They are Chris! I have ordered some slightly longer ones, as they were half the price! I am afraid I have started a new thread! Would you like to join them? http://www.clubgti.com/forum/showthread.php?t=215756
Sorry Danny, just re-read this, and I did not reply. SPOT ON. I had missed out completely on your idea, like it a lot. But not sure I want to lighten the flywheel on my car. I want grunt and an AUG box to for 2nd and 3rd gear blasting between the many tight bends on Eire's beautiful back roads. Too, too, old for high reving screamers now! OH! I don't NEED a diesel! I will never buy an oil-burner even if they are the last type of IC engine we are permitted to drive. ps Mrs daved wants an A2 1.4 TDI Sport (90bhp), in black, with a black interior, when the Audi Avant dies. She'll have a long wait then. 250,000 miles is the next goal. Won't live long enough to see 500,000 though!
The 9 bolt problem Are there any recommendations for uprated m7 flywheel to pressure plate bolts? I have just picked up my newly lightened and balanced flywheel and pressure plate (now located with x4 solid steel dowels) My machine man is an ex formula ford engine builder and he has suggested m7 Allen bolts? Any suggestions or recommends? Cheers, Chris
Bump for VWsingh and some new pics. Having recently stripped my 6A engine out of the rocco, I came across this when removing flywheel and clutch. This engine has only been run with this clutch setup for a few track nights. Great care was taken when bolting this all together. The PP was lapped to the crank to improve the surface area in contact with each component. The PP to crank bolts were OEM new and correctly torqued, as was the flywheel to PP bolts. (flywheel is a lightened version). This pic shows the mating surface of the PP to the crank. It was lapped in using valve grinding paste. The outer perimeter of the PP to crank bolt holes appear to show there has been movement. In these 2 pics you can see the shiny polished area in the bore of the bolt holes of the PP. These last 2 pics show the movement between the PP and lightenedflywheel. This was the std mk2 double dowel type. The car was used aggressively for the duration of the track sessions, one of which was wet which one would think would mean less duress on components due to lack of grip. It suggests to me that running with this setup when driving hard will eventually cause a problem.
Interesting stuff! Well here is my attempt at putting a hole through the casing at Bedford Autodrome: Note: This is a Mk2 16v LUK clutch that was fitted new and has lasted a over a year going to the Ring x1, Combe 2x, Curby x2 and Bedford x1. I also have a lightened flywheel and use standard VAG bolts & torque. To be honest, I am quite surprised that I was still able to drive the car! I managed to use it for 2 weeks before taking it apart. However, it was vibrating very badly which could shake other things loose. Gurds
Single spring plates. Seen this happen before, there's loads of strain in this area. Don't the Sachs sporting PP's use a triple design? Easy engouh to make some rivets and add more yourself if you're confident to do it, and will give more clamping pressure.
Three thin leaves, on each of the drive links, would be a lot better. They would be much more flexible and less prone to break due to fatigue at the rivet hole. The three links are only there to transmit torsion between the cover pressing and the pressure plate. A single thick link will not flex as well as three leaves, over its length, it will try to bend at the weakest point, the rivet hole. When the driven plate facings are worn, or a thinner competition plate is use, the three links will see even more stress due to bending. That system is not really a good design for bending with big holes at each end, and quite small areas of grip at the rivets! Also. One wonders what material they use for the links? If it is,actually, spring steel, it will be basic silicon/manganese steel I guess. This is used in multileaf cart springs. For single taper leaf springs, we used special cr/ni steels.
Just noticed the way the PP is put together is considerably different on the Sachs and Luk clutches. Here is my Sachs PP with the 3 steel ties mounted on the outer perimeter. IE in the 2 o clock position. Here is Gurd's Luk PP and the 3 steel ties appear to be mounted considerably nearer the centre. Would have thought the leverage will vary in these two designs.
OK. Here's the low down on the drive links. The LUK system puts lateral bending into the links, because the link is not aligned tangentially with the two parts. As well as the bending within the flat plane of the links as the PP moves axially along the axis of the gearbox input shaft. The load transmitted into the LUK links is shown by the yellow arrow. This gives rise to the black lines, giving lateral bending, through the two reaction forces at the rivets. And, the blue line, axial force. The reaction being on the first rivet. Because the Sachs clutch uses tangential links, the only forces are axial, plus bending within the flat plane of the links! I am personally anti LUK, cos they bought out, and shut down, Laycocks. BUT. The engineering speaks for itself. Laycock clutches were far superior, as they did not use links at all. The drive between PP and cover was directly by the lugs which supported the belleville spring. Trouble is, it cost more to make!
Found a couple of pics from mk1 driver's old thread on his 1272 engine. This shows that it may well be possible to convert the 020 to a more conventional clutch arrangement. These days there are a lot of cars that use a concentric hydraulic release bearing arrangement that may be able to fit inside the 020's bellhousing.
Bump for this thread. Ianb & ScottG both suffered failure of a number of the x9 (m7?) flywheel to pressure plate bolts at castle Combe yesterday... Both flywheels run extra dowels so the failures are from tensile loads rather than shear. Surely a better set up must be achievable?
Over-revving, crank harmonics or clutch type? The similarity of the cars is a possible clue? Thing is, plenty of 020 folk seem to not have this issue, and CFJ has done it before, but not as far as I know in the former owner's hands. Does it point to the track, ie Combe, and revs maintained at one place?
Vibration is certainly a possible cause Both cars suffered clutch slip (loss of clamping pressure) & vibes (from flywheel running out of true) allowing them to be parked before total failure. I reckon the bolts are working loose over time & the shock load from gear changes is what finally breaks them. I know that MKD used to suffer from regular fractured pas bracketry & even fractured an alternator mounting- rpm related no doubt. I did a set of flywheel bolts too The VW flywheel bolts just aren't strong enough sadly.
It's interesting as I run a hillclimb Mk1 with sticky slicks, ATB diff and a fair amount of power (not turbo power - just N/A) and the drive train takes a real hammering. It destroys gearbox bearings and syncro cones in the 020 but I don't suffer from clutch/flywheel problems. I use a lightened std flywheel and a competition helix clutch setup (std design and full plate - not paddle) and I always change the outer and inner bolts for new genuine VW when I strip it down. Following on from the info in a thread on here I use the thickest plate under the heads of the pressure plate to crank bolts that I have as I understand the works cars had thick plates under there to stop breakages. Accepted the car doesn't do a huge amount of miles in an event and is probably about 750kg but it is extremely violent for the few miles it does with lots of grip and weigh transfer etc. Again the ATB diff is not as vicious as a proper LSD but still adds to the pressures on everything. That said, over the years, it has done trackdays, raced in Eurosaloons and Welsh Saloon car racing without problems so it's strange that some cars seem to suffer. Are the bolts new and genuine VW and torqued up to the correct torque setting? Many people don't realise the importance of the correct torque setting for the type of bolt - I'm not saying you guys don't but it seems that something is not quite right. Maybe it is balance or harmonics but I'm a little sceptical on how critical harmonics are. I recall a thread on here I think about mounting the crank sensor on the outside of the crank pulley and the impending doom of such a thing due to the harmonic imbalance etc. I've had one mounted there for years with no problems so it can't be that sensitive - well that's my opinion from my experience.
In my experience (non trackday but hills & sprints): Not exactly working loose - they appear to fatigue hence require a better bolt
Are the bolts Loctited in? It's so long since I've touched an 020, I cannot remember if I used to. The pattern which is emerging is shortblock and the same cast 9A crank? 4th one down: http://www.clubgti.com/forum/showthread.php?t=212060 Plus cams, and raised output over a particular range. Thing is, a lot of other cars don't exhibit this problem, meaning the bolts are fine in those instances.
Don`t recall Granted, the application is pushing the standard spec - are the `other cars` similarly `pushing the original design` ?
