im in the middle of up rateing my fuel system im going -8 from the pump to the rail then from the rail back to the tank all with aeroquip fittings but the hose from the tank to the pump is larger anyone no what size hose this is please so i can order the fittings for my pump and tank

 

Hose to pump from tank is -10 (5/8")

 

-8 ? Holy fuck, how much power you intending to make ?

Even -6 will support 1000bhp.

 

Really? I was told more like 500 to 550hp - 6 is small I have used dash 8 as some of the fittings are smaller inside and it can't hurt to be a bit large but a bit small could end in real tears.

 

To OP I will look up the pipe I used, I thought it was dash 12 but I will check it.

 

Most LS guys in the US just use -6 from pump to rails.

I flow tested my as installed fuel system -8 feed with -6 return and it supported 486lph measured after the FPR and via the -6 return line at 60psi rail pressure
Flow would have been higher with better battery voltage.

I dont imagine too many cossies needing that sort of flow ability.

And the biggest restriction in the system will be the FPR anyway.

Plus, how big are the fittings on any fuel filter ? How big is the "rather tiny" outlet on the pump ?

Unless you have a multitude of bad bends, -6 will be more than adequate for 99% of Cossie engines.

 

Even an 8mm OD hardline steel line will support 500bhp ( at a push though ). That's only around 6.5mm ID

But always use a quality hose. I think some of the cheaper -6 stuff may be smaller inside than proper hose. So always check actual ID.

Defo cant hurt going too large. But it can be harder to install due to the hose size, and is obviously more expensive.
-8 is serious overkill though.

I think fuel tank outlet is 5/8 approx ? ie -10

 

I thought they use 2 dash 6 to the rail as it is a v8? I ditched all the small fittings and used a fuel lab reg with 2 dash 10 inlets on it and I'm only using one and a dash 8 and they say a dash 6 return in the fitting instructions.

 

Nobody in their right mind would use 2 lines when one is easier and works. Many people either Y block, tee, or flow through to each rail.

Engine size or configuration makes no difference to fuel flow required. If you need 100 litres of fuel to make 100bhp, then you pretty much need 100 litres of flow regardless of what is consuming the fuel.

Many regulators will come wit oversize fittings to accommodate various applications, including methanol etc which will require around double the flow of a petrol based setup.
For normal applications, thats why they offer them with -6 ports all round.

 

Sorry it has 2 inlets in the reg at dash 10 so one from each rail on a v8 not from the tank but as long as it can't hurt I'm happy with dash 8. They seem to all spec a larger delivery hose, say dash 10 or 8 and a smaller return an 8 or a 6 to allow room for fuel used. Do you know is there a calc for fuel to hp ratings? Cheers

 

I know, but unless it was well into four figures power wise on methanol, -10 at the reg is massive overkill also.

Especially if there is a single -6 return lol

very approximately, a boosted engine will want around 560cc/min of fuel per 100bhp.

 

That's over 3 litres a min at 550hp ouch lol Mines all done dash 8 flow and return I think a dash 6 return would be fine but the feed was a little to close with a safety margin so I went dash 8. As I replaced it all the cost wasn't much in it 6 to 8. Cheers

 

Missed a few posts here as ive been away all weekend. I put -8 but meant -6 which im told is good for up to 600bhp!

 

And Ive already stated -6 will easily support 1000bhp.

 

id rather take the advise of the tunner i use mate

 

You may do.

I'd sooner believe fact and those who have actually done it.

But he is of course correct in saying -6 can support 600bhp. But it will far exceed it with ease too. He's maybe just never got over 600bhp

 

yeah hes gone way over 600