I now think that what was happening was that there was sufficient heat in the carburettor to boil the fuel, the vapor from the boiling increased the pressure above the float preventing it from rising and shutting off the supply. Holley 12-804 Fuel Pressure Regulator Brand: Holley 415 ratings -11% $6614 Was: $73.94 3/8" pipe thread ports 7/32" restriction Pressure ranges from 1 to 4 PSI Includes mounting bracket Satin finish See more product details + + Total price: $115.81 Add all three to Cart These items are shipped from and sold by different sellers. I still suspect the flooding was due at least in part to fuel boiling in the carburettor bowl and venting the vapor above the float could assist. I feel lucky that this did not damage my generator because at one point I saw 30lbs of pressure while trying to start the generator. Holley part number for the kit is 12-807; Summit sells it for about $6. If this is true, how come adding antifreeze to water raises the boiling point? 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. You can wire a by-pass switch for priming if it is really required. There is supposed to a marking on the spring with the correct color, red or gold if it is the low pressure spring. Accurate description. The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles: WARNING: It is against the law to install this part on an Emissions Controlled Vehicle. In fact I can completely remove the adjusting screw and it still does not go down to 3psi. ***The inlet pressure limitation is 7 psi. Yes you can adjust fuel pressure with this regulator. 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. From start to finish, Holley has the parts to make your dream a reality. 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. US $57.76 Finish:Gold Zinc billet aluminum bracket that conveniently mounts a 12-803 Black anodized 12-804 or 12-803BP fuel pressure regulator utilizing the passenger side carb studs on any 4150 / 4160 style carburetor. 3/8Inch Npt Ports 1 Inch 2 Out. . One needs to have studied Chemistry as I have to actually know how this works. Two 3/8" nipples/hose connections and a 3/8" to 1/8" reducer. When it burns however, it is an eye and throat irritant, even though it raises octane, burns hotter, easier, and cleaner. (see reg-setp.pdf), This is the same design as a Holley 12-803 or 804 knock off, so I looked up Holley's instructions. Is it a product that would be sold by a panel beater's supply shop? 9 really is max. Had to reset to Zero. All petroleum distillates have different chemical properties which change depending on what you mix them with. If so how? I've had some luck using LeadMax2000 but it's not a 100% cure. It looks like WhatsApp is not installed on your phone. Walk back over and looked again, 9lbs. Some parts are not legal for use in California or other states with similar regulations. It is a measure, as I understand it, of how readily the fuel will evaporate in open air. On occasions here in NZ, we get extreme heat and old cars vaporlock. There are two kinds and they look the same. 2023 Holley Performance Products, Inc. All Rights Reserved. The 12-804 is made from durable aluminum and has a satin chrome finish that is extremely resilient to corrosion and abrasive chemicals. See also Tom Ogle's "modern" vapor fueling system - google it. I did, works great & looks beautiful. This Holley universal low pressure fuel regulator is factory-set to 2.7 PSI, but is fully adjustable from 1 to 4 PSI. If I could get 75-85 octane, non-ethanol, Regular gasoline that vaporized at above 180 deg F, I think my car would run fine all the time. Too much anti-freeze - (typically ethylene glycol) causes the opposite effect even under pressure of the cooling system. The Holley 12-840 fuel pressure regulator features 3/8" NPT in/out ports. See Standard conditions for temperature and pressure - Wikipedia, the free encyclopedia. 1996-2023, Amazon.com, Inc. or its affiliates, Select a location to see product availability, Holley HOL 12-804 12-804 Fuel Pressure Regulator. If your having pressure controll issues with the Holley regulators you can eliminate most problems with stability by installing a by pass line back to the tank and usualy a street car can use 1/8 copper. Some can be used for either - or. 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. I had a chrome dial regulator, which leaked gas everywhere but luckily didn't actually burn down my ride. Cool. ESPECIALLY a 10% ethanol blend - once generically called the gasohol summer blend in that vapor system would really be a problem. Putting kerosene into gasoline - while both are hydrocarbons - and they will blend - the lighter oil nature of the kerosene to the solvent of gasoline; in an amount of 5% is not enough to change the STP vapor point of the gasoline, but it will weaken the octane rating of the gasoline enough to feel it under acceleration AND under pressure will raise the vapor point enough to perhaps prevent vapor lock depending on the ambient and under hood temperatures of where one is located. The regulator is a Holley 12-804, I was told it went down to 1 psi and I have a stock mechanical fuel pump. The reg takes 3/8" fittings and the gauge takes 1/8" fittings. Check the status of your Now my equipment sits idle while I wait for a response from the vendor. [{"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"}]. I tried to bring the 0-140 pressure feed regulator down to 30 by adjusting the two - to up the return flow and lower the feed pressure - but the 15 psi reg I had just worked on started to climb past 9. 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. But it is not the ethyl acetate alone that causes the effect to raise the vapor temperature point of fuel. 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. You may receive a partial or no refund on used, damaged or materially different returns. Find an Automotive Service Professional Ships from and sold by Performance Guarantee. I will be trying one of these but am curious what is the active ingredient(s). 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. Q: HWYoF~Ta77[Z4"bG K=yK Each Holley fuel pressure regulator is fully adjustable so regulating the fuel pressure to your engines needs is a simple task. [endif]-->, . Please use a different way to share. Some cars are much more apparent to vapor locking than others, I"ve never experienced here in NJ with either of my older Packards which see all kind of hot summer driving conditions. To add the following enhancements to your purchase, choose a different seller. My bypass line has a shut-off valve that I can use to manually adjust the pressure, but when air bubbles develop within the input fuel line, this valve requires adjustment to maintain the fuel pressure. Takes a little time to peel back the rubber case then remove the glass with a fine blade screwdriver, reset to zero. Will changing the orientation change the preset pressure setting (checkball falling instead of raising)? Each Holley fuel pressure regulator is fully adjustable so regulating the fuel pressure to your engines needs is a simple task. Can i install a fuel pressure guage on the unit itself? $59.69 . For more information go to www.P65Warnings.ca.gov. P/N 12-803, 12-501, 12-804, 12-500, & 15812NOS Installation Instructions WARNING! THESE INSTRUCTIONS MUST BE READ AND FULLY UNDERSTOOD BEFORE BEGINNING THE . 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. store THE SECOND ISSUE - the vapor system on the Packard is going to be a problem no matter what today. Yes. The float has a needle that projects through the top of the carburettor so it is possible to see whether the float is "floating" or not. Much of the excess engine heat will end up soaking the fuel system under the hood. The thinner, lighter products are at the light end of the scale the thicker heavier products are at heavy end. 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. the installation of a Holley 12-810 oil pressure safety switch is recommended for installation into the wiring circuit. Any of these heavier than gasoline petroleum distillates above will raise the vapor point of gasoline if mixed into it. Adjustable Fuel Regulation From 1 To 4 PSI .220 Inch 7/32 Inch Restriction. Loosening the regulator locknut and turning the adjustment screw clockwise increases the pressure. and a rotary click style one here on the shelf pete, you are welcome to borrow them to troubleshoot your problem.. let me Know. The fuel pressure is at 1 - 3 psig since the pump is not running. Reviewed in the United States on January 15, 2021. Another thing you can do is wire the fuel pump to be hot in run and start through an oil pressure switch - so if the motor shuts off or looses oil pressure the fuel pump shuts off too. None of these contain lead and so should not damage a catalytic converter if you have one, HOWEVER too much IMCT will prolong the burn and may result in unburnt - STILL burning HOT gas being exhausted in the exhaust cycle. Discussion in 'The Hokey Ass Message Board' started by oldrelics, Oct 12, 2010. 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. Designed using state-of-the-art technology and with customers in mind. For over a century Holley has driven the cutting edge of fuel-system design. We currently do not have an estimate when this item will ship. I like the attached simple explanation of the issue. This part is Backordered. I installed this on my Onan 7000 generator as part of a project to resolve vapor lock issues in hot weather and high altitudes. All Holley regulators are pre-set at the factory so there is no guesswork when first installing the regulator. Some have reported more power, easier starting and cooler running especially in very low compression cars of the twenties and early 30s. For cars that require 4.5 to 9 PSI, the Holley 12-803 is the right model. I have no idea - you are in uncharted territory. . Product very good. The following vehicles are considered Emissions Controlled Vehicles: *Free Shipping & Handling only offered to the contiguous US on orders over $100, excludes clearance parts and oversized packages. The Holley 12-804 is a 1 to 4 range PSI regulator. A: As Raywith pointed out, you need to let the pressure go somewhere. I'm still looking for the reg in this pic. There is no "chemistry set" method to measure fuel vapor points. 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. 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 . 12-804) is a Low Pressure (1-4 PSI) regulator. The Holley Fuel Pressure Regulator (Part No. Exclusive, high-quality Global Featured Holley Transmission Kickdown Cable Bracket 20-121; Gold Zinc Steel for 700R4 . I had a chrome dial regulator, which leaked gas everywhere but luckily didn't actually burn down my ride. We encountered an error while updating this page. This approach is not recommended for higher compression cars made from the mid fifties onwards. Any thoughts on this? Chrome Finish. So this thread has been a great find for me particularly at this time. This satin finish regulator feature 3/8 pipe thread . In refining crude oil they distill it to separate out the different products. Holley 12-803 Two Port Chrome Fuel Pressure Regulator - 1-4 PSI. I commented that it was already vented by the clearance around where the float needle projects through the top but he advised that this was not enough and the vent needed to be at least a 1/4" tube and that he could see it venting vapor. It feeds fuel directly from the tank to the carburettor. Holley 12-804 Carburetor Fuel Pressure Regulator 1 To 4 PSI Bottom Is Inlet Sides Are Outlets for a sandrail, rock Crawler, KOH, Ultra4, truck, UTV, side-by-side, dune buggy, mini buggy, manx, king of the hammers, 4x4, or Jeep. In this document is a chart for Seasonal Gasoline Specifications. I have the one I have set up in a deadhead setup. Holley fuel pressure regulators are designed to precisely control the fuel pressure from the fuel pump to the carburetor. September 21, 2010 in Technical. 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. Most certainly it will be my plan to fully explore the possibility of "treating the Fuel", with hopes that diesel fuel will make just enough difference to avoid any re-engineering. Please make sure that you are posting in the form of a question. ***The inlet pressure limitation is 7 psi. $12.15: ac000400: Front Axle Beam Bushing Reamer For 1.34 Up To 1.50 Diameter . I cannot help you - and no one can without knowing the exact make up of the gasoline being refined where you are. . WARNING: Operating, servicing and maintaining a passenger vehicle or off-road vehicle can expose you to chemicals including engine exhaust, carbon monoxide, phthalates, and lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. 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). TURNING THE ADJUSTMENT SCREW ALL THE WAY IN WILL RESULT IN EXCESSIVE FUEL PRESSURE . Its a bypass arrangement with non return valves to prevent reverse flow and is operated by a switch for use in event of vapor lock. I would welcome your advice on this - with apologies for the length of this post. They sold more gas than coal oil.