Fuel leak

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v8cougar, Jun 25, 4:59am
im having trouble getting my fuel line to stop leaking, it has a 30cm peice of 1/2inch flexi line from the fuel filter to the fuel rail, has 3 hose clamps on each end, but it still keep leaking out the ends, any help would be great, i just dont know what else to try.

skin1235, Jun 25, 5:05am
replace the hose, it is perished, no amount of clips will stop the fuel pushing through the granular structure now

suppose I should now ask, what pressure are you running!, to find you've got it loaded to 100psi and feeding some 540cu+ through 1/2inch stainless

v8cougar, Jun 25, 5:12am
its a brand new 1/2inch flexi, not perished at all, its on a rb20det with 550cc injectors, and 2x 500hp fuel pumps from the fuel cell wired up full time, im just lost on what to do, its fine for about 10 mins and then it starts to leak in a differant place each time,

v8cougar, Jun 25, 5:14am
not sure on the pressure the fuels running at, will check that tomorrow

v8cougar, Jun 25, 5:15am
, very true mate, it doesnt do it when its getting thrashed around the track, only at idle, will look into the pressure, cheers!

skin1235, Jun 25, 5:22am
lol, so the second part of my post was just a good guess huh!

v8cougar, Jun 25, 7:18am
yeah pritty much haha. my engine needs that amount of fuel to stop it from leaning out though, maybe braided fuel lines!

bae13, Jun 25, 7:23am
id check the pressure, you should upgrade your return to 1/2 inch if you find its to high and your reg cant be adjusted any lower. are you running a surge tank, if so do do you have a return from surge tank to main tank!

thunderbolt, Jun 25, 7:24am
Make sure it is EFI hose and meets SAE 30R9 specs.
More expensive than carb fuel line, but for very good reason.
Different tube and reinforcement and built to handle 180PSI working pressure.
Carb hose meets SAE 30R6 and 30R7 specs and is designed for 50 PSI working pressure.

snoopy221, Jun 25, 7:26am
aye 3 hose clips to me mean it's bog standard not high pressure fuel line.
Normally high pressure stuff has a nut fitted like hydraulic hoses.

thunderbolt, Jun 25, 7:33am
Nope, EFI hose is fine with a clamp, what is happening now is that fuel is pushing through the tube and running out the ends of the cover.

Buy some marshmallows for the inevitable fire.

snoopy221, Jun 25, 7:49am
Well he sayeth clip-you sayeth clamp.LOL
Every std hose CLIP being worm drive will load at one point. Wurth ones are a cut above.hence why sometimes people use 2 alternating the loading points.
3.well
Oh and a hose CLAMP being a non worm drive clip.mmmkay.
But e said clip-LOL

thunderbolt, Jun 25, 7:51am
Ok, to be clear, I am referring to a worm drive clamp.

v8cougar, Jun 25, 9:03am
they are good quality hose clamps im using, it must has something to do with the pressure im running to help suply the engine, going shopping tomorow for some braided steel lines with bolt/nut attachment at the ends, hopefully this solves the problem

thunderbolt, Jun 25, 9:32am
Good clamps, what spec is the hose!

richardmayes, Jun 25, 10:07am
Excuse my ignorance please as I've never built a custom EFI setup.

But isn't 2x 500hp fuel pumps a bit excessive for this application!

Surely if the mixture's a bit lean, adding extra fuel pumps is not the answer!

v8cougar, Jun 26, 4:10am
one internal 500hp fuel pump feeds a 2l surge tank, then has a external 500hp fuel pump feeds the engine, it is a little bit excessive but the engine seem to like it, the rb20det is around 450hp and runs 550cc injectors, seems to be allsorted now with the braided fuel lines and flanged bolt fittings, cheers for everyones help

skin1235, Jun 26, 4:40am
no probs kaz, sometimes it's a good thing to be invisible - then ya can't get into trouble lol

skin1235, Jun 26, 4:45am
tho must admit, if the pressure is suffice to push past 3 clips each end on a new hose isn't it just a bomb waiting to explode, whats going to happen when he gets a bit of heat under the hood and like all rubber/plastic the hoses start to give a little more
can understand the need for higher flow but at that pressure!
Whats the pressure/temp scale say about flame point of petrol!

v8cougar, Jun 26, 6:23am
looking into a new fuel pressure regualor aswel, see if i can drop the pressure a little, its only an issue at idle, when it screaming along it runs perfect and the exhaust temp guage reads exactly what it should, never ending problems when building a car up from scratch, the are the last few things left

skin1235, Jun 26, 6:31am
obviously you're enjoying it, and kudo's for the efforts so far, hope it can be sorted, and safely sorted
you only have the second pump to worry about, there is no pressure at the engine from the first, seriously have a check re pressure and flow required, flow is probably more important as long as you can maintain rail pressure
what is the rated pressure for the injectors and by how much does the current setup exceed that, wouldn't think you'd be short of flow and that engine couldn't gobble up more than a few litres per minute even at full rich full song oryou'd be trying to fit a 200ltr tank so it could last 30 laps

snoopy221, Jun 26, 8:21am
All good then and yeah and adj fuel pressure reg is a good idea as with the setup ya runnin-and the possibility ya cammed er a tad ya might be low on manifold vacuum and running 60 PSI or so in ya rails at idle with such a flow rate that .ya gotzzz-LOL
Yeah if manufacturers could use worm drive hose clamps they would.LOL
Incidentaly ANY duel fuel instalation HAS to have the full circle *bandit* EFI stye hose clamp with a bolt and nut.
Not a worm drive load in ine point sucker.
But swaged and nutted and well all good for WELL over 60 PSI.
End of the day OVAKILL in this respect is ONLY common sense.
NO-one needs a petrol spray on a hot mota.
THE OTHER INCIDENTAL NOTE HERE IS I WOULD recomend A high flow rate adj fuel regulator.
As with 2 pumps feeding as you have got
5 getz ya 10 the flow rate of the pumps at idle is HIGHER than the flow rate of the STD fuel regulator.
(which may ALSO further explain ya INITIAL probleeemo.)

snoopy221, Jun 26, 8:25am
i.e a std fuel reg uses manifold vaccc to open a releif passage.
and the damn pump setup ya gotzzz.mmkay tryin to unload dozee rails at idle might be a tad like.
ya needz ta dril zee relief hole BIGGA-LOL
(OR GET A high FLOW ADJ REG)

snoopy221, Jun 26, 8:31am
btw skin took maggie out for a trot 2day-sheesh squirtin cow filled a damn wheelie bin.
sprayed he dribble damn near 30 feet at full chat.
Ah LOL she's a RIPPA.Drag QUEEN 4 SURE-lol

v8cougar, Aug 6, 3:45am
I cannot understand half of what you wrote sorry mate, cheers for your help