cant find the thread i'm looing for, but read http://www.rx7club.com/showthread.ph...9&page=3&pp=15

 

Are you worried about the rest of the bolts in the car? There are lots of other things that have been through those same heat cycles.



One way to look at it is that if the bolt has never been overtightened and thereby stretched out of shape, it should last indefinitely. They have already been proven in use, although some simple nondestructive testing beyond a simple length check isn't a bad idea if you're really over-toilettrained.



New bolts, on the other hand, are an unknown factor. One tech writer I know likes to say that NEW means Never Ever Worked, and this is true for bolts as well. Best to do some NDT on new bolts, or get certified bolts that get NDT as a matter of course, otherwise you are actually inducing more risk than using the old bolts.



Modern engines are assembled with bolts that are specified to be overtightened (torque-to-yield) which is why you must replace the bolts for a shocking number of services nowadays. Older engines aren't. I've built engines from 40 year old cores and reused the stock bolts.

 

I just took the bolts out of my engine and they are still shiney. So it looks like i may not need to re-plate them. I'm considering doing the dye/lamp to look for cracks. The motor I just opened up is absoltely mint. It's a S5TII jspec I bougth off someone who was quiting the rx7 scene. paid 200 cdn for the keg. It has brand new housings, plates the works. You don't even see wear on the housings... wowsers... all the bolts so far are cad plated shiney still.

 

Well thats a great idea. How long should my tention bolts be? How about my stat gear bolts? I'll check em right now...



But I must admit, in the grand scheme of things, it still seems better to just put new bolts into the more critical parts. I just cant help but think about those people finding main bearing soup in their oil, or developing a coolant leak 6 months down the line and not knowing why. Words like "it should last" dont comfort me.



Cheers: What a steal, i need to find someone quitting the rotary.

 

Just check them against each other. If one bolt is stretched, it's highly unlikely that they would all be damaged the same. If they are all close to identical they are okay. Given that bolts usually fail at the threads, and that the realities of mass production mean that no two bolts will actually be identical in length, a better check might be to just check the bolt threads against each other.





Assuming that you know that the new bolts are any good, which you don't unless you have them checked out, like Magnafluxing or X-raying.

 

So, new bolts it is, Thanks.

 

Is it true Pettit Racing torques some of their stock-bolted engines to 50 lbs? I just read that in an old thread the other day, and I can't get it off my mind...

 

forgive me if i wasn't familiar with one guys car out of the many thousands.



interesting though.