Quote:
Originally Posted by Ivan D.
I got #60 jets in my primaries, can't even find these unless order directly from Holley, and even the Holley kits start at #64. Secondaries get #62 jets, and are delayed all the way to 3/4 throttle, so unless I really floor it they don't even crack. Really, the secondary opening motion is a pretty much 1:1 copy of my Q-jet, somehow i wasn't too happy with the secondaries opening at 1/4 throttle. My power valves are 8.5 primary (half the idle vacuum, which is 17"Hg) and 6.5 secondary, may go down to 6.5 primary and 4.5 secondary tho, test driving will show which is better combo. It's definitely not yer typical double pumper, and I'm firmly determined to make it hit the 15mpg mark 
By the way, that may be a real dumb question, but if the engine runs lean all the time will it still be a gas hog? I never see black smoke coming outta the exhaust, so I can't be running too rich, yet again the fumes have a pretty sweet and heavy smell to them... |
Ivan D, what are you running for a cam in that recently "refreshed" engine? If you are running a rather lumpy cam, then you are trying to make up for it with adjustments to your idle circuit on yur carb, to keep it at an even idle when stopped. This is especially hard to do when the truck is in gear, with an automatic tranny. This process takes the idle mixture out of the idle circuit and puts it in the "transition" area towards the primaries coming open, because you are trying to make up for the idle by making the engine idle faster. I solved some of that when I put in a different stall convertor in my tranny and got the truck to sit at a stop light without trying to pull the truck through the light on a high idle. Along with a bigger cam, comes that sweet heavy smell of gas fumes that you are talking about. I managed to get my 383 stroker to a 15 MPG with the lopey cam and an auto tranny.
Don't take the engine too lean or it will hurt your internal parts.