Part #: 12-807. . Post in the forum instead. It will get you close. With this set up, pressures throughout system varies only very slightly from atmospheric, lower up to the vacuum tank and higher in the gravity feed from the vacuum tank to the carburettor. For over a century Holley has driven the cutting edge of fuel-system design. So in an open cup the boiling points would also appear the same as water but under pressure the boiling point is different. Add some heavy ends. 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. Volatility is a measure of the gasolines tendency to vaporize under a given set of conditions. Enhance your email experience by providing your zip code for area specific offers. [endif]-->. Note also that PURE ethylene glycol is also flammable but also miscible with water. September 21, 2010 in Technical. P/N 12-803, 12-803BP, & 12-804 Installation Instructions 199R7914-3 NOTE: 12-803BP IS NOT TO BE USED WITH MECHANICAL FUEL PUMPS! By 1913 it was the other way around. [endif]--> http://www.bp.com/liveassets/bp_internet/retail/retail_australia/STAGING/local_assets/downloads_pdfs/f/FN_modern_petro_vintage_engines.pdf,