82transam

iTrader: (18)

Ok, I'm getting to the point where parts are going back on my 83 GS restoration project (12a), and I have a few questions about the fuel system. I took everything out of the car in order to repair rust and undercoat, so nothing is currently on it. Can anyone explain what the hell all that stuff back by the gas tank is for? Seems like all of it is on the return side of the system. Do they have something to do with pressure reduction or something? I plan on putting a Mallory comp 70 pump on there along with the appropriate filter and regulator setup. Can I remove any of that other stuff? Also, what size is the rubber hose? I want to replace all of that while I'm at it. TIA

82transam

iTrader: (18)

no one can help eh?

jutny

one of them is a rollover valve... i know that much

but i was asking myself the same question when i was on my back under the car just staring at them... right before i got my eyes full of rust.

vipernicus42

iTrader: (4)

Hey.. I can help, I'm running exactly the same pump!

Mine's an 84 so it might be a little different, but there are two different valves. One goes between the pump and the front of the car to stop fuel from being pumped if the car gets in an accident and flips. The other valve is for similar reasons and I believe is in the return system. My vent system just seems to vent to nowhere.

If your car is in danger of being safetied any time soon, then no you can't remove the valves. They'll fail you for not having them there.

Remember to mount your mallory as vertically as you can manage. I have mine mounted so that the "out" spout is level with that first check valve and is mounted over the metal lines. This isn't a *bad* place (I need to move mine down a bit more because the rollbar hits it) but if I had it up on a hoist I'd have found a better way to mount it.

The pump makes no noise compared to Holleys, Carters and other brands. Very good, very quiet pump that can't be heard over idle.

As for the hoses, you're lookin at 3/8 for the send line and 1/4 for the return, if memory serves me.

Don't forget that with the mallory you need a fuel pressure regulator. Mount the mallory with rubber washers and drill through the bins from the inside, it's easier (harder to tell where you come out though... be careful not to puncture the metal lines!!).

I drilled the first hole from the underside, then took the mallory, put it in the bin matching the first hole with the bracket, then drilled the other three from the inside. That's the easiest way to do it.

Check your Heynes manual, but look in chapter 13, the revised section. That should give you all the routing info you need.

Hope that helped. Any other questions PM me or e-mail vipernicus42@hotmail.com

Jon

Edit: Oh, and btw dude... dont' get impatient on the forum. A half hour is barely any time to wait for a response!! Some of us can only log in once a day. If you need info immediately, it's a hit-or-miss proposition, so don't get pissed if "nobody can help you" in the half-hour you're online!

82transam

iTrader: (18)

I appreciate the info guys. That should answer most of my questions for now. but a half hour? Look at the original post date, 8-1-04, I've waited over a week for a response. I meant to bump it up earlier, but I forgot. Anyway, thanks again!

cdrad51

I thought both the main and return lines were 3/8ths. That's how I have mine setup anyways.

rhinor61

The supply and return hoses are 5/16" on 12a engines. 3/8 supply on GSL-SE cars.

1- supply, roll over valve between pump and tank.
2- return
3- vent to charcoal tank under the hood, has a ventilation valve near tank.

Confusous says:
"Sometimes free advise takes its time..... Books cost money. What do you have more of?"


John

cdrad51

That's right, 5/16" is what I meant. That's what I have for fuel hoses in my car.

deimox

How do you figure out what size hose you need when they are measured in –AN, I read -6 AN is what most people use, but I don't understand the measurement system and can't find the needed information on it with searching.

MarkPerez

The term AN is for fittings, and could include braided stainless steel hoses.

rhinor61

Found this information for you:

The AN (Army-Navy) standard was established many years ago by the US military to set a common measurement for hose and fittings. It designates the outside diameter (O.D.) of the ridged metal tube that is compatible with each size of fitting. Still today, this AN dash standard is the benchmark measurement for military, industrial and the performance hose applications. These dash sizes are
expressed as the numerator of the fraction, with the denominator always
being 16. For example, a -04 port is 4/16 or 1/4-inch.


Metric..............AN-......US Hose ID
Size Hose ID...............Inches
_________________________________
1.59 mm ...........1 .........1/16"
2.38 mm ...........1.5 ......3/32"
3.18 mm ...........2 .........1/8"
3.97 mm ...........2.5 ......5/32"
4.76 mm ...........3 .........3/16"
6.35 mm ...........4 .........1/4"
7.94 mm ...........5 .........5/16"
9.5 mm ...........6 .........3/8"
12.7 mm ...........8 .........1/2"
15.9 mm ..........10 ........5/8"
19 mm .............12 ........3/4"
25.4 mm ..........16 ........1"


J.

82transam

iTrader: (18)

Hmm, interesting stuff, I always wondered what AN meant. I have another question, what type of pressure regulator do I need? Where did you guys get your stuff? I see summit racing sells the pump for $145, seems like a good price, is it? TIA