Aluminum fuel rail - anodize necessary?

[JonKBmw]

Hello all -

I recently upgraded from a -6AN fuel rail to a -10AN fuel rail. I am making the -10AN from an extrusion I bought since no one makes a kit for this vehicle.

I plan on only running 93 octane pump fuel regularly, with up to C16 fuel (leaded) when I dyno/track the car.

I know with methanol/alcohol anything aluminum should be anodized, but what about conventional fuel or race fuel?

If it's not necessary I will not do it. I powder coat the exterior of the rail so I end up blasting that anodize off. It's the inside I am concerned about - the -6AN rail I had was clear anodized inside. It's relatively expensive to get one part done and I don't have others to do. It will also take a bit of time in my project.

Any help? I do not plan on running the car on E85, alcohol, methanol, etc., only unleaded usually and occasionally leaded fuel up to C16.

Thanks!

 

[swall]

Which alloy is the rail made from?

 

[patdaly]

For what it is worth, my fuel rails I made in 2000 for my car are not anodized and show only normal dulling on the outside. I run only pump gas and the occasional leaded 108 octane.

It is not a normal road car though, I do not know how well it would handle road salts, etc.

My rail is made from 6061T6.

 

[JonKBmw]

The alloy is 6063 aircraft grade aluminum. I am not worried about how the external side will weather, as I am powder coating it, but more concerned if the leaded fuel will corrode the inside at all.

 

[patprimmer]

Leaded and unleaded fuels seem OK with aluminium and zinc parts in carburettors and fuel pumps.

Regards

eng-tips, by professional engineers for professional engineers
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[WGJ]

It's methanol that attacks aluminium.
See:

http://en.wikipedia.org/wiki/Methanol#Automotive_fuel

So if you can guarantee that your fuels will never have methanol in them, there's no obvious need to anodize to protect the interior of the rail.


Bill

 

[patprimmer]

Ethanol also attacks aluminium, but it is somewhat less aggressive than methanol due to the larger molecule.

Regards

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Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.