Sorry in advance for another dumb question.

My carbs, intake manifold, and just about everything else were installed with nylock nuts. I want to reseat the carbs and I've been advised against using the nylock nuts. I went to two hardware stores known for having *everything*, and discovered 13mm nuts aren't so easy to come by. Looking online, I've noticed some nuts are actually branded Porsche! I would have assumed nuts were fairly standard things, but now I'm wondering if it makes a big difference which hardware to use and where it's purchased?

They aren't actually a "13mm" nut; that's just the wrench size. Nuts are sized by their thread size, not the size wrench you use on them-no worried, a lot of people get confused when they start wrenching. M13 nuts are rather uncommon and hard to find (as you experienced), but luckily you don't need those.

Pretty sure the intake manifold uses M8 nuts (let someone else confirm) which are definitely available in the metric bin at any hardware store.

Belmetric has everything you need.

www.belmetric.com

https://www.belmetric.com/metric-nuts-c-3.html

m8 x1.25 thread pitch normal wrench size is 13mm they do make some with 12mm wrench size for tight areas

And even in my state where there seems to be a war against the metric system, I can find yellow zinc or chromate plated M8x1.25 nuts in the specialty parts drawerss at the local Ace Hardware.

The 12mm wrench size works great for the carbs try to get those if you can just makes it easier.

Just order from McMaster-Carr. You'll get more than you need for less money. And especially M8x1.25 nuts are nice to have on hand.

Oh, and standard shipping arrives next day to most locations.

The case nuts on a T4 are not nylock, you can add a drop of loctite to the regular nut if you like, but I've never seen them come loose.

On your manifolds, the dell whistle stop gaskets, require less than normal torque so nylocks would be wise. Regular nuts on the manifold/head should be OK.

The nuts are M8 x 1.25. The smaller ones, used mostly for engine tin, with the 10mm head are M6 x 1.0, for the most part they use the thin spring "wavy" washers.

Also, a note about wavy washers, I've done a bit of testing from different suppliers. They're spring-factors are all different, but the stainless ones are always the worst. Don't buy stainless wavy washers unless you really need them.

I seriously doubt any nut from ace is Chrome plated. White Zinc, yes. Chrome? No.

Not "chrome", "chromate." The yellow stuff. Most likely yellow zince but I don't know which. They look the same to me.

100%! McMaster are very good and I use them all the time. Odd ball ones like these are not available from McMaster. Used on Weber carbs to get more purchase on these "trumpet" studs.
https://www.belmetric.com/stainless-high-type-c-3_752_1481/

Click to view attachment

GOOD LUCK!

Thank you. I'm kind of embarrassed that I didn't know nuts weren't designated by their wrench size, but it makes sense now.

Now that the case and manifold have already been done with nylock nuts, do you recommend leaving them in place or changing them?

ACN nuts- for tight areas like intake manifolds

http://vwparts.aircooled.net/ACN-10mm-Flan...acn-nuts-50.htm



-HB

The Porsche 13mm nuts use a 13mm wrench and the Subaru se a 12mm wrench. Same thread size on both.

Audi V8 exhaust manifold nuts.

Wow, that’s cool. I had no idea.

A year from now I hope I am asking smarter questions here.

Great information on nuts

What is the size of exhaust nuts that attach the SS heat exchangers ? 1.8 L

Your intake manifolds can get quite get hot, so nylocks aren't the best (although they should withstand up to 600° ). Just use standard M8 nuts with wave washers and you'll have no worries.

Torque them all to spec (I know some folks who've developed vacuum leaks because they were too lazy to torque 'em). If running insulators between the intake manifolds and the carbs, nylocks should hold up OK, but like has been said, the ones that take the 12mm wrench are easier to deal with.

911 engine outside M8 and M6 is all nylocks, except for exhaust nuts. that said I only use what was on the engine...T4 no nylocks.

Note that Japan uses 12mm wrench size for their M8 hardware but almost always the same 1.25 thread pitch (though finer pitch used in some applications) . I've converted three Japanese race cars (two Acura and a Nissan) and have boxes of the stuff. I much prefer the 12mm hardware, but it feels kinda funny using that on a Fritz-built car...

Its nice to use 12mm nuts on the exhaust. More room for the wrench.

Tacoma screw products. Stores in Kirkland, Georgetown area?, and Tacoma. MCClendons in woodinville. The Belleville/Schnor serated washers, used on CV bolts, are thin, fit the intake studs right and work well. Avoid using cut lock washers.

U pull it and big pockets are what I use most just hit the import isles

Most of the time I have found European manufacturers like odd size wrenches on their hardware and the Japanese use even sized wrenches on the same pitch. It is not just in automotive, they do the same thing in machine tools.

It's the difference between DIN fastener specs and JIS. (Deutche Industrie Normung; Japanese Industrial Standards.) Each one specifies a wrench size for the standard fastener of a given shank diameter, and for most fasteners above M6 (10mm) they disagree.

--DD

Geez Mark, you're knowledge of nuts is profound. You're like a.... nut expert.

I was a squirrel in a previous life.

Or you're just used to staring them in the face all day...

Lately I've been staring at torx bolts on 996 engines.