Stainless steel bolts - bad for aluminum?

So, I stripped and broke more than zero bolts in the process of taking the head off my KZ750.

I definitely pulled ALL the exhaust studs and replaced them with stainless steel bolts that I cut off. I lubed them with engine oil, having heard of the galvanizing problem that SS has with aluminum, but I wonder if I should re-replace them soon?

Second, and more scary, the two head bolts that go under the cam chain.. I may have replaced these with SS as well, but put a bit of Locktite Tite'n on the threads.

My question is: how quickly do things galvanize? How doomed am I if I used SS for the head bolts? Any tips? It seems like all I'd have to do is take the valve cover off and pull the cams to get at the head bolts. I may not even have to replace the head cover gasket...

Never had a problem with SS bolts in ally.
All my bikes are dripping in them,
My daily rider (for the last 10 years - I only have bikes,Not cars) is used in all weathers and nothing has cold seized or corroded.
I use a bit of copaslip on the exhaust studs and oil or loctite where appropriate elsewhere.
I wouldn't use them in the motor though due to tensile strength.
Standard cosmetic SS bolts for blinging up outer cases etc are A2 grade and the high tensile version A4 grade is still not as strong as the hi tense steel bolts in the motor.

Am satisfied using Permatex from AutoZone, inexpensive, and requires very little product on the threads.

Especially enjoy using it on case bolts.

Good Fortune!

staniel wrote:

So, I stripped and broke more than zero bolts in the process of taking the head off my KZ750.

I definitely pulled ALL the exhaust studs and replaced them with stainless steel bolts that I cut off. I lubed them with engine oil, having heard of the galvanizing problem that SS has with aluminum, but I wonder if I should re-replace them soon?

Second, and more scary, the two head bolts that go under the cam chain.. I may have replaced these with SS as well, but put a bit of Locktite Tite'n on the threads.

My question is: how quickly do things galvanize? How doomed am I if I used SS for the head bolts? Any tips? It seems like all I'd have to do is take the valve cover off and pull the cams to get at the head bolts. I may not even have to replace the head cover gasket...

I have not heard of stainless galling aluminum. Stainless will gall similar formulas of stainless, I have seen that on a lot of guns it's a well known problem. Normally, barrels, receivers and slides are usually made out of dissimilar formulas of stainless to minimize the galling.

As stated above, stainless usually has lower tensile strength than carbon steel.

www.boltdepot.com

Alright. The vibe I'm getting here is that it's not that big a deal, especially if I put stuff on them (like motor oil!) and I can probably wait until my next maintenance episode to consider replacement.

Thanks, y'all!

Here's an interesting read on the subject.

www.estainlesssteel.com/gallingofstainless.html

And this is helpful as well www.boltdepot.com/fastener-information/m...olt-grade-chart.aspx

Thread Locking Compounds

Loctite #222MS PURPLE, low strength thread locker
For screws under ¼”.

Loctite #242 BLUE, Medium strength thread locker
For ¼” to ¾” bolts.

Loctite # 262 RED, High strength thread locker permanent
For up to ¾” bolts (can be loosened by 300 F heat).

Loctite #271 RED, High strength thread locker for sealing plugs, nuts and bolts (can be loosened by 300 F heat).

Loctite # 272 RED, High strength, high temperature(450 F) thread locker.

Loctite #565 Pipe Joint Compound.

Loctite #567 High Temperature Pipe Joint Compound

Loctite #6749 Primer

Loctite #515 Flange & Gasket Sealers

Permatex # 24310 Low strength thread locker, PURPLE, fasteners under ¼” diameter.

Permatex # 22210 Medium/high strength thread locker, BLUE, ¼” to ¾” fasteners, surface insensitive (can be used on oily fasteners).

Permatex # 24210 Medium strength thread locker, BLUE, ¼” to ¾” fasteners.

Permatex # 27710 High strength thread locker, RED, 3/8” to 1 inch fasteners, may require heat for removal.

Permatex # 26210 Permanent strength thread locker. RED, 3/8” to 1 inch fasteners, will require heat for removal.

Next time your around any outboard and marine engines, see how many Exposed bolts you can find that are Not stainless.
These get exposed to the Fresh and salt water, you have to have fasteners that won't rust up. Those outboards are similar materials to bike motors, similar technology too. First the Two Strokes ruled, and now its being dominated by 4 Stores, at least in bigger displacement.
They also have a sacrificial anode to corrode first, before the Money components. Won't see a problem on a bike, except where the higher grade tensile strength is needed.

It's true that stainless stands up on account of the automatic chromium plating magic it does.

It's true that there'll be plenty of water spraying up on these header studs, but I don't imagine most people use SS studs. Other (treated) kinds of steel can hold up to rust, too and run much lower risk of galvanization, if I understand the internet correctly...

On the older Kz's(900's and Z1's) I believe a M6x1.0 stud was used for the exhaust clamps(8 Each).

The later "J" engined bikes went to M8x1.25 studs for the exhaust clamps.

To make your bike unique, look at getting a set of ARP SS studs with the 12 point nuts: www.summitracing.com/parts/ARP-400-8001

Check your parts breakdowns for correct length before ordering and use the silver anti-seize when installing them.

An update, after several rebuilds, because I found this thread on google when searching about valve cover gaskets.

The stainless studs are heroically good. They still come out with just my fingers.

The stainless head bolts may have ruined my block. Because they don't stretch at all, like the OEM head bolts (which, I was correct, neck out and snap before reaching spec torque), they just pulled the back end of my block up, making a crack which then dumped moderate amounts of oil out the back.

Anyway, now I'm a few top end jobs done on the same engine, and although I know I'll never get a head bolt to torque (18 ft-lbs is close enough to 22, especially when I know I turned it enough degrees to reach 22 with a good bolt), I will never use a hard bolt again, either.

And the studs I would use SS again in a heartbeat.