<VV> '65 140 engine bay featured in today's Hagerty "Daily Driver" Tech Tips, see link below

Jay Maechtlen jaysplace at laserpubs.com
Wed Jul 3 00:56:11 EDT 2024


On 6/17/2024 10:53 PM, tony.. via VirtualVairs wrote:
>
> All that having been said, it used to be that almost nobody ever 
> bought new hardware when putting an engine together.  I never did, and 
> never had any issues.   Maybe the hardware isn't quite what it used to 
> be... ?   This goes for head bolts, rod nuts, main cap bolts etc.  
> Likewise Corvair crankcase bolts and rod nuts.  None ever failed.
>
>
> Then there's the Cadillac Northstar 4.6 engines that still had head 
> gasket failures even with all new head bolts/inserts etc... kinda hard 
> to trust some of the modern engine hardware/designs. I did have one 
> bigblock Mopar head crack after a few years following assembly but it 
> wasn't because of reusing the head bolts (crack between chambers).  
> Maybe I just got lucky along the way?

Steel in most cases has an unlimited life if kept out of yield. Don't 
actually stretch it so that it deforms, and don't let it rust/corrode, 
and it keeps its strength.

Stretch it - take it past its yield point so it actually changes its 
dimension, and - initially it gets stronger.

Yeah, those bolts you torque until they start stretching - they are 
getting stronger.

Of course, at some point they start getting skinnier, and greater psi 
doesn't compensate for fewer inches of cross section.

So, yeah only the brave reuse torque-to-yield fasteners, and they don't 
follow the original instructions, exactly.

I do know of some tty rod bolts that seem to be doing ok, fwiw.

Corrosion, of course - reduces cross section and causes stress 
concentrations that you don't want in anything highly stressed.

Ok, enough for how - happy wrenching, or better yet, happy cruising!

Jay



Jay Maechtlen
61 Corvair coupe
custom fiberglass skin
GM3800 supercharged
4T65E



More information about the VirtualVairs mailing list