AN hoses and fittings for the fuel lines

[backdated]

This stuff connects the long, underbody fuel lines to the short pipes mounted on the engine.

Apart from the the fuel filter and TBI adapters (the black aluminum parts), the components were acquired from Dunlop Hiflex. These guys were quite helpful, I just gave them my crappy pencil drawings and they assembled the correct hoses and fittings for me on the spot.

Assembled:

Fuel feed line: top right-to-left, counter clock wise

• Vinyl(?) gasket, replaced w/ Teflon
• Aluminum adapter: TBI (14x1.25mm) to AN-6
• Hydraulic hose assembly: AN-6 / ??mm teflon hose / AN-8
• Fuel filter: AN-8 / AN-8
• AN-8 to ?? thread adapter 
• Compression fitting for 10mm pipe w/ ?? thread
• 2x Compression fittings for 10mm pipe
• Compression fitting for 10mm pipe, barb fitting for 10mm hose

Fuel return line: bottom right-to-left, counter clock wise

• Vinyl(?) gasket, replaced w/ Teflon
• Aluminum adpater: TBI (12x1.25mm) to AN-6
• Hydraulic hose assembly: AN-6 / ??mm teflon hose / ?? thread
• Compression fitting for 8mm pipe w/ ?? thread
• 2x Compression fittings for 8mm pipe
• Compression fittings for 8mm pipe, barb fitting for ??mm hose

Golan fuel filter aqcuired

(backdated)

The Golan fuel filter arrived in the mail.

According to the instruction sheet, the filter can be used in a "racing", or bypass, configuration in addition to the standard one simply by reversing the order of the internal components (or turning the whole filter around). Apparently in this configuration the fuel pressure would force (part of?) the fuel to travel around the actual filter element.

I was surprised to find that the filter shipped in this reverse configuration. If I hadn't taken it apart, I might have installed it the wrong way around, thereby allowing impurities to reach the fuel injectors. Not fun.

The flow direction arrows on the filter are opposite from those in the documentation, so that could explain the weird configuration.

Also, the filter element is bent:

Gollan installation manual:

E85 Fuel Filter Choices

The stock fuel filter also uses those pesky GM flared connectors, so if I wanted to use one, I'd have to use those repair pipe kits on both sides of the filter and connect them up with some ugly compression fittings - not a very clean solution. Also, there are no guarantees that the stock filter (which would have been a Wix 33481) can withstand E85 fuel.

According to the service manual,

[a] fifteen micron fuel filter is used in the fuel feed pipe ahead of the fuel injection system and mounted directly in front of the rear axle. The filter housing is constructed of steel with threaded Fittings at both ends. The fittings are sealed with O-rings. The filter element is made of paper, and is designed to trap particles in the fuel that may damage the injection system.

This should apply to all engines (3.1L, TBI, TPI).

So, at least a 15 micron filter is required, and it should somehow connect to the AN plumbing that will be used at the TBI unit. A reasonable price and availability of replacement filters / elements would also be nice. The Wix filter is even rated at 4 micron.

---

I actually sacrificed two days from my life trying to find a suitable filter. The local supplier's knowledge and/or motivation on this matter proved practically non-existent, and the manufacturer's specs aren't always clear either.

The Fuelab 8183X series have male AN fittings and use a disposable, 6 micron, fiberglass, E85-compatible element. This would seem optimal, but a bit pricey. They go for around €140 at turbozentrum.de, and replacement elements are about €33. 

Summit Racing sells filters by Russell performance with 10 micron paper elements. Filters go for around $75 (about €130 including delivery & customs), replacement elements for about $23. Only Summit and a random magazine article claim that they're E85 compatible; Russell's own web pages or catalogs don't mention it at all.

The Magnafuel inline filters claim Ethanol compatibility, but the marketing text is ambiguous. The filters have metal elements down to 25 micron, and the 10 micron model has a paper element. The chapter where the compatibility claim is made refers to a "[choice] between 75 and 25 micron filters", and the 10 micro model only appears in the product listing. Their PDF catalog has the same text, but doesn't list the 10 micron filter at all. One could read this either way; I'd rather not reward such ambiguity.

The SX Performance 41002 is available for $91 and includes a 10 micron paper element, but the brand seems a bit obscure -- how long will replacement elements be available?

AES Performance sells an element w/ NPT fittings for $50 on eBay. Cheap, but likewise a small company.

Finally, I went for a Golan "40 - Large" filter,  $85 from Jay Racing. Express Mail International shipping was $59,40, total w/ VAT & customs will likely be around €150 ($185). It has AN-8 fittings (AN-6 was out of stock) and a washable metal element, and the company's propaganda was convincing enough. Here's one installation (scroll down to bottom), and some people having (scary) issues w/ the Golan filter. Hopefully these are just, eh, individual cases.

There's some generic talk on E85 filters here and here.

Also, there are 40 micron filters available for $19 at anfittingsdirect.com with a cleanable, reusable bronze element, suitable for pre-pump use.