Shipping was fairly fast. Free Shipping - Holley Fuel Pressure Regulators with qualifying orders of $99. In theory the vapor carburetor was the way to go in that day - with lower flash point fuels like poor grade fuels that all pretty much resembled the weight of kerosene in that early day of motor fuels. neglect, accident, improper installation or adjustment, dirt or other contaminants, water, corrosion or faulty repair, or used in applications other than . 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. Find an Automotive Service Professional Q: 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. It is no different than mixing water with ethylene glycol to make what we call anti freeze or with methanol to make windshield washer fluid - you get a completely different product - it is not just water any more; and nor can you separate them back into their original separate entities - so you cannot think of them that way any more either. All Holley regulators are pre-set at the factory so there is no guesswork when first installing the regulator. Much of the excess engine heat will end up soaking the fuel system under the hood. But the heavier elements will raise the boiling point of the mixture. 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. The BP article does not address how to re-blend your own fuel, and indeed - each batch of gasoline - and even how long it has been sitting in a tank will change it's properties as certain things evaporate out of the fuel changing it's properties if in a vented tank. Discussion in 'The Hokey Ass Message Board' started by striper, Aug 12, 2009. The Holley 12-804 fuel pressure regulator features 3/8" NPT in/out ports. 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. . Holley low pressure reg woes #12-804. Copyright 2008-2023 OReilly We are sorry. Can anyone speak to the validity of this or is anyone currently using an additive for this? Too much anti-freeze - (typically ethylene glycol) causes the opposite effect even under pressure of the cooling system. loyalty program 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. One is a deadhead and one is a by-pass. Steve, gasoline isn't a single chemical compound but a mixture of hundreds of individual chemical compounds which have a large range of boiling points. Post in the forum instead. 2-Port Carbureted Fuel Pressure Regulator (12-804) by Holley. Right & left, Customer Reviews, including Product Star Ratings help customers to learn more about the product and decide whether it is the right product for them.Learn more how customers reviews work on Amazon. We tend to speak of pressure as higher or lower than atmospheric however it is a relative measure and pressure applies under all conditions. Had to reset to Zero. The chemistry class experiment you are referring to will yield the approximate boiling (vapor) point at STP - Standard Temperature and Pressure ONLY. The fuel pressure is at 1 - 3 psig since the pump is not running. The fuel pump and fuel line setting top center of the engine was not only in the hottest ambient temp, except for the exhaust manifolds, under the hood they acted as a heat sink transferring heat from the block to the air. We will have the previous answer corrected. Wouldn't the water still evaporate at the same temp? Profile Page . December - February gas mixture begins to vaporize at 11-15psi at 105 deg F, April gasoline is 9-11.5 psi at 124 deg F. If you had winter gasoline in your Antique car on a 100 deg day you would only be about 5 degrees from vapor bubbles in the fuel. Will rise to above 180 degrees on the Temperature gauge. By 1913 it was the other way around. 1996-2023, Amazon.com, Inc. or its affiliates, Select a location to see product availability, Holley HOL 12-804 12-804 Fuel Pressure Regulator. 3/8 Inch NPT Ports 1 Inch 2 Out. The higher the RVP, the greater the tendency to vaporize or vapor lock. It makes no discernible difference to power but if the conditions are sufficiently adverse it will still vapour lock and then you just have to wait until it cools. September 21, 2010 in Technical. Generally speaking if your car was made before 1953 it has low compression. 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. The BP article explains causes - not how to change fuel formulations - so for this discussion it explains nothing. YES the boiling point of gasoline can be raised (or lowered) by an additive - depending on what it is - as can the autoignition temperature which will increase "knock" - using the right additive for the fuel you just bought and put in your tank is the trick and it is always going to be hit and miss - depending on what refinery produced the gasoline in the first place. Holley's products include carburetors, fuel pumps, fuel injection, intake manifolds, and much more. It's unlikely that anything's stuck. The regulator that was shipped to me has an internal spring from a different model of regulator, the spring should be red. What if any additives would do this and why? They put everything they could into the coal oil including what we would consider low grade gasoline. These will raise the boiling point of the fuel but reduce the octane. To add the following enhancements to your purchase, choose a different seller. [endif]-->. Depending what your compression is you could add 5% kerosene up to 25% for cars from the 20s with very low compression, like 5:1 or less. Open the unit and check the spring color, Reviewed in the United States on April 9, 2018. 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. 12-804 : Quantity: Share : . Going to check my VW bus fuel pump pressure. Amazon has encountered an error. Please make sure that you are posting in the form of a question. Works, don't use a liquid filled gauge in an engine compartment! $59.69 . To keep it on simple terms, several people have confirmed that adding some kerosene, diesel fuel or stove oil will reduce the tendency to vapor lock and will NOT hurt an older model, low compression engine. the cause for your fuel pressure fluxuation is because the fuel pressure is bumping up against the regulator and the extra fuel has no where to go , the quick fix is run a return line . It will get you close. Check "Reid Vapor Pressure" in Wikipedia, or similar. te4cmCbGnt]&~`N@RPyBTa$=~fo:/T 92YE)3Uofo4Ou].-zowDt*ae^qf9z/?. The Holley 12-804 fuel pressure regulator features 3/8" NPT in/out ports. Remember STILL transporting fuels was a dangerous thing - and higher grade fuel could just as easily have exploded on it's way to the fueling station or in those glass top hand operated early gas pumps on a hot day. Q: 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. . 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. Bobburns thank you for the confirmation and technical explanation. Quadrajets should have 6 to 9 at the inlet or they flood past the needle seats. Error posting question. As an example water would boil and thus "vapor lock" at a really low temperature without ethylene glycol. Interesting theory. So, I take the reg apart to see if it is all clean and looks good. 9 really is max. Prewar cars have very low compression and will run better on gas that has some kerosene added. A: Mounting Bracket Included. I can start my car instantly after sitting in a cool garage at about 75 deg F. Drive 30 miles and then park for 20 minutes. Unfortunately, these FPR are now made in Korea and they no longer include an alternate spring. Then, we got what was loosely described as winter gas, all year round, with RFG. Add to cart. If this is true, how come adding antifreeze to water raises the boiling point? Purchased the regulator from Baxter, unit arrived in 4 days.. 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. Too much fuel pressure for a given needle and seat assembly can overload the needle and seat and may cause flooding or drivability problems. NOTE: P/Ns 12-841, 12-842, & 12-879 utilize 3/8" NPT inlets and outlets. the installation of a Holley 12-810 oil pressure safety switch is recommended for installation into the wiring circuit. 0 Adding heavier weight hydrocarbons WILL raise the vapor point under pressure - usually enough to keep the fuel from vaporizing in the line or boiling off in the carburetor bowl while flowing. Regards, Mike. They sold more gas than coal oil. Some of these items ship sooner than the others. The Holley Fuel Pressure Regulator (Part No. Holley 12-804 low pressure regulator, Weber, jeep etc. I've had some luck using LeadMax2000 but it's not a 100% cure. 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. Holley Carburetor Fuel Pressure Regulator 1 To 4 Psi Bottom Inlet Sides Are Outlets from Pacific Customs Unlimited your best source for Street, Off Road, Sandrail, Dune Buggy, Manx, Rock Crawler, Volksrod, or Mud Buggy VW Parts. If I wait a hour for the system to cool to ambient temperature then it starts easy. I feel I am 95% there, and a slight improvement would be all I need - for now, that is unless the ethanal mix changes (your tax dollars at work). Holley Fuel Pressure Regulators 12-803 HLY-12-803. I am not going to quote all you said, but the flooding from the electric pump was caused by too much fuel pressure over coming the needle seat (or whatever kind of seat it has for the bowl) of the carburetor. Browse In Stock and Ready to Ship Alternatives, Universal Fit, 1-4 Fuel Pressure Rating (psi), Aluminum. Sorry, we were unable to perform your search at this time. Unfortunately, this fuel pressure regulator does not even come close to regulating the pressure and keeping the pressure down. I had a chrome dial regulator, which leaked gas everywhere but luckily didn't actually burn down my ride. Holley 12-804 Fuel Pressure Regulator Installation Instructions . So with that vapor fueling system - you are stuck "downgrading it" to a lower quality fuel. Many thanks for taking the time to clarify this interesting subject . The Holley 12-840 fuel pressure regulator features 3/8" NPT in/out ports. I adjust it up to 2.5 pounds and clean my hands. So - you cannot just say whether it will work or not. I installed this on my Onan 7000 generator as part of a project to resolve vapor lock issues in hot weather and high altitudes. Use with standard pump only - not recommended for maximum pressure pumps. Will buy again if I need another one for a different project. Yes the light elements will still be in there. Posts: 32372. Then I got this good one, to try to get 1.5 PSI to the Kadrons. I have found IMCT is a happy medium that does both in the right quantities - raise boiling point and octane just enough to be a "goldie-locks" kind of additive to help prevent vapor lock. A long time ago it was in use in the oil business. (that is this one in the image below) The adjustment spring under the adjustment screw is pushing down on the diaphragm holding the ball off it's seat. To avoid extra back pressure on the pump, and to keep cool fuel flow past the lowest pressure point in the fuel system; a by-pass line should be used and it should NOT "dead head" to the carburetor - that is put the return line as close to the carburetor inlet as possible. However the part number on the box was 12-804 which should be a 1-4 psi regulator BUT the Part number etched on the unit was 12-804 4.5-9 psi which doesnt exist. The summer gasoline vaporizes in the line and the heat soak is quicker and longer on hot day's. It's easy! 10 in stock. P/N 12-803, 12-501, 12-804, 12-500, & 15812NOS Installation Instructions WARNING! For more information go to www.P65Warnings.ca.gov. I did, works great & looks beautiful. It will meet your needs and deliver great quality at an affordable cost. Thus the "lowest boiling point are the cause of vapour lock" is also NOT CORRECT thinking. A quart of diesel added to the gas tank solves the problem without any more in side effects than a slight smell from the exhaust. Free shipping for many products! The Holley 12-804 is a 1 to 4 range PSI regulator. #2. Google ethyl acetate and pay attention to it's "pure" boiling point, and remember IMCT is a blend of a white gas family of a petroleum distillate and ethyl acetate.