You got that chunk of metal to 80-90C with nothing more than a heat gun and a cardboard box? That's impressive.

How long did that take?

 

About 60-70min!
I was surprised that my $40 heat gun didn't die in the process...
I setup a deflector plate in the middle at the base, so it pushed the hot air up and into the casing

 

With the way the weather has been in auckland last week or so ambient temp had him halfway there haha. Was like 34c the other day outside couldnt imagine how hot it would get inside a tin shed.

 

That helps. Still a big deltaT for a heavy chunk of metal.

For a minute I was imagining doing that in my 0C unheated garage.

 

Before I drop the fuel tank to get to inspecting, any of you guys experience and find an issue to fix on "extreme" fuel slosh starve?

I say extreme because I have to run nearly a full tank right now. Like to the brim so it doesnt cut out on left hand corner exit. I can confirm it fuel pressure drop via motec logs showing relays for direct high voltage is on but pressure is dipping. Motec compensates with IDC as much as it can but eventually runs out.

My setup is,

• Walbro 450 w/ stock wiring high voltage at idle and then a relay running batt voltage basically as soon as things start moving. Its high voltage entire autox run.
• Radium hanger, radium feel line/filter, radium rail and regulator, stock feed as return, and standard radium venturi

This started a couple years ago with needing more and more fuel. I use to get away with like 1/8th tank, then 1/4, then 1/2 all on the walbro 255 pump and stock hanger. I put in the 450 on stock hanger and it required nearly full tank.

Then I did all the radium bits but no change in the fuel level required.

So I can only assume theres something wrong in-tank or maybe in the siphon tube.

This car has been on E85 99.5% of its last 12years. So if something is going to be eaten up by ethanol, its probably happened here.

 

do you still have the evap? wonder its venting/tank pressure related. back in NJ I had a job to vent someones gas cap right at the starting line lol

 

IIRC, @kikiturbo was working on something

 

Nah, all that junks been gone a while. Id have to go back and check but Im pretty sure that vent line is now just open? Dont remember TBH, did it like a decade ago

He was running a separate pump for power the crossover.

 

yeah when I hear fluid transfers and venturis i just feel theres an ideal pressure differential required to let nature do what its supposed to do. I remember reading some gumming issue with overly vented e85 thats why I put a check valve on mine. still works. I remember putting in 10 gallons post race in my last few 2 days events

if i ever get this issue I would just pump from the drain to the return line. I bought the parts for the experiment but have not figured out how to measure the fluid level inside the bowl after adding the gate at the balance tube whatchumacallit

 

I was just casually thinking about it, I dont know what the flow rate needed is for crossover but the pressure is pretty much nothing. Just the head loss from the line. So a low pressure pump could be added inline with the venturi to just increase the pressure head.

Or maybe just pull the venturi and run an small external pump rated for carb use (low pressure) that just constantly pumps to the left. I just dont know how to protect it from if it over pumps and either dries the right or fills the left side.

Im definitely going to drop the tank to inspect but I will have to do something robust so its not a future concern.

 

maybe you can read the fuel sender resistances (levels on each side) and use that to trigger the pump. I say that as someone with an Electronics Eng'g degree but didnt really learn anything practical/useful

standard carb pumps are designed to fill the bowls within the carbs itself and keep going. i think they have pressure relief at the pump itself

I learned something about 'gravity fed fuel pumps' not so long ago. it got me into trouble. these pumps have very little suction to lift fuel to the top of the tank.

 

First things first, I should just pull the siphon line and run it to a jar and see if that actually sucking fuel

 

Pull the passenger side hanger out, make sure the filter on the pick up tube isn't clogged, and make sure the crossover flows freely.

Theres no reason you should need a full to the brim tank of fuel.

 

Cool, I'll check that.

For sure, even running upside-down I shouldnt need to be that full.

 

run the pump into a measuring cylinder and time how long it takes to hit a certain volume work out your flow rate. also check the syphon is working from left to right. Something definitely wrong there. Could also be the way you have it plumbed up. i plumb the return to the surge tank and then overflow from the surge back to the main tank. with the main tank constantly feeding surge also