what fastener to use for header to sidepipe square flange

Whaler · #1 (**permalink**) 10-12-2002, 08:37 PM

Can I use SS here?

I was wondering what everyone has used and did you use lockwashers with flatwashers too??

I don't want rust later on

Tim

Jeff Frigo · #2 (**permalink**) 10-12-2002, 09:37 PM

Mine are stainless with no lockwashers. Have never had a problem.

A Snake · #3 (**permalink**) 10-12-2002, 10:27 PM

Stainless will work fine, like Jeff said. If you're worried about it coming loose, use metallic self locking nuts. You can even make them yourself using a small sharp chisel. Just make a triangular pattern of three marks at the thread edge. Done right, the chisel marks will slightly collapse the first thread, making it hard to turn. They are also easy to get at a good hardware store. The poly lock inserted plastic locking type will melt.

Al

Whaler · #4 (**permalink**) 10-13-2002, 10:46 AM

Thx for the replies guys. Nice to know I can use SS here. My pipes and headers are coated as well, so I don't want to really mar them TOO much using the/a lockwasher if I can get away with it.
I think a locking/crush nut of some sort is the way to fly as well..

Tim

Rick Parker · #5 (**permalink**) 10-13-2002, 01:10 PM

Tim:
Your local aircraft maintainence facility (large or small) will have several sources for very nice compact half height mechanical locking nuts. They use several different designs for various applications.

..............Rick

Rick Parker · #6 (**permalink**) 10-13-2002, 01:14 PM

Tim:
Your local aircraft maintainence facility (large or small) will have several sources for very nice compact half height mechanical locking nuts. They use several different designs for various applications. 1/4 inch "Jet" nuts are one recommendation.
.............Rick

oops!

snake farmer · #7 (**permalink**) 10-13-2002, 02:36 PM

Whaler. Go to www.stage8.com for the fastners that are tits! I have my engine done in several areas with stage 8 stainless. Every where else ARP. I think @ one time I had figured $800 in external stainless specialty hardware. But for headers at the block and collectors alike, they won't come loose. They have kits or sets available or will put a kit together for the same price. FE stuff is considered oddball compared to sbs etc. Check them out, they are great people to work with. I ordered over a $100 worth of hardware the wrong size and they sent me the right stuff w/o charge and told me to send back the wrong stuff and it wasn't even their error. Don't see that much anymore.

Jack21 · #8 (**permalink**) 10-13-2002, 05:10 PM

Header bolts are ARP header bolts. They are not stainless, but don't seem to be rusting. Uses a skinny 3/8 wrench to install and tighten. Used a little anti-sieze on the bolt threads.

Header to sidepipe are stainless nut/bolt with non-stainless starlock washers. No corrosion or vibration induced loosening.

Turk · #9 (**permalink**) 10-13-2002, 06:01 PM

Some clerifications on the anti seize.
When I was assembling my headers, I swear someone told me to use a little anti seize, and for a long time I had problems keeping the bolts from creeping back.
Others since, have told me "NO"!

What do the pros say and do??

TURK

kountzecobra · #10 (**permalink**) 10-13-2002, 06:36 PM

Turk, any exhaust fasteners should be coated with anti-seize. Due to the constant heat/cool cycles threaded fasteners, be they stainless or steel, will be much easier to disassemble. Especially stainless steel is very bad about galling and pulling threads out. The fastener loosening is usually due to gasket compression. The very best thread lubricant I have found is made by ARP. The ARP thread sealant is real good stuff also. Frozen, galled bolts really suck!

Whaler · #11 (**permalink**) 10-16-2002, 03:21 PM

Thanks to all for the replies.......that site with all the locking fasteners is sure a nice idea.

Anti-sieze is awesome especially where aluminum is involved.
Heat cycles are another matter too. I have seen header bolts broken by such( and a little too much tightening too)

My flanges will be 3/8"SS x 1" bolts with a store bought locking nut. Will the nut lose much of its locking ability if taken on and off a couple times? I plan on putting on the pipes for break-in then take them off for the paint shop. If so, I will just use normal nuts for now and save the lockers for the final install.

Tim

Rick Parker · #12 (**permalink**) 10-16-2002, 03:40 PM

Tim:
If you are using a mechanical lock nut, the type that has a small deformation of the thread you should be ok. If it can be run onto the threads by hand (without a socket or wrench) replace it. This would hold true for any locking fastener application as well.

Rick

Mr.Fixit · #13 (**permalink**) 10-16-2002, 03:54 PM

Sidepipe to header bolts, I have tried different combos and this is what I use everytime nowadays: 5/16" bolts, 1.5" long, grade 8, with flat washers. No antiseize, no splitlock washers, regular non-locking nuts. Zip them on with a small impact wrench and a 3' extension. If you ever remove them, throw them away and use new ones. They get brittle and oxidize heavily on the surface from all the heat. If a customer insisted on locking fasteners, I would use prevailing torque locknuts, the ones that look like they were smashed partway so the hole is more of an oval. Don't put a strong shearing load on them either, such as when the sidepipe is droopy and you are temped to put a jack under it and force it into position, this snaps them good.