Rusted exhaust nuts and bolts.

[DavidR]

During the rebuild process what do you guys do differently when replacing these fasteners?
Besides anti-seize, do you used hardened SS? I noticed the three nuts used on the bottom of the Cat
are SS. and they look good despite all the heat they receive.
BTW, the engine is ready to be pulled for the new timing belt, clutch, main seals, new gaskets and a CT27 turbo. These cars are time and cash bandits for sure.

[MR2Jedi]

Originally Posted by DavidR

During the rebuild process what do you guys do differently when replacing these fasteners?
Besides anti-seize, do you used hardened SS? I noticed the three nuts used on the bottom of the Cat
are SS. and they look good despite all the heat they receive.
BTW, the engine is ready to be pulled for the new timing belt, clutch, main seals, new gaskets and a CT27 turbo. These cars are time and cash bandits for sure.

yeah, if you can find good ones. The anti seize is the biggest help.
But even they will eventually rust.

And yes, money pits!
And why do we do this?
We love our 2's!

[ToyotaTechGeek]

i use stainless hardware, but it's difficult sometimes. not many people realize that there are different grades of stainless steel. some stainless has high amounts of carbon (ATS-34), but then there is 409 which doesn't rust like crazy. so there are some variables! you can look into buying a aircraft set of fasteners, but i think you'll find that it won't match-up to your metric fasteners...no i am not a fan of using the SAE 'equivalent'.

[DavidR]

Originally Posted by ToyotaTechGeek

i use stainless hardware, but it's difficult sometimes. not many people realize that there are different grades of stainless steel. some stainless has high amounts of carbon (ATS-34), but then there is 409 which doesn't rust like crazy. so there are some variables! you can look into buying a aircraft set of fasteners, but i think you'll find that it won't match-up to your metric fasteners...no i am not a fan of using the SAE 'equivalent'.

True enough! These bolts have a hardness rating that is important for certain apps. Don't think a SS of any type will meet the strength needed.
How about a super hardened steel? I think it might hold up against the heat changes better.
I just want bolt to be removable the next time the car needs work.
A couple of these bolts where soft to start with and rusted to the point that the flat sides rounded over too easily. I can deal with bolts that snap off, but those that round over are a real B buster! As you all know already!!!!
Thanks.
D.

[ToyotaTechGeek]

i don't know if it's any better or not to use grades 10 or 12 as i've seen them rust just the same. if this is just for attaching the cat onto the existing exhaust, then just use regular hardware and slather the antiseize. if you can, then the stainless hardware available for aircraft can replace all of the hardware and would be able to replace what is already there. otherwise, mild steel is all that is usually used. maybe an off-the-shelf stainless nut can be replaced when it shows signs of rust/deterioration might be best. i don't know.