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. 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. 1 oz per gallon - not more than 2 is usually in the right "goldie-locks" range. [endif]-->, Many thanks for taking the time to clarify this interesting subject . ). Carb Part, 14 PSI Fuel Pressure Regulator Set 3/8in NPT Port 12804 for Holley : Amazon.com.au: Automotive Reviewed in the United Kingdom on January 31, 2016, Reviewed in Canada on January 27, 2023, Reviewed in Canada on December 18, 2019, Reviewed in Canada on November 10, 2020, Automotive Performance Fuel Injection Systems, Automotive Replacement Fuel Injection Pressure Regulators, Learn more how customers reviews work on Amazon, Holley 12-804 Reg, Fuel Press 1-4 Psi Pol. What you write in post 12 is NOT correct. store the installation of a Holley 12-810 oil pressure safety switch is recommended for installation into the wiring circuit. Shipping cost, delivery date, and order total (including tax) shown at checkout. Holley Bracket Secondary Adjusting Lever Kit Steel Gold Iridited Holley 4150. It needed a bit of adjusting for my purpose, but other than that, it performed perfectly. That's not to say that adding something like kersene won't help, but it can't eliminate the volatile components. 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. Generally speaking if your car was made before 1953 it has low compression. Quadrajets should have 6 to 9 at the inlet or they flood past the needle seats. 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. . I wanted to upload the map, but at 2.73mb, it was too big. 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. When it burns however, it is an eye and throat irritant, even though it raises octane, burns hotter, easier, and cleaner. THE SECOND ISSUE - the vapor system on the Packard is going to be a problem no matter what today. Thinking Kerosene is probably the way I will go at this point. $5 Off Your $100 Mobile App Purchase . The other possibility is that it is due to the higher pump pressure. NOTE: P/Ns 12-841, 12-842, & 12-879 utilize 3/8" NPT inlets and outlets. All petroleum distillates have different chemical properties which change depending on what you mix them with. ESPECIALLY a 10% ethanol blend - once generically called the gasohol summer blend in that vapor system would really be a problem. Thanks again fellows, for such informative posts. If youre looking to dial it in accurately its not going to do it. Each Holley fuel pressure regulator is fully adjustable so regulating the fuel pressure to your engines needs is a simple task. Some can be used for either - or. I mix Industrial Maintenance Coating Thinner (IMCT) around 1 oz per gallon - which is basically a blend of petroleum distillate in the paint thinner / mineral spirits (once called also "white gas") family and ethyl acetate and not only does it cure vapor lock it increases octane because you can feel it in the power and acceleration. When I got it to down to 30 - then the 0-15 psi reg would not hold anymore and climbed to 15 flooding out the engine. I have no idea - you are in uncharted territory. Cool. All Holley regulators are pre-set at the factory so there is no guesswork when first installing the regulator. 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. WARNING! Steve_Mack_CT P/N 12-803, 12-501, 12-804, 12-500, & 15812NOS Installation Instructions WARNING! Reasonable . As Raywith pointed out, you need to let the pressure go somewhere. 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. In fact I can completely remove the adjusting screw and it still does not go down to 3psi. I got all of my supplies in the Home Depot fittings section. 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. It is not all the same. This will keep your pressure steady and have instant pressure change when adjusting. Q: Is there a brand name? . Pre-set at 2.8 PSI There are two kinds and they look the same. Each Holley fuel pressure regulator is fully adjustable so regulating the fuel pressure to your engines needs is a simple task. I will be trying one of these but am curious what is the active ingredient(s). It was about this time that car makers lowered the compression ratios, went to long stroke motors, and developed hot spots and vaporizers on their intakes to burn the new low grade or low octane gas. For cars that require 4.5 to 9 PSI, the Holley 12-803 is the right model. NPT Inlet Attachment: 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. May God's grace bless you in the Lord Jesus Christ. . This product is intended only for the thinning of industrial maintenance coatings. . Overview. How much should I add to every gallon of gas.I believe they are adding about 5% ethanol to the fuel here. I realize this is an old post - but when people write things that are WRONG - it leaves the next Joe who comes along thinking that is the correct answer when especially in this case - it is NOT. 4.9. It was not. The engine was running. [endif]-->