George C

Most people seem to use the F9 and the change to 45s will be noticeable - its trial and error and may not work. You will need to adjust the idle mixtures after and best to balance too. If its still too rich then there may be a problem with something else - out of adjustment (ie float levels?), something leaking (ie pump jets) etc etc. Good luck.

As said above there are many things to check etc etc etc but you could drop to 45 idle jets which will lean the low speed running. 50 seems quite high compared to the main jet you are running. If its too lean you will know quickly as it will cough and spit back through the carbs whilst driving slowly. Once at higher revs it will run on the mains so will have no effect. You need to be certain with the jets as they are often drilled out. If you are near Suffolk I can lend you some 45 jets and have a jet measuring thing.

Roger - Thanks for the explanation on the ignition timing etc, very informative.

You could talk to Scholar Engines who have been doing Xflows since the beginning of time or Vulcan Engineering or Burton or Wilcox. There are many more. Good luck.

It depends on the actual damage. I had a dent chap out who carefully removed two dents from my car and did a very good job.

If you look at the Burton website they have a nice selection of specs and prices for different heads including alloy ones. I don't think the stage 1,2, 3 etc means very much, you just need to get someone who knows what they are doing to make something nice. I would push the boat out and do it really well and then another year when you have some more money do something else - the bottom end or 3d ignition. I don't have any experience of the alloy heads but I havent heard anything negative. They use them in classic Formula Ford now so they must be fine. I think they save 6kg or more which is a great upgrade in itself by taking weight from high up at the front of the car. Also have a look at the Wilcox engines web site. These guys seem to know what they are doing but probably expensive. Roger K built me a big valve head (cast iron) with narrow stem valves etc and its great, unleaded too. I have since upgraded the bottom end to all steel so have the Accralite pistons, polished rods etc, all low mileage if any use to you.

A couple of things: A really light weight steel flywheel is a cheap good upgrade and not too expensive but only worth doing with the rest of the bottom end. I had one (on a crossflow) with slots machined out and a small diameter clutch and it gave the whole car a much more exciting feel as the revs picked up very quickly. No problems with tick over either. The 123 distributers look interesting but quite a few people don't get on with them, don't know why.

For the £ 500 budget I would concentrate on the head which you can remove yourself and then get a really good engine tuner to properly port, maybe some bigger valves, convert to unleaded, match to the inlet manifold. It all depends on what you have now but you would get a power increase from simply refreshing the head plus the other work will add to this. Some second hand Webber 45s would also work well. The bottom end could then be upgraded at a later date as your budget wont stretch to that at the moment. Don't worry about the pistons, if they are in good condition they will survive for the moment. Changing the cam is a relatively cheap upgrade but would lead to an expensive list of other things which would need doing so I would do that later.

Also check the prop shaft. I was surprised to find that mine needed rebuilding after only 10,000 miles although 1,500 of these were on track. Its about £ 60.

With clams the steering could be turned to the full extent of the old rack (mini rack upside down I think). But, with cycle guards the guards catch on the ali bodywork and also the wing brackets catch on the anti roll bar when turned the other way. I converted from clams to cycle and this was a downside of the conversion. I seem to remember reading somewhere that the turning circle with clams is second only to a London taxi. Caterham fitted rack stops to restrict steering movement and this then became standard and was carried over when they made their own rack. I have thought about sculpting a piece of the cycle guards and reprofiling the brackets to get full lock back which would be quite handy.

Some not very technical and probably useless feedback... I have a racing 2 stroke kart and so I tend to have spare 2 stroke fuel in my garage, mixed with expensive two stroke racing oil. Throughout the year I always end up running short of normal fuel and use the 2 stoke stuff in my 4 stroke lawn mower, strimmer and dare I say it, a little in the Caterham (170bhp steel crossflow) to get me to the fuel station. What has suprised me is that all these engines run really well with it. Maybe there is some sort of octane booster in the racing oil. You also get the added benefit that they smell of a racing kart which is a happy event for me.

If its an engine that gets reved hard and thrashed then my experience of XFlows in Caterhams and Formula Ford is that they need rebuilding to check for cracks and this together with a freshen up will keep everything running well and prevent failure. Often when they go bang there is no warning and its not that great if you are mid corner and accelerating etc etc (I have had that one!). A rebuild isnt too expensive and the engine will then be in good shape for many more miles - you might like to upgrade at the same time. If you are unlucky and it goes bang then you are in for a big bill. A compression test will tell you if the engine is worn out but it won't tell you about the components that could be about to break. If the engine is used on the road and is treated with respect then I am probably being pessimistic.

My experience is that they will work with softer springs (also on 87 dedion). I can't remember the rates but there is no right and wrong, its what works for you and how you like to drive the car. 170 is quite hard for an 87, maybe drop to around 130 / 140 but it depends on the front spring rates.

If its similar to my 87 dedion then the poundage of the springs (also on Spax adjustables) is much lower that the current springs (by about 40 or 50%). Mine also went down quite a bit when you got in the car and was really low with 2 on board but it all worked well and with the shocks stiffened up it worked well on track. I later fitted stiffer springs to the Spax which reduced suspension movement and bottoming out. I then changed to the Freestyle AVO setup which works well.

I have done a bit of both. Some people say powder coating is more durable and is what I have done to the rear suspension. Its durable other than when it is chipped and it then flakes off as the rust spreads underneath. My front suspension is spray painted to a high gloss and I prefer the look. I thought it might chip quickly but it has lasted very well. The earlier Caterham chassis were spray painted and they seem to last well - mine is 25 years old and looks good.