions of this piston. It is important to check this beforehand - as unfortunately we cannot accept returns once a piston has been removed from its packaging and trial fitted.

As a final point - although most people associate 'Slipper' type pistons with racing engines - they are a high quality forged piston that have a steady and reliable expansion rate and are very stiff and rigid in construction.  And surprisingly - the total 'touching' side wall of the thrust face of these Omega pistons is actually fractionally more than the original Heplex 572 Norton piston shown in the photograph.

Fitting Pistons: As with the fitting of all pistons to older engines (which may have been previously modified) - we strongly advise you satisfy yourself there is sufficient piston to head/clearance in your own engine when fitting one of these pistons - I always put a thin layer of plasticine on the top of a piston crown - then slowy turn the assembled engine over by hand first - there should be at least 60 thou of clearance on valve cutaways and to ensure the piston is not touching the head at any point.  a Digital caliper, using the depth gauge prong into the plasticine is ideal for this.  

Piston Weight: These pistons weigh 450grams complete with Gudgeon Pi, rings and circlips - which is within a couple of grams of the weight of the original Norton Heplex 572 piston (unlike other non forged modern OHV substitutes, which are considerably heavier).  Therefore the balance charateristics when using these pistons should be comparable to original specification 

Little End Width: This listing is for a piston to fit a Norton OHV/SV or CS1 specification engine - i.e. the piston is designed to take the Norton conrod which has a Little End width of 1.200"

Bore Size Information: 

Original OHV and SV Norton (Longstroke) 500cc pistons had a standard bore of 79mm, and were then offered in standard oversizes of +20, +40 and +60 thousandths of an inch.  Occasionally +30 thou oversize can also be found.

We can currently only offer these pistons in two bore sizes - 79.62mm (Item 1061) or 80.13mm (this item listing)

79.62mm in OHV/SV oversize parlance can be converted to 79mm + 24thou, while the 80.13mm version can be converted to 79mm + 44thou.  Hopefully one of these two 79mm oversizes will be suitable for your engine (or of course you can consider re-lining your cylinder if already out at +60.  If based in the UK we can recommend people we have used for this in the past).

When taking your barrel to be bored/honed, ask for the barrel to be honed to the exact size shown on here (79.62mm or 80.13mm), Omega will have worked out the correct clearances for these pistons for that bore.

In case you are wondering why we have chosen these two bore sizes for our pistons - our original Omega forge patterns were made for the Manx Norton piston size of 79.62mm and one oversize of this - as original Manx Longstroke pistons were a slightly larger bore, to allow the full 499cc capacity to be used for Grand Prix racing.  These two sizes also allowed a useful 'oversize' piston for standard 79mm engines.

This Rocker Adjuster and Tapered Locknut are to fit Flat Tank OHV Models (i.e Model 18 and Model 19) between approximately 1926 and 1929 - the distinguishing features of this type being that this type screwed into the front of the OHV Rockers, and had a 'ball' profile at the end - that fitted directly into the top Pushrod cup - see the period photographs that accompany this item listing.

We have CNC manufactured this type of rocker adjuster using an original 1920's Norton item as the pattern - and replicating all dimensions as per the original.  They are made from case hardened EN32B, but like the Norton originals - the threads are 'painted off' before hardening, so the threads do not go brittle in the hardening process.  The reverse end of the adjuster has a square head milled into it, for adjusting tappet clearance iwth a small spanner - again replicating the dimensions of the original Norton square.  It should be noted that the thread of these early type Rocker Adjusters (and the slightly later adjusters we also offer - Item 1121 and 1122) is actually 9/32" x 26tpi BSC thread - as per the original item.

As well as teh actual hardened adjuster, we also include the correct profile locknut - which has a slight taper on one end - which should fit into the original Norton OHV Rocker recess.  The other end has a minimum chamfer.  Again, this locknut is copied from an original period Item - but unlike the original, ours are CNC manufactured from stainless steel - to prevent rusting.  It should be noted that on the original 1920's nut that we coped - we noted that the depth of this nut was fractionally shallower than the original 1930 onwards original nut we also manufacture (Item 1123) - but the difference is minimal, and I suspect either type could be used.

Each Rocker Adjuster and Locknut is supplied assembled with high melting point grease applied - to prevent corrosion in storage.

Price is for a single adjuster and locknut (i.e. 2 parts) - Therefore 2 of these are required per engine.

Backgound:  This distinctive 'Ball Ended' rocker adjuster were fitted to 1920's Flat Tank OHV Nortons.  I am not an expert myself on flat tank Norton's - but from what I can see in original Photos and Spare Parts List's (and talking to helpful customers with more Flat Tank knowledge than me!) - I beileve the very first Norton OHV in 1924-1925 may have had a slightly different design of Rocker Adjuster - and this type were probably not fitted until approximately 1926.  

Therefore if you have a very early OHV Norton before 1926 (lucky you!) - then please confirm for yourself if this type of adjuster will fit your engine.  I believe the very first engines had an adjuster with Part Number 1027 (i.e. earlier than the design listed here) - so you will need to check your engine for yourself (but if you do have an earlier design - we would be interested to see a picture, and get dimensions from you, thx).

We believe this adjuster was introduced sometime around 1926 and it was still listed in the Norton Model 18/Side Valve Spare Parts List of 1929 - by which time the Walter Moore CS1 and OHV ES2 models were showing the later Rear Rocker/Flat Pad (our Item 1121) design of rocker being fitted.  Therefore there looks to be a short period where both types of rocker adjuster were being offered concurrently - but on different models. 

Please satisfy yourself this adjuster type is correct for your model - but you can email us on sales@racingvincent.co.uk if you require more information.

Update October 2022:  As you can see, these items are not cheap - but reflect the amount of time we have spent checking originals, and setup on very small batch's (as well as greatly increased material and hardening prices in recent times).  Hopefully you will understand that the price reflects the small batch quantities of these we manufacture.  And of course - original examples are now almost impossible to find!

These are the distinctive 9/32" x 26tpi BSC tapered locknuts as fitted to the Norton OHV Ball type rocker adjusters from approximately 1926-29.  These have been CNC manufactured in stainless steel to exactly the same dimensions as a Norton 1920's example.  Note we also sell the locknut with the actual adjuster - see Item 1119, but as the original nuts are often chewed or come loose and fall off - we sell them on their own here.  

Price is each (i.e. one locknut)

The thread on these locknuts is - 9/32" x 26tpi BSC thread - as per the original item.

This nut is CNC manufactured in stainless steel to the original Norton design - which has a slight taper on one end - which should fit into the original Norton OHV Rocker recess.  The other end has a minimum chamfer.  This locknut is copied from an original period Item - but unlike the original, ours are CNC manufactured from stainless steel - to prevent rusting.  It should be noted that on the original 1920's nut that we coped - we noted that the depth of this nut was fractionally shallower than the original 1930 onwards original nut we also manufacture (Item 1123) - but the difference is minimal, and I suspect either type could be used.

See also the description listing for Item 1119 (Ball Type Adjuster and Locknut - Pair) for more background information on these items.

If these nuts are showing out of stock - then Item 1123 is a possible alternative as the depth difference of the later nut is only fractionally deeper than this type - we decided to make both types because we wanted each Rocker Adjuster/Locknut combination to be true to the original patterns we copied

This Flat Bottomed Rocker Adjuster and Tapered Locknut are to fit the first SOHC Walter Moore (i.e. Cricket Bat type) and 1930 - 1937 OHV Models.  They were fitted to CS1 models from 1927-1930 (approximately) and OHV models from 1929 - 1937.  This type of rocker adjuster were fitted to the rear rocker arms and acted directly on the valves.  We have CNC manufactured this type using an original early 1930's Norton item as the pattern and includes the correct profile locknut, with tapered bottom face, the locknut being in stainless steel. 

Price is for a single adjuster and locknut (i.e. 2 parts)

We have CNC manufactured this type of rocker adjuster using an original early 1930's Norton item as the pattern - and replicating all dimensions as per the original.  They are made from case hardened EN32B, but like the Norton originals - the threads are 'painted off' before hardening, so the threads do not go brittle in the hardening process.  The reverse end of the adjuster has a square head milled into it, for adjusting tappet clearance iwth a small spanner - again replicating the dimensions of the original Norton square.  It should be noted that the thread of this type Rocker Adjusters (and the slightly earlier  ball type adjusters we also offer - Item 1119) is actually 9/32" x 26tpi BSC thread - as per the original item.

As well as the actual hardened adjuster, we also include the correct profile locknut - which has a slight taper on one end - which should fit into the original Norton OHV Rocker recess.  The other end has a minimum chamfer.  This locknut is copied from an original period Item - but unlike the original, ours are CNC manufactured from stainless steel - to prevent rusting.  It should be noted that on the original 1930's nut that we copied (which was still fitted to a flat bottomed adjuster) - we noted that the depth of this nut was fractionally deeper than the original 1920's nut fitted to the earlier 'Ball type' rocker adjuster (Item 1119) - but the difference is minimal, and I suspect either type could be used for either application.

Each Rocker Adjuster and Locknut is supplied assembled with high melting point grease applied - to prevent corrosion in storage.

Price is for a single adjuster and locknut (i.e. 2 parts) - Therefore 2 of these are required per engine.

Backgound: 

This flat bottomed rocker adjuster is of the type that looks to have been fitted to most OHV models and also early SOHC models from approximately 1927 (in the case of Walter Moore CS1 Models) through to 1937 OHV motors.

This specific design - which has a flat foot, slightly wider than the thread shaft, is pictured in the 1933-34 Norton Spare Parts Catalog - and given the Norton part number 9163 - and was shown there as an adjuster and locknut, as we offer here - i.e. 2 parts.

As well as having this flat foot, the other distinguishing feature of this type of adjuster s that the thread is 9/32" x 26tpi BSC.  And finally, the other feature is having a 'square' top at the other end of the adjuster - to allow tappet clearance to be adjusted, once the tapered locknut is looesened.

The reason these features are important - is that there does seem to have been some variations on this adjuster offered - particularly on earlier Walter Moore CS1 and OHV models in the late 1920's - for example, I have also seen early examples that look to have a pad which is closer to the diameter of the shaft, and other examples that have a Hex pad, rather than a round pad - Which I assume was to make adjustment possible from the lower end.

Therefore please satisfy yourself before ordering that your model of Norton has the correct 9/32" x 26 tpi thread in the rocker - and that you are comfortable to use this design with the wider flat pad - which seems to have been standardised on all OHV models by 1933 at the latest.

Wtih regard to the use of this type of Rocker Adjuster on SOHC Engines:  It is difficult to be distinct about Walter Moore CS1 development between 1927-30 (and I am definitely not an expert on this model) - but they were definitely fitted with the 9/32" x 26 tpi adjuster - although early examples may have had a slimmer hardened head than the type shown here -this type should be interchangeable, but please satisfy yourself before ordering us, or email us on sales@racingvincent.co.uk before ordering.

Having consulted with some early SOHC experts- I gather that occasionally worn CS1 rocker arms were drilled out to a larger thread to take later 5/16" SOHC Adjusters (see our SOHC Cambox section for standard 3 part SOHC tappet adjuster sets) - but before ordering these adjusters - please satisfy yourself that your CS1 (Walter Moore) rocker arms still have a 9/32" thread.

Likewise - the earliest Arthur Carroll SOHC cambox's - i.e. 1931-33 era also had differnces to later SOHC cambox's.  I cannot be certain, as I do not have a complete earliest type Arthur Carroll cambox in my collection - but there is also a good indication that the early versions of this type of cambox may also have used this type of adjuster (early Arthur Carroll Camboxs are often identified by a more curved front bevel cover casting thant the standard later version).

With all of this background - the key thing to remember is:  It is very difficult to be definitive about types and sizes, as so few engines are totally original  . .. and a high mieage engine may have had its consumable parts replaced many times over the years - often using whatever parts are available at the time.

However, with all these 1930's engines - up to the introduction of the adjustable pushrod on 1938 onwards OHV engines - these 9/32" rocker pads are manufactured to an original and well tested Norton design - hence why it is important to note that the thread diameter is the most important point to note if you have a Norton single model from late '20's to 1937 where the tappet adjuster sits directly over the valve stem.

You can email us on sales@racingvincent.co.uk if you need more information or need to check