Forum Admin Issues

Unfortunately, we are having difficulties with the forum and at the moment Mike Stevens, our Forum Admin, can’t log on as an Administrator. This means he can’t action any of the administration actions (such as authorising new members or sorting out logging in issues)

This is being investigated and hopefully will be resolved soon. We apologise for any inconvenience and thank you all for your patience.

Stoneleigh Goes Down a Storm!

This year’s MG & Triumph Spares Day was memorable in more ways than  one. Not only was Storm Ciara doing her best to bring the country to a standstill, (and nearly bring the roof down with the mid-afternoon hailstorm) but the Register stand was buzzing all day long. Congratulations go to Matt Field (and polisher Sue) for picking up ‘Best Triumph’ at the show and also to Maggie for handling the steady stream of membership transactions with no let-up. In fact she had 21 renewals, 2 rejoins & 2 new family members sign up during the show. Besides Matts lovely MK1, the Register stand also featured the Bradbury’s super MK2 estate – both drawing admiring glances. A lovely show enjoyed by all, despite the weather.

Register Members Discounts with DMG

David Manners Group are now pleased to offer Register members a discount off various part lines purchased through their Abingdon MG operation. It may seem an odd trading name for a supplier of Triumph parts but Manners assure us they have a good selection of items applicable to our vehicles. 

 One bonus is that you will be dealing with Register member and PI MK2 owner SIMON CARR – whos tale of tinworm can be found in the last edition of SIXappeal (Dec ‘19, page 22). Speak to Simon on 0121 543 1615 with your membership number to hand – and see what deal he can do for you.

Roll Up, Roll Up!


To get the new website off to a flying start we’ve just had a short run of these 9cm square, self adhesive vinyl stickers produced. Emblazoned with the new ‘favicon’ (new one on me too…) logo as designed by our website creator Paul Girling, they are a fun new take on the Register name – pop one on your ride and show your allegiance! Available FREE to the first 40 members who send an SAE to the SIXappeal editor (address inside the front cover of the mag). Pop your membership number on the top left corner of the envelope. If you have a couple of cars then ask for 2. (Max 2 per household!)


CHRIS WITOR 117/29 February ’01
How to make a really clean start, plus some advice on lubrication and oils

WWW.CHRIS WITOR.COM Triumph 2000, 2500, 2.5 Specialist Parts SupplierI would regard cleanliness of the components as the most important aspect of an engine rebuild, in particular the block and its oil galleries. Any residual machining particles or dirt in the oil galleries can get pumped straight into the bearing journals of the mains, big ends, camshaft and rocker shaft. Damage can be costly in terms of either premature wear or even total bearing failure resulting in another rebuild.


Dirt in the crankcase should not find its way into the oil galleries, as no particles below 15 – 20 (metric) microns (i.e. 0.0005906 – 0.000787 inches) should pass through an industry standard oil filter, unless the filter is so clogged that its by-pass valve opens. I have seen an instance where the inner O-ring was not fitted to a spin-on oil filter conversion, resulting in rapid wear to the bearings on a rebuilt engine, as the oil by-passed the filter picking up more and more debris, as more and more wear took place! Apart from this, dirt in the crankcase small enough to pass through the strainer of the oil pump will wear the lobes of the pump rotors.

Another less obvious place that crankshaft dirt particles end up is embedded in the seat of the oil pressure relief valve in the block itself, preventing the valve plunger from seating properly. The valve itself can stick open even further off seat. Soft, substandard reproduction valves are especially prone to this as particles embed into the soft metal more easily. The Original, and properly remanufactured, valve plungers have a hardness of around 40 Rockwell B. A stuck open valve can result in a sudden large loss of oil pressure, whereas particles on the seat in the block cause consistent low idle pressure, particularly when the engine is hot. A good rebuilt engine should idle at between 25 and 30 psi when hot. If less, and the rest of the engine is in good condition, it is worth cleaning the oil pressure relief valve seat in the block.

I had this tool made to clean the seat. It is made from a 9/16 inch drill bit shortened and reground to 118°, the angle of the pressure relief valve seat in the block. The cutting edge angle was reduced, so that this works more like a scraper than cutter. The tool is turned by hand using the wrench shown. It is surprising what granular debris comes off the seat in some blocks. The more dirt that comes off, the larger the increase in oil pressure.

It is not only the block itself that will harbour dirt. The following components should also be cleaned thoroughly:
Rocker cover (including internal gauze in later versions)
Rocker shaft assembly
Cylinder head
Engine front plate
Timing cover
Bridge piece across n01 main bearing cap
Timing sprockets
Rear oil seal housing
Connecting rods
Main bearing caps and bolts
Cam followers
Distributor/drive gear and pedestal
Petrol pump (where used)
Oil pump
Oil filter adaptor or housing
Cleaning the Crankcase

Some engine reconditioners offer a service where the whole block is immersed in powerful cleaning agent. H T Howards of Slough use a “decarbon fluid” which removes all external traces of oil, gunge and even paint from the block. This saves a lot of physical scraping, scrubbing and brushing, especially if the block is covered in thick, sticky, black gunge.
After degreasing, I mount the block on an engine stand, and remove any surface rust with a rotary wire brush, so that the block is ready for painting later. The core plugs are also removed at this stage. I prefer to use an oxyacetylene cutting torch to remove the plugs, simply heating around the edges to red heat and blowing a hole in the middle of the plug. When cooled, they will have lost their interference fit. A screwdriver is inserted into the hole, then the plugs can simply be levered out. I prefer this to any hammer and chisel method, as there is no risk of scoring their housings.

Tool to clean oil pressure relief seat

Oil pressure relief valve, spring and nut in special blue anodised alloy. Steel nut weighed 110g (Alloy 40g)

However, despite the block being clean externally, it is never to be assumed that the internal oil galleries will be clean enough for use. The main oil gallery that runs the full length of the block should be thoroughly cleaned. The distributor/oil pump drive bush should be drifted out using a 1/2 inch shouldered drift such as a 1/2 inch socket cap bolt. This is drifted up out from its underside.

Oil pump/distributor drive bush,
Left – late Mkl & all Mkll Right – early Mk I

The 1/4 inch BSP plug (O/E no 118632) is removed from the rear of the block using a suitable Allen key. The plug at the front of the block is a bit more tricky to remove. I drill a 1/8 inch hole through the middle of the plug. I then use an oxyacetylene torch with its intense localised heat on the aluminium plug until it just starts to melt. The plug tries to expand but has to expand inwards as the block prevents expansion outwards. When it cools it contracts leaving a loose fit in the block. I then lubricate the thread with penetrating oil, drive a flat bladed screwdriver into the soft plug and simply undo it.

Front 1/2 inch UNF oil gallery plugs, OE No PS1103 supplied on a stick of 10, removed piece above

The six 1/8 inch BSP plugs (O/E no 118686) can be removed from the side of the block using a 3/16 AF Allen key. If struck a sharp blow with a hammer and punch, they will normally break their hold. If this fails heat up as with the front plug.

With all the plugs removed, a rifle brush and extension can be passed through the main gallery. Wash the brush in degreaser after each pass. Rifle brushes can be purchased from a gun shop. I made my own extension out of a piece of 5/16 inch old and 24 inch long rod. I use a combination of appropriate drill bits – turned by hand – and thread taps: 1/8 and 1/4 inch BSP to clean out the cross drillings to the cam and main bearings. A 5/16 inch UNF tap is useful to clean out the many other threads of this size on the block.

Rifle brush and extension used to clean main gallery

Next, the block is given a thorough flush as follows:
The oil pump bush is drifted back in with a shouldered bush. Don’t drive the bush too hard as the flange nears the block as the flange can be broken off. The old pump is refitted and the block placed in a domestic water tank (cost less than £10 from a DIY superstore). The block is supported on some wooden blocks so that the strainer of the pump is just above the bottom of the tank. The oil filter and the pressure relief valve and spring are also refitted.

Twenty-five litres of new degreaser (available from any good motor factors) are emptied into the tank.

A shaft will be needed to engage the tongue and groove drive of the oil pump. A PI distributor/metering unit shaft with the gears removed is ideal. If not available make a shaft out of a 6 inch length of 1/2 inch old bar with a groove cut out to engage in the tongue of the pump. The pump turns anticlockwise when viewed from above, so a reversible electric drill with a 1/2 inch chuck will be required. I usually run the drill for about 10 minutes, swapping gallery plugs around to divert and intensify flow of degreaser through the galleries.

Remove the oil filter and pressure relief valve. The engine can be removed from the tank and put on a table, or ideally, on an engine stand to wash with hot water. Dry with a blowlamp and paint with engine lacquer. I usually put a magnet in the bottom of the tank to see how much ferrous matter has been washed out of the block. The degreaser can then be salvaged for more basic tasks. When the paint is dry the gallery plugs can be refitted to the block.

I always use a drop of Loctite pipe sealer (available from engineering or bearing suppliers) on their threads. Refitting the plug to the front of the block isn’t so straightforward. The intended stick of thread (PS1103) tends to wind far further into the block than the original, which is not reassuring. I use the 1/2 inch alloy rod that comes with a Kenlowe fan kit and run about 3/8 inch of 1/2 inch UNF thread onto the end of the rod with a circular split die and die stock. By this method the thread is more tapered. It can be wound into the block after being covered with pipe sealant, cut off flush and filed flat.

Forged blue anodised alloy blanking plugs. Adds a nice touch for the discerning engine builder

Other useful tips

If the engine has had the bores honed, or has been rebored, and new piston rings fitted always run the engine in on special running in oil. This helps the piston rings to wear/bed to their bores preventing glazing and thus premature oil consumption problems. Normal oils contain anti-friction additives which are detrimental to running in. I use Comma R05L. When the engine is installed in the car and filled with oil the reversible drill and pump drive can be used to prime the galleries, pumping oil into all the bearings and the rocker shaft before the engine has even turned.

Magnetic sump plugs, before use

Magnetic sump plug with ferrous particles collected

When the assembled engine is first run with new piston rings on honed bores, a lot of ring swarf will be deposited when the peaks of honing marks wear into plateaux as the rings and bores bed in. At this stage a magnetic sump plug is highly beneficial which will pick up a lot of grey metallic paste, especially for the first 1000 miles after which the running-in oil should be changed.


Mobil 1 5w/50 synthetic oil is great for our engines, but has been superseded by thinner 10w/40 which I first tried on a high mileage 2000 engine. Oil consumption became unacceptable! My (since rebuilt) 2000 is now on Comma (who own Mobil) synthetic 5w/40, which I am evaluating. Oil consumption is no longer a problem. Modern engines use thinner synthetic oils because they create less drag, improving power output and fuel economy. If f were going to use a 2.5 engine to do a lot of heavy towing in a hot climate I would use Castrol RS10w/60. 2.5 engines run a higher crank bearing load with their longer stroke than the shorter stroke 2000. One can, of course, use cheap old 20w/50 non-synthetic oils which are relatively high in tars and waxes creating drag and thus need replacing more frequently than modern synthetic oils. Semisynthetic oils offer a good compromise.

Engine – Engine rebuilds

I don’t regard any of the oils I know of as being totally ideal. There are many compromises involved. I would ideally prefer to try 5w/45 on my 2000, which, as far as I know. doesn’t exist. However. the oil pressure does not drop below 20 psi when hot on 5w/40. The greater flow rate of a thinner oil will help cool the bearings more than a thicker oil, but a thinner oil has a lower film strength. The lobes of a high lift cam would be my greatest concern, if the oil were too thin.

It will be interesting to hear what oil other club members are trying.

Oil Coolers

These are less necessary with modern synthetic oils which are designed to cope with lubricating a hot turbo charger. A temperature gauge can be used to evaluate the situation. Cleanliness of oil cooler. hose and thermostat is essential as any dirt will be pumped straight into the oil galleries and bearings. In most cases the oil is filtered before it passes through the cooler.

Oil Pump

Very much at the heart of the matter, I wrote about this in my first Technical Article seventeen and a half years ago. (See first Register Service Notes page 1.151.) The key point for attention is rotor end float. Getting down to one thou of end float was a bit optimistic. 0.001 – 0.0025 inches is more realistic. If you have a new pump with more end float than this (0.004 -0.006 inches isn’t uncommon) then it will be beneficial to have the body machined or simply use a blue printed pump to start with.


88/16 April ’96

Having stripped, cleaned and prepared the engine for decoke and reground the valves as described in the last month’s article, the engine has to be rebuilt and tuned.

The refitting of the valves into the cylinder head is the reverse of the procedure for removal, using the spring compressor in the same way. Remember to fit the close coils of the spring towards the cylinder head. The valve springs should be checked before replacing. The easiest way of checking a valve spring is by comparison with a new one. Do not be misled by the difference in free length of the spring as this does not always have any bearing on their load at the fitted length. The best way of testing springs is to place a new and an old spring into a vice, end to end, with a flat piece of metal between them. Determine the fitted length of the spring by placing a valve into the cylinder head complete with cotters and caps, but less the spring. Measure the distance between the two faces on which the spring rests. This distance will be the fitted length. Tighten up the vice with the two springs in opposition until the new spring is compressed to the fitted length. If the old spring is then shorter than the new spring this indicates \weakness.

Remove the carbon deposit from the crown (or top) of the piston leaving a ring around the outer edge of about 1/2″. A certain amount of carbon will have formed round the edge of the piston inside the bore. By removing the carbon to the edge of the crown, this ring would be broken which could cause heavy oil consumption. When removing from the top of the piston take care not to damage the piston with a sharp instrument such as a screwdriver. Stuff some clean rag into the openings on the nearside of the engine to prevent the particles of carbon from getting onto the cam followers. The hard carbon will cause uneven wear on the cam followers, which in turn will cause noisy tappets.

Refit any studs which may have come off with the cylinder head nuts and check those in the head for tightness. (I find it much easier to clean the top of the block with the studs removed. Uncle Stan Part) Clean all the flat faces of the cylinder head and the top of the cylinder block in readiness for re-assembling and remove the rag from the cam follower chest. Place the cylinder head gasket on to the top of the cylinder block. The gasket should first be coated with nonhindering gasket cement or grease. (I always use grease. Gasket cement can ‘blow’. – USP) Always fit the gasket with the seams uppermost.

Replace the cylinder head, nuts and washers remembering to use the high tensile nuts and tighten down. Cylinder head nuts should always be tightened evenly, starting from the centre and working outwards towards the ends. If a torque wrench is available tighten the nuts down to the correct torque. (The Mark 1 engine is prone to blowing head gaskets because the studs are too small to allow it to be tightened down effectively. This was fixed on the Mark 2. It is therefore IMPERATIVE that you use a torque wrench, and tighten the nuts down to the maximum recommended setting (46 lb. ft.) in the recommended order. You must also be sure to tighten down all of the head nuts again after 100 miles. Unfortunately, this entails removing the manifolds. But nobody said life was easy. – Uncle Stan Part)

When the head has been refitted and tightened down, the push rods can be replaced. The push rods are better if kept in order. Fit and secure the rocker shaft assembly, making sure the cups of the push rods are located on the ball pins on the rockers. The rocker pedestal nuts again must be tightened evenly to prevent bending of the rocker shaft.

As the cylinder head, valves and rockers have been disturbed the tappets will have to be reset. There are many different ways of setting tappets, the most popular method being the 13 method. Number the valves 1 -12 starting from the front. Rotate the engine a few times to give the valve and rocker gear a chance to find their natural position and check their action. To set the tappets look for the valve which is open, the one where the spring is compressed, subtract the number of that valve from 13 and that will tell you which tappet to adjust. Slide a 0.010″ feeler gauge between the top of the valve and the rocker. The adjusting screw can be tightened or slackened so the feeler gauge is a slide fit between this valve and rocker. Rotate the engine so the next valve is open and adjust the corresponding tappet; repeat this until all 12 tappets have been adjusted.

Place the manifold gasket onto the studs the correct way round; on close examination it will be found the rear stud hole is lower than the front. If fitted wrongly blowing will take place at a later date. Before fitting the manifolds unscrew the nut joining the inlet to the exhaust manifold. Clean off any remains of the old gasket and renew the carburettor joints. After fitting the manifold tighten the nuts and bolts with their retaining plates, tighten the nut joining the two manifolds. Reconnect the exhaust pipe using a new gasket and if the front mounting has been slackened, re-tighten it. Refit the throttle and choke controls to the carburettor and check their correct function, replace the air cleaner.

Either clean or renew the distributor points, setting the gap to 0.015″ when the fibre heel is on the peak of the cam. Clean and reset the spark plugs and if they show any sign of burning on the electrodes renew them. The plugs should be set at 0.025″.

Replace the spark plugs and distributor top. Make sure the correct lead from the distributor top is connected to the correct plug; this is made easier by marking the leads. Re-connect the H.T. lead to the coil.
Renew the gaskets on the water pump and thermostat housing and refit the pump to the head securing at the same time the petrol pipe and dynamo/alternator stay. The petrol pipe can then be connected to the carburettors. Prime the petrol pump with the lever on the side of the pump and examine for leaks. Examine the radiator and heater hoses for cracks or perishing and if necessary replace them. A light smear of grease on the inside of the hoses makes them easier to fit. Refill the radiator and cooling system with clean water, or with the old coolant if it contains antifreeze and has been kept. Examine the radiator filler cap and check the small valve in the centre. Check the seal in the top of the cap.

Place the fan belt around the pulleys and re-connect the dynamo/alternator stay. Pull the dynamo/alternator away from the engine, this will tighten up the fan belt and finally tighten the dynamo/alternator mounting. Join up dynamo/alternator wiring and temperature gauge.

Before replacing the rocker cover oil the rocker assembly and fit a new gasket to the cover. Do not over-tighten the rocker cover nuts as this will distort the cover and cause leaking.

Check that all items have been reconnected and finally reconnect battery. Run the engine for a little while until the normal working temperature has been reached. All that remains is to tune carburettors.


87/16 February ’96


This series of technical articles has been designed for the “mechanically minded” reader who feels capable of carrying out his own maintenance to this degree. If you have doubts about your ability to cope with the instructions you are earnestly advised to leave the job in the hands of an experienced mechanic. During the combustion of the petrol air mixture of an engine, deposits of carbon are formed. Although the majority of these deposits are ejected through the exhaust system, a certain amount remains and collects on the walls of the combustion chamber, valves and piston. This build up of carbon prevents the engine from breathing and robs it of its performance, in the same way a fire loses its brightness when the chimney becomes blocked with soot.

Very high temperatures are also produced during combustion, which are necessary for the running of the engine. The high temperature and heavy loads exerted on the valves will sometimes cause them to burn after very big mileages. The question now arises as to when a decoke and valve grind are necessary. To give an answer in terms of mileage on this question is virtually impossible, as no two engines are alike. The best guide is in the symptoms; the loss of compression is the key. Loss of compression will cause loss of power, heavy petrol consumption, difficult starting and uneven running, and even misfiring. As the fall in performance is gradual it is often not noticed until the condition gets very bad.

1. A set of ring and open-ended spanners from 3/8″AF to 3/4″AF.
2. Valve grinding stick.
3. Screwdrivers, one large and one small.
4. Grinding paste, coarse and fine.
5. A scraper or rotary wire brush if available
6. Valve spring compressor.

1. A set of decoke gaskets.
2. A set of exhaust valves.
3. Spark plugs, points, and hoses etc. as and if required.
Obtain your spares from a Triumph parts supplier and always quote your engine or commission number you are then certain of getting the correct parts.


Whenever working on an engine the first safety precaution to be carried out is to disconnect one of the battery leads.

There are quite a lot of components connected to the cylinder head and other parts of the car, these all have to be removed or disconnected. Drain the Cooling system by the tap on the lower tank of the radiator (if fitted). All the hoses can then be removed including the heater hoses and manifold heating hoses on the Triumph 2000. After unscrewing the clips, give the hoses a twist to break the seal. This will make them easier to remove. Slacken off the dynamo / alternator mountings and remove the fan belt. The water pump can now be removed by unscrewing the three securing bolts, the top right hand bolt also secures the dynamo / alternator stay, the left one the petrol pipe. All three are just above the water pump pulley.

There are only a few electrical points which require disconnecting. These are simply the water temperature gauge, if one is fitted, and the H.T. leads to the sparking plugs. To save damage, remove the distributor top. It is also a good idea to number the leads, thereby preventing them from being connected to the wrong plug.

The carburettors can be removed with the manifold as a complete unit or separate. Disconnect the throttle, and choke controls, remove the air cleaners and disconnect the petrol and vacuum advance pipes. If the manifold and carburettors are being removed as a unit, disconnect the exhaust pipe. A single row of bolts and two nuts, one at each end secures the manifold to the head, these can be removed and the manifold lifted off.

Having removed all the controls and components from the head we can now start removing the head. Unscrew the nuts securing the rocker cover; these have fibre washers and plain washers under them, the fibre washers to prevent oil leaks. Removal of the rocker cover gives us access to the rockers themselves. The rockers are mounted on a shaft and are removed as a complete assembly which is secured by 9/16″AF nuts, one on each pedestal. From each rocker there is a push rod connecting it to the cam follower. When removing the push rods give them a shake, this will free them and prevent dislocation of the cam followers.

With the rocker shaft and manifold assemblies removed we can now have access to the cylinder head nuts, which can now all be removed. The cylinder head nuts are all high tensile nuts and should not be mixed up with other nuts of the same size, so keep them separate. If in doubt about the correct nuts, the high tensile nuts are identified by the letter “R” on the upper face.

The lifting can sometimes be difficult to start with, as sticking sometimes takes place between the faces of the head block and gasket. A slight sideways tap with a piece of wood or soft hammer sometimes helps. The cylinder head removed and on the bench, we can now concentrate on the valves. Removal of the valves from the head is one of the most difficult tasks to be encountered on the decoke.

A special tool is used to compress the spring; this relieves the pressure on the two collets allowing them to be removed. After releasing the spring compressor, the valve cap, springs and valves can be removed. If the compressor is not available the springs can be compressed by placing a block of wood under the valve heads and using a strip of metal pivoted on one of the rocker pedestal stands. When removing the valves from the head, mark them so they can be replaced into the same guide. When new valves are being fitted this is not necessary of course. Clean off the deposits from the valves and combustion chamber, and clean out the ports. A rotary wire brush in an electric hand drill is a useful tool for this job. Wash all loose dirt from the head so it is nice and clean for examination.

Inspect the valve seats for bad pitting. If the seats are too badly marked, they will have to be cleaned up with a special cutting tool; this is best done by a garage. The valve guides are also best removed and replaced by a garage if they are worn at all. Worn valve guides cause heavy oil consumption and reduce valve life considerably. To check a valve guide, place the valve into the guide so it is about 1/8″ off its seat. Then try rocking it from side to side. There should be no more than .020″ movement. A worn guide can also be detected by looking at the stem of the valve; a dull black deposit of carbon on the stem indicates wear on the guide.

Assuming the valve seats and valve guides are in order, we can start grinding in the valves. This is done by smearing the valve seats with grinding paste. Before putting the valve into the guide, lightly oil the stem. Using the valve grinding stick rotate the valve back and forward using the palms; rotate the valve occasionally allowing the paste to return. While grinding in the valves gradually rotate them so they are seated all the way down. Ensure after grinding in, that all the grinding paste is washed off, as an abrasive will produce wear if left in. Inspection of the seats will show if the valve has been ground in correctly. The seat both on the valve and head should have an even mat grey mark all the way round about 1/10″ wide. Too wide a seat will collect foreign bodies.

(Were there any Mk1s factory fitted with non-six cylinder engines? – Uncle Stan Part)


ANDY ROBERTS 45/08 April ’89

The manual says that oversize thrust washers were not fitted to the 2500 engine, and therefore some engine reconditioners only supply standard thrust washers. There is no reason why you can’t fit oversize thrust washers to a 2500 engine, and if the end-float is outside limits with the standard washers every reason why you should. Note that the allowable endfloat on the 2000 is 0.006″ to 0.014″, whereas on the 2500 engine it is only 0.006″ to 0.008″. This is what the book says, but I am a bit sceptical! Certainly 2500 engines seem more prone to dropping their thrust washers than 2000’s, but I would not worry until the end float exceeds 0.014″ in either engine. Thrust washers are available 0.0025″ and 0.005″ oversize, which of course reduce the endfloat by 0.005″ or 0.010″ respectively, since there are two of them.

(Ed’s note -You can use a standard one and an oversize one to give endfloat reductions of 0.0025″, 0.005″, 0.075″ or 0.010″!). (Other oversizes are also available – Uncle Stan Part).

Engine – Crankshaft