enough carburetor

tomj wrote: OK, i give up! the 44 IDF is a too-large carburetor. wow did i learn a lot about carburetors... the low-speed stuff tuned up ok and by the book, but adjustments felt soft. that wasn't the problem, which was the fact that i was driving over 60 mph on the low-speed circuit. big hint that this engine is simply not pumping enough air to make the main venturi work. even with 2.2mm main jets it was still lean. i stopped messing around when i realized that even if i got it jetted right, i would be doing a lot of driving right on top of the low speed/high speed crossover region. so the 38/38 DGV is back on, but this time i made a very nice plenum, similar to the one i made for the 44 IDF. it bolts to the opened-up 2V cover (Rochester 2G pattern). WORKS PERFECTLY. man i learned a lot and sadly spent a lot of money. updated the main web page for it: https://195.6ohv.com/INDUCTION/index.html

tomj wrote: thanks. i have almost as much money in jets as i do carb. dunno what i'll do with the thing. it's a nice carb to work with!  no choke is a minus though; i have to start it three times to get it to drive off, not so good on the starter.

I know what all the CFM charts and fun VB script and Java stuff on various car pages out there says - but I ran across a CFM calculator that said my 360 was fine with the dual quads I have - they suggested for my car 1100. Well, the two Edelbrocks (which suck, literally and figuratively) exceed that a bit but it's pretty close. I think it was either a Holley page or perhaps a site selling intakes. In any case, the idea was that my engine was ok with what's on it - and it flies in the face of all the "conventional wisdom" out there. It's got torque - plenty of low-end, no slouch even putzing around town with it (but the 2500 converter can be an issue trying to keep under the speed limit in some places in town as I have to keep feathering it)

It's not just the diameter of the valve head - it's the stem, the shape, and any shrouding, etc A big valve that's shrouded is worse than a smaller one with no shrouding, IMO. There's a whole lot of design factors. 

tomj wrote: i think you either design the snot out of it (eg. the current lean-burn stuff, runs at 65:1 afr!), or you rule-of-thumb it and swap and tune. so i'm swapping and tuning :-) foolishness, but fun and knowldge-gaining. then i get to drive it.

Good attitude - and more fun. You do learn more that way, don't you, rather than someone always telling you what's what....... get your hands dirty and your feet wet. And you'll remember what you've discovered a lot better, too, IMO.