Fun, Not Fun, Fuel hose Options

[NARP74]

For a 3.2 conversion that I was trying to bring out to a meetup on Sunday. Relocating my fuel pump to a better up front location, under the steering rack. Redoing some of the hose connections to make them longer. 8mm, 10mm for most of them from the tank and the supply and return lines in the car.
The Bosch fuel pump I have needs 12mm, maybe 13mm to get over the bulge.

I have;
5/16 hose which is 7.8mm, good enough for the 8mm connections.
3/8 which is 9.5mm, good enough for the 10mm connections.

I tried everything to get the 3/8 to stretch over the 12/13 mm needed to install on the feed side of the fuel pump. I tried heating in the sun on a black car, lazy way. Then I tried a heat gun. Then I tried needle nose pliers to stretch the hose opening out. Tried alcohol to slip it over. Nothing I did would get more than a 1/4 over the fuel pump inlet and then it would bunch up and not budge any further.

Then I went to the store and bought some 1/2 inch which is 12.7mm. Fits great over the Bosch fuel pump, but is too sloppy over the 10mm supply line from the tank. And I don't have a fuel hose clamp that big yet.

What's an idiot to do? I spent a day on this and am not much further along and I still need to wire it!

All of the hose is the good stuff from NAPA, Gates Barricade for fuel injection.

Help

[technicalninja]

https://www.amazon.com/Joyway-Reducer-Splic...mp;gad_source=1

That will work for the suction side of the pump. Most of the time the suction side is the largest hose.

That will also work "half assed" for a pressure line but the barbs MIGHT cut through the lines and on the pressure side it's a recipe for a bar-b-que...

I've found the Gates "Plant Master" hoses to be significantly stronger than the Barricade.

They are rated for ANYTHING at fairly high pressures (300psi ?) but they are stiff and a BITCH to work with.

I use lube to get them on barbs and you CANNOT remove them later.

They fit SO tight that clamps are optional on low pressure applications.

Only problem with the above adaptors is you are now limited by the ID of the adaptor.

[technicalninja]

My stuff (1/2") is Plant Master Extreme 325 and is rated for 325psi (22 bar).

It is the ONLY hose I've found that is impervious to my AC flushing chemicals.

Liquid B12, AC flush (both extremely aggressive), and alcohol is what I run through them.

The Barricade stuff lasts about 3 months.

If you were close, I'd give you a chunk...

Orielly's, NAPA is my usual source for this stuff. It can be a little hard to get.

Edit: Tip for removal of the PM on a plastic fuel pump fitting. Cut 3/4 through the hose until you cut through the inner braid (you can feel it) and it will come right off.
An Exacto knife and human spit works easiest.
If you just try to twist it off it might twist the plastic barb BEFORE the hose releases.

Like I said it can be a bitch to work with...

I've never had a failure with it.

[Superhawk996]

Only problem with the above adaptors is you are now limited by the ID of the adaptor.

Have yet to see an engine consuming so much fuel that an adapter in a fuel line limits fuel supply.

We are not talking about Top Fuel drag motor levels of fuel consumption even for a 3.2L here.

Use an adapter. Have a thin wall stainless tube adapter made up if you truly are concerned with fuel flow rates.

What ever you do, don’t try to use a hose clamp to squish 1/2” line down over a 3/8” fitting. Fuel leaks / fires are dangerous.

[NARP74]

@Superhawk996 I am trying to do the right thing. I have bailed on getting it done before tomorrow. I will slow down and keep looking. I have had some good suggestions from my local support group. Back to research before implementation.

[rjames]

Do you have a filter in between the tank and fuel pump? The late style filter has an 8mm in and 12mm out which then would go to the fuel pump’s 12mm in.

[technicalninja]

Only problem with the above adaptors is you are now limited by the ID of the adaptor.

Have yet to see an engine consuming so much fuel that an adapter in a fuel line limits fuel supply.

We are not talking about Top Fuel drag motor levels of fuel consumption even for a 3.2L here.

Use an adapter. Have a thin wall stainless tube adapter made up if you truly are concerned with fuel flow rates.

What ever you do, don’t try to use a hose clamp to squish 1/2” line down over a 3/8” fitting. Fuel leaks / fires are dangerous.

(IMG:style_emoticons/default/agree.gif)

Now, having a restriction in the suction line is WORSE than having that same restriction in the pressure side of things.
The old school Bosch fuel pumps often had big ass suction lines (even in the Z-cars) which made fuel mods difficult (Flaps often didn't have 1/2, 9/16 fuel hose available).

The recent crop of brass adaptors (I believe they are ALL made in China now) often have extreme restriction.
It's common now for me to run a drill bit through adaptors to "port" them out.
This was not an issue in the past!

If you use a brass adaptor LOOK through it before you just stick it on.

I'm also a FIRM believer that the fuel pump should be INSIDE the tank.
No more inlet restriction at all and if you keep the pump immersed it will live forever.

Always fill up at the 1/2 full mark and you will NEVER have a fuel pump failure is what I tell my customers...

Now this doesn't work easily with a 914.
I'd mount pump under tank with adaption between pump and tank or modification to tank bung to take it up to 1/2" as well.

The idea of a thin wall SS adaptor (like the Tangerine stuff) is EXCELLENT!

[NARP74]

@rjames I do not have a filter before the pump, only the sock in the tank. One of the local suggestions was a WIX 33274. Roughly 10mm on one side and 12mm on the other. Filter and adapter both. The hose I am trying to use is only 10 inches from the tank to the pump. I will see if I can fit the filter inline there and make it work somehow.

@technicalninja one of my first stops was the adapter page for Tangerine. He does not have a 10mm to 12mm adapter yet. Maybe we can show him the need for one.

[technicalninja]

I'd use an inline filter 10 X 12 in a heartbeat.

Sounds like the easy button and will work with the fuel lines you already have.

If they really are 12mm I once special ordered 7/16 fuel hose for exactly that reason.

The 1/2" stuff fits too loosely on a 12MM barb for pressure IMO.

Now, that Plant Master stuff might work fine on 12mm.

It's SO tight on 1/2" anyway it's hard to install.

[NARP74]

Once this is running leak free, I may go back and do it the really right way. It cracks me up to walk into a FLAPS and ask for metric hose. They bring out 3/8 that has 9.5mm stamped on it and say see, it is metric.

Another local suggestion was this;
Cohline from Bel-Metric. https://belmetric.com/hose/

Maybe I'm being Roadkill and just want to get my junk running, I'll fix it the right way later. I'll do some shopping and look for the ultimate answer. What would an F1 team do???

[Superhawk996]

Maybe I'm being Roadkill and just want to get my junk running, I'll fix it the right way later. I'll do some shopping and look for the ultimate answer. What would an F1 team do???

I’d be looking at pumps. 1/2” inlet is overkill and leading to this issue.

Like Ninja alluded to - ultimate solution is in-tank pump.

If memory serves me Tygaboy did some primo work to put a Holly in-tank pump into the LS conversion.

@tygaboy

[rjames]

OD 12mm/8mm

[JeffBowlsby]

Tangerine Racing reducer:

https://tangerineracing.com/shop/ols/produc...SSF-UEL-ADP-180

[NARP74]

That reducer is a 8 and 10. I would have needed a 10 and 12 for it to work.

[JeffBowlsby]

You listed your hose as 7.8 and 9.5 ID in the first post. This should be perfect for that.

[NARP74]

The item that messed it up is the Bosch fuel pump that has a 12mm on it.

[JeffBowlsby]

Got it.

https://www.ebay.com/itm/314258554339

[NARP74]

Well there you go! I have several solutions finally. Thanks for all the help. Now I need to figure out the best leak proof way to get it running again.

[Artfrombama]

For a 3.2 conversion that I was trying to bring out to a meetup on Sunday. Relocating my fuel pump to a better up front location, under the steering rack. Redoing some of the hose connections to make them longer. 8mm, 10mm for most of them from the tank and the supply and return lines in the car.
The Bosch fuel pump I have needs 12mm, maybe 13mm to get over the bulge.

I have;
5/16 hose which is 7.8mm, good enough for the 8mm connections.
3/8 which is 9.5mm, good enough for the 10mm connections.

I tried everything to get the 3/8 to stretch over the 12/13 mm needed to install on the feed side of the fuel pump. I tried heating in the sun on a black car, lazy way. Then I tried a heat gun. Then I tried needle nose pliers to stretch the hose opening out. Tried alcohol to slip it over. Nothing I did would get more than a 1/4 over the fuel pump inlet and then it would bunch up and not budge any further.

Then I went to the store and bought some 1/2 inch which is 12.7mm. Fits great over the Bosch fuel pump, but is too sloppy over the 10mm supply line from the tank. And I don't have a fuel hose clamp that big yet.


What's an idiot to do? I spent a day on this and am not much further along and I still need to wire it

All of the hose is the good stuff from NAPA, Gates Barricade for fuel injection.

Help

I have a long tapered “line up” punch I shove the 3/8” hose over after warming it up in boiling water. Let the hose cool on the punch. Done this many times, works and you don’t have to wait a week on UPS

[NARP74]

Funny @Artfrombama . I actually did both of those things but not together. I tried the taper punch and a big set of tapered needle nose. I tried the heat. I did not put the 2 together...