Someone feel free to correct me, but i dont think they are 'stretch' items so it is ok... They arnt bolts are they though? studs with nuts... I replaced the nuts on my race car.. thats all..
No you shouldn't re use them. Buy new ones. They aren't very expensive and you don't want your engine to go bang in a horrendous way if one of the fails do you. I replaced all of mine on my G60 lump in an old Rado i had as a matter of precaution.
They're allegedly single use. New VAG ones are about 7 quid each. I know of people who have re-used them without a problem, but if you're building something high spec, I'd change them - ideally for ARP ones.
It's for my mates 8v Gti that I'm rebuilding . Kent GS2H , lightly ported and polished . I dropped out the 4 Pistons to hone the liners (water mark on middle 2) . Feck it , he has a lot invested in it at this stage , another 8x 7 isn't gonna break the bank.. GSF ones a no-no? What's the torque actually?
I doubt GSF would stock them.. Stealership only, then take them to an engine builder, or garage or whatever your fancy, and get them pressed in.. new nuts would be a good idea to.. Not so cheap now is it! Con anyone confirm if they are a strech stud? - not convinced..
Toyotec has reused most bolts including head bolts on his 315ps WolfR. So i reused my big end nuts. I used ARP head studs though
I have reused all fasteners actually including head bolts. I have had no problem what so ever. But that is just me and experiementing. If you would feel more comfortable it is not expensive to buy new items from the stealers.
The bolts are reusable, nuts don’t need replacing but I would replace the bolts as they are stretch items and you don’t know if they’ve been off and reused before, better safe than sorry
One thing to remember when replacing the bolts is to tighten the nuts evenly, check the torque several times before moving on to the angle stage to make sure the studs are seated correctly against the con rod, also look at where the stud rests on the con rod to make sure the head of the stud isn’t binding against the side of it’s seat, this will give you a false impression of the bolt being torqued correctly. If the con rods are out of the engine, it’s easier to lightly tap the bolts into place with a copper hammer, never try and pull the studs into place without the big end cap on the con rod, and never exceed the specified torque to seat the bolts. Also remember to lightly clean the inside of the big end caps with wet and dry before fitting the bearings
DO NOT use the the GSF ones. They are complete ****e and don't fit. And as above, if you change them, put the new ones in with either a copper hammer, or better still a small hand press to push them home(don't go mad!)
No, just a light tap, once again with a copper hammer just in case youre a hand fisted and miss the stud
i had mine pressed out and new ones pressed in, apparently the holes they fit in can distort and may need machining afterwards. tbh for the amount of effort to change them i'd fit arp bolts, if you ever need to strip it down even once they've paid for themselves. set of arp con rod bolts is about 100 am i right? vw set of ten 70 or so with the vat.
Had a long discussion with a friend of mine who has a doctorate in metallurgy and he was very clear on. If a bolt is a stretch one then they have a single cycle use only, he took me through a 1/2 hour saga on how the metal deforms and etc etc.. Basically if you want to toast you engine then reuse stretch bolts.
Toyotec's a doctor in motorology, and his 300bhp engine isn't falling apart with them. In theory you're right, but does your metallurgist build many engines?
LOL how many time have I heard that one at work... These guys do get very excited about corrosion pitting in offshore pipe work, which should only last 20 years. But most of the first generation platforms are over 30 and still going strong with carbon steel pipes.. Point taken.. If you think about it in the case of head bolts the worst case will be the head gasket may leak, but if you heat your engine up and cool it down properly then it should last... I had a 9A that lasted about 8K miles with a leaking head gasket and when i took it apart it was noticeable that the head bolts where definitely loose compared to a freshly torqued one..
Yeah, who knows what's been done to an old engine though. I did a head swap on a 9A with GSF bolts, which went soft before they were torqued properly. Threw them away and bought some FEBI ones from VWSpares. If the previous owner built it with GSF Cheese-Bolts, then that could well be the result... or maybe they just didn't torque it up properly.
