I bought new head bolts and they look great but are definitely not the same hex drive bolts that I took off. Here is a picture:

http://www.dropbox.com/gallery/59922...0Bolt?h=2e07d5

For our grand prize, what drive is used to torque these babies down?

I am coming up uncertain after way too much time looking for an answer and no help from the vendor yet.

Best guess so far - 10mm Ribe. A 10mm allen driver fits in the center OK and will spin them down, but doesn't feel tight and right for torquing.

After my stripped head nightmare taking the old bolts out I am not interested in taking any chances going back in!

 

It is called a Star Bit http://www.sears.com/shc/s/p_10153_1...8&blockType=G8 not sure of the size.

 

The proper name is "Torx" bit, some times called a Star bit by the general public...

http://en.wikipedia.org/wiki/Torx

 

I will take another look at those, but it looks quite different from star bits, with perfectly squared off points and a hex shaped center. A T60 torx fits pretty tightly, but is slightly different and needs to be filed slightly to fit all the way in. I will check out the star bits.

Why these bolts are not named by the drive design is perplexing. Thanks Gus.

 

Thanks Barry. I may have to go with a torx though it is slightly different. At least I can find one of those.

I am hoping to hear from anyone who has successfully torqued a set of these through the whole sequence without anything breaking.

 

Dam! I thought I got it! OK what is the prize?

 

Free room & board in Florida at the Classic Jaguar Restoration Adventure theme park?*

*Some restrictions may apply ;-)

 

Well with the more detailed description you've given I'll now say it's a 'Polydrive' screw...

http://en.wikipedia.org/wiki/List_of...ives#Polydrive

I should have looked at the enlarged image the first time and not just the thumbnail...
Please excuse my initial haste

 

I'd say Polydrive is the winner!

 

I have a Ribe or Polydrive driver on order and will confirm this conclusion. I guess there aren't many head jobs going on out there that have used this new bolt!

Size is another matter... I went with 10mm measuring across the points. The good news is these drives are designed to torgue very efficiently (Once you figure out which driver to use.

Perhaps the quiz should have been: Name any vendor selling these Jaguar head bolts that includes a driver designation in their item description!

Thanks to everyone for playing Name That Fastener!

 

OK, this is the definitive answer on the new style cylinder head bolts from both the Jaguar dealer and the rebel alliance Jaguar repair here in town (Renaissance Motors): use a T60 Torx Bit.

It may very well be a polydrive, ribe, or whatever, but I went to NAPA and bought a LISLE 37720 T-60 Super Torx Bit and it fit both the bolt and the cylinder head like a glove. Getting this exact spec is important because Lisle makes two T-60 Torx drivers and the other one (a one-piece version) won't go far enough into the head to engage the bolt due to a larger diameter.

I had previously tested cheapo regular Torx 60 bits at Ace and Pep Boys but they didn't actually go all the way into the bolt head so that threw me off the whole Torx possibility. It pays to buy quality tools, duh!

 

PS) thanks to Jaguar of Sarasota and Renaissance Motors for helping the grease covered guy carrying a bolt into their shops asking questions. I am lucky to have two Jag shops within a mile of the house!

 

You did not say we could do a shout out!

 

Hmmm... well I'm sorry, call me a synic, but I don't trust dealers. After looking at the full size image of the bolt-head you posted, IMHO it is definitely not a 'Torx' head bolt. If you read the link I'd posted earlier you'll see that though a 'Torx' bit may fit, it is not the proper tool for the job. I'd wait until the 'Polydrive' bit you ordered arives before attempting to install the heads with the 'Torx' bit. My 2¢, take it for what it's worth...

 

So, I might still in the game??

 

I hear you Barry. I will get the Polydrive I ordered today and will report. Whatever the difference truly is, the Super Torx did the job flawlessly.

Another Yogi Berra quote that fits: Nothin' succeeds like success!

 

“O” Ok now it is a “Super Torx” OK who won the prize?

 

I still think you did... I can use a crescent wrench in many cases, when a 6 point socket is really the correct tool.

 

It seems anything is open to interpretation these days... I got the 10mm Ribe/Polydrive yesterday and it sure looks like the right tool for the job. But, the bolt turns out to be about a 12mm version so I can't actually try it out to confirm.

The 10mm size is available all over the net, but here you could get a 12mm I can't say and that's probably why even Jaguar is using a T60 Torx... or Super Torx. That's what Lisle calls it.

Guess you are all winners...

 

Hello: I have hex heads on my jag 4.0. wondering how you got that stripped bolt out. I have one of them that is very tight and so far the socket just spins off it with pressure. All the others came of with a bit of pressure but this last ons just keeps flying off the bolt. Any ideas, please?