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Old Apr 11, 2023 | 06:08 AM
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Default LSX gas tank pressure

Hello All,

Thank you in advance for responses. -- Question I have is I'm running a fairly new lsx in 67 Chevelle and noticed a fuel leak on ground.. which was odd.

I went to back of tank gas filler and opened the cap and air pressure shot out... I currently have a Non- vented filler cap..

Would a vented cap be better to use OR is there another solution to resolve.

much thanks

Chuck
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Old Apr 11, 2023 | 03:39 PM
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You have to use a vented gas cap.
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Old Apr 11, 2023 | 04:21 PM
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Thank you Sir!

I don't know why I had a non vented -- go figure...

just fashioned my own from the non vented tiny drill in center for air -- Presto no more pressure ;{

Thank you again for the quick rely.
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Old Apr 12, 2023 | 07:24 AM
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On my builds I do not use a vented cap but install a "rollover valve". It provides a tank vent but will shut of in a case where the car get upside down. Last thing you need is a case like this is a gas leak.
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Old Apr 12, 2023 | 08:26 AM
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A lot of guys will also use the rollover valve in conjunction with a charcoal filter so you won't get the fuel vapor smell in your garage.
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Old Apr 16, 2023 | 06:07 PM
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Originally Posted by Chuck M
Hello All,

Thank you in advance for responses. -- Question I have is I'm running a fairly new lsx in 67 Chevelle and noticed a fuel leak on ground.. which was odd.

I went to back of tank gas filler and opened the cap and air pressure shot out... I currently have a Non- vented filler cap..

Would a vented cap be better to use OR is there another solution to resolve.

much thanks

Chuck
What you heard was air rushing INTO the tank, not out. As fuel is being used, if the tank is not vented, it will create vacuum inside the tank.

Andrew
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Old Apr 20, 2023 | 01:17 PM
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Thank you for the Feedback... I'll pop on a regular vented cap that will allow air in -- Chuck
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Old Apr 20, 2023 | 01:18 PM
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Thank you ! I'll look into those Roll over valves Appreciate the quick response! -- chuck
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