TimW Posted November 23, 2011 Author Share Posted November 23, 2011 908 wrote:Steady on mate ;D ;D ;DWould it be advisable to filter the fuel after the tank but before the high pressure pump to prevent anything damaging the pump. I plan to do that and another filter at the end of the return line just to try and take out as much air as possible. I am on Pi though and it creates a lot of frothy petrol I have been told :) I am also putting a fuel cooler in the return line too. Hugh :BLogic says yes but the research i have done says otherwise. I think it's something to do with not restricting the flow before the pump but i may be wrong.Anyone shed any light on this??? Link to comment Share on other sites More sharing options...
Clive Posted November 23, 2011 Share Posted November 23, 2011 Use a filter before the LP pump is the usual way. There are some nice big filters designed to go between tank and HP pumps, the cossie sierra's had them, but they are LARGE and have 1/2" in/out connections to match the pump.I am being "different" and using a Golf IV in-tank pump. Well, I plan to WHEN I get my finger out :B Link to comment Share on other sites More sharing options...
CHRIS211083 Posted November 23, 2011 Share Posted November 23, 2011 Just wondering but why are you guy's going back to the fuel tank? If you have a swirl pot the return goes back to there and is then resent back through the high pressure pump. The low pressure pump should have a pressure cut off so will only fill when needed so why return to the fuel tank???Chris. Link to comment Share on other sites More sharing options...
CHRIS211083 Posted November 23, 2011 Share Posted November 23, 2011 Sorry ignore me it's for removing air in the system.........my bad but here is a cool graph for converting carb cars to efi.Chris. Link to comment Share on other sites More sharing options...
TimW Posted November 23, 2011 Author Share Posted November 23, 2011 2402 wrote:Sorry ignore me it's for removing air in the system.........my bad but here is a cool graph for converting carb cars to efi. Chris.and also to help reduce the temperature of the fuel. I have heard that the fuel can get very hot being pushed around the system so returning it to the main fuel tank should help to dissipate this heat. Link to comment Share on other sites More sharing options...
TimW Posted November 23, 2011 Author Share Posted November 23, 2011 cliftyhanger wrote:Use a filter before the LP pump is the usual way. There are some nice big filters designed to go between tank and HP pumps, the cossie sierra's had them, but they are LARGE and have 1/2" in/out connections to match the pump.I am being "different" and using a Golf IV in-tank pump. Well, I plan to WHEN I get my finger out :BI don't think i will need any sort of filter. I have a plastic filter from the main tank outlet then a micro filter before the low pressure pump. The swirl/surge tank is very clean so in theory the high pressure pump shouldn't need a filter. Saying that i have bought a fuel injection filter with 8mm OD push on ends. I could do with confirmation on were in the system to put this filter. Link to comment Share on other sites More sharing options...
Clive Posted November 23, 2011 Share Posted November 23, 2011 between the HP pump and the fuel rail.Sounds like you have adequate filtration :) Link to comment Share on other sites More sharing options...
Clive Posted November 23, 2011 Share Posted November 23, 2011 Just thinking out loud here.....What is the fuel delivery of the HP pump? if greater than the Lp it may drain the swirl pot? most of the fuel is returned to the tank/swirl pot whatever, only a small proportion being used. I think anyway :-/If no swirl pot/lp pump then it will suck fuel from the tank, but with a swirl pot it my suck air?Just thinking, happy if I have got the wrong end of the stick ;DAs an aside, the kitcar chappies do return the fuel to the swirl pot. Link to comment Share on other sites More sharing options...
TimW Posted November 23, 2011 Author Share Posted November 23, 2011 cliftyhanger wrote:Just thinking out loud here.....What is the fuel delivery of the HP pump? if greater than the Lp it may drain the swirl pot? most of the fuel is returned to the tank/swirl pot whatever, only a small proportion being used. I think anyway :-/If no swirl pot/lp pump then it will suck fuel from the tank, but with a swirl pot it my suck air?Just thinking, happy if I have got the wrong end of the stick ;DAs an aside, the kitcar chappies do return the fuel to the swirl pot.Hey CliveI would have the same concerns if the return from the fuel rail was going straight to the main tank while still using a swirl/surge tank. I am sending the returned fuel back to the swirl/surge tank and then onto the main tank from the swirl. At idle the injection returns most (prob 99%) of the fuel to the swirl/surge anyway.This setup will work fine. I just need to make sure i fill the swirl with fuel to prime the system before turning on the HP pump. Link to comment Share on other sites More sharing options...
Clive Posted November 23, 2011 Share Posted November 23, 2011 OK, I am confused ;DYep, think you have the "best" setup then. Well, apart from my in-tank idea anyway (and that wasn't my idea, I pinched that from somebody else, just can't remember who. Seems to be the way now, dodgy memory. Now, must go to work....) Link to comment Share on other sites More sharing options...
esxefi Posted November 23, 2011 Share Posted November 23, 2011 hi all,my efi is as per chris' diagram and as mentioned the fuel can get very hot in hot weather,to the point that one year when sitting in traffic the fuel actually boiled and created an air lock killing the engine dead.only happened once though and the ambient air temp was around 35c.(funny never had a problem during CLM2010 considering how hot it was there)i use a facet competition pump as a lifter with a small pre filter to a swirl pot then 1/2" feed with large micron filter to hp pump,to and from engine to swirl pot return,restricted air/excess fuel bleed back to main tank.never had a problem with fuel delivery,unless i drove at full throttle for 10mins or so it wouldn't exceed the lifter pump capacity and that is using the original 1/4" feed from tank.this system has it's advantages in elimination of surge problems in the tank,the lifter pump gets a bit vocal on hard cornering when the fuel level is low and is a last chance warning when about to run out of fuel altogether meaning i have about 2 pints left in the swirl pot. :) Link to comment Share on other sites More sharing options...
CHRIS211083 Posted November 23, 2011 Share Posted November 23, 2011 In my current setup the feed goes from the fuel tank to a large fuel filter (600ml) and then the line runs the length of the car to the engine bay where the huco pump is. The huco is good because its a sucker as well as blower and the large fuel filter acts as a mini swirl pot. The huco will then fill the swirl pot which will feed the Hp fuel pump. This way fuel surge wont happen. Chris. Link to comment Share on other sites More sharing options...
TimW Posted November 23, 2011 Author Share Posted November 23, 2011 ChrisI would have thought the hurco wouldn't keep up with the HP pump if you don't have the fuel return into the swirl aswell Link to comment Share on other sites More sharing options...
CHRIS211083 Posted November 23, 2011 Share Posted November 23, 2011 The hp feed does return via the regulator valve to the swirl pot. See the graph I posted? Link to comment Share on other sites More sharing options...
TimW Posted November 23, 2011 Author Share Posted November 23, 2011 2402 wrote:The hp feed does return via the regulator valve to the swirl pot. See the graph I posted?Granted but you didn't say you were doing it this way!! Link to comment Share on other sites More sharing options...
CHRIS211083 Posted November 23, 2011 Share Posted November 23, 2011 That's what the graph's for, it reminds me what bits I need etc. I got it off a lotus esprit efi site hence the two fuel tanks. Ha Ha. It's much easier to show people what you mean with a diagram. Looking forward to seeing how you go on with this efi setup. I take it you have a dyno of power/torque from before the conversion?Chris. Link to comment Share on other sites More sharing options...
Hugh Posted November 23, 2011 Share Posted November 23, 2011 I have bought a Jaguar XJS V12 fuel filter after the LP pump to go before the HP pump and a smaller one before the swirl pot on the return line I copied this setup. ;D ;D Link to comment Share on other sites More sharing options...
TimW Posted November 23, 2011 Author Share Posted November 23, 2011 2402 wrote:That's what the graph's for, it reminds me what bits I need etc. I got it off a lotus esprit efi site hence the two fuel tanks. Ha Ha. It's much easier to show people what you mean with a diagram. Looking forward to seeing how you go on with this efi setup. I take it you have a dyno of power/torque from before the conversion?Chris.The diagram is very helpful and the same as in the megasquirt manual. I have had it on the dyno 131bhp with 152ftlbs of torque, I'm hoping for about +20 bhp but don't think it will improve the torque any Link to comment Share on other sites More sharing options...
Gt6s Posted November 23, 2011 Share Posted November 23, 2011 When I did the PI Gt6 thing donkeys years ago fuel surge was a problem for a while untill I vented the PI's CAV filter efectively making it a swirl pot. however my EFI ran without a swirll pot the pump located right next to the fuel tank outlet, this arangement gave no surge ill effects at all. In fact I used to have the habit of doing donuts in the back yard at work. Untill one day my boss walked out of the thick cloud of tyre smoke and said "Laurence please stop doing that" Well that's not what he said but that was what he meant. Link to comment Share on other sites More sharing options...
Nick Moore Posted November 23, 2011 Share Posted November 23, 2011 Guys, how are modern car fuel systems set up? Do they have a surge pot arrangement inside the fuel tank? The pump as well? An HP pump immersed in fuel wouldn't need a booster pump? I'm going to EFI my GT6 as well, but ideally want to keep the spare wheel well for a spare wheel! Link to comment Share on other sites More sharing options...
CHRIS211083 Posted November 23, 2011 Share Posted November 23, 2011 Yes nick you hit the nail on the head hp pump in tank and regulator can be by the tank too. As for the spare wheel, in my setup the lot will be under the bonnet. I currently don't have a fifth alloy wheel but will be getting one so need the space.Chris. Link to comment Share on other sites More sharing options...
Nick Jones Posted November 23, 2011 Share Posted November 23, 2011 Most modern cars (from later 90s say) seem to have in-tank fuel pumps which incorporate swirl pot, filter screen and sometimes fuel gauge sender. These are mostly intended for flattish tanks so more suited to GT6/Stag/estate cars than Herald/Vitesse/Spit/saloon - but then the latter are fairly easy to arrange with an external pump. Not sure what donors to suggest. Freelander might be ok - just looks a bit tall?I think this would be a really nice solution but would obviously involve significant tank mods.Nick Link to comment Share on other sites More sharing options...
Clive Posted November 23, 2011 Share Posted November 23, 2011 The intank originator I think (I have been trying to remember) Mike Bestard. IIRC he used a freelander pump in a spit tank. I scored on on ebay, but discovered it has a built in regulator. As my system is a complete setup less pump(typical) I needed an unregulated pump, so it got sold on. I took a punt on a golf intank jobbie, and from measurements it should just reach the bottom of the spitfire tank. The idea is to remove a section of the vertical flange in a position that won't interfere with the original fuel sender, and then braze a flat plate over with a suitable hole pre-cut. Sort out a sealing ring, and job's a good-un. Well, that's the idea. I have a tank that has been unused for years and been left with no lid/sender, no smell of fuel so it should be OK to braze. I think a good clean out is in order too once it is modified.May be a while until this happens, much else to do first. Link to comment Share on other sites More sharing options...
Deleted User Posted November 24, 2011 Share Posted November 24, 2011 seems you will be making these swirl pots to order?PM me a price please Tim, if your fab man can?Rob Link to comment Share on other sites More sharing options...
TimW Posted November 24, 2011 Author Share Posted November 24, 2011 guysI need the brass air bleed valve that is fixed to the side of the front Lucas throttle body. Anyone got one?????? Link to comment Share on other sites More sharing options...
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