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Mon Jul 10, 2023 10:12 am

Hello all,
The full restoration of my '79 bus is finally nearing an end. I ordered a fuel tank (the correct "fuel injected" version) from Cip1. The tank seems to be fine, but the "spigot fittings" they sent are 5mm.

I called and they said "yeah, just buy a barb adapter and run a 5mm hose to it and upsize it to 7mm"

I'm not a huge fan of this (and think it's kind of BS overall) and while 5mm is probably big enough to transport fuel, seems janky.

They also suggested buying part# 298-221-113A which is 8mm, and could adapt better to the 7mm hose.

I'm interested on the thoughts here on the best route forward.

Thanks everyone!

Mon Jul 10, 2023 10:27 am

Too late to return it I suppose?, that's going to stress your fuel pump just like a partly clogged filter does, another reason to avoid CIP :? .

What was so horribly wrong with your OG tank?

Mon Jul 10, 2023 10:29 am

The "nipples" on the bottom of the tank were essentially non existant. Had rusted away to little nubs. The hose could still attach, but it was getting janky, and I just wanted to replace it while I was in there.

Mon Jul 10, 2023 10:33 am

return the cip1 tank, and buy a used og tank?

Mon Jul 10, 2023 10:36 am

dodger tom wrote: return the cip1 tank, and buy a used og tank?

I likely can't return it, since it's been sitting since January when I ordered it :x

I guess I eat $300 and NEVER order from those idiots again.

I could look to have my tank repaired I guess. Sourcing parts for this restoration has been absolutely brutal. Soooo many garbage parts, incorrect parts, NLA parts, etc.

The fact that the VW community has to put up with all of these horrific parts suppliers is really sad. So much absolute garbage.

Mon Jul 10, 2023 10:57 am

looks like ken at the bus co might have 1-3 @ $100 each.

then there’s avery’s air cooled, way out salvage, busted bus, and the samba classifieds.

just saying you can probably find one in decent shape, maybe just needing a cleaning.

Mon Jul 10, 2023 11:02 am

Thanks, I will hunt for a used one. I apreciate the source suggestions!

Mon Jul 10, 2023 11:08 am

you’re welcome.

i assume your bus is fuel injected. if so, make sure the tank is set up for f.i.

Mon Jul 10, 2023 11:19 am

A good radiator shop could probably weld in larger fittings onto your new tank.

Wed Jul 12, 2023 7:40 am

I'm running one of those aftermarket tanks - I guess they are the Brazilian tank as I found when looking more into the fitment.

It's been a couple of years since I installed it - I will run this tank until I have the time to clean out my original. I pulled the original to clean out the coating that was installed over a decade ago, that had sluffed off and clogged up the outlet...long story but I've posted it somewhere here before.

Anyway, the barb fits fine and works - like you, I was a little taken aback by the install at first but it's actually a good fit in the tank area. And the barb is just like a Beetle and installs the same, get a sock filter too.

The return line I had to tweak just a bit to get the right angle. and the vent barbs also had to be tweaked just so. Heat them slightly and bend very easily until they sit properly.

One other downside to this tank is that it has no baffle in the bottom, so I found that when low on fuel, taking a hard right will starve the pump since all the fuel slings to one side.

OEM tank is better like everyone is saying so go that route if you can, but you can make this tank work if you need to.

Wed Jul 12, 2023 3:42 pm

Just for the record, having an 8mm outlet barb on a fuel injected tank will make "0" difference to how the system runs with L-jet and the stock fuel pump.

I have used bus and other stock L-jet pumps on a wide range of D, L and digifant systems with standard 8mm fuel tank nipples and it makes 0 difference. The systems only use roughly 10% of the fuel circulating in the loop at any given second and the rest is returned to the tank.

If you move to a tank with 8mm outlet you do not even need to adapt it to your filter. Just buy the square D-jet filter. It's identical to the bus filter in every way inside and out. It just has an 8mm nipple on each end.

The most probable reason the bus used a 10mm inlet and 8mm outlet is that they were worried that the L-jet pump may not suck as well as the earlier D-jet pump. That turned out not to be a worry.

A tank without a baffle? That can be an issue but only below about 1/4 tank. Ray

Wed Jul 12, 2023 5:58 pm

I bought the FI aftermarket tank from CIP1 back in 2020 as my original gas tank leaked after having it boiled out at a local rad shop. I don't remember the inlet and outlets being too small though. They were bent and angled towards the tank but I don't remember any hose fitment isues.

Mine doesn't have a baffle inside either and that is a pain from time to time on long trips. On my last road trip, I had less than a gallon left in the tank when I pulled off the hwy on a long offramp to the right. The Bus died as I rolled up to the stop sign and I had to wait 10 secs for the gas to even out and the fuel to fill the line to the pump again.

My FI fuel pump cycles on and off so having smaller connections should be okay if you are using the square fuel filter as it will act as a reservoir but maybe ask CIP1 to see if there was a special order tank that you received instead of the reg one.

Wed Jul 12, 2023 7:38 pm

raygreenwood wrote: Just for the record, having an 8mm outlet barb on a fuel injected tank will make "0" difference to how the system runs with L-jet and the stock fuel pump.

I have used bus and other stock L-jet pumps on a wide range of D, L and digifant systems with standard 8mm fuel tank nipples and it makes 0 difference. The systems only use roughly 10% of the fuel circulating in the loop at any given second and the rest is returned to the tank.

If you move to a tank with 8mm outlet you do not even need to adapt it to your filter. Just buy the square D-jet filter. It's identical to the bus filter in every way inside and out. It just has an 8mm nipple on each end.

The most probable reason the bus used a 10mm inlet and 8mm outlet is that they were worried that the L-jet pump may not suck as well as the earlier D-jet pump. That turned out not to be a worry.

A tank without a baffle? That can be an issue but only below about 1/4 tank. Ray

The pre 1986 Vanagons which used similar hose sizes and the same filter as a Bay gave problems. When I first bought my 83 1/2 model I had to carry a half dozen or more filters with me so that I could change them out as the sediment worked free on a long trip or the pump would start to howl. Duplicating the 1986 and later set as close as I could took care of the problem.

Thu Jul 13, 2023 7:54 am

Wildthings wrote: raygreenwood wrote: Just for the record, having an 8mm outlet barb on a fuel injected tank will make "0" difference to how the system runs with L-jet and the stock fuel pump.

I have used bus and other stock L-jet pumps on a wide range of D, L and digifant systems with standard 8mm fuel tank nipples and it makes 0 difference. The systems only use roughly 10% of the fuel circulating in the loop at any given second and the rest is returned to the tank.

If you move to a tank with 8mm outlet you do not even need to adapt it to your filter. Just buy the square D-jet filter. It's identical to the bus filter in every way inside and out. It just has an 8mm nipple on each end.

The most probable reason the bus used a 10mm inlet and 8mm outlet is that they were worried that the L-jet pump may not suck as well as the earlier D-jet pump. That turned out not to be a worry.

A tank without a baffle? That can be an issue but only below about 1/4 tank. Ray

The pre 1986 Vanagons which used similar hose sizes and the same filter as a Bay gave problems. When I first bought my 83 1/2 model I had to carry a half dozen or more filters with me so that I could change them out as the sediment worked free on a long trip or the pump would start to howl. Duplicating the 1986 and later set as close as I could took care of the problem.

What was the difference in the later ones compared to early?

Usually if it's a sediment problem it's either the way the pick up tube is bent or angled inside or a missing or incorrectly designed baffle.....or the sock filter (if it has one) is too fine or situated poorly so that return fuel does not constantly flush away sediment. Ray

Thu Jul 13, 2023 1:23 pm

Later tanks /Vanagons had a larger nipple/outlet. And lost the pre-filter before the pump. Many available Vanagon new tanks seem to be the same model, probably only made by one factory, with the later larger outlet . Any way, larger hose to the pump inlet , then large round metal filter after the pump. It works well on our ‘84 Vanagon.

Fri Jul 14, 2023 11:24 am

jlrftype7 wrote: Later tanks /Vanagons had a larger nipple/outlet. And lost the pre-filter before the pump. Many available Vanagon new tanks seem to be the same model, probably only made by one factory, with the later larger outlet . Any way, larger hose to the pump inlet , then large round metal filter after the pump. It works well on our ‘84 Vanagon.

Ah!

Based on what you and Wildthings note...the larger outlet nipple really isn't the improvement. There is nothing unique about the bus L-jet system or its pump. It...or many virtually identical pumps were used in so many EFI systems on other cars. Most had 8mm outlets or more had them than 10mm.

Plus, going from tank at 10mm into a filter that exits at 8mm and into a pump with an 8mm simply moves any restriction the nipple made...4" upstream.

Decades ago when the square filters were still original with high surface area square pleated filter and a packed lint pre-filter inside....its "possible" that a larger inlet "may" have helped some but its been since the mid to late 80's that all of these stock square filters for both D and L-jet have a simple round pleated filter inside of them.

The removal of the sock filter in the tank was a big help I would bet.

Before L-jet and the type 4 engined bus came on the scene, those of us with type 3 and 4 cars were already having "some" issues with the 8mm nipple COMBINED with the in tank sock filter/strainer.

Not enough surface area and a poor design (more on that in a minute). Yes, possibly the bus with L-jet and the larger 10mm nipple helped with that somewhat. The bus with its larger tube has larger surface area to the strainer. Harder to choke off.

The biggest benefit of the later vanagon system that you mentioned ....was also mentioned by Wildthings. Putting a HUGE volume upstream pressure side filter ...and especially the filter in question....is really the key.

This is the same high pressure filter used on digifant and digifant 2 in mk1 and mk2 cars.

The surface area inside is probably 10-15X the surface area in teh stock cube filters. That and the rolled/crimped steel construction means that it can be used on the pressure side with virtually no restriction.

https://www.amazon.com/Purolator-F60146-Fuel-Filter/dp/B000C6MM8A

I commonly recommend it for any low pressure fuel injection system.

The sock filter design. Not beating on VW/Bosch...I mean who knew any better back then....but our in-tank sock filters were a terrible design compared to later years of efi in other cars and especially modern designs.

This is a timely conversation....about filtration mesh. I work in the industrial screen printing industry. The companies around the world (there are a handful of really large ones) that make the expensive high precision mesh we use in our screens are also the exact same companies that weave, cast or laser ablate virtually all of the fuel/liquid/water filtration mesh used across all industries.

In fact, 90%+ of what they make is actually for filtration. These mesh range from polyester, polyaurylate, polypropylene, nylon, polyethylene, stainless steel, black stainless steel etc.

In April I spent most of day of visiting one of the larger better manufacturers whose US offices and stocking warehouse is in Chicago. We were looking over the range of what they make in their sample room and got into a conversation about filtration mesh. Then fuel filtration mesh.

Enlightening!
Some of these details I posted a year ago when I broke down a fuel strainer and its mesh.

The gist is that the range of actual dedicated filtration mesh types there are are huge. The weaves are precise, specific, exotic and nothing like the basic plain weave mesh that our sock filters use.

Filtration meshes can have larger holes, flow higher liquid volume and actually filter finer particles than plain and twill weave meshes.

The gent I was speaking to pointed out that a lot of the in-tank filters yof find in modern cars are special weave, thread diameter....and very high surface area....and many of them are very flat...not tubular like ours. I always figured this was simply for space in the area they need to be under the modern fuel pump sump in the tank.

The samples he showed and we looked at under the microscope....showed that the filtration mesh (a variant of a double Dutch weave) was designed to flow the highest LATERALLY to the holes in the weave. So the filter sock is flat, wide and long and occupies a space maybe 0.25" deep.

Fuel is pulled laterally across the thread filaments dumping particles that lay in the valleys.

But because its very wide and flat....its designed so that the sloshing in the tank from movement....literally washes the particles away because they cannot actually "lodge" in the mesh.

The modern, well designed inlet strainer filter is designed to be self cleaning. Ray