The Holley 12-804 fuel pressure regulator features 3/8" NPT in/out ports. I got all of my supplies in the Home Depot fittings section. I adjust it up to 2.5 pounds and clean my hands. Please refresh and try again. neglect, accident, improper installation or adjustment, dirt or other contaminants, water, corrosion or faulty repair, or used in applications other than . In fact I can completely remove the adjusting screw and it still does not go down to 3psi. [endif]-->. You need to be a member in order to leave a comment. It's a diaphram with a spring. [{"displayPrice":"$58.17","priceAmount":58.17,"currencySymbol":"$","integerValue":"58","decimalSeparator":".","fractionalValue":"17","symbolPosition":"left","hasSpace":false,"showFractionalPartIfEmpty":true,"offerListingId":"UhTnfcw7IZxaNntXlJwDKCZdMn2swwW9Qa8PxzrWBz%2By8RC0ilxVsHIj8toGUO%2FPmmF8b2HD1iNYooZ7n4ER0XuKiQsQQvJG86lgqsni6KYZs%2FdLcIOIE0Ukulbz%2BJYBuUOC820ciUZxU2UEL9sUjtoq8gdk8bOPIZ3QChg8zpgyIZxlTaXQEA%3D%3D","locale":"en-US","buyingOptionType":"NEW"}]. My plan was to install a fuel pressure regulator on the line going to the generator so that the bypass valve needs less fine tuning to maintain the same pressure in all temperatures. All Holley regulators are pre-set at the factory so there is no guesswork when first installing the regulator. I turned into a side street and opened the hood. I suspect as the article suggests even with all these steps you can still get the crap gas to boil if it is hot enough under the hood. The issue is simple that one is seeking to "re-blend" their own gasoline from one already sold. So with that vapor fueling system - you are stuck "downgrading it" to a lower quality fuel. Lower octane will not hurt your car if the compression is low. Holley 12-803 Two Port Chrome Fuel Pressure Regulator - 1-4 PSI. Loosening the regulator locknut and turning the adjustment screw clockwise increases the pressure. Contact Us - DO NOT EMAIL CAR QUESTIONS. The '54 Bentley already has an electric SU pump back near the tank, and it's low pressure output is just about right for the two SU H6 type carbs. To minimize exposure, avoid breathing exhaust, do not idle the engine except as necessary, service your vehicle in a well-ventilated area and wear gloves or wash your hands frequently when servicing your vehicle. 3/8 pipe thread ports; 7/32 restriction; . 4.9. I put it . The other possibility is that it is due to the higher pump pressure.