The one way valve needs some pressure to open it, so its a simple solution to gravity feeding into worn valves in carburettors. But with all these precautions, the end game is no longer filling the sump with fuel but flooding the engine to a halt when the vibration induced wear gets so bad the float chamber overflows while the engine is running. It floods to a halt at idle or driving gently at 30 mph which has happened to me twice in 100000 miles or so. This is just a pain as you arent going anywhere until that fuel evaporates.. with a centremount thats about 40 mins with a cold engine, less for duals or 4 barrel arrangements.
That’s a Carter/CB pump and metal filter with an additional plastic filter as an 8mm to 6mm adapter. It’s a shame aircooled.net no longer trade but there is a lot of useful information on the website.
Heh-heh, I hadn't seen that but it's more or less what I do except finding somewhere to locate that somewhat inflexible string of components would not be easy so my adapter filter is near the tank outlet a the filter/pump crimped hose combo is elsewhere.
Mine is more or less the same except I have a brass adapter instead of a plastic filter near the fuel tank, the pump and metal filter are mounted on the inside of the LH chassis rail.
I think mine are on the sloping bit above the gearbox, it's been a long time since I was under there.
Brilliant advice all round . Excuse the school boy drawing but what do you think of this set up .Instead of using a step-down I thought I would use a 8mm and 6mm tail unions in the one way valve and on the regulator as well .Any recommendations/advice changes appreciated .Kinda think the one way valve out of the engine area makes sense to lessenthe chance of fuel leaks .
Rotary pumps don’t suck very well so if that non-return valve doesn’t open easily the pump might not prime, it would be better to have the valve after the pump. If you’re not using a rotary pump, it’ll probably work as you have it. Better to have a filter from the tank, a fuel cutoff valve, the pump then a regulator (if you need one), and into the engine bay to a ‘T’ to the carbs.
Good to know on the pump so order I will try is Fuel tank, , step up hose adapter , metal fuel filter, rotary pump (wired into a cut off relay ) ,one way valve , regulator , T-piece and carbs .
Both the regulator and the one way valve are potential flow restrictors. A solenoid valve is better than a one way valve because of that. And using a Carter style pump with a pressure relief fuel regulator ( sends excess pressure to pump inlet internally) gives you no restriction. But it does not look as cool as a Malpassi Filter King.. If your fuel pump is low pressure and you add resistance to flow downstream, there is a risk of the pressure becoming too low on hills.
Hi , Thanks for the advice . After reading up on numerous threads and articles on this whole subject my brain is somewhat fried and I have kinda come to the conclusion it is a bit of enjoyable trial and error and hopefully with some tweaking it will eventually run okay . A work in progress shall we say ! Carbs are off and going to pop into my local jewellers and see if they will weigh the floats for me . Much appreciated advice from 77 Westy and Betty the Bay I am looking into in best place underneath where to fit the pump ? Thinking the rear chassis rails adjacent to the heat exchanger bellows . I replaced some large plastic undertrays from a modern T6 last week and the old ones have sections of the aluminum heatshield that's stops anything being cooked next to the DPF and exhaust system may be able to utilise some of this around my new pump .
