Replacing head bolts

[overdrivegear]

I'm putting the head back on the rebuilt motor (CR) and I bought some new head bolts.  They weren't OEM replacements and as I was torquing them down, the last stage made one of the heads snap off.  Just really poor quality steel.  So I can either reuse the old ones which are still in length spec 98 mm length and 11 mm diameter or buy new OEM ones.  I honestly do not see any problem with reusing the old ones if they haven't stretched but I wanted to get everyone's input before I make my decision.

[ilikevwdiesel]

get new bolts and if you went far on the torque sequence get a new gasket too. I like autohausaz.com

[Vincent Waldon]

2X.

The word "stretch" is probably a bit misleading in this case... more like the bolts "deform" as they are torqued using the correct sequence.

The service manual is very very clear on the fact that the head bolts are single-use only (same with the gasket) and given the pressures and temperatures involved and the fact that new OEM ones are only a few bucks each it's hard to argue for re-use.

EDIT: opps... if they are 11mm then Mr. Bentley gives you permission to reuse 'em.

[maxfax]

You got 11mm bolts, get head studs!   That'll save you tons of hassle, head gasket failures, and cracked blocks...

[jtanguay]

You got 11mm bolts, get head studs!   That'll save you tons of hassle, head gasket failures, and cracked blocks...

a good way to understand how head studs will help, is that the head bolts don't thread in all the way... so you're not getting as much bite as with head studs.  the studs are to be screwed in deeper into the block.

i like ARP as they have allen heads for easy removal while the head is still on the car, or even easy installation.  the raceware ones do not have this feature, but are apparently better, but i'm not 100% sure on that.

i'm pretty sure you could buy the right head studs from a fastener type place a bit cheaper - but you want the top portion to be much finer, to give you better clamping force.  a lower torque number is specified though when you change the thread pitch.  has anyone tried going this route? would probably only be about $50, as compared to $100.  and just buy the moly lube from a parts store...

[maxfax]

Thankyou for explaining that jtanguay..  I couldn;t remeber if the post explaining that was on here or Vortex..  I agree that the allen head on the arp stud makes them nicer than the raceware studs...  Not to mention arp are half the price too..  On a MK1 you can't get the head on or off with the manifolds bolted to it with the studs in teh block..

I checked with teh local Fastenall store and the idiot behid the counter has no clue on a stud they may carry that will work... Guess I need to call someone more knoledgable/ambitious in the company..   The arp studs can be had for around 100 bucks shipped on ebay..

AS far as the torque spec goes I remeber discussing that the final torque with the stretch bolts is aound 100 lb/ft.. Just by the feel when tightening the 12mm bolts I suspect there is more clamping force than with the stock 11mm bolts..   Makes me wonder if VW didn;t know that the block won;t handle any more torgue with 11mm bolts..

Anyways now that I've made a short story long, Excluding the first car I used the ARP studs on (I used the VW spec on that one with not so good results) I've always used the spec provided by ARP with teh studs  (80-85 lb/ft).. 4 cars and alot of miles later I've had 0 head gasket issues since..

[conor]

For the 11mm block, ARP# 204-4701 (1.8T 8v studs)

I just installed a set in mine. Picked them up locally from headbolts.com and would definitely use those over the stretch bolts. I actually had contacted arp and they said they didn't have any that were for the 11mm, but the ones i picked up worked fine. Use plenty of the moly-lube and you'll be fine. I did have to use an allen wrench to get the studs all the way in and even...though maybe i should have just cleaned the threads better.