samba-lee

Hi all,

Just wondered if anyone used stainless bolts to replace the stock M6x30 valve cover bolts. I have a few leaks (it might get better now I changed to 5w-40) but if I have to do the covers and seals then original bolts are very rusty so I'd prefer to replace them with stainless rather than just new OEM ones.

Of course it'll probably take another 10-15 years for new ones to go this rusty again, but hey...

Lee

Akerlie

Aluminum and Stainless steel don't mix very well, I would stick to the original bolts.

Some info on galvanic corrosion here : http://en.wikipedia.org/wiki/Galvanic_corrosion

samba-lee

Good call (and an interesting read which took me on to the USS Thresher accident). I made some stainless steel brake bleed nipples many years ago and they did seem to freeze in the callipers after only a short time - this explains a lot. Probably only sensible to use stainless when going into steel parts, and stick with steel for alloy with maybe some anti-seize grease.

I'll stick with oem bolts then for the covers.

thanks

Lee

Doink

Also, the OEM bolts are hardened (8,8) which your stainless bolts may not be. You do not want to risk rounding those beauties out, so stick with OEM, or the hardest you can find. (But do not overtighten - the rocker cases are aluminium !) OEM bolts are cheap enough I recall.

Also, by the time the OEM bolts corrode again, it will be 10 years, by which time the covers and gaskets will need replacing again anyway. Ask me how I know.

Ahh, the joys of 993 ownership.

When you remove the old bolts, take great care to ensure you use the best quality tools, (Snap on etc), and ensure the heads are clean and the tools 100% well seated before you try turning. Again, ask me how I know.

samba-lee

Ok, all sounds sensible yeah oem bolts are $1 each from Pelican. At least if they are hardened then they are a bit less likely to snap. My bolts look like they've never been out, so it's time for some tlc on each one. How did you get the rounded ones out ?

Lee

Quadcammer

they are about $.50 each at parts.com

BSL

So if someone had a bolt that started to round, hypothetically of course, what is a good way to remove it? It still has corners as I quickly stopped when I saw what was happening, er, I mean I would have stopped if this actually had happened...

I think that I may be able to get vice grips on this one, but haven't gotten back to it is on the driver's side, and I needed to replace the lifters on the pass side.

Doink

Well, hypothetically of course, what I did was hammer a 9mm 1/2" drive socket onto the rounded bolt(s) and turned them out easily enough that way. That gets just enough purcase to turn the bolts (which are loctited in. I have heard of people using chisels and heat, and I am sure there are many other ideas on here. The last resort is presumably to drill and tap, but the best advice is not to get into that situation (like I didn't). Of course some of the bolts are so inaccessible, the best option is engine out if you get to that stage.

Sorry didn't want to put anyone off, just be real careful, take your time, and go real slow. It was rushing that always does it for me.

Doink

Just thought of another good idea, if you have rounded out your allen bolts, one guy suggested hammering in an oversize "torx" star type key, I found this difficult, but it may be worth a try.

IXLR8

I have in other applications and always use an anti-seize compound. Stainless steel hardware is nice, but it can be very problematic. Just try a nylock SS nut with a SS bolt. I don't mind using them in a bolt/nut configuration where the worst case is I can snap them off if they seize, but in a casting...no thank you.

Stainless steel fasteners has its advantages in marine use, but I would stick to the original fasteners on the Porsche.

BSL

Thanks Mark, will work on it a bit when I have some time and give this a try.

Slow Guy

You might try these too if you round out the head of an allen bolt. (The Bolt-Out set on top)

I have not had to use these on valve cover bolts but they worked well on a very stubborn distributor cap philips screw.

BSL

I think that I may go pick that up.

Vorsicht

Another trick which works great is to cut the head off the bolt with a dremmel/ cut off wheel. Then, the rest of the bolt usually can be spun out by hand.

Another trick which has worked well for me is to heat up the bolt with a mini-torch (I used the kind used for cooking - butane). You have to be very careful given the plastic around the bolt.

Good luck, Peter

Edgy01

You can mix metals (on fasteners) but you should install wet with sealant, but most shadetree mechanics are not set up for that.