Is there such a thing?? I think I have broken/damaged mine due to a fluffed gearchange with big rpm (7600) earlier.... Engine seems fine...touch wood! All vital signs are good. Pressures/temperatues etc...as i thought my over-rev may have clipped a valve Car now shakes & vibrates...& flywheel sounds like it is contacting the inside of the bellhousing on start up or fails to engage with the starter, hence the diagnosis.... I know IanB had similar issues on more than one occasion with his 7800rpm 16v...so wondered if such a thing as an uprated bolt set existed??? Bolts were only replaced last summer when i broke the clutch & were correctly torqued & Loctited [:^(] Edited by: chrismc
Best bet would be to change them to a 12.9 grade M9 fine allen bolt. I'm not sure that you can actually get an off the shelp made for the job uprated jobbie, so by gling up a grade and size you'll get what you want.
arn't there any dowels that help secure the flywheel ? if not then dowel it, should take some strain off the bolts
Silly question but how do the bergcup guys manage to rev their 16v's so high without going bang also .
Yup pretty sure its some of them that ive broke... Not sure til the box comes apart but trying to source some beefier bolts from EIP, Raceware or ARP.... Believe TSR can & have put extra dowels in previous cars, soo will investigate that too
How critical is the torque setting on these bolts? I've never bothered to use a t-wrench on them, just nipped them up about as tight as they were when I took them off (pretty well tight with a short 9mm spanner!). Changing the gearbox on my valver AGAIN at the weekend for a very good nick 8v one, so will have the flywheel off to swap clutch plates. I drive it very hard, and I hate pulling gearboxes - but I also hate arsing about with torque wrenches!
hey here is the info you need you 16v high revvers,, get onto the bolt manufacturers with this,, just been out to the store and measured one up m7 x 1.0mm thread pitch 40mm long to base of bolt head 20mm smooth shank,, 20mm threaded 12 pointed 9mm head with flange,, 10.9 tensile stress rating see if you can get an uprated spec on these beasties,,
Over here, the MK2 cars used two 6mm locating pins in the flywheel, used to center the flywheel. For the MK3 cars, they changed the PP design to include raised portions along the edge of the PP, and the flywheel is machined to fit those raised sections to center the flywheel. A single 7mm locating pin is used to put the flywheel in the right position on the PP so the timing marks stay aligned. I was recently discussing these bolts with a person on the Vortex who swore up and down the bolts were a one-time use fastener, and should be replaced with each clutch change, and in the course of the argument, I tested the bolts by raising the value on the torque wrench a ft-lb at a time until I got the bolt to stop clicking the wrench over and just start turning and breaking. The spec for that bolt is 15 ft-lbs, and I broke 3 of them in a row, each of them breaking at 40 ft-lbs +/- 3 ft-lbs. The Vortex thread is here http://forums.vwvortex.com/zerothread?id=2452123 Broke
very interesting broke,, i too was a swearer blind that these bolts were infact strech bolts and i change them everytime,, after seeing your findings i see no rason why we cant yp the torque to 20 or 25 ft lb and use locking compound on them,, first we need to see though if chris mc`s bolts have infact snapped or come loose as if they have snapped this means some other kind of force is breaking the bolts, and a bit more torque will worsen the situation, maybe it has something to do with the lightened flywheels which are not balanced with the crank from the supplier,, simply machined to the center of the factory balancing groves,,,
Chris My problem was eventually solved on my car by putting in 4 extra dowells. You can however use an upgrade bolt made by a local manufacturer close to TSR. There was mention that Cosworth bolt may fit and they have a greater strength?? I also had an inspection hole made to check they were all in place/torqued up. Looking at Broke's comments it's interesting and it is another consideration.My flywheel and crank were balanced and it is testiment to Justin at TSR who has been engines for along time that when he balanced the bottom end the end result was a much smoother unit. I felt it was much smoother than Matt's car which wasn't balanced....you could definately feel the difference when driving them back to back. I'd definately get more dowels put in place as your car is now running power much higher up like CFJ. Thankfully I don't get these issues in the MKIV but there again I'm going thru the process of new clutch/diff at the mo Ian
I think Olly & myself are going to fit extra dowells mate. One of mine had come out of the flywheel & 6 out of the 9 bolts had sheared Do you know the name of this company who do the upgraded bolts or would i need to speak to TSR??
I'm puzzled by this - I never had a problem in 25k miles, on a fairly ferocious 2.0 litre 16V which some will recall. I wonder if it would make good sense to have the flywheel balancing checked, just to be sure that there isn't a problem with that. I always loctited the small bolts with green 270 / 271 compound, torqued to roughly the normal figure + a bit, albeit with a half-inch torque wrench operating at the lowest end of its scale (ie potentially a bit innaccurate).
