John Scott Posted March 30, 2001 Share Posted March 30, 2001 Fianlly got my 30 psi fuel guage. Set it up like Scottie GNZ, adding boost to the regulator and noting pressure. 0 vacuum was 9 psi. 5 lb= 14psi, 10= 15 lbs uh-oh, 15 psi boost still 15 psi!!! You can't push 15 psi of fuel into a 16 psi pressurized float bowl. Sam, at century performance insisted the Mallory 140 works well with boosted engines, regardless of what the flow chart says. I was sceptical. Set the pump wide open, as recommended, adjusted regulator, and presto. 7psi fuel at 0. 22psi @ 15 psi boost. I know line size is very important at the lower naturally aspirated pump levels. Now I'm questioning how much a smaller line will flow at a higher pump pressure. I'd guess with my application, I'll still be in the zone,...we'll see. In the meantime I wonder if my bowls had enough fuel for the time spent @15+ psi boost? Ignorance is another strong vote for forged pistons. Addendum 11:40AM I have to cringe at my last sentence NOTE: If you have a high pressure pump, don't forget to disconnect the lines to the carburtetor and plug them securely! The needle and seat can handle only about 11 psi, or so I've been told. Anyone care to guess what happens in about 15 seconds if you dont? Gas will run out the top of the carb, and quickly fill all the cylinders. What a dumb #$%! If anyone were unlucky enough to have this happen and manage to get a cylinder to fire, a hydro lock would occur and possibly bend a rod. Remove all sparkplugs, turn engine over by hand. Of course the battery was disconnected and fire extinguisher is handy. After my oil pan is drained and the engine is aired out. I'm going to put on my pointy hat and sit in the corner. JS [This message has been edited by John Scott (edited March 30, 2001).] Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted March 31, 2001 Share Posted March 31, 2001 Just remember there were a lot of Rocket's that Rocket Scientist tested which "Fell short of Successful" before they got it right. Yea; maybe your test could've been a little more "laboratorily" controlled; but just be glad you 'learned' something w/out anything bad happening....like the fuel from the carb spiling onto the engine while running & catching fire/thankfully you did take safety measures. Live & Learn so that you can Live & Learn another day. Just another fine example that Safety First should be everyone's motto. Kevin, (Yes,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted March 31, 2001 Share Posted March 31, 2001 Hope you did not hurt anything when you washed down the walls. ------------------ Scottie 71 240GN-Z Scottie's GNZ Quote Link to comment Share on other sites More sharing options...
John Scott Posted April 1, 2001 Author Share Posted April 1, 2001 I turned the engine 1 revolution by hand to purge the gasoline, let it air out overnight, then sqirted oil in all the cylinders from the spark plug hole, rotated a few more times. I found I had too little fuel pressure @ 10" vacuum, 1-2psi. Added a universal check valve inline to the regulator so only boost would alter pressure. Now I have 7psi @ all vacuum to 0. Finally, everything is where it should be. JS [This message has been edited by John Scott (edited March 31, 2001).] Quote Link to comment Share on other sites More sharing options...
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