Exhaust nuts replacement

[Chazzle]

Hey Guys,

I had difficulty removing the exhaust manifold nuts because they were caked with rust. After spraying WD40 on them for a week, they came off but were stripped. What types of replacement nuts should put back on. stainless steel? generic 10mm nuts?
Thanks to you guys for making an awesome forum!

Chazzle

[martynkim]

I would use just a good hardened nut. Just hope you stud threads are still good.

[fastplastic]

there not a 10mm nut they are 6x1.0m

[TiffanySpree]

Find a nut that is a little thicker so you get more threads on it. Make sure your washer is big enough to cover the exhaust flange to get a good clamp on it. You can also double up on the nuts so they are more secure.

[SuprasNsprees]

for future reference this stuff http://www.pbblaster.com/ is better than WD , imo

[Bear45-70]

for future reference this stuff http://www.pbblaster.com/ is better than WD , imo

And a home made mixture of 50-50 of ATF and acetone will out preform PB Blaster any day of the week. I even have the test results to prove it and that is why I use it.

[evilone]

My 2 cents....

GM rust penetrant and inhibitor heat valve lubricant #1052627 is amazing.

[Bear45-70]

Various penetrating oils compared

Machinist's Workshop magazine actually tested penetrants for break out torque on rusted nuts. Significant results! They are below, as forwarded by an ex-student and professional machinist, Bud Baker.
*Don't forget the April 2007 "Machinist's Workshop" magazine comparison test.*
*They arranged a subjective test of all the popular penetrants with the control being the torque required to remove the nut from a "scientifically rusted" environment. *
Penetrating oil ....... Average load*
None ........................ 516 pounds
WD-40 ..................... 238 pounds
PB Blaster ............. 214 pounds
Liquid Wrench ..... 127 pounds
Kano Kroil .............106 pounds
ATF-Acetone mix..53 pounds

*The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic
transmission fluid and acetone.*
*Note the "home brew" was better than any commercial product in this one
particular test. Our local machinist group mixed up a batch and we all
now use it with equally good results. Note also that "Liquid Wrench" is
about as good as "Kroil" for about 20% of the price. *
*Your experience may vary, etc., etc.

[evilone]

I'll have to try the ATF/Acetone mix sometime. Do you just put it in a spray bottle then?

[Bear45-70]

A buddy of mine who collects and restores old outboards asked my help with one of his new acquisitions. He had found a 1958 75 horse Mercury outboard (a dock buster) that needed to be torn down. Everything was frozen solid. Tried PB Blaster for 3 days and no joy. Three days of ATF/acetone and every d*** bolt, screw and nut came loose. Several engines later using the stuff and we use nothing else now.

[Chazzle]

wow, thanks guys! I will definitly not use the WD 40 anymore. I bought new nuts and doubled up on them to keep the flange secure. by changing the spark plug and baking the carbon out of the muffler, I gained easier starts and an extra 3-4 mph in speed!

Happy Scooting,

Chazzle

[motormike]

Congrats on fixing your rusty nuts. The additional conversation that ensued was informative.
I will continue to use WD-40, PB Blaster, Liquid Wrench until the current supply on the bench is gone.
Curiosity will eventually lead to trying the Acetone/ATF mixture. Good stuff, guys...... ...period

[Bear45-70]

there not a 10mm nut they are 6x1.0m

Actually 6 mm threaded nuts are loosened and tightened with a 10 mm socket or wrench, but that does not make them a 10 mm nut.

There are two theories of thought on exhaust nuts; soft (brass nuts) so the nut stripes and not the stud and hard (grade 8 steel nuts) so the nut will not strip, of course it can tear up a standard grade stud. I have always found the stainless steel studs and nuts work best. They don't corrode or rust so the problem does not exist.

[fastplastic]

i know why studs are used and i know they are the correct way to go but on my scooter motors (and only scooter motors) i use socket head cap screws (allen head bolts ) and had great success.....