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In-tank pump or external?

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Old Jan 2, 2003 | 08:19 AM
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Default In-tank pump or external?

Alright, I figure the external pump, regulators and filters and AN fittings and such are going to cost around 500 or 600 bucks and then quite a bit of labor to assemble and properly locate. I can get Rockvalley to make me a tank with an internal high flow holley pump for about 650. 800 for a stainless tank. Ready to install. So, which should I do. I get the feeling that external pumps do not last very long. What are peoples opinions on this?
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Old Jan 2, 2003 | 01:18 PM
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Default Re: In-tank pump or external?

Intank Holley pump is a Walbro pump, relabeled and sold for like twice as much.

What are your goals/needs? What hp level, and is it a full on drag car that will see 1.5 or faster 60' times?

If it's a big horsepower racer...do external, no doubt. The externals are the only ones that can support 600+hp on a single pump, and sumped setup is almost necessary on a hard launching car.

If it's a street car, 300-500hp, want to keep it quiet, I'd do an intank Walbro pump. FWIW, you can get an external Walbro pump good for ~550hp, for maye $120 or so. Past that, you are talking Aeromotive etc for an external, $200++.

Hope that helps
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Old Jan 2, 2003 | 02:20 PM
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Default Re: In-tank pump or external?

Jeff, do you have a part number and source for the external walbro pump? The stock vette regulator you speak about is external to the tank? Are there two filters? Did you use the vette fuel rail? If not then does the vette regulator have a 3rd port for the return?

Brian, my short term goals are to get it running. It used to be a 1.70 60' big block car running 11's. My long term goal would be similar with supercharger plans. Because of this, I was leaning towards the external method which would allow me to just change the pump as my hp goes up.
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Old Jan 2, 2003 | 02:57 PM
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Default Re: In-tank pump or external?

I'd do a new metal tank (stock like) with a weld in sump setup, and probably an Aeromotive external. This could be done for relatively cheap probably.

Not sure how racy your car is, may want to do a cell in the trunk even.
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Old Jan 2, 2003 | 03:13 PM
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Default Re: In-tank pump or external?

oh FYI

http://www.autoperformanceengineering.com/

run by a buddy of mine, Ron Gregory. best prices I've seen anywhere for Walbro stuff. has some good pump data on the page as well.
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Old Jan 2, 2003 | 05:49 PM
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Default Re: In-tank pump or external?

I am using the 99 Camaro fuel rail. Same as the vettes with only one supply and no return line. The stock 99 and newer vette regulator is a pressure regulator/ fuel filter all in one and it has a return port. They sit just forward of the tank on the vettes. I just ran a line from the pump to the regulator then from the regulator to the fuel rail. My return line from the regulator back to the tank is about 2' long. Right now, I am not running a filter before the pump, but have plans to install a small inline filter.

The pump has the markings GSL 392. I picked it up from the classifieds section here on the forum for $100.

Here is a pic of the fuel pressure regulator. The quick disconnect that was cut off the fuel rail was brazed onto the fuel line and fits into the filter <img src="http://temp.corvetteforum.net/c3/70lt1//fpr.jpg" alt=" - " />
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Old Jan 3, 2003 | 12:47 AM
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Default Re: In-tank pump or external?

That sounds like a whole lot of money. I spent about $100 on a pump, $50 on the regulator/filter and about $50-75 on fuel lines. All with AN fittings. Thats $225. I have run the tank pretty low and have had no problems at all with fuel starvation.

I am running an external walbro pump with a stock 99 vette regulator/filter through steel lines that I bent up to the fuel rail. I had the fuel rail modified for an AN -6 male fitting. I am still running the stock 70 vette fuel tank which just happened to have the right size supply line out the bottom and the return in the top.
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Old Jan 3, 2003 | 06:42 AM
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Default Re: In-tank pump or external?

Thanks guys. I think a can save some substantial money now!! Jeff, those don't look like AN fittings to me. Thanks for the pics. No problem running 60 PSI through hose clamps and rubber line?
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Old Jan 3, 2003 | 10:19 AM
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70 LS1's Avatar
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Default Re: In-tank pump or external?

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Jeff, those don't look like AN fittings to me. Thanks for the pics. No problem running 60 PSI through hose clamps and rubber line? </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You caught me, they aren't. I have had no leaks, though. I had the fuel rail modified for AN and the other end of the line coming out of the filter has AN along with the various pieces in between.
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Old Jan 16, 2003 | 12:04 AM
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Default Re: In-tank pump or external?

Going with the factory pump and regulator/filter, would the system exhibit better performance if the regulator/filter was placed closer to the fuel rails rather than further away? It seems that increased demand for fuel would cause a slight dip in pressure before the regulator was able to respond with the regulator back toward the rear of the car. It seems that if it was mounted in the engine compartment close to fuel rails, the response time would be lessened and thus performance enhanced. Any thoughts on this??
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Old Feb 3, 2003 | 09:34 AM
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67ls1CamaroProject's Avatar
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Default Re: In-tank pump or external?

Hey 70 LS1, you mentioned below:

"The quick disconnect that was cut off the fuel rail was brazed onto the fuel line and fits into the filter "

I too used the male side quick disconnect from the fuel rail line, but I just inserted it into the 99 vette fuel filter/regulator output port. From there I connected it to my main line using AN fittings. My concern is that the OEM fuel fitting clips do not fit in this location because the clip doesn't fit around the female fitting on the filter/regulator. Will this be a problem? The line is clamped to my frame rails so I do not think it can be pushed out of the quick connect fitting from the fuel pressure. How does the 99 vette fittings connect at this location? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
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