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tfrasca's 142 Turbo Project

1/4 line is a restriction to a flow of 400hp of fuel, for sure. Will you get a decent lot of fuel through it? Sure, but the pump will be working a lot harder to do so, drawing more current, and heating the fuel more as it goes.

FWIW you're better off with 1/4 feed and 5/16 return than the other way around in terms of regulator linearity and worse off in terms of outright fuel flow available to the engine.

5/16 line will flow enough fuel to make some decent power without excess restriction. On my truck I went to 3/8 feed, and used the factory 5/16 carby suction feed line for the return, ditching the factory 1/4 return line. But I have lofty goals for that thing :-)

Outright flow depends on when the fluid breaks out of laminar flow into turbulent flow, and what that turbulent flow limit is. Adding pressure doesn't help much past that point.

Not sure what your goals are, but you don't seem to have ample valves, and if thus unless you throw money at it, it'll never be super high in horsepower, so your lines are probably fine as is.

In my recently 16v swapped 240 as mentioned above I'm planning to make around 350crank hp/300whp or so and have no plans to replace the 1/4 return line or 5/16 feed line (just cut it and inserted the pump/filter setup from a 940 in between, will upgrade the pump if required later).
 
Good info, thanks. For some reason, I want this car to produce a 300whp dyno sheet. I don't need 300 everyday, but I want it to be capable of that. I think this could be done on my unported 405 head and iPD Turbo cam, but at some point I think it'd be fun to do some porting and bigger valves. I gave up on the 16v because the thought of redoing everything I (and Noah) had done with the intake manifold seemed stupid.

Anyway, I appreciate the reference to laminar vs. turbulent flow and how that impacts fuel delivery. I was always thinking about it in terms of the smallest bottleneck in the system being the overall limit for capacity. But I get that a 10 foot line is going to introduce additional flow restriction. Cool stuff.

I'll update this when I decide on a fuel system.

1/4 line is a restriction to a flow of 400hp of fuel, for sure. Will you get a decent lot of fuel through it? Sure, but the pump will be working a lot harder to do so, drawing more current, and heating the fuel more as it goes.

FWIW you're better off with 1/4 feed and 5/16 return than the other way around in terms of regulator linearity and worse off in terms of outright fuel flow available to the engine.

5/16 line will flow enough fuel to make some decent power without excess restriction. On my truck I went to 3/8 feed, and used the factory 5/16 carby suction feed line for the return, ditching the factory 1/4 return line. But I have lofty goals for that thing :-)

Outright flow depends on when the fluid breaks out of laminar flow into turbulent flow, and what that turbulent flow limit is. Adding pressure doesn't help much past that point.

Not sure what your goals are, but you don't seem to have ample valves, and if thus unless you throw money at it, it'll never be super high in horsepower, so your lines are probably fine as is.

In my recently 16v swapped 240 as mentioned above I'm planning to make around 350crank hp/300whp or so and have no plans to replace the 1/4 return line or 5/16 feed line (just cut it and inserted the pump/filter setup from a 940 in between, will upgrade the pump if required later).
 
Laminar vs turbulent impacts all fluid flow. You have laminar meaning in layers, outer moving slowly or stuck to the walls, and inner rushing through the middle with a sheer of sorts in between. When that gets too much, it breaks into turbulence and flow can actually fall.

I used to live in a back yard with storm water culvert passing through, a few times when it rained hard enough the water would be streaming down the straight at about 1 foot deep moving pretty quickly, and then it would find the start of the corner and do a one foot hydraulic jump into turbulent flow at half the speed, twice the depth, same volume throughput. You can see a small hydraulic jump in your sink with your tap running, smooth from impact out a certain distance, then pops up deeper.

Not sure on where that limit would lie for 1/4 with fuel inside, but 1/4 isn't generally recommended for higher power applications.
 
So after all that talk about not having fuel lines, etc. in my trunk, I'm putting the 034 Motorsports surge tank in my trunk. It'll sit up on the hump above the axle, so the floor of the trunk will still be clear, which was my main concern.

I got a Holley/Facet carb pump that I'll mount in the same tray as my old pump, near the passenger butt cheek. The surge tank with the Bosch 044 inside will go in the trunk, and I'll use -6 bulkhead fittings to pass through the floor and tie into the fuel lines. I'm going to change the 1/4" pump>rail line to 5/16" while I'm at it.

Question about mounting a surge tank. Can I soft mount the thing to keep noise transfer down, or is that frowned upon because of the possibility of it ripping off in a crash? The pump is supposedly much quieter than an externally mounted 044, but I'll take all the NVH reduction I can get.
 

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Soft mount doesn't have to be non-captive.

Question: does that "surge tank" perform correctly on its side?

Some people call surge tanks "swirl pots" which is fitting as it gives the fuel somewhere to settle before being consumed. I feel like that unit would struggle even the right way up?
 
Soft mount doesn't have to be non-captive.

Question: does that "surge tank" perform correctly on its side?

Some people call surge tanks "swirl pots" which is fitting as it gives the fuel somewhere to settle before being consumed. I feel like that unit would struggle even the right way up?

Yes, it's designed to be used horizontally, although I think a front-to-back orientation would be better. Have a look at this cross section rendering, and look where the pickup is. Very close to the bottom of the cylinder. It's small, only a liter capacity (a full liter, not a liter minus the pump itself.), but since the return gets plumbed back in to the surge tank, I think it'll stay pretty full for a street car.

034_IAC_FUEL.JPG


How would you soft mount it in a way that's still captive? The mounts I have are miniature version of redblock motor mounts, and could possibly shear in half.
 
A metal clamp around it that is hard mounted, but a rubber isolator between the band and the tank should keep the NVH down. Think something like the rubber covered harness clamps Volvo used, that kinda concept.
 
The BMW I stripped recently was full of mounts that were like a grommet with a steel tube in the middle. The steel tube was bolted down hard, and the grommet held the sheet steel item between it's outer layers. I CBF going to the garage to photograph one for you, but you could probably do something similar with any thickish rubber grommet just by enlarging the holes in the legs. Here's something similar form an old Holden wiper motor:

WM1000.jpg


https://www.ebay.com.au/itm/Holden-...rommet-Kit-EK-EJ-EH-HD-HR-LH-LX-/271444472066

It's also similar to the way the stock EFI pumps are mounted in a 740/940 (at least).

With the tube installed, you can't get them off without massive force. With the tube removed, you can easily squish them through the required hole.

You could use both this and the band with rubber isolator in between for double isolation if you really wanted to kill the physically transmitted noise.
 
Good call man!

Tyler...hit up the yards, find a late 9-series, grab the driveshaft center support bearing mounting plate. It's isolated using the same stuff Fred mentioned, should be a nice plate you could mount the tank solid to.
 
It's always something. I removed my intake manifold to easily access fuel rail lines, and to have it powder coated. I noticed cracks where every runner entered the plenum. The cracks were right outside the weld, on the plenum side. I always thought the plenum seemed a bit thin, and I guess that combined with a lack of any bracing made it crack. The fuel system project is slowly progressing, and now I have to address the manifold thing, as well.

This is how the manifold currently sits. I ordered a 3/16" plate that will be the new bottom of the plenum. That way Noah can weld the stacks to the top of the plate, then weld the runners to the bottom. The previous design involved some questionable fitting of the stacks to the plenum. I'm hoping the thicker plate and the addition of some bracing will prevent cracking. Also, does anyone know about post-weld annealing of aluminum?
 

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typically normalization post process is done over a pretty long amount of time, and alot of time it distorts the material. But I'm not sure with aluminum. We never run any post process after machining aluminum, but the parts never reach temps high enough to need retreated.

I really wouldnt bee worried about annealing or normalizing the material, it shouldnt work harden much.
 
Does anyone know about post-weld annealing of aluminum?

I have made weldments out of aluminum and also replacement body panels out of 3000 series. You can anneal some alloys of aluminum unscientifically with an oxyacetylene torch by first covering the area to be softened with black soot from an over-rich acetylene flame. Then heat the area with the torch using both fuels until the black soot disappears. At that point you will end up with a soft piece of alloy which may or not work for what you application.

A little research into aluminum grades and filler rod will uncover the ones that are the most weldable, and also resist post-weld cracking could pay off before moving forward.

Learning the proper post-weld heat treating for the alloy would also be a benefit. Check w/heat treaters in the area.

Part of the problem may be caused by engine vibration.

Good luck!
 
Thanks for the input, guys. The problem is definitely caused by vibration. I read a bit about annealing, and saw that acetylene method you mentioned. Seems easy to do the wrong thing and end up with a noodly manifold.

I'll ask some of the engineers at work what they think about heat treating. I always forget that they build aluminum bikes here sometimes...
 
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