Bilbo Posted May 19, 2002 Share Posted May 19, 2002 Hi all Well I found an excuse for my slow times at Curborough . I was surprised all day at my slow exit speeds. Times well that I could except, but the exit speeds were well down. I could not get any power down out of the bend before the straight thought it was just out of tune or the wet track, the engine sounded fine. I have taken the engine out today and the clutch has worn out. The rivets are a bit worn, worse on the flywheel side. I thought the peddle seemed very high on the last 2 runs, thinking about it had been a bit higher than normal all day! I had to adjust it on the way home it was so high. I had rather suspected it was slipping on the last run but put it down to me covering the clutch. Not something I normally do. In hindsight wonder if that was why I spun seemed to loose power into the bend after braking. At the time I thought it was the front wheels locked up. Somebody said he though the clutch was slipping when I warmed the tyres up. Still the fan belt was slipping a bit, so I thought that was all he had heard. The clutch slipped afterwards on the way home, unless I gently accelerated at 4000 rpm. Its slightly blued the flywheel in places but not that bad and there are no deep scores. Still best get it skimmed. The bell housing is full of dust. It was fine on Thursday when I gave it a blast, so its a bit odd as the peddle seemed to be moving up slowly all day on Saturday with a big change during the second lap of the last run. The old clutch plate is marked up as a LC 04DW024 and ???556 in white paint, with a LC 03GB 008A pressure plate. Plus the marking 3748.1. Well as its only done under 5000 miles, not the 7000 I posted last night elsewhere, so I am looking for a better one. Think its a formula ford one. I have never worn a clutch out before so I am a bit miffed at this one. Normally the engines been out for other reasons and had a new clutch fitted at the same time. Say every 25K. Still it was only a BDR then. So any recommendations for a new one. Will get the flywheel off tomorrow, that should be fun! Need to order a new clutch on Tuesday and tomorrow find somewhere to skim the flywheel. Then there's balancing it. I want it back on the road Sunday. I am at Cadwell Park the following Friday. Is this low mileage something I need to except with this power or have I just had a duff one. 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BDX with Brooklands and Clamshell wings Q 979 CGY Edited by - Bilbo on 19 May 2002 21:28:34 Link to comment Share on other sites More sharing options...
Bilbo Posted May 20, 2002 Author Share Posted May 20, 2002 Well no replies! Oh well. Seems I have the same clutch as fitted to the R500 so I am going for another the same. I will take he engine out after 4000 miles next time see what it like then. So what are you R500 drivers getting off a friction plate.question.gif 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BDX with Brooklands and Clamshell wings Q 979 CGY Link to comment Share on other sites More sharing options...
Mike Bees Posted May 20, 2002 Share Posted May 20, 2002 Hi Bill, I've been using the same AP clutch as the R500 (and SLR, and some Superlights) for some years. The one that came out this winter had done 3 seasons of sprints and hillclimbs with very little wear on the friction plate. I replaced it because I'd never liked it, it had always been very heavy with a long travel. The new one (same type) is much lighter and shorter in travel, very odd. Mike Link to comment Share on other sites More sharing options...
Bilbo Posted May 20, 2002 Author Share Posted May 20, 2002 Hi Mike Thanks for the reply. Its rather odd it seems that the friction plate just wore away all day hence the rising peddle syndrome. Odd you should say old one very heavy as I have found it rather light! Hum. Seems the pressure plate marking 3748.1. is now 3748.6. So there seems to be a later one than the one fitted last year as was mine to those that came before. As to the wear, well the peddle seemed to rise all day to the extent that I had to adjust it on the way home, I could not keep my foot above the peddle! Last run at the track was a bit like that. It was not the cable had a bit of trouble loosening the lock nuts on the way home and the bell housings full of fresh dust with the engine out. 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BDX with Brooklands and Clamshell wings Q 979 CGY Link to comment Share on other sites More sharing options...
Mike Bees Posted May 21, 2002 Share Posted May 21, 2002 If it was slipping then it would wear the plate away very quickly. Mike Link to comment Share on other sites More sharing options...
Jason Plato Posted May 21, 2002 Share Posted May 21, 2002 I also fitted a R500 spec clutch over the winter , it is a different design to the previous R500 spec one both lighter in action nd weight . The clutch should be safe for 170lb torque . Dave Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted May 21, 2002 Share Posted May 21, 2002 I use a Quatermaster twin plate with sport plates. Very heavy pedal but just the right amount of slip for trackday and occasional sprint use. Has the characteristic twin plate rattle with the clutch disengaged. After about 10 trackdays and lots of road miles, the plates had plenty of material left on them. Alex Link to comment Share on other sites More sharing options...
John Posted May 21, 2002 Share Posted May 21, 2002 Theres a company up near Leamington Spa selling Quarter Master clutches. They also market organic lined single and double plate clutches that use aluminium 7.25" bodied covers (very light) under the brand Super Clutch. As the plates are organic, they last a long time (apparently) Cant find the tel no. at work but the guy who run it's wife is the membership secretary of the HSA. I think they work from home and their surname is Tewson from Offchurch, near Leamington Spa. John Link to comment Share on other sites More sharing options...
Bilbo Posted May 21, 2002 Author Share Posted May 21, 2002 Hi All Well as posted going for the same again need the car for Cadwell on the 31st with Master Wong. As to everyone's comments well the above the cheapest option, rather important at present, but may not be in the long run! Oh well. Dave J said ------------------------------------------------- The clutch should be safe for 170 lb torque. ------------------------------------------------- how do I do thoese nice snips? Well I think thats not the whole issue the weight of the cars a factor, me in the car on 75% full 11 gallon tank is 737 kg. Lot heavier than a R500! With Simon in the car its over 800kg. So wave when you pass me at Cadwell! The clutch still has to move the cars mass relative to the engines torque! 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BDX with Brooklands and Clamshell wings Q 979 CGY Edited by - Bilbo on 21 May 2002 22:35:37 Link to comment Share on other sites More sharing options...
Mike Bees Posted May 22, 2002 Share Posted May 22, 2002 >> The clutch still has to move the cars mass relative to the engines torque! << That's only an issue when you're slipping the clutch. Once it's properly engaged the max torque that can be thrown at the clutch is the max torque that the engine can produce. If your car is heavier then you'll likely be subjecting the clutch to that torque for longer because it will take you longer to accelerate... Mike Link to comment Share on other sites More sharing options...
Bilbo Posted May 22, 2002 Author Share Posted May 22, 2002 Hi Mike Thats exactly what I meant. My car is 640 kg the R500 is 2/3 of that with me in more like 50%. As to the output the R500 is Max Power: 230 bhp @ 8600 rpm Max torque: 155 lbsft @ 7200 rpm so I am 30 bhp down bit only 9 lbsft. Not saying all the range of power or torque is the same, its not... rather just the max. So a lot longer to move on very fast pull away, seems more than the tyres has been smoking. The reason I am normally light on clutches is that I normally move THEN really accelerate. Its often faster anyway. I have not been doing this on the 2 sprints. Also warming up the tyres may have resulted in the increased wear. Alternatively its the pressure plate not been holding the friction plate. I have had a lot of trouble getting into gear, with the new box fitted when the engine went in, so may be the friction plate was sticking on the splines. Will see how much better it is with the new clutch. Shame I spun at Curborough, seems up to that point I had been going well on the first half. The last run was poor clutch kept slipping all the way round. Thought it was ME covering the clutch as the peddle had moved up a lot. Still that would indicate it lost a lot of material in one go, there is loads of fresh dust in the bell housing. I recived the new friction plate in the post and picked up the pressure plate after work. The Flywheel has had 7+ thou off it. Nice hard and soft effect in the metal. I must say the amount of material on a new friction plate above the rivets is only about 1.5 mm that surprised me. Think I will go for a new one every winter from now on. The face of the new pressure is smaller in width but if you look at the old one that missing area has not been used anyway. Just to cover all options I have another new clutch cable and release bearing, not that there is anything wrong with the old ones but..... 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BDX with Brooklands and Clamshell wings Q 979 CGY Edited by - Bilbo on 22 May 2002 21:25:11 Link to comment Share on other sites More sharing options...
Paul Ranson Posted May 22, 2002 Share Posted May 22, 2002 It seems likely to me that your clutch hasn't been releasing cleanly, sticking on the splines or whatever. FWIW spinning ones wheels and launching doesn't involve the clutch in much wear, as long as you are sure you are really popping it. Paul Link to comment Share on other sites More sharing options...
Bilbo Posted May 22, 2002 Author Share Posted May 22, 2002 Hi Paul Just edited the previous post. Well I will just have to see when the new ones in this weekend. As to popping it in and out don't think so? Its not that hard to spin the rears. Especially as the track was wet the first 2 goes. We all did it but is it a worth the effort marginally warmer rears cooling as you wait to go and cold fronts. Still its FUN. 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BDX with Brooklands and Clamshell wings Q 979 CGY Link to comment Share on other sites More sharing options...
Bilbo Posted May 25, 2002 Author Share Posted May 25, 2002 Hi All Well the engines back in tonight. The plumbing and ancillaries tomorrow. I tried the old friction plate on the splines.... seems it may have been sticking! It was quite hard to push on but after a little oil and effort it seems fine, so may be a bit of surface rust over the winter question.gif So may be Paul was correct in his comment. The engine went in much easier than last time, when the box was new and the engine upgraded. As its a very tight fit in the engine bay this is always luck rather than judgement. So tight that it needs the dizzy wheel off to go in and thats only about an 1/8". Still it was a real pig last time and I had tried the box on the engine before fitting them separately. 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BDX with Brooklands and Clamshell wings Q 979 CGY Link to comment Share on other sites More sharing options...
Paul Ranson Posted May 25, 2002 Share Posted May 25, 2002 When you spin slicks the surface definitely changes, and the effect is worthwhile, even if it's only dust being cleaned. Whether it is worthwhile for road tyres is more debateable. Anyway it gets you in the mood, and saves risking stalling driving to the line..... Paul Link to comment Share on other sites More sharing options...
Bilbo Posted May 25, 2002 Author Share Posted May 25, 2002 Hi Paul Agree cleans the plugs and also gives the oil a bit more chance to warm up! I think that the oil temperature is the most worrying thing in sprinting. The engine water temperature may be OK but the oil may be still relatively cold. Looks good tyre effect, very little me thinks... 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BDX with Brooklands and Clamshell wings Q 979 CGY Link to comment Share on other sites More sharing options...
Bilbo Posted May 28, 2002 Author Share Posted May 28, 2002 Hi All Well its finally back in as always takes longer to refit the engine than it does to take it out! The new clutch is going instantly in. Nearly hit the bench Opps. Thats a bit worrying but I expect it will be better after a run and the friction plate settles in. Still it was not like this last time. Couple of things to do balance carbs, fit the filters and put some antifreeze in the water. So all being well Cadwell Park on Friday. 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BDX with Brooklands and Clamshell wings Q 979 CGY Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted May 28, 2002 Share Posted May 28, 2002 When I tried my Bridgestone S-03's at curborough, I did loads of rear tyre warming - the result was lots of rear end traction and no front end grip. The car was useless as was my driving. With A24 compound ACB10's, I think it is worthwhile, mainly for getting off the line. Having the car understeer a bit for the first left hander at Curborough is no bad thing, and by the time you get to the molehill, I suspect the fronts have some heat in them as well. Alex Wong www.alexwong.net www.slipstream-trackdays.co.uk _________ / __ __ / ___ _//__T/__/_ ___ / (_) (_)/ /`-'/o/ _______ /o/`-'/ / /// ( VDU7X ) // / /___/--_________/--/___/ Link to comment Share on other sites More sharing options...
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