It needed a bit of adjusting for my purpose, but other than that, it performed perfectly. It is as said - of the "paint thinner" family in weight with ehtyl acetate blended in to make it's solvency properties a little "hotter " and stronger. For the best experience please upgrade or visit the site on another browser. store Holley Fuel Pressure Regulators 12-803 HLY-12-803. . September 21, 2010 in Technical. Volatility is a measure of the gasolines tendency to vaporize under a given set of conditions. Generally speaking if your car was made before 1953 it has low compression. Once the fuel fills up the float bowls in the carburetor and the needles and seats shut, it starts to build pressure, pushing the diaphragm against the adjustment spring under the adjustment screw and allowing the ball to go "up" against the seat, effectively shutting off fuel flow to the carb. on this design the adjusting screw all the way out should decrease the pressure the most - IF the ball valve will seat TIGHT, When I adjusted pressure below 30 - it would not seat any longer even with the adjustment screw all the way out. Holley part number for the kit is 12-807; Summit sells it for about $6. (Maybe this arrangement was intentional to assist in vaporising the fuels of the day but it is all bad in hot weather with today's fuels). Each Holley fuel pressure regulator is fully adjustable so regulating the fuel pressure to your engines needs is a simple task. I do not think we hi-jacked the thread - the article is not even available anymore online to read. TURNING THE ADJUSTMENT SCREW ALL THE WAY IN WILL RESULT IN EXCESSIVE FUEL PRESSURE . A vapor lock condition would be caused. The Holley 12-804 fuel pressure regulator features 3/8" NPT in/out ports. Two Port So in an open cup the boiling points would also appear the same as water but under pressure the boiling point is different. It's easy! Easier said than done - especially without a "chemistry set", OD says a simple high school chemistry experiment will show this - BUT I said the boiling points will appear the same under STP (Standard Temperature and Pressure - which is one atmosphere of pressure at 77 degrees F - commonly room temperature ) - BUT under pressure in a fuel line the boiling point (vapor point) will be raised enough to prevent vapor lock at higher temperatures. Never tried it with my old Model A Ford but I heard that they will actually run on Kerosene.. You could arrange them on a scale from naptha gas, gasoline, kerosene, stove oil, diesel fuel, light lubricating oil, heavy lubricating oil, grease, asphalt. LOW PRESSURE REGULATOR 12-804 quantity. Purchased the regulator from Baxter, unit arrived in 4 days.. Somewhat of an inconvenience but that's why it's probably cheaper than other places selling the same part Great product from holley, but these do not come with the supplied tap that's suppose to be in box for the 2 machine screws that mount the regulator to the bracket. The Holley 12-804 is one of the most popular low fuel pressure regulators that works perfectly for setups that require 1 to 4 PSI. Please try again. Holley HOL 12-804 12-804 Fuel Pressure Regulator. I have the one I have set up in a deadhead setup. It seemed to work fine for a while after I dialed it into 2psi at idle, but now it reads 6psi and it won't adjust down to 3psi. Some have reported more power, easier starting and cooler running especially in very low compression cars of the twenties and early 30s. This item: Holley HOL 12-886 Regulator $13129 MEASUREMAN 1-1/2" Dial Size, 304 Stainless Steel case, Liquid Filled Fuel Pressure Gauge, 0-100Psi, 3-2-3%, 1/8"NPT Center Back Mount $2597 Moroso 65380 Fuel Line Fitting $1701 Total price: $174.27 Add all three to Cart Some of these items ship sooner than the others. couple more questions, Rusty, what exactly are "heavy ends"? Could you explain a little more about how you would run the bypass? Otherwise it's good. MFG. One needs to have studied Chemistry as I have to actually know how this works. As an example water would boil and thus "vapor lock" at a really low temperature without ethylene glycol. A: '92 Ford Mustang GT: 385"/6.3L SBF, Dart SHP 8.2 block, forged steel crankshaft & H-beam rods, forged pistons, Trick Flow Twisted Wedge . [{"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"}]. Each Holley fuel pressure regulator is fully adjustable so regulating the fuel pressure to your engines needs is a simple task. I remember when I was a teen in the 50's and everyone had a flathead Ford V8 or a Chevy stovebolt 6. Holley recommends applying PTFE paste to the NPT thread of the fittings before installation on these applications. here's one installed,same holley low pressure regulator, line pressure in the top, one side is hooked to the fuel pressure sender, other to the line going to the fuel block. Lots of Chinese Holley 12-803, 804 etc knock-offs are available. Our payment security system encrypts your information during transmission. I would like to try IMCT, how is it sold? But the heavier elements will raise the boiling point of the mixture. I have a electric pump at the tank to try and speed up the fuel cooling process but if you have a 100 deg F day you may have fuel near 100 deg F in the tank. The point is the 0-140 regulators (they are all coming out of China now-a-days) will not regulate lower than about 20 reliably so you need a staged system - and even Holley says so on the 803BP design set up. As you can see from what it replaces - it is "hot" solvent - but not quite as hot as acetone in its ability to dissolve other things. It will get you close. readings of the carb. IMCT is a "new product" from Klean-Strip they call "Industrial Maintenance Coating Thinner" that provides good solvency and can be used in place of MEK, Toluene, Xylene and VM&P Naphtha for thinning Industrial Maintenance Coatings. The only difference that the Holley tech told me between the two springs is the color. Much of the excess engine heat will end up soaking the fuel system under the hood. A larger tank might need two quarts. This is the complex world of Chemistry - which is far too complex to go into here. Product very good. This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles. Why does this occur only under increased pressure? Click here to find a ***The inlet pressure limitation is 7 psi. i'm trying to figure out why you are running a T when there are two outlets. Copyright 2023, Antique Automobile Club of America. Quick & Hassle Free. The term heavy ends may be old fashioned and obsolete. The two will be very close to the same just as would Water and Anti-Freeze boiled in an open pot. None of them worked. All Holley regulators are pre-set at the factory at 2.8 PSI so there is no guesswork when first installing the regulator. 2-Port Carbureted Fuel Pressure Regulator (12-804) by Holley. The BALL shuts off the fuel flow until the pressure on the other side of it lets fuel get past it to keep the pressure constant. . Part Number: HLY-12-803. The check ball is held shut with the diaphragm and spring and once the desired fuel pressure builds up it opens that valve and allows fuel to go back to the tank. The 12-803 4.5-9 psi spring is plain, (just the gold colored plating) the spring is accessible and replacable The cheap dial units are terrible. Sorry, you're using a web browser that is no longer supported. Posts: 32372. As a single solution, or partnered with products from other Holley companies - Hooker Headers(R), Flowtech(R) Exhaust, NOS(R) Nitrous, Weiand(R), Earl's Performance Plumbing(R), or Diablosport(R)- Holley products can give you the edge you need over the competition. It IS variable and a result of the various fuel blend components. For any further assistance please feel free to call us at: 1-877-238-2623 or visit the nearest Advance Auto store and one of our representatives will gladly assist you with any questions or concerns you may have. Add some heavy ends. I ordered the 12-804 regulator online because I couldn't find one locally, this is for an engine on a piece of equipment that I make my living with. Shiny Finish. What Rusty writes IS correct. So - you cannot just say whether it will work or not. Holley's products include carburetors, fuel pumps, fuel injection, intake manifolds, and much more. In a deadhead design the fuel comes into the regulator from the bottom past a check ball which is held open by a pin on the diaphragm. . Estimated Ship Date: Today. The unit however is working fine but am curious about the missing gaskets and how important they are? Seems like the first "RFG" was closer to the old "winter" blend, which had more higher-end distillates so it'd vaporize nicely in cooler weather. I have used up to 20% kerosene with no discernible change and have spoken to people who told me that years ago on farms these old cars would run fine if started on gasoline then switched to 100% kerosene. if you run a holley blue pump it is set at 14psi from the factory and you must run the regulator that came with the pump . Neither the Holley instructions nor anywhere I can find says what the maximum inlet PSI should be allowed to the regulator - but I was told it was 16 psi and one other spot on the web says something similar. This item cannot be shipped to your selected delivery location. the installation of a Holley 12-810 oil pressure safety switch is recommended for installation into the wiring circuit. Today's fuel is made for high compression engines - and it has an intentionally lower vapor point, with a higher flash point and autoignition point. Is there a brand name? The 12-804 is made from durable aluminum and has a satin chrome finish that is extremely resilient to corrosion and abrasive chemicals. WARNING! Exclusive, high-quality Global Featured Holley Transmission Kickdown Cable Bracket 20-121; Gold Zinc Steel for 700R4 . finish) . This will keep your pressure steady and have instant pressure change when adjusting. I do wish there were some stamped values on the adjustment screw like other models I have seen. How much should I add to every gallon of gas.I believe they are adding about 5% ethanol to the fuel here. The fuel pressure is at 1 - 3 psig since the pump is not running. 4.25 out of 5 stars. To keep it on simple terms, several people have confirmed that adding some kerosene, diesel fuel or stove oil will reduce the tendency to vapor lock and will NOT hurt an older model, low compression engine. Needs you to make/tap your own threads for screws, Reviewed in the United States on February 4, 2023. It works but not as well as some of the off brands like spectre. The Holley 12-804 fuel pressure regulator is adjustable from 1-4 psi. Please refresh and try again. This went on until they developed the cracking process which allowed more flexibility in what they got out of the crude. Holley 12-804 Holley Fuel Pressure Regulators JEGS 41040 JEGS Fuel Pressure Gauges Now you need fittings. All kinds of remedies were tried. Driving on a warm day in heavy stop start traffic it started vapor locking on a climb - using 10% ethanol fuel with no additive . The reliable, albiet slower, stovebolts never suffered vapor lock because the fuel pump and lines were up front in the airstream of the engine fan. The project involved installing a 250LPH electric fuel pump on a relay system and then T off to a bypass line and a fuel pressure regulator on the fuel line going to the generator. In this document is a chart for Seasonal Gasoline Specifications. This item can be returned in its original condition for a full refund or replacement within 30 days of receipt. 10 in stock. In those days before 1905 kerosene had a strong piercing odor and coal oil lamps sometimes exploded. It's unlikely that anything's stuck. They sold more gas than coal oil. From propelling the LS-, Coyote-, and Gen 3 Hemi-swap trends, to continuously innovating late-model and vintage vehicle performance, Holleys commitment to its customers and their cars is at the core of everything we do. Hydrogen Power Central | The true source for powering engines with Hydrogen - not "HHO", Standard conditions for temperature and pressure - Wikipedia, the free encyclopedia, https://www.holley.com/data/Products/Technical/199R7914-3rev3.pdf. Brands like MSD, Flowmaster, Hurst, Accel and many more make up the offering of enthusiast-driven products to deliver robust, complete performance solutions for builders, racers, and drivers. [endif]-->. 4.9. For now, in 70 degrees ambient, the bowls are 100 F. at shut-down and after 15 minutes they rise to 115 F. At these temperatures the engine starts back up fine, but I believe another ten degrees will be in the problem zone. [endif]--> Many thanks for taking the time to clarify this interesting subject . The thinner, lighter products are at the light end of the scale the thicker heavier products are at heavy end. This part is Backordered. 3/8 pipe thread ports; 7/32 restriction; . In the early days of the oil business the demand was for kerosene or coal oil. Works, don't use a liquid filled gauge in an engine compartment! You would'nt just be reading the inlet pressure would you? The other part numbers utilize an AN O-ring inlet, outlet, & return ports, and do not require any sealer on the threads. 2023 Holley Performance Products, Inc. All Rights Reserved. What you write in post 12 is NOT correct. The issue is boiling points UNDER PRESSURE we are talking about here - though the BP article speaks to other issues of engine and carburetor design contributing to the vapor lock problem. Mr. Gasket 1561 Fuel Pressure Gauge 1.500 in. A long time ago it was in use in the oil business. I am intrigued by you statement, "Once these chemicals are blended - the over-all resulting chemical properties - especially boiling point under pressure is changed - they are NO LONGER SEPARATE boiling points in play.". When it does light - the flame spread is faster but not so fast as to "knock" or be a violent explosive hard burn of the fuel. Adjustable fuel regulation from 1 to 4 psi, Holley 12-804 Reg, Fuel Press 1-4 Psi Pol. ***The inlet pressure limitation is 7 psi. Holley 12-804 low pressure regulator, Weber, jeep etc. Adjustable fuel regulation from 1 to 4 psi, 1965 and older U.S. manufactured California Certified vehicles, 1967 and older U.S. manufactured Federally Certified vehicles, 1967 and older Foreign manufactured vehicle, 1966 and newer U.S. manufactured California Certified vehicles, 1968 and newer U.S. manufactured Federally Certified vehicles, 1968 and newer Foreign manufactured vehicle. Designed using state-of-the-art technology and with customers in mind. FREE SHIPPING on most orders of $35+ & FREE PICKUP IN STORE. You can do a Google search for it, though. That was in the 1990s, so you can project to more current times and suspect we have something more sophisticated now. Fuel pump regulator has 3/8" NPT inlet/outlet ports.