QRP Fuel Systems

[LS MAN]

We have been working on a complete fuel system to match our aluminum fuel tanks.
We are using Holley's new billet fuel injection pump,http://www.holley.com/12-700.asp and are really impressed with it. Plenty of pressure & flow, & extremely quiet operation, & easy to mount. Also use an Areomotive small regulator, 85 micron inlet & 10 micron Billet pressure filter. We offer the complete system with all hoses, fittings, pressure gauge, rubber isolators for the pump, etc. Includes a fitting that connects directly to the factory fuel rail, with no modification. Really like the black/endura color combination. Very clean & functional. We can get any pump you like. We can get any color fittings, any brand you like. Russell, Earl's, XRP, Aeroquip. Fragola etc.

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Individual prices for all components would be over $1,000 from any online retailer. We offer this system at an introductory price of $930

We are direct dealer for over 950 product lines, with over 1mil products, so can get you any parts you want.

Thanks,

[kabacj]

That is a nice looking setup you have there Ted.

I am in the market for a fuel system as we speak. I spoke with the Aeromotive guys and they were pushing me toward their Aeromotive 350 in tank setup. The logic being that an in tank system will not pull a vacuum and as a result have a lower tendency toward cavitation.

That does make sense, however I have no idea what volume and pressure ill need to pump fuel to a 650 hp ls3 with ITBs.

Sure I guess an Aeromotive 700 would be fine as it will have plenty of volume and pressure, but also have to pull a vacuum on the fuel to get it up out of the tank. Not ideal. The other item they mentioned is that the more you pump the fuel the more you heat it and as a result hotter fuel is more likely to cavitate/ vapor lock. Are these things we need to worry about on the track? I dont know. The street im sure would be fine with just about any performance solution.

I am building a single tank on the passenger side with a fill plate on the top so I don't have the option to pull fuel from the bottom of the tank.

Any ideas on the fuel requirements and pressure?


Also like your transaxle cooler . That is another item on my list as well. I would like to hear about that setup too.

Thanks
John

[VRaptor SpeedWorks, LLC]

While I have no experience with the fuel system Ted is advertising, I can tell you that I have ordered some other items from him that I would have normally ordered thru Jegs or Summit......and received the items extremely quickly and at a competitive cost. He's a great guy to deal with.

John......As for what Aeromotive is telling you.....I suppose the part about pulling vacuum could be true up to a point (if you have the pump mounted up high above the tanks), but if you have the external pump mounted down low behind the fuel tanks, it is not trying to "pull a vacuum" any more than an in-tank pump. And if you have a fuel injection system running 55-65psi that is vapor-locked, it probably means that your engine is on fire, and has been for quite some time. ;-) I don't know at what temperature fuel boils at when it's under 55psi of pressure, but I can guarantee you that it's much higher than your fuel rail will ever get to without a complete melt-down of your plastic intake manifold!

[The Stig]

That is a nice looking setup you have there Ted.

I am in the market for a fuel system as we speak. I spoke with the Aeromotive guys and they were pushing me toward their Aeromotive 350 in tank setup. The logic being that an in tank system will not pull a vacuum and as a result have a lower tendency toward cavitation.

That does make sense, however I have no idea what volume and pressure ill need to pump fuel to a 650 hp ls3 with ITBs.

Sure I guess an Aeromotive 700 would be fine as it will have plenty of volume and pressure, but also have to pull a vacuum on the fuel to get it up out of the tank. Not ideal. The other item they mentioned is that the more you pump the fuel the more you heat it and as a result hotter fuel is more likely to cavitate/ vapor lock. Are these things we need to worry about on the track? I dont know. The street im sure would be fine with just about any performance solution.

I am building a single tank on the passenger side with a fill plate on the top so I don't have the option to pull fuel from the bottom of the tank.

Any ideas on the fuel requirements and pressure?


Also like your transaxle cooler . That is another item on my list as well. I would like to hear about that setup too.

Thanks
John

Hi John,

A one-way check valve mounted between the pump and the engine will maintain the prime, so you don't have to worry about spinning the pump forever to get fuel flowing. I'm using the external Aeromotive 700 pump, mounted at the bottom of the driver's side tank, and I've not had any problems so far.

Sorry Ted. I don't mean to hijack your thread.

[kabacj]

Thanks for the feedback Shane.

If fuel vaporizes at 140' F thats not hot at all for an engine compartment with a high HP motor running at full tilt on a hot day on the race track. You come off the track with a hot motor and it would be easy to get the fuel in the lines up to those temps. I tend to agree with you that unless the pump is on the roof you are not pulling much vaccume. however if you just lower the vaporization point of the gas 15 degress now you are very near under hood temperatures.

Worst case with a nearly empty fuel cell i would be pulling the fuel up 17 inches. My fuel plate is on top of the tank. The pump needs to lift the gas up from the bottom of the tank out the top.

Since we very quickly get into the land of theory where little details matter a lot and will change your theoretical result. I was wondering what the rule of thumb is and what people have successfully used under those hot conditions without issue.

Teds tanks pickup the fuel from the bottom so using those outputs to a fuel pump mounted at the same level you would not see this issue. Most times the fuel is pressurized to the pump by the head of fuel in the tank. Using an external pump is just as good as an internal pump.

If I can put a pump in the tank with good volume and pressure chacteristics in theory I can enjoy the benefits of the setup Ted can use.

I know im over thinking all of this, but if I ever have a problem with the setup and vapor lock at least I can say I tried.


John

[VRaptor SpeedWorks, LLC]

John,

As with any liquid, the boiling/vaporization points increase dramatically with pressure. In my 20+ years in the automotive industry and working as a mechanic, I have never once seen or heard of any modern fuel injection system experiencing vapor lock. It just isn't going to happen. Water is really not much different. You can put water under a vacuum and make it boil at room temp. Your cooling system has a 16-18lb pressure cap and that pressure increases the boiling point of the water to well over what it normally is.......GM doens't even program the hi-speed fans to come on until the coolant has reached over 236 degrees! Last I checked, the boiling point of water is 212.......which also happens to be the reason why you never take the radiator cap off of a hot engine.....because it INSTANTLY changes the boiling point of ALL of the coolant in the cooling system and instantly turns in all to steam.....which is why it all comes gushing out of the radiator, burning you. As long as it's under the pressure of the radiator cap, it can not boil. Pull the cap, it boils instantly. Exact same thing with the fuel system, except now instead of 16 psi, we're talking about 60psi. Huge difference in pressure with a coresponding huge difference in boiling point.

[crash]

It doesn't matter if the pump is internal or external. Once it is primed, and if you use a check valve to keep it from losing prime, then the only thing that matters is at what level relative to the fuel in the tank that the pump is mounted at. This is why a siphon works as long as your outlet is lower than the fluid level. On the other hand, an in tank pump is easier to prime and the pump can run cooler because it is surrounded by fluid that cools it. This allows tighter tolerances in the pump and a smaller unit to be used. The two real negatives to in tank pumps are the wiring, which must go through a fuel sealed bulkhead, and servicing the pump, which is a MESSY job if it is in tank.

Why not put a pickup location on the outside near the bottom of the tank if you are building the tank? I probably wouldn't do it for safety reasons as if the fitting gets knocked off fuel goes everywhere, but plenty of systems do this with no issues as long as the fittings are quality and they are relatively protected. Alternatively, if you use an external pump, just mount it low in the car and it should be just fine.

[LS MAN]

Hey Guys, as with any fluid, it is easier to push fuel, than pull it, so the best place for the fuel pump is in the tank, as it is with all modern production vehicles. That being said, an external pump works just fine.
I thought of mounting down low by the tank, but I too was worried about heat transfer from the headers. I chose the location that was as far from the headers as possible, but still easy to mount & service if needed. Didn't know how the pump would self prime, but just put a few gallons in the tanks, & the pump instantly built pressure, over 90# until I adjusted the regulator. So far it looks like a good system. As with anything on these cars, there is a compromise from what the ideal solution may be, to being practical & efficient. I don't think that vacuum in the inlet line is a problem, as long as you can keep the hose relatively short. We return off of the pressure reg to the opposite tank, so that helps cool the fuel as it has to migrate back through the transfer tube.

John, I think an in tank pump would be a good solution, but drawing fuel up thorough the top fill plate is no different that what we are doing with the external hose, you are just doing it internally. As for fuel pressure & volume, that is based on several parameters, but mostly HP requirements, fuel injector size, & duty cycle (injector on time), I think most of the Vette info I read is the stock pressure is 58-60lbs, but if you increase injector size, you lower the duty cycle, so less pressure is needed, but more volume may be required. I need to study this a little more, & practice my tuning skills also. I rely on Don V. to help with this as he has done a lot more research. I hope we can all add more to subject as we go on.
Thanks for all the nice feedback & comments, much appreciated.

[mendo]

John,

As with any liquid, the boiling/vaporization points increase dramatically with pressure. In my 20+ years in the automotive industry and working as a mechanic, I have never once seen or heard of any modern fuel injection system experiencing vapor lock. It just isn't going to happen. Water is really not much different. You can put water under a vacuum and make it boil at room temp. Your cooling system has a 16-18lb pressure cap and that pressure increases the boiling point of the water to well over what it normally is.......GM doens't even program the hi-speed fans to come on until the coolant has reached over 236 degrees! Last I checked, the boiling point of water is 212.......which also happens to be the reason why you never take the radiator cap off of a hot engine.....because it INSTANTLY changes the boiling point of ALL of the coolant in the cooling system and instantly turns in all to steam.....which is why it all comes gushing out of the radiator, burning you. As long as it's under the pressure of the radiator cap, it can not boil. Pull the cap, it boils instantly. Exact same thing with the fuel system, except now instead of 16 psi, we're talking about 60psi. Huge difference in pressure with a coresponding huge difference in boiling point.

We are talking about the fuel line before the pump, that is under vacume. it will be less than atmosphere pressure because the pump is sucking.

[kabacj]

Thanks.

Shane I agree I have never heard of vapor lock on a production car. My assumption was that somebody engineered the system so it would not vapor lock. (that may or may not be true)


True with a check valve you will not have the pump run dry and that is definitely useful. Ill add one of those.

If the pump is at or below the tank on the outside its reasonable that the weight of the fuel in the line on the way down will cancel the weight of the fuel needed to be lifted out of the tank. The pump would be siphon fed unless the fuel cavitated somewhere in the circuit and that would break the lifting power of the downward leg and the system would stop siphoning. That most likely will never happen.

Crash I agree a bung on the lower section of outside of the tank is the easiest way to solve this problem, but I was looking to have my fill plate below as the only hole in the tank.



I really wanted to use the same fill plate and pump plumbing setup on the conventional tank and the racing fuel cell.

Well guys this has been very useful.

my take always.

Cavitation is not really a big problem.
Put a check valve in the system and locate the pump as low in the system as possible and everything should be fine.

Now all we need is for Ted to get me the parts.

Thanks guys.

John

[LS MAN]

Hey John, just email a list of what you need & we will get you some prices.
[email protected]
Thanks,

[Fred Brewer]

John

John,,,
I got a Fuel Safe fill plate kind of like the one you posted some time ago. I was never able to source a nut ring. Did you fine one or are you planning to use a bladder?

Thanks

[kabacj]

Yes Fred the Fuel safe fill plate does not have a nut ring for use without the blader.

I am building two tanks one with a bladder and one without both using the same fill plate.

In order to mount the fill plate without the bladder my plan is to weld and blind tap a thick 3/8 x 3/4 inch ring of aluminum on the inside of the can.

Trace the fill plate and mark the holes on the 3/8 inch sheet drill and tap them without going through. Cut out the ring then run a weld bead around the ring on both edges sealing it to the tank.

I have not welded anything yet, however this is what I have come up with.

Maybe somebody else has an easier way, but my main goal is to force any fuel perpendicularly across the fill plate gasket and not allow any fuel to weap into the middle of the gasket traveling up or out of the mounting hardware.

Ill post what I come up with.

John

[TNT Electric]

Ted,

I don't recognize that car, but it sure looks cool. I'd love to see more of it. The work looks awesome1

Brian