James Arnold Posted October 17, 2001 Share Posted October 17, 2001 My xflow is now in the garage floor, whilst I sort the gearbox. Anybody care to guide me around a couple of questions? The clutch friction plate is virtually down the rivets. What sort of spec should I look to replace it with? The engine is a 1700 with 130bhp. I looked at Burton Power web site. Are they are good place to source from? I weighed my flywheel and its about 13 lbs, from which I imply that its been lightened already. The engine response it still far from electric, I'd love that race car blip. Is there scope for further mass reduction? I can now push the crank back and forth (longitudinally) and get a quiet 'clunk' each time. The amount of movement is small, not really visible. Does this sound bad and warrant further investigation? Cheers, James Edited by - James Arnold on 17 Oct 2001 12:55:24 Link to comment Share on other sites More sharing options...
R2D2 Posted October 17, 2001 Share Posted October 17, 2001 I would tend to use an AP racing heavy duty 8" plate. I think Burton's are quite reputable and prices are about average. See the thread on ChitChat "What damage a bursting flywheel can do" before you take too much metal away. Crank end float shouldn't be sufficient to hear a "clunk" when you move the crank. Every time you operate the clutch you will be moving the crank assembly. I think you need to drop the sump off measure the end float and check the thrust bearings. Link to comment Share on other sites More sharing options...
Casbar Posted October 17, 2001 Share Posted October 17, 2001 Just re-built my xflow. Clutch from Burton's great service. Flywheel, around 13lbs is quite lightened. You may wish to make sure its dowled on though. And if you have removed your flywheel, you should replace the flywheel bolts when you refit it. You can get these from Burtons as well. They are stretch bolts, so shouldn't be used more than once. Crank shouldn't move to that extent. Link to comment Share on other sites More sharing options...
cdg Posted October 17, 2001 Share Posted October 17, 2001 I would seriously recommend a lighweight steel flywheel. They are not as expensive as you think (£100ish) and you may find a good used one in the back of Motoring News. Lotus twincam flywheels are steel, and you can use a H/D 8.5" Twink/BDA clutch assembly, which is cheaper than the cintered paddle type. Sounds like your crank has excessive endfloat. Thicker thrust washers are available from Burtons, but make sure they go in the right way around. (I once stripped a so-called professionally built x-flow with excessive end-float to find the washers were the wrong way around, and had turned the crank to scrap!) Chris. Link to comment Share on other sites More sharing options...
James Arnold Posted October 18, 2001 Author Share Posted October 18, 2001 I measured the endfloat last night, with a borrowed DGI - 9 thou. According the Hayne's escort workshop manual (oh the shame of it) I am OK from 3 up to 11 thou. With the sump off the movement is quite noticeable, maybe I should look to fit thicker thrust washers anyway? The thread about lighten flywheel on ChitChat has frightened the life out of me. If my flywheel was lightened with the same level of expertise as the rest of the engine was built, I'm in real danger! James Link to comment Share on other sites More sharing options...
oilyhands Posted October 18, 2001 Share Posted October 18, 2001 If the flywheel is no thinner than 11mm in section then it will probably be safe, changes in sectional thickness should also be made with a gentle radius, the flywheel should really be thicker towards the centre, removing weight from the outer section is more productive then removing from the centre, on no account should the flywheel be drilled or slotted inside the diamter of the friction area, even if it is steel. Oily Link to comment Share on other sites More sharing options...
R2D2 Posted October 18, 2001 Share Posted October 18, 2001 I checked in an Autobooks manual last night and the end float figures were .003" to 0.008". Which one to believe? I would worry about anything that I could hear when it was moved but I have never run an engine with this much end float so I can't be 100% sure. Link to comment Share on other sites More sharing options...
Roger King Posted October 18, 2001 Share Posted October 18, 2001 Torque is the real specification that you need to consider when speccing a clutch. However, a 130bhp 1700ccm Crossflow will be absolutely fine if you use the standard Caterham Quinton Hazell 7 1/2" cover with the AP clutch plate CP2257-? The question mark is simply because the last number varies according to the spline spec you need to suit your first motion shaft. Any attempt to fit a larger diameter clutch will mean loads of work modifiying or changing the flywheel. It will also be totally unnecessary. The standard Caterham cast iron flywheel weighs about 5.5kg and is the lightest sensible one to use in this material. Be aware that some steel road type flywheels are actually heavier than this. If you go for a very light steel flywheel it will almost certainly be for a 7 1/4" full race clutch which is a totally different animal. It also needs a different release bearing assembly etc. It will be like an on off switch and cost a fortune. Lots of people love race clutches, but even more hate them for road use. Ideal endfloat on crank would be .005". Link to comment Share on other sites More sharing options...
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