GT4 fuel lines sizes in question

Sorry, I can only partially help.

Highly recommend you buy SRI's fuel hose kit for your model from Ricambi (sponsor here) and that will solve all your problems; sourcing and length-wise.

You will get a few more bumps with the same advice I am reasonably sure.

 

Very good suggestion as Ricambis kits have superior line materials...

I think in the 308 Section sticky thread there's a list of alll the sizes you need from the small carb return line to the RH fuel tank, up to the cross connect pipe couplings and the fuel filler neck...

Have fun!!!!

 

I once did all of my GT4 fuel lines, brake vacuum line, and coolant hoses for $200 (if my memory serves). I am sure the SRI kit is much more. But, I figure if I keep on top of it, it would not be a problem using inferior hoses from Napa.
Oh, yes, sizes are all over the map because there are so many different little ones. I suggest you take them all out, measure the lengths of what you need, take some samples to Napa and buy what you need.

 

I understand a VW dealership may be the best place to find the metric sizes, from other threads.....

 

I just buy standard sizes at Napa. Fuel injection hoses, fuel hoses, coolant hoses, gates hoses, etc.. The car does not seem to mind that these are not metric denominations

 

OP is in the UK....

I agree though I just ended up buying the remainder of the spool at the Parts Store I was using, left with a armful of Goodyear tubing!!

 

Be mindful that mandated high ethanol content in gasoline has just raised hell with old-spec nitrile fuel lines in older cars in the US. Even if you don't have high percentage E-fuel yet, its coming in the EU too, so select your new hose accordingly.

 

That's what the special Ricambi kits are designed for.

 

I also recommend getting the hoses from Ricambi. I actually sourced my own (most from West Marine), but what a pain. I spent WAY too much time working on getting the hoses for my Mondial. I saved a few bucks, but it was not worth the effort.

When you replace the hoses, make sure to have some "good" screw-clamps available to replace rusty ones that you remove. The good ones to look for are ones that don't pinch the hoses. I bought some good ones at West Marine, but you may want to search here on FerrariChat to see what others have used.

(By the way, West Marine is a "boating supply" chain here in the U.S. They carry some higher grade hoses and clamps than most of the auto parts stores around where I live...)

 

Marine ratings are alcohol tolerant as it's a water emulsion additive LONG before they had the bright idea to use it as a fuel strecther in autos.

Mercury Racing outboards moved away from rubber fuel lines about 20 years ago.

 

I agree. All standard are still better then the original quality anyway, and they lasted for how long... Save money and use it for gas instead.
/Pero

 

I sent Dave all the info on my hose lengths from my measurements. If you do not decide to use his which I would really encourage as that is where i got mine. i could send you my data if you e-mail me and dont mind a few days wait...

Rob

 

I was able to find braided oem type fuel lines at a local desiel truck shop. I used oem tank crossover fuel line from Trutlands (130.00 us dollars).

 

By any chance did they (truck shop) have 19mm ID braided hose?

 

Posting in this old thread as it has the right title.

Most posts I recall seeing suggest 5/16 for most fuel lines and 1/4 for the return line from the last carb to the right hand side tank nipple.

This hose:
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On my car (75 gt4, Us spec) the 1/4 (6.35 mm) between carb and tank felt sloppy and so I measured the o/d of the brass carb outlet and the tank inlet nipple with some simple calipers. Both were 5mm.

Today I fitted 5mm i/d braided hose bought from Pelican Parts - I wasn't looking for braided but thats what they had. The line fitted snugly and felt very 'right'.

Ofcourse, the line looks puny to the 1/4 but I suppose that the amount of fuel it needs to carry is substantially less than the fuel lines to the carbs. Perhaps it even provides a little back pressure so that the 4th carb gets the same pressure as the first in line?

Just wanted to mention it here as I cant recall seeing elsewhere that this return line/hose has an i/d of 5mm.

Happy to be told I've got it wrong.

Comparison 5 mm to 6.35mm (1/4)
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The correct IDs needed are 7.5mm and 5.5mm for the hose from the last carb back to the passenger side fuel tank. Readily available in the metric world.

These are the lengths (in mm) for all pieces from the pump to the carbs, between the carbs and back to the right tank. For a GTB, but I assume GT4 is the same.

Ø7,5:

1550
200
200
80
160
370

Ø5,5:

700

Best Regards
Martin

 

I used choline from stoddard Porsche braided looks the same just a little smaller od

 

While Cohline is OEM-manufacturer and supplies good quality, with today's fuel I would only use DIN 73379-E3 hose.
This is FPM/ECO-hose, much more resistant than the old NBR (cloth braided) or NBR/CR-hose (smooth rubber)
The Cohline no. for these FPM/ECO hose is 2240.
I have Wurth-hoses on my car. Supplied by Cohline with this specification.

Best Regards
Martin

 

Thanks Martin, 5.5 would make sense too, especially getting over the flair on the Weber outlet (although the 5.0 went on easily enough.
I agree with the comments on the braided hose. Will seek out some good 5.5mm hose. Thanks for commenting.

 

I believe mine were e10 or e15

 

This E3 in the number has nothing to do with ethanol. It's simply a DIN- number. Like ISO or SAE numbers.
Those FPM/ECO-hoses are even flexi-fuel or E85 resistant.

Best Regards
Martin

 

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