Broken Head/Main Bolt removal

[labcoatmonkey]

Im posting this because Im sitting in my garage right now assembling the block and going with the odds, I broke a main bolt... DO NOT REUSE those bastards are frail after the first torque.

One thing I realised is that if the bolts are not rusted and relatively clean, getting a broken piece out could be as easy as pie.
As physics still apply in our world (sadly yet not) one of the rules is that any rod torqued beyond its capability, should break at a perfect 45 degree angle (or relatively so). The pulling force on the rod should also create a cavity big enough for a flat head screw driver.

If you discover that the piece of the bolt that is stuck inside the block is not flat, find a plastic tab long enough to reach it and not ruin the threading, catch the angle and carefully twist the broken piece out.

Its almost 3 am and I just broke one of the main bolts, thinking that it means re-tearing down and sending the block to the shop to spend another $200 on a piece of 20 year old iron when I remembered... properties of materials!

Now to order those new main bolts...

[evildky]

I'm confused, did oyu break a head bolt? a rod cap bolt? or a main cap bolt? and of all the bolts I've ever broken, most shear nearly flat, as they twist off so if oyu can get it out without a trip to the machine shop, more power to you, me I've foudn taht if it doesn't come out fairly eassy I'm better off taking it to the machine shop, and fwiw I have broken a brand new Nissan Headbolt before, sometimes you just get a bad one, and if you clean all the threades before assembly you have a better chance of removing a broken bolt with little effort

[labcoatmonkey]

I broke a main cap bolt on the 2nd bearing cap. It came of at a precise 45 degree angle. I guess I was more fortunate, not having to break it down again. I just remembered a lesson in statics and strength of materials, that a rod, composed of a homogenius material, when torqued will break at an exact angle. Ive tested it before with chalk, acrylic, but never with hardened steel hehe. Either way I ordered new bolts I cant wait. Hopefully Ill have all the parts for full motor assembly by the end of this week.