Attention to detail fail..
 

My NCOs in the Army would always push the importance of "ATTENTION TO DETAIL", making sure to do the job correct the first time. This applies to bolt torque levels too. I wanted to double check my valve clearance before taking my new motor on it's first semi-hard run. I didn't have a torque wrench out in the boondocks, so I just tightened up the bolts to the valve cover when I was done, not crazy tight mind you, but a bit too tight as it turned out. I putted around getting the motor up to temp. Well after a couple runs at about 3/4 throttle a hear a *PING!!* and things get noisy and another *PING!!* and I smell hot oil..Dang it if I didn't have two valve cover bolts snap halfway down their hole.. :yuck: I won't bore you on how badly the broken bolt extraction went.. On the plus side, I was talking to Taida and they have these cool new valve covers :biggrin: The new Taida catalog is 4.8MB, so just a tad too big to attache to a forum post. I'll put up a pic, when my stuff gets in..

Wow you must have really man handled those bolts. I have never used a torque wrench on valve cover bolts on anything.

Yeah, I'd never used one on those either, but maybe i need to cut back on the coffee, because I must have cranked those things down.. The bolt extraction was a classic on how not to do it as well..

were they stainless? cannot imagine a heat soaking causing a valve cover bolt to snap even if it was over torqued.

Well, not sure of the bolt material, but as I mentioned, the extraction was sub-par and i wanted to see how badly I'd killed my threads. so i took one of the existing bolts and screwed it into the hole.. made it maybe 3/4 of a turn when that one snapped too.. almost like a shear pin. I'd love to replace them, but I have no idea what this type of bolt is called as the 4V valve cover bolts are a different kind. Lemme put some pics up...

To be clear, i used VERY little force turning the bolt that time..

Chinese buggies do have the worse quality bolts ever.

Yeah, but it was a Taida head, they're pretty top of the line as far as parts go. I ordered 4 sets of bolts while I was talking to those nice folks in Taiwan as the guy at Napa looked like I'd handed him a spaceship warp core when I asked if he could get me some of those. None of the GY6 or Ruckus places seemed to have them either unless I was buying the entire 4V head. The motor rips though..

looks like thread pitch mis-match

If I'm not mistaking the bolts are a torque limiting type in that they have a shoulder that contacts the head so as not to squish the rubber gasket just as used on most newer cars. I have never torqued them but tighten using a 1/4" ratchet with thumb and first 2 fingers. Maybe they had a bad batch, I would ask them.

Yeah, are these things available stateside? What are they called? I just spent $35 on bolts (4 sets) from Taiwan... The holes threads are mangled too..I need to get a mechanic buddy to do a broken bolt extraction clinic. It was broken too far in for my Eazy-Out tool to reach (story of my life)..

I kinda doubt. You would have to try a Fastenal or someone like that. I would guess it to be a specialty bolt since you would have to factor in the thickness of the cover, gasket and the rate of squish of gasket.

Could you use the correct length bolt with a piece of tubing and a washer? Slide the tubing over the bolt then a washer to act as the lip.

You would spend more time and money and maybe not work than it would cost to get the correct part.

While waiting for the right parts to arrive, I've done some pretty creative rigs..lol