Maybach_Man

Hi

Is there any reason i cant use normal hi tensile socket caps for the flywheel to crank?? i know the heads are smaller??

Thanks

85euro928

You may be able to but why would you? If you're looking for a set and the '85's will fit your MY I have a good used set, just pay shipping.

Maybach_Man

I ve got loads.... but you shouldnt re torque hi tensile bolts.

http://www.fastenal.com/content/feds...0Fasteners.pdf

85euro928

Agreed, that's why I have old one's, but they're too nice to just throw away

Maybach_Man

perhaps we should start a jewelry buisiness, ive got loads

69gaugeman

You should replace the crank too. It is under the same tensile forces...

Of course I am kidding, but the reality is the fasteners will be fine to be reused. one of the considerations is the length of the bolt. The clamp forces change with temperature and the minimum force required to hold the two pieces are factored into the torque value. Couple that with the fact that these forces are measured in change per degree of temperature per length of bolt, means that the longer the bolt, the higher the torque needs to be, and the closer to yield it will be.

In all my life I have never seen a flywheel bolt fail. That and mechanical engineering will tell you that the 8 or 10 bolts on there are WAY more than adequate.Not that it couldn't fail, but only if severe over torque was used to install and the fastener had some previous damage due to yielding into the plastic stage. More likely in this case the crank threads would let go before the bolt ever did.

If you are super scared check for cracks at the head joint. Maybe even invest in some crack checking dye.

Maybach_Man

Perhaps i should replace the crank...ive replaced most of the rest of the car, guess youve beenn there as well... thanks for the input

Bill Ball

I've never seen anything to indicate the stock bolts are single use. Porsche is pretty good about noting single use nuts and bolts in the WSM.

Mrmerlin

.the only bolts or hardware I replace on a 928 engine are the water pump bolts and the water bridge bolts and the rod nuts.
The cam pulley bolts also get replaced if there was a cam failure.

I have Never seen a flywheel bolt fail unless the head was buggered up with a bogus tool.

Unless the hardware is damaged with corrosion or over torqued it gets reused

mark kibort

i had to go to a metric shop to find different bolts, because the stroker crank had the wrong thread type vs stock! Ugggg. anyway, the stock bolts, even used should be just fine!