Thread: Cam cap bolt grades?

Okay so I was able to re-tap the cam cap bolt hole that has been plaguing me, but it's not perfect. For instance, I went to tighten down the cap, and the bolt went in a little more than half way, and then snapped in half. Fortunately, I now have all the RIGHT tools to extract a bolt, and it came out with EXTREME ease.

Now, I need to know what grade the bolts are, because I'm going with a stronger grade. I want some grade 8's in this baby, but I'm not sure if they're already grade 8's. IF they are, it's a lost cause and I REALLY need that head, (ToKeS!!!! )

I'm thinking that if I go with grade 8's, the installation of the caps can be done, and once the cam is properly installed, the bolts will actually have less stress, being that the force will be applied across the entire head and not just one or two caps.

Thanks in advance, as always.

Anybody? Bueller?

You just had me raking through my box 'o' bits to try to find the answer to this one as i know i have a brand new set of OEM bolts.

I see your problem, no grade stamped on the bolts...

Let us in on your secret of bolt extraction! It's a job i hate as it never seems to go right

It was actually very tedious work, that took a few different tools to find the right one.

What I found works flawless, is to buy some steel left hand drill bits, in addition to the standard bolt extraction kit. If the bolt is snapped off, but can still be turned in or out a tad bit using a normal drill bit, you just use a left hand bit and drill a little bit until it grabs, and backs the bolt right out. If it's stuck, use a left hand bit to first drill out a tiny bit, and if it doesn't grab, you go to the screw extraction kit. Just take a normal drill bit the same size or a tad bit larger, and drill the hole a little, then use the extractors to grab it in reverse and SLOWLY back it out with a wrench.

The key is to use a small tap/center punch and first tap the bolt, so that you don't start drilling on the edge and make things worse.

First off, there is no such thing as a grade 8 metric bolt. There is 8.8 (mid grade) and 10.9 (equal to a standard grade 8). Secondly, it is a bolt tighting a cast cap into/into a cast aluminum head. im pretty sure that the stock bolt is 8.8, but, a 10.9 would be fine. Most importantly, make sure everything is lubed, and follow your torque specs/tighting procedure!

Also, if u had to re-tap it... I would look into a heli-coil

ARP carries our cam cap bolt size...I had a whole set but the shop that did my orig build never gave it back. it had all the P/N on it too...