Fuel swirl pot
Discussion
Hi Simon
Don't want to be negative but!
Is there an internal baffle? If not then with your design being square the fuel entering will not swirl and so no deaeration will take place. Having the outlet opposite the inlet is not good, as any air bubbles in the fuel will be directed straight towards the outlet. Your EFI pump in conjunction with your regulator will compress the air. This air will then be released through your injectors causing a poor spray pattern.
Sorry for sounding so negative.
Regards Dave
Don't want to be negative but!
Is there an internal baffle? If not then with your design being square the fuel entering will not swirl and so no deaeration will take place. Having the outlet opposite the inlet is not good, as any air bubbles in the fuel will be directed straight towards the outlet. Your EFI pump in conjunction with your regulator will compress the air. This air will then be released through your injectors causing a poor spray pattern.
Sorry for sounding so negative.
Regards Dave
Ive had an intercooler made by Docking that i was going to adapt up for my project - but i couldn't bring myself to cut up such a work of art and decided to sell it on.
Must admit its an odd shape. I guess that it goes the other way around with the single fitting at the bottom of the tank to feed the injectors. Depends if its a swirl pot or a surge tank, My guess is that it's the latter.
Edited to add: Rememeber to put a dab of copperslip on fittings, otherwise ally on ally can 'grab' and chew the thread up.
>> Edited by eliot on Friday 25th November 09:01
Must admit its an odd shape. I guess that it goes the other way around with the single fitting at the bottom of the tank to feed the injectors. Depends if its a swirl pot or a surge tank, My guess is that it's the latter.
Edited to add: Rememeber to put a dab of copperslip on fittings, otherwise ally on ally can 'grab' and chew the thread up.
>> Edited by eliot on Friday 25th November 09:01
thanks for advice guys i will not be offended so speak up , the tank is going to be used to collect fuel from the low pressure ultima tank pumps ( -6)and feed a high pressure pump(-8) for injectors then after the fuel has gone through injectors it will be returned to tank ,once the tank is full fuel will return to ultima tanks hope this makes sense all i need it for is a head of fuel to supply high pressure pump . shape is down to space on bulkhead ,need to keep it high as possible with pump as low as possible . Simon
Hi Simon
You say the returning fuel from the regulator will be returned to your new tank!
In my case I am returning it directly to the fuel tanks. The reason is that under idle and steady cruising speeds most of the fuel is being returned and not used. This returning fuel will collect heat from the engine bay and be detrimental to performance.
You might consider connecting yours this way. I'm sure the low pressure pumps will have no problem keeping the new tank full.
It's just a thought.
Cheers Dave
You say the returning fuel from the regulator will be returned to your new tank!
In my case I am returning it directly to the fuel tanks. The reason is that under idle and steady cruising speeds most of the fuel is being returned and not used. This returning fuel will collect heat from the engine bay and be detrimental to performance.
You might consider connecting yours this way. I'm sure the low pressure pumps will have no problem keeping the new tank full.
It's just a thought.
Cheers Dave
Am also scheming FI fuel system. My plan is to return to swirl pot - heat build up at low demand could be problem but I will return to upper of two swirl pot inlets with feed from LP pump to lower and a return to main tank out the top (I have a round swirl pot, unfortunately just push fittings though so not so pretty). That way I hope there will be sufficient circulation of fuel through main fuel tank to keep cool. On twin tank issue, I've been running a single pump with carb with low link between tanks - for FI plan is to draw and return on one side (left) only, with a low link to the other side to just allow it to top up by gravity.
If you do much track work it might not be a bad idea to draw from the nearside (UK) tank and return to the offside, because the balance system might struggle to drain back against the sideways gforce of going round a track clockwise. (or if like me you live in milton keynes with all those roundabouts!)
Pulling fuel from opposite side you return to risks overfilling return side, if like me you are just using -6 balance line. Have thought about effect of cornering loads causing more fuel to end up in nearside tank (certainly beter to draw from this side). Unless I get into several minutes on skid pan I hope should be OK but will watch out for overfilling via balance line due to g-force (still have independent fuel gauges, so can monitor nearside tank). No problems with single pump & carb arrangement using same balance line so far on track. In worst case can install manual valve in balance line to effectively go to single tank for track (or if I ever have to negotiate my way through MK )
As regards the fuel return I have purchased a 3 port electric valve for the purpose. These items are typically used on Jags, and are safe with petrol!!! I found it on ebay for the bargin price of £38 inc postage (brand new). All I need to do is put it in what is now the balance pipe fuel line and the feed from the surge tank return. The soleniod 3 port valve will then be powered by just one pump so that it can 'route' the return fuel to the tank that it came from.
I looked at those valves but I was concerned about fuel flow. The flow rate of those valves is quite low. You don't want any back pressure in the return line. I'm making my own valve. I'll post a pic when it's finished, it will be solenoid controlled.
>> Edited by CanAm Dave on Saturday 26th November 11:19
>> Edited by CanAm Dave on Saturday 26th November 11:19
How about Pollack valves? I have used them on GT40s in the past.
They are used in the bio-fuel cars and are for petrol. Also, they are not solenoid, they are motor driven so no heat problem. They make the return flow to the correct supply tank so easy.
I have some in stock.
>> Edited by canam-phil on Saturday 26th November 18:17
They are used in the bio-fuel cars and are for petrol. Also, they are not solenoid, they are motor driven so no heat problem. They make the return flow to the correct supply tank so easy.
I have some in stock.
>> Edited by canam-phil on Saturday 26th November 18:17
Further to my previous post, and it will depend on your exact setup. The high pressure return line from the regulator will enter the top of the "surge tank", what feeds the surge tank is one of the standard low pressure pumps (as Simon describes). The return from the surge tank back to the appropriate tank is therefore also low pressure and really provides a bleed (helpful in allowing the surge tank to fill without pushing air into the fuel rail. So what I am hinting at is that the flow back to the appropriate tank does not require a significant flow. In fact a minimal flow will allow any air to bleed and as we know the low pressure pumps are fine feeding a carb with no return so I think all would be just fine.
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