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Old 12-10-2010, 04:14 PM   #1
craazy22
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gas lines questions..

Hey guys, see if y'all can help me out. I am installing a 454 in my 81 stepper that originaly had a 305 and some guys I was talking to said I had to swap my fuel lines for something bigger cause the 750cfm carb will demand more fuel. Is this true? I do plan to also install a blower eventually. Is he right or full of it? I have dual fuel tank. Thanks in advance...
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Old 12-10-2010, 04:16 PM   #2
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Re: gas lines questions..

I would upgrade the fuel system for a blown 454
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Old 12-10-2010, 04:37 PM   #3
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Re: gas lines questions..

So you would? Huh? Guess he was right.. thanks for the quick response.. any more opinions
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Old 12-10-2010, 04:44 PM   #4
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Re: gas lines questions..

a bit more detail... you would gain more from making fuel tank modifications than just a larger fuel line. the line leading into the tank is also small. you could upgrade to a better fuel tank and possibly keep the main fuel line size, although if your spending the cash for a blown big block, why take a chance of burning pistons over fuel line and gas tank?
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Old 12-10-2010, 05:50 PM   #5
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Re: gas lines questions..

Check the current line size. If you currently have 3/8's line it will be fine. The carburetor has NOTHING to do with the amount of fuel the engine uses. Its the size of the engine that will require more fuel. If your planning to build a blower motor thats a whole different animal. Just throwing a blower on top of an otherwise stock-ish engine is a bad idea and will result in broken parts. Once you move into the 550-600hp range with a blower your going to be looking at running -8 braided line an electric pump and probably a fuel cell just for ease. It can be done otherwise but if you want everything to last its going to cost
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Old 12-10-2010, 06:49 PM   #6
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Re: gas lines questions..

Running a mild 454 with the stock small block fuel lines, works fine here, and always has on every small block vehicle that I put a big block in. Was even going to add a blower to my truck at one point, but it wouldn't fit under the stock hood, and still wasn't going to upgrade the lines.

Blowers can work fine on stock engines, its all up to how much boost you want to run.

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Old 12-10-2010, 07:08 PM   #7
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Re: gas lines questions..

yes, I suppose it is possible to have a blown 454 and use a stock line. If I had a blown 454 I would certainly make enough power that I would need more fuel, but it could easily be set up for show and not use any more fuel than a stock engine. I sometimes forget that some people are less concerned about performance.
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Old 12-10-2010, 07:36 PM   #8
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Re: gas lines questions..

You can move a hell of a lot of fuel through a 3/8" line.
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Old 12-10-2010, 09:48 PM   #9
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Re: gas lines questions..

Ok guys thanks. So I am going to have to upgrade my lines cause I'm pushing 540hp right now at afterthe blower my motor is going to be thirsty for more fuel.. thanks guys.
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Old 12-10-2010, 11:12 PM   #10
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Re: gas lines questions..

Quote:
Originally Posted by Allensracing View Post
yes, I suppose it is possible to have a blown 454 and use a stock line. If I had a blown 454 I would certainly make enough power that I would need more fuel, but it could easily be set up for show and not use any more fuel than a stock engine. I sometimes forget that some people are less concerned about performance.
I'd run a blower on a daily driver though, with plenty of power. Also in some set-ups with a blower you will get better mpg, than naturally aspirated. Research will even show that.

Last edited by Dru; 12-10-2010 at 11:14 PM.
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Old 12-10-2010, 11:41 PM   #11
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Re: gas lines questions..

Quote:
Originally Posted by Dru View Post
I'd run a blower on a daily driver though, with plenty of power. Also in some set-ups with a blower you will get better mpg, than naturally aspirated. Research will even show that.
yes, your absolutely right. I am not disagreeing at all. I am the type that would crank up the boost until it was barely streetable, and I would have my foot in it all the time
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Old 12-11-2010, 01:19 AM   #12
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Re: gas lines questions..

The decision for me would depend on the type of blower. If I was running an 8-71 or larger blower with dual carbs I would upgrade all the fuel system from the tanks to the lines and pumps.

If it was on of the low profile blowers with a single carb I'd say with a 3/8 inch line you'd be ok - just make sure the pump flows enough for the application
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Old 12-11-2010, 01:33 AM   #13
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Re: gas lines questions..

the way I see it the original line is 30 years old or so it doesn't hurt performance to have upgraded line one bit. at some point the original will rust out anyways get it out of the way
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Old 12-11-2010, 03:04 AM   #14
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Re: gas lines questions..

true.. never thought about the age of the lines. Well my 454 is built somewhat. I really can't tell you what all got done to it but I know I was putting 530 to flywheel and 480ish to the wheels. The stock heads got worked on also. I paid an old man that used to build engines to do mine on the side and so far so good. I don't think I will pushing that much boost but I love how steppers look with the b lower throuh the hood
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Old 12-11-2010, 03:06 AM   #15
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Re: gas lines questions..

Pic of the motor before it goes in...





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Old 12-11-2010, 11:54 AM   #16
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Re: gas lines questions..

Allensracing, I can understand, and yeah it definitely is hard to keep off of the gas pedal, only wish I had enough money to keep replacing the tires.


craazy22, mmmmmmmm pics. I so love big blocks.
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