ashaughnessy

Some news on my predicament. The problem was down to a cam follower, as a couple of people had guessed. The engine builder is fixing it at no cost to me. He got the cam from Kent and the followers from AE. He spoke to Kent who say that when they make their cam, they grind the lobe with a small slant or taper on it. They also grind the followers they supply with a matching taper (so the follower is slightly cone shaped) and this is supposed to encourage the follower to turn. Kent guessed that the AE followers are ground flat and so a slanty cam lobe running against a flat follower won't run so good, hence the problem. He has replaced the followers with ones supplied by Kent so they should match properly. He's also going to measure the AE followers and see if they are flat and then talk to AE and see what they say. Interesting. Anyway, he's got the car running now, so I should have it back soon I hope. Anthony

I believe it is very important to flush all traces of the silicone fluid before filling with the normal stuff, I don't think the two mix. I don't know the most effective way to flush though.

No, I was wrong and Peter's mathematics was right. I withdraw my "tosh" allegation and apologise to Peter. I've been trying to get my head round this so-called "basic" physics for the last hour and I think I've got it now and I am convinced by Peter's arguments. Sorry Peter. Anthony

Another thing in favour of the power argument. Say car A produces N pounds feet of torque at 5000 rpm and car B produces N pounds feet of torque at 10,000 rpm. At any given road speed, to get the engine producing N lbsft of torque, car B is in a gear with half (double???) the ratio that car A is in (e.g. B is in second whereas A is in fourth, you know what I mean!) which means it has double the thrust available at the wheels (assuming all other things being equal, which I'm sure they won't be). I think I'm assuming that car A's maximum torque is N and car B's maximum is N. I'm also assuming that the torque production drop off reasonably rapidly after the maximum torque revs so that A isn't still producing N at 10,000 rpm. Anthony

Contents of this posting deleted - it was embarrassingly wrong Anthony 😳 Edited by - ashaughnessy on 19 Sep 2002 07:22:17

The car is now winging its way to the builder for him to look at it. There was nothing agreed up front about running the engine before giving it back to me and I wouldn't have expected it unless the builder had an engine dyno, which he doesn't. I removed the engine and refitted it myself. The problem might have occurred when I first turned the engine over. I cranked it with the plugs out to get oil pressure but didn't get any pressure. I cranked it until my battery went flat (which didn't take very long I can assure you) but still couldn't get pressure. I cranked it a little more after refilling the oil filter but only got pressure when I re-primed the oil pump. So I cranked it for a total of probably less than a minute in four or five bursts with no plugs in and no oil pressure. I would have expected the cam assembly lubricant to cope with that. Once I finally got the engine started, I followed good practice and immediately ran it up to 2000 to 2500 rpm for ten or twelve minutes. I think the oil filter and pump had been primed by the builder but the oil had drained out during transport and installation and the few weeks it took before I finally turned it over. I'll be double checking with the builder that the proper assembly lubricant had been used on the cam. Other than that it will be difficult to apportion blame and might just be "one of those things". I'll let you know how I get on. Thanks Anthony

Sod. Looks like I'd better call the engine builder and get him to pick the car up and fix it. Then I'd better start doing some overtime to pay the bil. ☹️ Very depressing. Thanks for the advice. Anthony

I was checking the valve clearances on my newly built crossflow (upgraded from supersprint spec with 244 cam). I've only done about 70 miles on it so far. It has been running very rough. Several of the clearances were out but one was out by a HUGE HUGE amount. The clearance was bigger than my full set of feeler gauges, it was easily half a centimetre (I only have a small set of feelers). So I adjusted all of them and started up. It sounded better for a couple of minutes but then started to run rough again. I drove about five miles and then put it away to cool off. I checked again a few hours later. The one that had been out by so much earlier on was out again. Not by so much this time but by a fair bit (took about three quarters of a turn on the adjuster nut to get it back). I notice from inspection that the adjuster nuts on all the other rockers are at about the same position but this one is much lower. There are six or seven threads showing at the top of the others but only two and half on this one. What's going on? Is my camshaft buggered? Perhaps a bent pushrod? I just ran it again and it was better but still rough. I'll check the clearances for a third time tomorrow and see if the offending valve has gone out yet again. I'll also be able to tell if the adjuster nut has shifted. Thanks for any help Anthony

Isn't this the "usual" symptom that the quick racks always suffer from when they need adjustment? It sounds like it. There have been lots of threads in the past about how to adjust the rack correctly and the fact that they are so prone to going out of adjustment. Have a look and see if those postings sound like your symptom. As for "turning circle of a dodgem" you've obviously got a different rack to me. When I changed from standard rack to quick rack, my turning circle became more like a supertanker than a dodgem. Anthony

Second attempt at posting this - apologies if it comes out twice! Your brakes are likely to be hugely better when really warm than when cold. When cold they will feel like they are rubbish. This obviously depends on the pad material but I reckon most pads likely to be used on a Caterham will feel this way. Mine need a fair amount of warming up before they feel really good. Once warm, they are hugely better. On my live axle car with Mintex 1144 pads at the front (pretty standard stuff) and Yokohama A032R tyres, I can make the free ends of my seatbelt straps stick out almost horizontally. Unless you drive like a lunatic, it's hard to get the brakes really hot on the public road (though I imagine a lot of drivers on this forum do drive like lunatics ) Saying that you shouldn't use sticky tyres with a live axle is rubbish. Any upgrades you make will put increased stress on the car but you just have to live with that. Putting Yokohamas on won't immediately make your car collapse, it just means you may or may not get less mileage before something breaks. If you're unhappy with grip, get better tyres! I've had A021Rs and they were good (in the dry), the A032Rs are even better (in the dry). Most things on the seven work better when you're going fast. The brakes get up to temperature. The tyres get up to working pressure. The rubber on the tyres gets to working temperature. This all helps. When you're driving slowly (like you have to on the public road) they don't work well. Also, hard suspension settings (overly stiff dampers) that work well on a smooth race track don't work well on a typically bumpy public road. Finally, make sure the rear brakes are working properly. These can give up the ghost without you really noticing. Anthony

If you can lock all four wheels "really easily" then I can't see why you want to upgrade the brakes as they are already bigger than you need. You need more traction before you need more braking. However, if you can only lock one end up (especially the rear) the comments about altering the balance are reasonable. You should already have different compounds front and rear, a more aggressive one at the front and a more standard one at the rear. Anthony

I believe the eyebrow is an MSA blue book requirement if you're going racing, to protect the switch. If you're fitting a switch you should definitely fit the eyebrow. Anthony

A warped disk will make itself very obvious as a juddering when you brake gently to a stop. You would probably notice. Also, you can check by jacking the front up and spinning the wheels by hand and looking for binding points. The car has a live axle. The rear brakes can be badly adjusted so there is excessive travel for the shoes to take up to the drum. This would cause a long brake pedal. If this were the case, you would expect pulling the handbrake on would make things feel better, as it would take up the slack. However, you'd notice excessive handbrake lever travel. Easily checked though, and it's always worth re-adjusting the rear brakes. Did the car behave well during the 200 miles and 4 laps of Curborough? If so, has anything else happened in between that might suddenly make the brakes not work? Did you drive the car home after Curborough or trailer it? Hard track work can give you a surprisingly long pedal when everything cools down. Now that you have pumped the brakes, do they work properly or do they still go to the floor on re-application? Is the problem still occurring, and what has to happen for it to re-occur after you have pumped the brakes to fix it? Anthony

Do you have the Wallage's book on rebuilding the crossflow (published by Haynes) ? This recommends driving one edge of the plug in with a flat drift, which tilts them over and they can then be levered out. It also says there is a special paste for sealing the new core plugs when you put them in. It then says to use a mandrel or drift that is a good fit inside the plug (e.g. a socket) and not to hit the rim of the plug. Anthony

It seems to me that using an inertia type starter on a crossflow with twin 40 webers is daft. When I start my engine it can take a LOT of cranking, depending on how long since I last ran it. Over a period of a few days, the petrol disappears from the carbs. When you try and start you first need to refill the carbs before the engine will run, hence the cranking (note - people with electric fuel pumps don't have this problem). If I'm in this situation, I just crank with my foot OFF the accelerator until it starts to cough. Once it does this, I start dabbing the throttle gently to introduce some petrol and it will catch. It make take several dabs and several coughs before it catches properly. At each dab and each cough, if I had an inertia starter, the starter would probably dis-engage and I'd have to try again, hence why I think the pre-engaged type is better. Each time you pump the throttle pedal, the accelerator pump jet things in the carburettors squirt a big dollop of petrol into the inlet. If you do this too much, this fuel will probably end up flooding the engine and the plugs and make it difficult to start. Hence why I only dab the throttle once the engine is already starting to cough by itself, because then I know it "wants it" :-) If you crank with the throttle wide open, this is probably a bad thing. The engine is harder to crank with an open throttle (so you'll kill the battery), plus you will get very slow air through the carbs which won't pick any fuel up. A closed throttle will mean fast air flow (though not much of it) which will mean nicely mixed mixture. Anthony

I've never achieved more than an indicated 100mph in my car before its engine rebuild, with its bog standard supersprint engine, four speed box, and live axle. I would suggest an indicated 110 for your car is quite reasonable. The manufacturer's claimed top speed for the Supersprint is only 110, and that's presumably on a straight several miles long with a tail wind. Anthony

If the engine coughs and whines then the starter is the inertia type, not the pre-engaged type. When the engine half-starts (i.e. a cylinder fires and spins the engine but the rest of the cylinders don't follow suit) the engine spinning disengages the pinion of the inertia-type of starter and so the starter then whines in the manner described. On a car with a pre-engaged starter (i.e. mine), the usual method of starting after a layoff is to crank constantly until it catches and keep cranking until it is finally running. You don't keep turning the key to repeat the starting attempt. It definitely doesn't sound like the battery because a) you've replaced it, b) it could turn it over 20 times. It does sound like ignition or fuel because it is half catching. It sounds from your description like the starter correctly turns the engine, the engine half-starts, just enough to dis-engage the starter. Have you checked that you are getting sparks in all the spark plugs? (remove the plugs but keep them connected to the leads, hold a plug with well insulated pliers and hold it against an earth, crank the engine and look for the spark). Check the ignition timing statically. A nice way is to disconnect the low-tension wires from the coil and connect them to a light bulb. Turn the engine over using a spanner on the crankshaft pulley bolt. When the engine is about to get to TDC on the compression stroke on number one cylinder, the bulb should go out and you can check at what point the bulb went out by looking at the timing mark on the pulley. This is your static ignition timing. This works well on my car with old lucas electronic ignition, I don't know if it is a reliable way for all electronic ignition systems. Checking the gap size on the plugs is an easy thing to do. If you take the distributor cap off, you're looking to make sure it is clean inside and out, with no cracks. Check the contact points inside the cap (four small pieces of metal in opposite "corners"). They should be in good condition. It is normal to have some corrosion due to arcing between this contact and the rotor arm but if this is excessive it could interfere and need fixing. Also check the carbon contact in the centre of the cap. It is sprung so that it makes good contact on the rotor arm. Check the end of the rotor arm for excessive corrosion due to arcing. You can clean the arm and the contacts in the cap with emery paper if the corrosion isn't excessive. Do you have electronic ignition or points? If points, you can also get corrosion in the points for the same reason. The "water down the plug hole" noise is interesting. I wonder if you have a leak somewhere in the fuel supply? Perhaps the noise is the fuel leaking back out of the carbs and down the supply pipe? Checking for proper fuel supply is the next step after checking the good functioning of the ignition. The fogging of the instrument dials is a red herring, they all do this. Anthony

I seem to remember reading that the radiator actually does most of its work through conduction, not radiation. Also, any extra radiative effect brought about by the blackness of the paint might be outweighed by the insulating properties of the paint layer??? And finally, a fine mesh in front of the radiator might block the airflow sufficiently to make a noticeable difference to the cooling efficiency. I remember a posting on here about meshes placed in front of carburettor inlets - someone described the effect that a fine mesh has on the airflow. Anyway, I think if you want maximum cooling efficiency, don't paint the radiator and don't put a mesh in front of it. Anthony

Do you mean stiff or heavy? I presume you mean stiff, if there is no self centering. Stiffness in the rack seems to be a very common problem but doesn't mean it should be accepted. It should be fixed. Search through the old threads for the recommended fixes (proper adjustment of the large adjusting nut plus correct lubrication seem to be the answers). If you have the 22% rack the steering is quite heavy at slow speeds (at least on my older car) but the steering should definitely not be stiff. Anthony

Dave, I presume you mean a cork rocker cover gasket, not head gasket? I hope you do. Cork is the standard material for the rocker cover gasket. Mayonnaise oil is not right but if it's been idle for six months who knows what state its in. Change the oil and filter, flush through, and see what happens. Do you have a fully sealed cooling system or the normal one with the filler neck on the thermostat housing? If the latter it will always lose water, the real question is how much is normal - can't really answer. It should run above 40, if it doesn't get above 40 I'd keep checking things out. Perhaps your thermostat is stuck open? Even so, it should get above 40 degrees, especially in slow traffic in town. Anthony

Watch out when replacing just one headlamp. I had one break and replaced just that one but the lens of the new one didn't match that of the old and I kept getting comments at MOT time until I eventually replaced the other side. If the MOT garage hadn't been so friendly, they probably would have failed me. Anthony

SteveP, I'll post something about my engine when it's run in. Might not be for a while yet... I didn't have many interesting changes to the engine. Still on 40DCOEs, though I'll get it rechoked and rejetted when run in. I've now got forged pistons, 244 cam instead of 234, additional porting work on the inlet and exhaust manifolds and in the ports, and a whole pile of detailed changes to allow extra revs (probably to about 7200). Anthony

My vote would be to pay full whack to Caterham for a reliable one. There have been plenty of reports on here from people with failed alternators who got them from somewhere else. I had the same problem until I finally got an expensive one from caterham which has now lasted me at least 8 years and maybe ten. Anthony

If you get a rebuild to exactly standard specification, budget at least £2000, that's assuming you take the engine out and put it back in yourself. For a modest upgrade budget at least £3000. It may cost more than this, but probably not less. 35,000 miles means your engine is probably ripe for a rebuild. I imagine it breathes quite heavily from the crankcase breather? My tired old bog standard 4 speed live axle supersprint accelerated well up to about 85 or 90 mph (as indicated on the speedo), but didn't accelerate much beyond that and only managed to get to 100 mph (again, according to the speedo) on the longest straights. I can't imagine much keeping up with it in 3rd gear or lower but once in fourth it never felt like you were setting the road on fire (though it did feel entertainingly quick). I'm just in the running in period after a rebuild (only done about ten miles so far) and it will be interesting to see what it's like once fully run in and re-jetted. The engine builder's bill was just over £3000 and the result might be about 150bhp, give or take five hp. I took the engine out and re-installed it myself to save money. Anthony

How many miles has your xflow done? It could be quite tired by now. Also, that five speed box might not help matters, I reckon the four speed box is better suited. "If it ain't broke don't fix it" - but it is broke, in a way, because you aren't happy with it. Check the valve clearances, ignition timing, carb balance, plugs, distributor, etc. - the basics. Perhaps get it fettled at a 7 specialist. Worth a try before you spend serious money. Also, check the brakes, especially the handbrake. Do the wheels run freely? Are you getting any drag that is sapping engine power? Anthony