Reasonable . Holley 12-840 4.5-9 PSI Adjustable Billet Fuel Pressure Regulator with 3/8" NTP Ports,Black Anodized Brand: Holley 24 ratings | 11 answered questions $10902 & FREE Returns The package length is 9.652 centimeters The package height is 6.604 centimeters The package width is 9.144 centimeters Package Weight : 0.2 pounds See more product details Yes. I switched on the electric pump and it instantly picked up and ran for a few seconds then reverted to the classic vapor lock symptoms. 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. 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. 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. As you can see in the photo it's gold, (the same colour as what's in the model 12-803) I called Holley directly and customer service is acting like they're unaware of the issue, even though I've read threads online going as far back as 2018 mentioning this. 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. $12.15: ac000400: Front Axle Beam Bushing Reamer For 1.34 Up To 1.50 Diameter . Average for the last 12 months. Applications. The reg takes 3/8" fittings and the gauge takes 1/8" fittings. I had a chrome dial regulator, which leaked gas everywhere but luckily didn't actually burn down my ride. They use gravity feed from vacuum tank mounted under the hood and directly over the exhaust manifold. 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. Includes initial monthly payment and selected options. Take a look at the article below. Much of the excess engine heat will end up soaking the fuel system under the hood. Overview. Copyright 2008-2023 OReilly This approach is not recommended for higher compression cars made from the mid fifties onwards. Please choose a different delivery location. All Holley regulators are pre-set at the factory so there is no guesswork when first installing the regulator. [endif]--> Many thanks for taking the time to clarify this interesting subject . 3 0 obj <>stream In fractional distillation (the refining of oil) - what we call "mineral spirits", "paint thinner", "kerosene" and "diesel fuel" all ALL "heavier" hydrocarbons (pretty much in that order) than what we call gasoline - in that they occur lower in the distillation tower and condense at lower temperatures back into liquid before what we call "gasoline" does. Please try again later. That work continues today through Holleys EFI products as well as through Holleys family of brands. You'll find they both have the same initial boiling point - been there and done it. Talk to the experts. Installation was made more complicated by the absence of a port for a pressure gauge, which means Too much fuel pressure for a given needle and seat assembly can overload the needle and seat and may cause flooding or drivability problems. For more information go to www.P65Warnings.ca.gov/passenger-vehicle, WARNING: This product can expose you to chemicals including Styrene which is known to the State of California to cause cancer. store I have adjusted a 6-9 lbs pump down. One common problem is when you have an abnormally warm day in the winter, and the low vapor pressure gasoline in the car will vapor lock on that hot day. But it is not the ethyl acetate alone that causes the effect to raise the vapor temperature point of fuel. Mounting Bracket Included. I Have problems with the fuel temp in my 1937 Buick. Then, we got what was loosely described as winter gas, all year round, with RFG. LASTLY on your first issue of understanding vapor lock and boiling point. Find an Automotive Service Professional 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. All Holley regulators are pre-set at the factory so there is no guesswork when first installing the regulator. I'm still looking for the reg in this pic. You refer to the problem of the additive increasing the propensity for the fuel to self ignite however in my case the compression ratio of the cars is so low (around 4 : 1) that I doubt that it would be a problem. We encountered an error while updating this page. Adjustable Fuel Regulation From 1 To 4 PSI.220 Inch 7/32 Inch Restriction. In fact I can completely remove the adjusting screw and it still does not go down to 3psi. 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. Loosening the regulator locknut and turning the adjustment screw clockwise increases the pressure. Also in Tools, Shop Equipment & Chemicals, Cataclean - Fuel and Exhaust System Cleaner, Cataclean Diesel - Fuel and Exhaust System Cleaner, Distribution Blocks, Filters, Adapters and Fittings, Microswitch and Solenoid Mounting Brackets, Mr. Gasket Fuel Pressure Gauge - 0-15 PSI - 1-1/2 Inch Diameter, Mr. Gasket Fuel Block with 0-15 PSI Liquid Filled Fuel Pressure Gauge, 25 GPH Holley Mighty Mite Electric Fuel Pump, 1.5-4 PSI, Earl's Fem.1/8" NPT to Male 3/8" NPT Pipe Bushing Reducer. Holley fuel pressure regulators are designed to precisely control the fuel pressure from the fuel pump to the carburetor. Regulator Box showed signs of being opened and clumsily closed and the advertised Rubber Gasket or Gaskets that were mentioned in the instructions were missing. Worked well out of the box. P/N 12-803, 12-803BP, & 12-804 Installation Instructions 199R7914-3 NOTE: 12-803BP IS NOT TO BE USED WITH MECHANICAL FUEL PUMPS! 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. I am having problems understanding why you say OD is wrong and Rusty is correct, it seems to me you are all saying much the same and that is that gasoline is made up of many components each having different boiling points and the components with the lowest boiling point are the cause of vapour lock. (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). Full content visible, double tap to read brief content. Some have reported more power, easier starting and cooler running especially in very low compression cars of the twenties and early 30s. The higher the RVP, the greater the tendency to vaporize or vapor lock. . We dont share your credit card details with third-party sellers, and we dont sell your information to others. We currently do not have an estimate when this item will ship. The other part numbers utilize an AN O-ring inlet, outlet, & return ports, and do not require any sealer on the threads. 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. Two 3/8" nipples/hose connections and a 3/8" to 1/8" reducer. I will be fitting a pressure regulator, it can only help and will have to wait for the next vapor lock to occur to see if it overcomes the flooding. Quadrajets should have 6 to 9 at the inlet or they flood past the needle seats. ). A: 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. It is an experimental thing and MORE IS NOT BETTER - less is better until you find the happy medium based the fuel you buy or have in the tank already. 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. Q: Show details The Holley 12-840 fuel pressure regulator features 3/8" NPT in/out ports. Q: If so how? Will buy again if I need another one for a different project. He asked about issues and thoughts of what causes vapor lock, so it is just answered in more detail and suggested solutions on how to fix vapor lock. 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. Can you adjust the fuel pressure? We tend to speak of pressure as higher or lower than atmospheric however it is a relative measure and pressure applies under all conditions. The Holley Fuel Pressure Regulator (Part No. TURNING THE ADJUSTMENT SCREW ALL THE WAY IN WILL RESULT IN EXCESSIVE FUEL PRESSURE . You would'nt just be reading the inlet pressure would you? See also Tom Ogle's "modern" vapor fueling system - google it. These will raise the boiling point of the fuel but reduce the octane. Sorry, we were unable to perform your search at this time. 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. These cars have the carburettor mounted in "V" of the engine with exhaust manifolds running along each side of the carburettor which combined with under hood engine heat makes these cars very susceptible to vapor lock. It works but not as well as some of the off brands like spectre. [endif]-->