Uprated bolts are listed here on VW Motorsport web site for the Group A 16V Golf: http://www.vwmotorsport.com/vwcat/files/Golf 2 Group A.pdf Very interesting site. Question now is can you still get hold of any of this stuff? Does anyone know the best avenue/ company for sourcing these bits. The 2.5mm plate can be made if all else fails but the uprated bolts maybe a bit more difficult. Ian
The pic Dave posted is an extract from the pdf. The parts are long obsolete unless they have mainstream VW part nos.
The 6 Bolt Problem - Spacers This is what I noticed when I cleaned up the face of the pressure plate. The plate has obviously been breathing around the periphery of the crank bolt heads! The face on the pressure plate is not super flat! It is also 'as rolled' smooth. IIRC, we used to specify a surface finish of 240 microns for faces that were bolted for friction drive. So, I would consider having the pressure plate face skimmed flat, minimum material removed, to 240 microns. This will also ensure parallelism with the pressure plate face, and thus, the flywheel. Looking at the build dimensions of the clutch/block/gearbox assembly, I came up with this! The 5.5mm spacer is the limit to still allow for location on the crank nose! To check the release travel, I made this! PS. The Arai helmet is a Rapide 3 - Medium - White - Unused - 100 + p&p These are pictures nicked from Brookster's post below. He recons., 5mm washers. The bolt heads look 5mm thick, and the length looks good. My head bolt washers are 3.85mm thick. ARP Crank Bolts ARP Bolts fitted with head stud washers I recon., if I was building a high performance Mk2 clutch assembly, I would look to use the 5.5mm under plate spacer. Clean the mounting face of the pressure plate. Use a 5mm under head spacer and ARP bolts. Usual Loctite etc.. But, I would dry assemble everything and measure everything twice before commiting, any given clutch, to any given flywheel, to any given gearbox. And check release travel.
The 9 Bolt Problem I have e-mailed Sachs for more clutch details, photos and drawings. I shall report as and when!
I lap my pressure plates to the crank with valve grinding paste to ensure the two faces are as flat as they can be. It takes a little while but eventually after lapping the surfaces are evenly grey over the mating surfaces. Just make sure to remove grinding paste from crank threads with a cotton bud. The two surface areas have a lot to do with the clamping of the parts and not just the bolts tension.
I fancy using spacers, so you would need to lap four faces on the crank side and, two on the bolting side!
I have now also e-mail LUK, Kiveton Park, Sheffield, asking for photos and drawings. I also asked for a factory visit, for old time's sake, as I used to work for Laycocks, on clutches, before LUK bought them out.
The ARP bolts, boxed in red, appear to be the ones if going for 5.5 mm + 5 mm spacers. Pt. No. 151-2801 - 200,000 psi = Grade 14.9 The ones below, 254-2801, appear good for a 5 mm combination of spacers, or a 5mm washer. Could be the one Brookster used. I have contacted ARP to try to obtain the actual head thickness. I shall need to look at the correct torque and turn requirements to give the correct bolt pre-load for yield (stretch).
There are 2 types of ARP kit available. One is VW specific made and supplied only through Eurospec (it's ARP quality!), whereas the other is a re-use of existing bolts from other installs, eg the Pinto above. I have all the data here I can dig out on the VW specific stuff. Let me know what you need.
The kit comes with 2 bolt shank sizes, differences highlighted. These are for a cable change flywheel - one hole is larger (little known). UHL = under head length 1) M10 x 1.0 - UHL=22mm/0.865 inch - unthreaded shank dia 10.63mm/0.418 inch - unthreaded shank length 5.5mm/0.235 inch 2) M10 x 1.0 - UHL=22mm/0.865 inch - shank dia 10.11mm/0.400 inch - shank length 5.5mm/0.235 inch
Chris, at present, I am really interested in the thickness of the Pinto bolt heads. It is for the operating clearance, between bolt head and underside of release plate, on the two thick spacers arrangement. They appear to be ubber thin compared with these from the Rosen Performance web site!
Received this from Hotgolf: Another option would to be to go to an M9 allen head bolt instead of the M7. I'm pretty sure there's enough room to put them in, and you'd only have to drill out and re-tap where needed. You'd gain a fair bit more strength and is a cheap option too. Either way I'm going down aditional 2.5mm strengthening plate and will look at everything else on offer on this thread to ensure longevity for track. Will be done for the RS day at Combe in July.
Just bought these for the experiments on building a better 020 clutch arrangement. M10 x 1.0 P x 28 mm. They are actually longer than I wanted, but half the price of the shoter ones! 10.99 Hopefully, they won't bottom out. I shall check carefully. http://cgi.ebay.ie/ARP-FLYWHEEL-BOL...arts_Vehicles_CarParts_SM&hash=item27b1f7ed0a These are the shorter ones. M10 x 1.0 P x 25 mm. 19.99 http://cgi.ebay.co.uk/ARP-FLYWHEEL-...arts_Vehicles_CarParts_SM&hash=item27b1f7ed0e
