Yeah, that ENTIRE engine would be in the scrap metal pile. I overrevved an engine by just a few thousand RPM's once (11,000) and thought a head rebuild would be enough (all 16 valves bent), and it did for about 6 months, until a crank bearing spun in the block at random one day. I'm sure it was attributed to the high revs. Later found out that there was other block damage that rendered it useless for a rebuild from some guy I sold it to.

I also doubt 15,000, had to have been a sensor issue. I doubt even a 5th to 1st shift would allow that high of a rev without just sliding the tires or breaking something else first.

n/m, actually read the thread now. Obviously it wasn't the claimed 15k.

 

And yet: Do it then.

 

That engine isn't going into this car. I have something... special in mind for it.

 

Sounds like you've got a pretty solid set up. The wheel I have has an aluminum center section. I don't see your set up suffering from the same problems that mine did. When my motor comes out of the car, I'll have a machinist cut a giant washer ring for me, but for the mean time I replaced the bolts with new, slightly longer and installed the largest washers that would fit. I also used red loctite. I had used blue loctite originally.

 

My socket cap bolts failed again. Two of them broke, mid shaft. Seriously.

The resulting noise made me think that something in the motor collided into something that it should not have. Luckily for me, that wasn't the case. I'm not saying that these bolts belong in Dante's 9th layer or anything, since they did last several thousand miles, but I wouldn't lose a minute of sleep if they found themselves condemned to the 7th or 8th layer.

I'm going to come up with something better.

 

Wow.

Knock on wood, but the 10.9s on my hub are holding up nicely. Again.

 

Ben,
is any area of the wheel coming in contact with the thread of the cap head screw?Could they have vibrated loose prior to failure.You may want to try stripper bolt or shoulder bolts,or even aircraft hardware.
http://www.mcmaster.com/#shoulder-screws/=6oz54m
(G)

 

Ben -- giant washer + hex head bolts = win.

 

i still say the worst day of my miata related life was when my harmonic balancer fell of do to 2 sheared bolts and 2 bolts that worked free. do the **** right joe walking back to pick up parts and installing them improv style after work to get home is no fun.

 

That's kind of what I was thinking too. Greg doesn't know it yet, but he's going to machine a giant washer for me.
The problem is that there's no room for hex head bolts due to the small ID of the trigger wheel overlay where it fits inside the pulley. So giant washer plus fancy socket cap shoulder bolts hopefully will be win.

Or I will get one of our 36-1 wheels off the shelf and run it similar to Joe Perez.

 

Can you open up the ID of the trigger wheel adapter on a lathe? That's what I had to do in order to fit that stuff. Just a little bit.

Oh, and you can just use the factory giant steel washer ring.

 

Thanks Jay, that sounds like a good plan. I'll take the pulley off and have a look at it as soon as I can.

 

Not sure I follow you here. What change(s) do you propose I make to my current setup?

 

no changes i am essentialy agreeing with your new bolt philosophy if you have any doubt in the intergrity of what you have. maybe some nord locks or lock washers for peice of mind but other than that you have just about all you can get.

 

So, here's pics of Joe's nightmare. Only it's my nightmare.

Jay, the factory washer-ring must be an NA thing because it wasn't on my car.

Taking this as an assembly to a machine shop in the morning. I'm going to have them drill the assembly, tap the pulley boss for larger hardware, and mill the bolt areas of the trigger wheel "cup" for larger hardware. Figure I'll stud the boss, then use nylocks or other self locking hardware on the trigger wheel.

Don't mind too much the red color in the first pic. It's just a camera phone capture, and it's overly sensitive to the little bit of georgia red clay that's on the motor. Yeah, the dirt here is red.

 

Before you go through all that, let me tell you what I did.

I have the exact same set up with an Electromotive, and I hated the allen head bolts. I got rid of them and used some bolts from a Yamaha dirt bike motorcycle. The head is an 8mm instead of the stock 10 mm. It has a washer boss on the bolt, and it installs easily with a socket. They are a very high quality bolt as well. I use them over and over, and the threads stay clean and straight.

Get a new crank timing belt pulley, and try those Yamaha bolts. I have had that damn pulley on and off a 100 times and have not had any problems. It is also much easier to install than the allen heads. I am willing to bet that you are not torquing them correctly. It is hard to do with those alan heads. I will get you a picture of the bolt for you today when I get back to the house.

 

Yes I was assuming NA. Didn't realize this changed for NB.

From your pics, this is pretty much what happened to all Vishnu adapters -- the bolt heads abrade the soft aluminum, which takes the preload out of the four little bolts. They then loosen and eventually snap.

Larger bolt underhead area (replace tiny allenhead bolts with integral washer hex head) and a steel backing (NA washer ring, in my case) fixed it for me. No need to mess with larger dia bolts and such, in my case...

 

Ben, this is what I use.

 

m2f--I bet you I did torque them down correctly, with a allen head socket on a midget ratchet. Also loctited them.

If you can find me a part number or application for those bolts, that would be great. There's 3 Yamaha dealers within a short drive. Extracting broken bolts out of the pulley boss is easy enough.

Down the road I'll probably switch over to a DIYAutoTune.com 36-1 mild steel wheel, which will never have this problem. Only hold up is I'd need to fab a sensor bracket, which takes time that I don't have this week. I'd like to make the car self locomote by the weekend because there's an event at Road Atlanta Thurs-Sun. I also want to powder coat the mild steel which would take a few days.

 

Well stuffs is at the machine shop. Saying good bye to 6mm hardware and hello to 8mm hardware with a much larger shoulder. That should help. With a steel backing, we should be in the win category again very soon.