http://www.jalopyjournal.com/forum/showthread.php?t=386155, Kingman, Arizona - The place on the way to other p, http://www.holley.com/types/Fuel%20Pressure%20Regulators%20-%20Carbureted.asp, (You must log in or sign up to reply here. #2. 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. P/N 12-803, 12-501, 12-804, 12-500, & 15812NOS Installation Instructions WARNING! 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. Unfortunately, these FPR are now made in Korea and they no longer include an alternate spring. Yes you can adjust fuel pressure with this regulator. The ethyl acetate in the IMCT loosens hydrogen bonds on the gasoline making it easier to light to burn, but the "oil" - heavier hydro-carbon nature keeps the vapor point higher and flash point still low enough to give good performance. 1996-2023, Amazon.com, Inc. or its affiliates, Select a location to see product availability, Holley HOL 12-804 12-804 Fuel Pressure Regulator. There was a problem adding this item to Cart. 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. . So, I take the reg apart to see if it is all clean and looks good. That is why fuel injection systems push usually 45 to 60 psi on the fuel at all times with a by-pass line - to keep it liquid and keep it moving - so it cannot turn to vapor in the lines. Then I got this good one, to try to get 1.5 PSI to the Kadrons. I do wish there were some stamped values on the adjustment screw like other models I have seen. Will rise to above 180 degrees on the Temperature gauge. Changing the vapor pressure (and thus the boiling point) of gasoline is not new. It's a diaphram with a spring. As an example water would boil and thus "vapor lock" at a really low temperature without ethylene glycol. But it is not the ethyl acetate alone that causes the effect to raise the vapor temperature point of fuel. Then I got this good one, to try to get 1.5 PSI to the Kadrons. I have just this Spring started taking temp. 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. Any of these heavier than gasoline petroleum distillates above will raise the vapor point of gasoline if mixed into it. 12-804 : Quantity: Share : . Point and secure it into a clean container Inlet pressure of 7 psi limitation means your pump can not put out more than 7 psi to the regulator for it to properly operate. I have heard true lead (LeadMax2000 or simillar) may do this as well? if you were packing them in boxes they would look identical. I did, works great & looks beautiful. One must understand the chemical reactions and interactions of blending other hydrocarbons into what we call gasoline and then still have it able to have the same properties desired of the product called gasoline. te4cmCbGnt]&~`N@RPyBTa$=~fo:/T 92YE)3Uofo4Ou].-zowDt*ae^qf9z/?. 12-804 Part Type: Fuel Pressure Regulators Product Line: Holley Fuel Pressure Regulators Summit Racing Part Number: HLY-12-804 UPC: 090127020234 Regulator Pressure (psi): 1-4 Regulator Style: Non-return Regulator Location: Inline Boost/Vacuum Reference Port: No Gauge Port: No Inlet Quantity: 1 Regulator Inlet Size: 3/8 in. Lots of Chinese Holley 12-803, 804 etc knock-offs are available. TURNING THE ADJUSTMENT SCREW ALL THE WAY IN WILL RESULT IN EXCESSIVE FUEL PRESSURE . Mr. Gasket 1561 Fuel Pressure Gauge 1.500 in. Holley's products also include performance fuel pumps, intake manifolds and engine dress-up products for street performance, race and marine applications. Use with standard pump only -not recommended for maximum pressure pumps. Too much fuel pressure for a given needle and seat . On the Holley 12-804 fuel pressure regulator, the factory preset is supposed to be 2.8 pounds - can anyone say is Holley usually pretty accurate on these presets? ***The inlet pressure limitation is 7 psi. There is no "chemistry set" method to measure fuel vapor points. Enhancements you chose aren't available for this seller. 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 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. A: For the best experience please upgrade or visit the site on another browser. Spring clothes pins, aluminium foil, wet burlap, etc. Average for the last 12 months. 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. This Holley universal low pressure fuel regulator is factory-set to 2.7 PSI, but is fully adjustable from 1 to 4 PSI. What you write in post 12 is NOT correct. Too much anti-freeze - (typically ethylene glycol) causes the opposite effect even under pressure of the cooling system. The thinner, lighter products are at the light end of the scale the thicker heavier products are at heavy end. Somewhat of an inconvenience but that's why it's probably cheaper than other places selling the same part number. 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. The other part numbers utilize an AN O-ring inlet, outlet, & return ports, and do not require any sealer on the threads. In the fuel use map in the Exxon or Mobil gasoline websites, there are a few places where the Reid Vapor Pressure spec is varied from other fuels. 9 really is max. What Rusty writes IS correct. Though I once has it working with only two 0-140 regulators, and since I had messed with the 0-140 regulator on the carb feed side trying to get it to work previously - it popped up to 50 psi - but the 15 psi reg held at 9 psi to the carb - for about 5 minutes, until I tried to reduce the 0-140 below 50 psi.