Archive for February, 2011

OF TRIUMPH AND DISASTER – Tony Hodson’s Season with a Cooper 500.

Friday, February 25th, 2011
 
Following a steady season in 2009, when significant improvements in times had been achieved, I decided that some more speed was required so asked Terry Ives to investigate the compression ratio in the JAP engine. I had thought, but never checked, that I was running at about 13:1 which is at the lower end of what can be expected. I was somewhat shocked therefore when Terry informed me that it was actually about 10:1 and then delighted when he said he had raised it to 15:1 which is near the top end of what is achievable with the engine.  
 
So it was with hopes high we set off for Wiscombe Park down near Honiton for a weekend’s competition, with the 500 Association event on Saturday and the VSCC event on Sunday. Saturday dawned cold but dry and we attempted the usual procedure of doing the first start, always a dodgy procedure with rather temperamental JAP engines, by running down the hill into the paddock. Only when we reached the bollom after several failed attempts did we spot that the fuel taps had been off all the time – oh dear. Matters did not improve during the dayvery much as a new, ie different, carburettor body which had been fitted without much thought proved to be all outof adjustment so that the engine was either running flat out or not at all. Not ideal when there are a couple of very sharp hair pin bends to negotiate. The best run proved to be the second practice run which showed some improvement over 2009 but everything else was slower. Worse was to follow! 

When in Devon, B&B is provided by my brother and repayment for a days pushing and a bed is usually a meal at the local. Upon arriving back at his I discovered my wallet was missing – everywhere was searched several times to no avail. This meant I had no cash (crucial for the autojumble) no credit cards (maybe no bad thing) and most importantly, no competition licence for production at signing on in the morning! Now No.2 Brother had also been competing in his MX5 and everyone had gathered at my spot in the paddock. After I had signed on I had put my wallet in what I had thought was one of my bags – wrong! In fact it was one of Nigel’s and he was on his way back down to Cornwall. A phone call established that he did in fact have it before too much damage had been done by way of cancelling cards etc but it meant competing on Sunday was out of the question. 

The next outing was in July, at the Classic meeting at Shelsley Walsh in the Malvern hills, a wonderful place which is the oldest motor sporting venue with a continuous history in the world. A visit should be on your list of 10 things to do in your life. An average sort of time for a 500 here is around 40 to 45 seconds with quick types getting down to 35 seconds. The day proved to be quite satisfactory with some gear selection bothers spoiling the first runs meaning that I could not get under 50 seconds. Everything came together on the final run when we just cracked 48 seconds. I was still smiling on the following Tuesday. This is counted as a triumph and we looked forward with great anticipation to the next event, also at Shelsley when we hoped for even greater things. Sadly this was not to be as the wheels came off, literally as the trailer shed one of these rather important items. Fortunately this was at the Henlow roundabout only a couple of miles from home and no damage occurred to the Cooper. Recovery was effected through a splendid RAC man who also organises recovery on the London Brighton run and Paul Clarke of Autoshift in Stevenage, who also runs a Morris Minor van – these old car types get everywhere. 
Ebay came up with a new trailer so we set off to Gurston Down near Salisbury for the next episode. Gurston is a splendid place set in a valley with the start on one side so that you go downhill for some distance before tackling a sharp right hand bend followed by a sharper righthander and a left to take you towards the finish. The place is a working farm and the farmyard doubles as the paddock on race days. The 500s assemble next to some old sheds because that bit is on a slope making push starting easier and those sheds contain treasure in some quantities. A V8 Rover head could be seen, with remains of all sorts of other things however time is always tight so inspection is usually limited to the visual. 

So there we were, 5 in the class, one we knew we could not beat, two we thought we could and the fourth was an unknown quantity. After practice we were third quickest and not too far behind the second car so with hopes very high and after a good lunch we set about the proper runs in the afternoon. Ah well – first run – rocketed into the first righthander and promptly found we were facing the wrong way! Pushed up the escape road by the ever friendly marshalls and returned ruefully to the paddock to face a quizzical bunch enquiring as my whereabouts. Still It does show you are trying when you do spin it and if it’s good enough for Lewis Hamilton etc etc. Second run went better but one of the chaps I thought I could beat had a demon run on the first session so we ended up 4th and a bit disappointed. 

Final event was the Prescott Classic, in the Cotswolds, normally one of my favourite places. 13 cars entered and we had our eyes set on a top ten .finish! Suffice it to say it rained. The driver bollied it altogether as the track was soaking wet durrng practice and when it started to dry out eventually, the gearbox played up again and we had a miserable time on the track but great fun off it as it was also set up as an American weekend. Elvis was in the arena but was not very good. A delightful ladywas also singing – if you closed your eyes it could have been Brenda Lee – I will explain later for those not into proper music! Lunchtime included a parade by members of the Vintage Hot Rod Association some of whom had been competing at the previous day’s event. 

So there you have it some triumphs, plenty of disaster but all part of running a 500cc racing car. My thanks go firstly to Terry Ives who looks after the engine for me. It has never let me down and goes faster each time he gets his hands on it. Stotfold Engineering comes highly recommended – have a look at his web site. Thanks also to every one who came and acted as pusher – Mrs H and John and assorted family members. Now to next year ………………… any volunteers? 

 

Article by Tony Hodson for ‘SPARKPLUG’ – the magazine of the Letchworth Garden City Classic & Vintage Car Club.
 

 

 

ANTIQUE UMBRELLA STAND RESTORATION

Wednesday, February 2nd, 2011

1. Fully restored antique umbrella stand.

2. The left stay in the picture is the new replicated one.

Recently we were asked to repair an  umbrella stand. The left hand stay was missing. Replacing parts on cast iron objects can be expensive. To cut down on costs and avoid having to go to a foundry to have the part cast I decided to replicate it in steel. The steel would be then coloured to look like cast iron. 

The missing bit had what looked like crudely turned parts. These were in the shape of flower petals, with a square section holding them together. These turned parts were replicated on  the lathe and the rough flower petal shape was filed using a triangular file. The square section was made from 16mm steel tube with a thickness of 3mm. This square tubing was then creased down the  middle of each flat side, its entire length. This produced a subtle star section that replicated the other side of the stand.

The parts were then TIG welded together to obtain a small unnoticeable weld area. The whole replicated part was then aqua blasted to give the surface a good key for blackening, so as to look like cast iron. The blackening was achieved using Zebo Grate Blackening, which is rubbed on with a rag, left to dry and then buffed up to give it a mildly glossy metallic lustre. As you can see from the photographs the replicated part is almost undetectable.

By Terry Ives

1920′s CLYNO GEARBOX – made from a reliant gearbox

Tuesday, February 1st, 2011

1. Reliant gearbox converted for use in a 1920's Clyno

A customer approached me with a gearbox problem and initially I thought great, just the sort of job I like. I love working on gearboxes, understanding how all the internal parts work and how all the different selecting methods operate to obtain a given gear.

As we walked over to his car to collect the gearbox from the boot he said “you’re going to find this rather challenging”. This should be interesting I thought. We collected two boxes from his boot an placed them on the big surface table in the workshop. He opened the first box and bought out a 1926 Clyno gearbox, which was very heavy and build like a brick shit house. It was heavily cast in aluminium with the gears and shafts being made to last a lifetime, but very simple inside. It was a three speed and reverse crash gearbox. The splined input and output shafts were big enough to drive a Sherman tank.

The second box was opened and he pulled out what I immediately recognised as a robin reliant gearbox. “Can you make this into a Clyno box” he says. This is not something I’d done before. I’ve made a couple of gearboxes from scratch before, for 50cc racing bikes. I asked him why he wanted to change the box. “I want four speeds with a synchromesh” he replied. The synchromesh will transform the car as the gearbox works in such a way that there is no grinding of gears on selection of a chosen gear. Older gearboxes, that are known as crash gearboxes require a certain amount of coaxing into gear at certain engine revs. If you try changing gear with no clutch it’s a similar action.

After some examination I said “yes I can do something for you”. He left them with me so I could strip them and give him a price for the work. I studied both of them for quite some time, thinking of the best way to do the conversion. My first thought was “I can cut the bell housing off the reliant box and it will give me the basic shape of the Clyno box, well that’s a start”. The input shaft was very similar, the output shaft was considerably different. Whatever fits the output shaft was going to have be drastically modified. It would need some spline cutting skills and this was just the beginning.

I gave the customer the quote and was told to ”get on with it”, with hopeful undertone in his voice. After two days I had a working gearbox with all the modifications required, plus some added extras to strengthen it and increase service life, such as outrigger bearings and double seals. I phoned the customer and said “its all ready for you”. He duly picked it up and fitted in back into the vehicle. Clyno boxes are awkward to fit and it took almost a day.

2. You can see the modified casing.

There’s nothing worst than getting a phone from a customer call after you think you finished a job, it usually means there’s a problem. Luckily we don’t get too many here, but truth be told I was expecting a few teething problems with this modified gearbox. In this case it was the customer saying “I didn’t give you the axle tube!, can you make a few mods?”. No problem. In came the gearbox and axle tube for modification.

Work complete the customer refitted the gearbox again. Two days later I got the call from a slightly irritated customer saying “I can’t get the gears to engage”. Next day the box was back on the bench. After going right the way though it I found it was binding on gear selection. Robin Reliant gearboxes in there standard, unmodified form are quite awkward to work on, as there are some small ball bearings that will pop out of the synchromesh if it is not set up right. Slightly misaligned gears, worn selector forks or worn spacers and bearings can cause the ball bearings to come out of their housings, making gear selection impossible. The problem was the gears were misaligned by about 1.5mm, so this was rectified with a spacer. The spacer caused other measurements to be thrown out by 20 thousandths of inch. This was solved by making a shim for the output shaft face, where the axle tube bolts on. Problem solved!, all of the measurements taken from the Datum Line central to the gearshift lever were within a few thousandths of an inch.

In conclusion a very interesting job, which as the customer said at the beginning ” a bit of a challenge”. Previous to the customer bringing this engineering problem to me I had not read much about Clyno cars, but after some web searching I found it was one of the leading car manufacturers of the 1920′s. The Haynes manual I found to be of no use when working on the Reliant gearbox as it does’nt give any running clearances and setting up instructions.

By Terry Ives