This is the multi-stepped crankcase bolt that is drilled through it centre to feed oil to the back of the crankcase wall, as well as providing a means to meter the feed of oil to the cambox, (in conjunction with item A11/41 , sold seperately).

This item is CNC machined out of Stainless Steel, it being copied exactly from an original bolt. As you can see - the bolt is cross drilled for the oilways in various places, as well as internally threaded for the adjuster bolt - which reflects in the price

Note: there have been slight variations in crankcase designs over the years. This part should fit most International and SOHC Manx type crankcases, but very early crankcases did have a smaller diameter on the bore closest to the lipped nut (the bolt can have its shoulder turned down to fit though). This type of early crankcase did not have such a pronounced counterbore at the back of the crankcase either, so length of this bolt may be nominal for that very early crankcase. If you are not sure, then email me for details of ours first, and we can confirm.

- This lipped nut is milled from solid round stainless bar and much improves appearance, particularly as the original are normally quite chewed. Not the cheapest of nuts due to the fact that it has to be machined from solid round bar. Update Dec 2010: New stock of these now in, CNC machined and beautiful to look at.

This is the adjuster screw that controls feed of oil to the barrel, through the rear cylinder bolt - Exactly as per original, but much prettier in stainless steel

This is the special reduced head nut, that acts as a lock nut for the adjuster screw A11/40 - Just as per original, but much prettier in stainless steel

This is the Copper washer that fits behind the cylinder feed bolt nut on all SOHC engines.  Price is each.

Nice quality uk sourced copper washer of correct ID/OD for the oil feed adjuster bolt assembly used on all SOHC engines.

This is the crankshaft bevel gear,, fitted to SOHC International (i.e. aluminium crankcase models - not magnesium) and 1930 onwards CS1 engines (not the Walter Moore engine). These gears faithfully replicate the original Norton tooth profile and pattern and we have them made for us by a top specialist UK gear manufacturer.

Price is Each. 

Because these have been made with the original (and correct) Norton bevel gear profile, they can be used in conjunction with original Norton lower vertical bevel gears (unlike some other pattern SOHC gears made in past years by others, that required they were always changed in pairs).  However, if required, we also sell the corresponding lower vertical bevel gear (Item 0421).

Photograph 1 shows the gear from front and rear. Photograph 2 shows an original Norton gear at the top of the photograph and our gears underneath. Photograph 3 shows the International bevel gear on the left, with the shallower SOHC Manx gear on the right. The International gear was fitted to all Aluminium crankcase engines.  If you have a magnesium (M30/pre-Featherbed Manx) crankcase engine, then look instead at Item 0423

Final point - for anyone building a SOHC Norton engine for the first time - shimming the crankshaft and bevel gears is one of the most important tasks to undertake correctly to ensure it results in a reliable and healthy engine.  Although not complex (compared to some modern engines), it needs to be undertaken in a specific order - and some elements of this process can be fiddly and time consuming . . . but it is definitely worth spending that time to get it right.  If you are not sure how to do this (and what parts it helps to have to make this task more efficient), then email us on sales@racingvincent.co.uk and we will try and offer technical assistance

This is the crankshaft bevel gear,, fitted to SOHC pre-Featherbed magnesium racing engines - i.e. M30/M40 and SOHC Manx type engines. These gears faithfully replicate the original Norton tooth profile and pattern and we have them made for us by a top specialist UK gear manufacturer.

Price is Each. 

Because these have been made with the original (and correct) Norton bevel gear profile, they can be used in conjunction with original Norton lower vertical bevel gears (unlike some other pattern SOHC gears made in past years by others, that required they were always changed in pairs).  However, if required, we also sell the corresponding lower vertical bevel gear (Item 0421).

Photograph 1 shows the gear from front and rear. Photograph 2 shows an original Norton gear at the top of the photograph and our gears underneath. Photograph 3 shows the International bevel gear on the left, with the shallower SOHC Manx gear on the right. The shallower gear was fitted to the magnesium crankcase racing engines - it being shallower, to allow for the Twin row timing side main bearing fitted to this type of engine. If you have an aluminium crankcase Internation or post 1930 CS1 model (with single row timing side main bearing - then we also sell the bevel gear for that engine as well - Item 0422

Final point - for anyone building a SOHC Norton engine for the first time - shimming the crankshaft and bevel gears is one of the most important tasks to undertake correctly to ensure it results in a reliable and healthy engine.  Although not complex (compared to some modern engines), it needs to be undertaken in a specific order - and some elements of this process can be fiddly and time consuming . . . but it is definitely worth spending that time to get it right.  If you are not sure how to do this (and what parts it helps to have to make this task more efficient), then email us on sales@racingvincent.co.uk and we will try and offer technical assistance

This is the lower vertical bevel gear, fitted to all SOHC International and Manx engines and also fitted to earlier DOHC Manx engines. These gears faithfully replicate the original Norton tooth profile and pattern and we have them made for us by a top specialist UK gear manufacturer.

Price is Each. 

Because these have been made with the original (and correct) Norton bevel gear profile, they can be used in conjunction with original Norton crankshaft bevel gears (unlike some other pattern SOHC gears made in past years by others, that required they were always changed in pairs).  However, if required, we also sell the corresponding crankshaft gear in either International (Item 0422) or SOHC Manx (Item 0423) configuration.

Photograph 1 shows the gear from different angles. Photograph 2 shows an original Norton gear on the left, and our gear on the right, as a comparison. Photograph 3 shows the gear fitted to one of our lower bevel gear housings. The gear has our PVN branding etched on the shaft.

Final point - for anyone building a SOHC Norton engine for the first time - shimming the crankshaft and bevel gears is one of the most important tasks to undertake correctly to ensure it results in a reliable and healthy engine.  Although not complex (compared to some modern engines), it needs to be undertaken in a specific order - and some elements of this process can be fiddly and time consuming . . . but it is definitely worth spending that time to get it right.  If you are not sure how to do this (and what parts it helps to have to make this task more efficient), then email us on sales@racingvincent.co.uk and we will try and offer technical advice

Driving plate for the oil pump on all SOHC engines, engaging with the oil pump drive gear on each ear, and from there driving the oil pump from the central slot.  Price is Each. 

This important part often wears badly on the original item, you should check the the ears on this drive plate regularly for wear. - a small amount of wear is ok, but it is not unusual to find original drive gear's with the ears badly worn - which eventually can shear.   

Background notes:

Also - when first building and running a newly created engine - it is important to check that ears engage with the magneto drive plate ok and plate does not foul oil pump bolts, because they are protruding from the oil pump slightly - all standard stuff, but it is easy to forget and overlook this, we sell oil pump bolts which have reduced heads for this reason, so they do not protrude beyond the brass oil pump cover plate.

If building a new engine, it is always worth checking that this oil pump drive plate will fully engage with both the oil pump drive gear slot (which also holds the magneto drive sprocket on its other end),  as well as engaging onto the oil pump drive gear ok, as many engines are built up from parts from different years - and small variations in machining of the timing covers exist over the years the SOHC engine was made.  A good way to do this is to loosely fit the timing cover with the oil pump drive gear in place in the inner timing cover, and this oil pump driving plate engaged onto the gear and the oil pump - but the crankshaft drive gear not fitted.  The magneto sprocket should also be fitted.  By doing it this way it allows for the oil pump gear to be turned by hand - which should allow the oil pump plate to centralise and ensure it is turning the oil pump ok, and also check clearances etc more easily.

These drive plates should also be checked periodically, as their design means that outermost tips/ears do often wear heavily, where they engage with the slots in the oil pump drive gear. 

Note: we supply these drive plates in a sealable plastic bag - but as we do with many other steel parts - we spray a small amount of Duck Oil on them to protect them in storage.  You may also see a some colouration on the plates - this is normal and just a side effect of the heat treatment operations as part of manufacture.

This is the oil pressure adjuster (and locknut)  that sits behind the inner timing case and controls the oil pressure to the entire lubricaton system on SOHC engines. 

We CNC manufacture these adjuster bolts to be identical to an original Norton SOHC adjuster bolt, but ours are made from stainless steel, and come supplied with the correct 'half nut' locknut.  The hex head is the correct Imperial spanner size - and is now very difficult to obtain - so we mill both the hex and screwdriver slot to ensure it is correct (which is why this adjuster is more expensive than standard bolts - this requiring 3 seperate operations).  They are also quite pretty and do not rust.

Price is for the special adjuster bolt, and correct Imperial Half Nut (do not try and fit a full nut)

SOHC Oil Pressure Adjuster Fitting and Operation:

As can be seen from the photographs, this special little bolt has an extending shaft that presses against a small ball bearing, which itself seats againt one of the oil ways, with a spring placed along the shaft of the bolt and pressing against the ball.  If the bolt was screwed in to its fullest amount - the tip of the shaft would push the ball bearing against its seat in the crankcase, stopping any 'bypass' of oil from the main feed circulation oilway, and therefore providing the maximum oil pressure.  But in normal use - this bolt is normally screwed back slightly (i.e. anti-clockwise) from from 'fully home', allowing the small ball (our Item 0244) to push against the spring (our Item 0245) and allow the ball to rise of the seat in the crankcase against the pressure of the spring, until it comes into contact with the ball and allowing oil to escape through a 'bypass loop', thus reducing the overall engine oil pressure.

Turning the screw anticlockwise (and then locking it with the special 'half nut') by different amounts will both allow the ball to raise off its seat by a greater amount, but will also reduce the spring pressure against the ball.

In the definitive 1950's Workshop guide called 'Norton Motor Cycles', by Edgar Franks - Technical Manager for Norton Motors in the 1940's/50/s, he recommends screwing the bolt fully home first (to ensure it is locking the ball to the seat), then turn it anti-clockwise two and a half to three turns back from fully home for normal operation.  

When stripping your engine down (providing it is functioning as normal) you should take a note how many turns from fully in this screw is set - so you can replace it in the same position.  If building an engine for the first time - first, ensure the ball bearing is seating correctly in the crankcase, then place spring on shaft and screw in this adjuster first - without half nut finished - so you can ensure it does fully lock the ball down, before it runs out of thread (just in case your crankcase has got a different depth to the ball seat from the 'standard' depth that this screw adjuster is deisgned for.  Once happy it is fully locking the ball to the seat, you can remove - fit the half nut, then lock down again, then screw outwards (i.e. anit-clockwise) until you are comfortable you have your initial starting position for running the engine.

It should be noted that Edgar Franks also highlights this area of the engine (with the ball seating in a taper within the crankcase hole) as one of the areas of the engine that can cause 'wet sumping' on these SOHC engines (along with wear to the oil pump gears being another major culprit), if the ball behind this bolt is not seating properly, or if dirt is trapped behind the ball.  Therefore he suggests, taking the ball out to check and clean periodically - and when placing the ball back in the crankcase, and it is on its seat - giving the ball a sharp blow with a (soft punch) and hammer - to help the ball seat properly. 

We CNC manufacture these adjuster bolts to be identical to an original Norton SOHC adjuster bolt, but are made from stainless steel, and come supplied with the correct 'half nut' locknut.

Note: We sell both the correct ball and spring seperately - Items 0244 and 0245.