Shake down runs…

The centrifugal clutch (called a traffic clutch apparently) went back together smoothly and on the bench worked as it should so the engine is back in and working. Like the Guru’s car our Riley engine is set to idle at 250 rpm although it will actually idle at 100 rpm (which doesnt even register on the Rev Counter..) try doing that with a modern car. The traffic clutch now takes the engine out of gear when I stop and lets it back in when the revs get to around 500 rpm. It is incredibly smooth. I can bring the car to a halt in any gear and the engine doesnt stall anymore. I am not sure it is possible to stall it – unless perhaps I try to pull away in top gear which I dont intend to try. The square cut gears in the gearbox howl when in neutral (which is normal) and have the classic whine in every gear apart from 4th which is direct drive.

So the car is now fully back together and on the road again and it was only a minor step back. The tuning of the engine continues and performance is improving every time with the spark plugs being checked after every run and the mixture being tweaked slightly until I get the spark plugs to be the right colour to indicate the mixture is not too rich nor too weak. So far the engine is staying cool too. The passenger seat has been bolted down saving passengers from being thrown into the foot well when I brake (well it made ‘me’ laugh).

I have fabricated a leather (and brass) bonnet strap preventing it starting to open at 45mph. It transpires the wind at that speed is enough to start lifting the sides of the bonnet by a good few inches. I have a couple of  locking pins to install which will do the job properly to prevent it ‘flapping’ – but the  leather bonnet strap is both aesthetic and a period fitting.

Although I am not counting, the car has had around ten 5 mile shakedown runs. Shake being the operative term as bits I had loosely fitted are reminding me that they are indeed loosely fitted by depositing fixing nuts onto my feet. Each trip is resulting in something else being adjusted / tightened / tuned / fitted. We have hit 50mph which I warn you is jolly windy and on the bumpy roads I am using – certainly an experience because the car has a mind of its own. Hopefully on smoother roads it will not decide to wander quite so much. Apparently have a steering wheel that you can move half an inch either way without affecting the actual steering is a ‘vintage thing to be embraced because you cant take the play out’. The brakes need a reasonable amount of pressure as there is no mechanical assistance in the circuit but they are beginning to actually work pretty well.

Below you can see my design for the bonnet strap mountings and the final look. The leather belt is allegedly from a Bentley (not sure I believe that but it is very old) which I cut down to size.

To round off this update:

The car has been accepted as being eligible to race by the VSCC so, fanfare moment….

I have entered the Riley into its first competition event!!!  Assuming my entry is accepted, we will be competing in the Brooklands Double 12 on 17th June. Our first competition will be ‘Driving tests’ where, against the clock, the car is put through its paces around eight ‘circuits’ vaguely laid out in cones. The convoluted route around the cones is only made available at the event and we will have to learn each route because you get time penalties for getting it wrong, or for running down a Marshall. I have a few weeks to get the car in a good enough shape to have the confidence to drive the distance but I am planning to take it to a car show this weekend if time permits.


The Guru

Over the last few weeks I have had a lot of help from a local Riley enthusiast who appears to have a huge amount of engineering experience and knowledge about these cars. I have begun to tap into all that experience as there is no workshop manual to refer to. Recently the Guru popped over to provide a little insight into my rather seized traffic clutch whilst also offering to take me for a ride in his Riley to demonstrate how the gearbox is used on the road.

It was almost disturbing how slow his engine idled. At a mere 250 revolutions per minute, you could almost hear each piston firing… but with 1st gear engaged and feet off all the pedals – the car just sat there. Slowly he increased the engine speed and around 500 rpm the car very gently eased forward. Taking his foot off the accelerator, the engine speed dropped and the engaged gear dropped out of operation and the car stopped moving. Right then off we go he said selecting 2nd gear on the steering column. The gearbox will remain in first he said – until you press the gear select pedal. So we pulled out of the driveway and he then pressed the gear select pedal and the gearbox immediately changed gear. He now selected 3rd gear in readiness for using it and once we were at the right speed he again pressed the gear select pedal and we were in 3rd. This is why it is called a ‘pre-select’ gearbox. You can be driving in top gear (4th) traveling at 70mph with the gear lever pre-selecting 3rd, in readiness for you needing to change down. Apparently you get used to this after about 20 minutes of driving – we shall have to wait and see…

Below is the The Guru’s Riley 9

A Day Out

Last weekend I was lucky to be invited to attend a large MG gathering at Brooklands. Obviously I don’t own an MG, so the invite came with transport to the event in a 1929 MG 14/40. This is a two seater tourer with a Dickey seat in the boot lid – I cant imagine trying to get into that seat, it was hard enough getting into the front seats after opening the door. It was raining so we were wrapped up in leathers, flying helmets and Goggles, oh and the ubiquitous grin. It was a little hard to say how fast we were going because the speedo doesn’t work, nor actually do most of the other gauges but thats an aside. I now know that people in the 30’s must have been stupidly slim because there is no room in these cars. I had to keep moving my leg out of the way so that the Driver could change gear. There was also no room for my arm next to the driver so that had to go behind him resting on the back of his seat. Driving in the old days, I have decided was very sociable.

The rain didn’t detract from the journey even when it started flowing under the windscreen and into my lap. It was cold and wet and I was having a fabulous time. My Driver had to seriously work at making the car progress, the steering was clearly very very heavy, we both used our arms as indicators and I found out later that the brakes were terrible. It was great fun. I look forward to returning the favour and taking him out in the Riley soon.

Flywheel re-installation

Meanwhile back at the Man Cave – work is continuing on the traffic clutch with the re-installation of the flywheel. You will remember that it took me a few hours to remove this in order to tighten up a loose locating pin. Putting it back into position was much easier EXCEPT that the instructions from the Guru were to ensure that the flywheel was positioned flat to the crankshaft or at least no more than 3 thousands of an inch variation anywhere around the circumference. Well I can tell you 3 thou is only 0.076mm so this task is easier said than done! Remember – the flywheel is held in place with 6 bolts BUT it has to be pushed into position with a pretty hefty hammer. Adjusting the ‘wobble’ to be no more than 3 thou – therefore took me 5 hours of ‘hit-it / rotate it / measure it’ then repeat and repeat and repeat and repeat…

Below you can see the dial gauge placed against the smooth clutch surface to check for the no more than 3 thou wobble – as you rotate the flywheel it pushes against the very sensitive rod (seen at the right side of the gauge) which in turn rotates the needle on the gauge. The further the rod is pressed (or released) the more ‘out-of-true’ the flywheel is. For many hours I was miles out but slowly brought it to tolerance. I now also know why there are so many hammer dents around the edge of the flywheel. I do not look forward to having to do this job again.

We will soon see the rebuilt Traffic Clutch being installed…

Centrifugal Clutch p2

The internet is a wonderful thing – Facebook has a Riley enthusiasts group and the folks in that group have been jolly helpful  over the last few months. I have now found someone who has a spare clutch drive plate to replace my grotesquely worn one *and* he is very kindly putting new friction material on the trashed friction discs for a very reasonable price. So life is positive again.

Whilst I am waiting for the parts to be delivered to me – I continued my work on freeing up the centrifuge weights and fettling all the worn/damaged metal back to a working state. I noticed that one of the square locating pins was free to rotate slightly and seeing as that sits in a rectangular guide slot, rotating (and possibly snagging) is a bad thing. All I had to do was remove the flywheel to get to the securing nut. This was a Haynes instruction manual moment – “simply undo the 6 bolts and remove”. Except the ‘remove’ part took several hours and much correspondence to the Riley forum. Apparently hitting it hard with a large hammer is an acceptable technique (which worked). The pin is now in its right position.

All I had to do now was clean up the faces of the flywheel and the pressure plate so the new friction plates had a clean surface to work against. I was rather pleased to find the surfaces were pretty good and it was only the damaged drive plate that took all the wear.

I now wait for the parts to arrive and the engine can go back in.

Bit of a setback

Although the car could be driven the gearbox was not working as it should. This car is blessed with having the ‘pre-select’ gearbox which is probably the best mix of a manual and an automatic gearbox that was ever designed. In theory it is impossible to stall the engine when coming to a stop with the car still in gear. There is no clutch to depress… which is how I knew that something was not quite right. Because in our car you *could* stall the engine which means that the automatic ‘traffic-clutch’ was not doing its job. I was a little hopeful that this was due to the car not being driven for 40 odd years and that it would free up naturally. Turns out I was miles away from the mark!

Fellow Riley enthusiasts advised that I could access the clutch unit through a small access panel which is sort of true and I could see that something was not right as the moving parts…. didnt!

After a fair amount of soul searching because I had only just got the car on the road – I decided the best way forward was to to take the engine out and take a proper look. Surprisingly this didnt take as long as I thought and I am glad I did because at some time in its life the clutch had failed completely and shredded itself AND a fairly chunky piece of metal.

The car looks a bit ‘hot-rod’… sorry about that VSCC…

Here we have the engine out and turned sideways so that I can access the clutch unit

…and this is the Amstrong-Siddley clutch unit. Around the outside are 3 heavy weights that swing out due to the centrifuge effect and thereby clamp the 2 drive plates together via the friction surfaces. When the flywheel speed reduces at tickover the weights fall back to their normal position – releasing the pressure on the friction material and thereby removing the drive. Quite clever really but it is soooooooo heavy.

And here is the clutch unit taken apart – you can see that both friction plates are destroyed and the metal plate (bottom left) has had its bunny ears snapped off…

I rather suspect that something would have exploded had I not taken it apart at this time!

The search is now on for replacement parts / a conversation with the racing boys who actually remove the entire unit and dont use it at all… apparently the factory grandprix ERA’s (English Racing Automobiles) which had far more powerful engines had the same gearbox but they threw away the clutch unit because of the sheer weight. At this juncture I have not decided what to do…

Boarding Step

Originally, like so many 1930’s cars, the Riley had running boards. I think  most people know what they are – a flat surface between the front and rear wheels that you could stand on to get into the car. These were one of many things that were missing from the car when I bought it but  I do not need them. However our car doesnt have any doors so all passengers have to step over the side into ‘the cockpit’ and take their allocated seat. This is fine whilst we are young and limber (coughs theatrically) but we will get older and less limber and will need that step. Getting out is easy, you can just jump.

The challenge was to fabricate something that was elegant but very strong. I have a large sheet of 10mm thick steel which should achieve the strength and provide a suitably stable plate to then bolt the more aesthetic ‘Riley’ Aluminum step onto. My design is to bolt one end of the steel plate to the chassis *but* that means that weight on the step will send all the leverage onto the threads of the bolt – effectively standing on the plate will literally (over time) lever the bolts out of the mounting holes. The solution then is to have a vertical plate welded on so that the weight stress is now transferred to a shearing force through the bolt. That is significantly stronger.

Below you can see the plate cut and drilled to shape – the curve on the front face is actually symmetrical, the camera angle has foreshortened it.

As you can imagine, cutting and shaping 10mm thick steel takes some time, as does drilling and filing it to shape. You can therefore consider that fabricating these components consumed much of my day.
In the next picture you can see the concept of the design

The supporting plate was then offered up to the chassis rail, the mounting hole position transferred and then drilled and a thread cut into the holes to take 5/16th high tensile bolts. This was to enable me to unbolt the step at any time in the future should I want to. Welding it to the chassis would have been much stronger but would mean I was stuffed if I find over time that it is in the wrong place!
Below you can see the support plate bolted to the chassis and a hole drilled and threaded for the vertical support. This was bolted firmly into place and then a small weld was applied to the edges of the vertical support to set it in the right position ready for a full weld to be applied.

That done, the whole ‘bracket’ was sprayed black and left to dry. I fully expect the paint to erode off the bracket over time BUT it is nearly twice the thickness of the metal used in the chassis so I imagine it will last.

Finally, the picture below shows you the finished step. The Riley plate (custom made by a chap in Holland which I purchased a long time back at a Beaulieu Autojumble) is simply bolted to the bracket using stainless steel machine screws. It too is 10mm thick but it does not take any actual load because the bracket is almost as wide as the Riley Plate

Now all I have to do is make another one for the rear passenger which I may put on the other side of the car. But that can wait for a while until I know whether it will ever get used or not.

Engine tuning

I had setup the engine well enough to start and tick over but I could tell it wasn’t really happy as it seemed to splutter above 1500rpm. Cutting a long story short, I had to reach out to the VSCC boys for some guidance as I *thought* I had set everything up as per the factory settings. I also discovered that water was leaking into the inlet manifold which means that it was mixing with the fuel as it was sucked into the combustion chamber – not ideal. This meant that the fuel/air mixture was severely weakened and that turned the exhaust pipe blue because the gasses were excessively  hot.

Resolving the water leak required the carburetors and manifold to be removed, the issue(s) fixed then everything reinstalled. The ignition timing it turns out was setup totally incorrectly. To enable vintage cars to start, the driver used to manually adjust the distributor so that power was sent to the appropriate spark plug when the piston was at the absolute top of its cycle. Then once started it was adjusted so that the spark plug started to fire around 8 degrees before the top of the cycle (which allows time for the spark to fully ignite the fuel). The factory information doesnt mention how to configure the ‘engine running’ setting and I was leaving it at the ‘starting’ position. It turns out that this okay to start the engine but to obtain driving power its an order of magnitude out. The nice boys at the VSCC advised me to simply move the distributor when the engine was running so that it performed smoothly and then to lock it into that position instead. So thats what I have now done until the car can be driven on the road and more accurately tuned. It has completely changed the sound of the exhaust interestingly – it is no quieter just a lot smoother.

The brake shoes have been sent off for new friction material to be fitted and I await their return.

Below are a few pictures of the car as-is as I think many people have not seen how the car currently looks. There is a long way to go but it definitely looks like a car… I have since polished the blue out of the exhaust manifold…



Fuel things

Today I was going to look at the charging system but changed my mind and instead focused on the fuel side of life. The petrol tank was custom made when the body was crafted and it mimics the original tank in looks but aside from that it is unique being made from aluminum with a few customisations. The fuel sender is a marine item whereby the fuel level in the tank is measured by a bobbin that floats up a vertical sensor shaft. Realistically, there are no moving parts to the sender as the bobbin is not actually attached to anything – the shaft senses where the bobbin is and sends a specific resistance down the sensor wire to the gauge within the range 0-180 ohms (0 being empty). Trouble is vintage fuel gauges had totally different resistance ranges and in all the spares I had the range was 250-0 ohms. Completely opposite in functionality. For a while therefore I am forced to use a modern alternative which sort of looks alright but sadly not really what i want… hey-ho I need to know the fuel level so this is put back on the job list for another day. On the positive side I know that this part of the new wiring does actually work.

My other non period customisation is to insert an inline fuel filter as a just-in-case. The tank may have tiny pieces of aluminium dust still inside which would not be great inside the combustion  chamber and it also gives me a visual that fuel is actively being pulled from the tank to the engine.

Below is the engine bay with the newly provided fuel system. It finally looks like a proper vintage racing engine. One day I will get round to polishing both the rocker covers on the top of the engine.

I may remake the copper pipe that runs from the petrol pump (top left) down to the first carburetor – I think I can improve on the route and I sense the 360 loop is not actually necessary. Sadly whilst I am making huge strides forwards I do have a few issues to resolve:

  • Cylinder 3 is noticeably running hotter than the other cylinders (really weird)
  • The rear carburetor has a slight fuel leak (which may account for the above issue)
  • There doesn’t appear to be any oil getting to the inlet valve rocker shaft

I also took a look at the fuel/air mixture and I found the front carburetor was set too rich so I spent a happy hour ensuring the fuel levels were the same in both carburetors. That will make a difference to the tuning and it also meant I had to remake the mechanical choke connections because the length of the original ones were too short resulting in their enriching the front carburetor without my knowing. This is all resolved now.

All of the technical issues need to be addressed before the car can be driven – oh…. and I need to rebuild the entire braking system which had slipped my mind for a while 🙂

We are getting ever closer to driving the car after which I fully expect to unearth a whole host of other challenges….