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Sat Feb 01, 2014 5:27 pm

After reading several threads on here about how important it is to replace the fuel lines, I went out and bought some. Yes, it is just temporary until I figure out how to handle the problem of the mismatched sizes.

Coming out of the tank, it appears to be 5mm. Same for the fitting on the carb. (Solex 34)

Everything in between is 1/4" because that is what came with the electric pump and the filter. What are you guys doing about that mis match in size? I don't think it would be wise to stretch the German braided hose and make it work, as I believe 1/4" = 6.2 or something close to that.

So anybody running an electric pump, how are you transitioning from SAE to a metric size?

Sat Feb 01, 2014 5:48 pm

The easiest way is to use a couple extra of those disposable plastic in-line fuel filters. They have two steps on them and make a good transition from the German hose to 1/4" or from 1/4" to 5/16"...plus it adds an extra filter.

Sat Feb 01, 2014 6:27 pm

Check this site out. They have metric hose that is rated for today's fuels in stock.

https://www.belmetric.com/metric-hoses-multifuel-h...0olmklnfn6

Hope this proves useful! Much easier than having to fiddle with all the different sizes etc. 8)

Edit: In addition, they've got all the right hose clamps you'll need too! You know, the "good" ones! :D

https://www.belmetric.com/metric-clamps-c-15.html

Sat Feb 01, 2014 6:35 pm

I've considered going to the hobby store and buying a length of brass thin-wall tubing - something that will slide over the stock brass tube to increase its size to 1/4 inch. Then solder the two together at the end to hold it in place, with lead-free plumbing solder and the matching paste flux, using a large (200 watt) soldering iron (not a torch). [Obviously, the parts must be dry and fuel-free]. These will now be permanently the right size for readily available high quality alcohol resistant 1/4" fuel line.

Sat Feb 01, 2014 6:44 pm

white74westy wrote: Check this site out. They have metric hose that is rated for today's fuels in stock.

https://www.belmetric.com/metric-hoses-multifuel-h...0olmklnfn6

Hope this proves useful! Much easier than having to fiddle with all the different sizes etc. 8)

Edit: In addition, they've got all the right hose clamps you'll need too! You know, the "good" ones! :D

https://www.belmetric.com/metric-clamps-c-15.html

Good find!

Sat Feb 01, 2014 7:01 pm

telford dorr wrote: I've considered going to the hobby store and buying a length of brass thin-wall tubing - something that will slide over the stock brass tube to increase its size to 1/4 inch. Then solder the two together at the end to hold it in place, with lead-free plumbing solder and the matching paste flux, using a large (200 watt) soldering iron (not a torch). [Obviously, the parts must be dry and fuel-free]. These will now be permanently the right size for readily available high quality alcohol resistant 1/4" fuel line.

I like that idea, my fiancé works in a industrial hose supply company but they do not carry metric sizes, I never thought of this as an alternative. Although I'd have to do the fuel tank, mechanical fuel pump and carb... Maybe when it's all ripped apart I'll tackle it...

Sat Feb 01, 2014 9:34 pm

telford dorr wrote: I've considered going to the hobby store and buying a length of brass thin-wall tubing - something that will slide over the stock brass tube to increase its size to 1/4 inch. Then solder the two together at the end to hold it in place, with lead-free plumbing solder and the matching paste flux, using a large (200 watt) soldering iron (not a torch). [Obviously, the parts must be dry and fuel-free]. These will now be permanently the right size for readily available high quality alcohol resistant 1/4" fuel line.

That's what I've done. But don't be surprised, the original stock size outlets are already CLOSE TO 1/4" dia. You need to get the brass tubing larger yet.

Sat Feb 01, 2014 10:07 pm

So:

- what size did you wind up at?

- how did it work out? Any problems? Any tips?

Sat Feb 01, 2014 11:41 pm

Another thought: if the stock tubing is ~1/4", how about just soldering a 1/4" compression ferrule on near the ends of the tubes?

Sun Feb 02, 2014 5:54 pm

telford dorr wrote: So:
- what size did you wind up at?
- how did it work out? Any problems? Any tips?
Just went out to measure and consider it all again. On T-1's there are 4 different situations needing resolutions to get good fitting 1/4" hose connections. And we've got a mix of stock vs. aftermarket parts. My tank outlets are .230 and .235 dia. Both of the formed steel lines thru the front tin and around the left end of the fan shroud are .250. German Solex 34 PICT-3's are .230. Aftermarket fuel pumps vary.
For both the .230 and .250 dia.'s a piece of the .280 OD/.253 ID brass tubing seems to give the best size for 1/4" hose fit. It can be soldered to the tank outlet and the stock steel fuel line. Maybe an inch long piece of the tubing.
But it only partially solves the concern with carb and pump connections. Fit is one thing but the fittings pulling out is the other big problem. I think drilling and tapping for a hose barb of else drilling for a larger tube stub is the better solution.
JB Weld says their product is gas proof so that suggests a soldering substitute. But Google searching suggests that the newer ethanol blends now eat the JB Weld. Maybe one of the "Tank Sealants" which supposidly are ethanol proof might seal the brass sleeve. Once the sleeve is slid on then the original tube could be flaired a tad to retain it.

A compression ferrule is a possibility but the OD would need to be turned down. One of my pumps has the .230/.235 connections but with an enlarged bulb/knob on the end which makes it similar to using a ferrule. 1/4" hose fits good to the bulb but the clamp has to be on the small straight portion and the hose can't be pulled off, doesn't leak, but it can be rotated by hand. It's not good. Similar to a compression ferrule solution might be a custom flare. I tried doing a very shallow incomplete inverted double flare on 1/4" tubing but no success.

Something else to consider is what else might solve problems besides the brass tubing. Here is a modified (cutoff and drilled out) hose barb soldered to a tank outlet. That was a way of obtaining a 1/8" NPT connection. OR if you wanted a barb then just drill a barb fitting to get a good fit for soldering. Also most hose barbs are larger and sharper than desired. Chuck them in a drill and knock down the barbs with a file.

Here is an effort to deal with other fuel line issues. http://www.thesamba.com/vw/forum/viewtopic.php?t=578216&highlight=fuel+shutoff+valve

BTW, that hobby shop (and some hardware stores) size selection of precision brass tubing is fantastic. I'm always having some use for it. Makes nice throttle shaft bushings.

Sun Feb 02, 2014 7:43 pm

Gates make 3/16 Barricade fuel line. 3/16 is .1875" and 5 mm is .1968 inch. We are talking only .009" difference. I would think it would fit but I no longer have a 1971 to test that theory.

example: http://www.jpcycles.com/product/534-768?utm_source...QgodEVwAww

Sun Feb 02, 2014 7:58 pm

That's what I'm using Steve and my fuel mileage got better :) .

Sun Feb 02, 2014 8:06 pm

babysnakes wrote: white74westy wrote: Check this site out. They have metric hose that is rated for today's fuels in stock.

https://www.belmetric.com/metric-hoses-multifuel-h...0olmklnfn6

Hope this proves useful! Much easier than having to fiddle with all the different sizes etc. 8)

Edit: In addition, they've got all the right hose clamps you'll need too! You know, the "good" ones! :D

https://www.belmetric.com/metric-clamps-c-15.html

Good find!

Any body had a chance to run this hose? Sounds promising as vendor says its good for high levels of methanol and even E85 diesel etc.

Sun Feb 02, 2014 9:03 pm

Desertbusman wrote: Just went out to measure and consider it all again. On T-1's there are 4 different situations needing resolutions to get good fitting 1/4" hose connections. And we've got a mix of stock vs. aftermarket parts. My tank outlets are .230 and .235 dia. Both of the formed steel lines thru the front tin and around the left end of the fan shroud are .250. German Solex 34 PICT-3's are .230. Aftermarket fuel pumps vary.
<snip>
Interesting info.

Brings up another question: is there a standard interference fit requirement between hose and tubing (e.g., for a given ID and type of hose, say 1/4" Barricade, the tubing needs to be X% to Y% larger)? I did a google search of various manufacturers looking for 'rules of thumb' and didn't find anything...

Sun Feb 02, 2014 9:21 pm

K&S is a hobby store brass tube supplier. If you can find a distributor of their stuff, they will most likely have what you are looking for.

As for tank outlets, I've heard you can remove the stock tank outlet on carbed buses and tap the area where the sock goes. Then you can use 1/4" pipe threads, put a ball valve shutoff and a brass 1/4" nipple. That would solve the tank side and provide the shutoff for easy maintenance/fuel line replacement. It's on my list of things to do to mine

Sun Feb 02, 2014 9:26 pm

As an aside, any chance a Splitty fuel valve (with the 'reserve' feature) will fit a Bay tank outlet? Don't need the reserve feature, but the mid-position fuel shutoff would be useful. Had one on my old '59, and always liked it...

Sun Feb 02, 2014 10:29 pm

telford dorr wrote: As an aside, any chance a Splitty fuel valve (with the 'reserve' feature) will fit a Bay tank outlet? Don't need the reserve feature, but the mid-position fuel shutoff would be useful. Had one on my old '59, and always liked it...
Yes, the reserve valve screws right in to a pre 75 tank but you are on your own to fabricate a bracket for the control cable.
And Green70 I've heard you can tap the outlet as well but there's also an AN thread adaptor available (can't find the link right now) that screws onto the existing metric tank threads. I think it was posted in the ethanol thread.

Mon Feb 03, 2014 12:01 am

I'm a little curious about the Belmetric hose. It sounds great but everyone makes their hose sound wonderful and then we find out it isn't. Now it is Flennor brand hose made in Germany but has Germany had any involvement and experience with fuels like we've ended up with and the ethanol problems? Is it a hose that Germans have a need for? I don't see where Flennor mentions ethanol. But its U.S. dealer, Belmetric, says Ethanol approved and also says it withstands higher levels of Ethanol up to E85. But we have found out that about everyone claims their hose is for modern fuels including ethanol but then we find out they really don't. A manufacturers design and claim means one thing but a dealer or distributors sales pitch frequently means little.
Flennor does mention the hoses comply with the requirements of the standards SAE J30R7, ISO 4639-2 and DIN 73379. Isn't SAEJ30R7 a fairly old specification and our U.S. hose manufacturers have been making hoses to comply with 30R9 or 30R14 for quite a while now. This is one of Wildthings pet concerns and topics and I doubt he would backtrack to a 30R7 hose.
But, who knows the real deal?? I hope a lot of folks try the Flennor hose so we can see how it's holding up in a couple years.

Telford- Somewhere in Gates Barricade literature they specify what fitting the hose should fit over. It seems like they recommend not using the normal hose barbs. That's why it's a nice trick to turn down the sharp cutting edges on common hose barbs.

Mon Feb 03, 2014 2:12 am

The 3 hoses (from left) are Goodyear 30R7 rated. What you see I installed in April 2006 and when I changed them in Aug. 2013 they had no visible signs of cracking nor were they stiff. I could still easily tie them in a knot. Couldn't say the same for the braided you see it was noticeably stiff with cracking on the ends. The Goodyear hose was installed prior to my moving from California ~ 2 months prior. I believe the higher rated hose is pretty much the same with the exception that it will allow for less evapration through the hose itself overtime.

Mon Feb 03, 2014 4:16 am

quarter inch is 6.35mm.

for 40 years i've been using 6mm inside diameter fuel hose, along with millions of others in europe.

why would you want to even think about attempting to fit 5mm tubing? :idea: