car stumbles on take off.

[dannyracer6]

I am going to try some stuff today. Big E, My cam card tells me my rpm range is from 42 to 82. It is a solid roller crane 300/310 with a lift of 535. It is an iron head with a very nicely done efi intake. Not just a big hole. I don't have the money or access to a dyno or I would get it done that way. I will not try too many things at once so as to not know what is theproblem. we will see.

[dannyracer6]

I put in the 4.5 power valve, I checked my vacuum and it is a 9ish, 1/2 of that is 4.5 so I used the 4.5. I have 5# of fuel pressure using 3/8 solid alum fuel line accept to the carb and it is same size flex hose. I stayed with the pink cam and installed a 28 squirter that I modified ala dave Carpenter. He knows what I mean. It is 80% better with the 30cc accel pump. No pull over to speak of, and from 3500 or so, when I accel it will rev without any problems all the way to 8000 and I only did that once, It is crisp and will come right back down to idle at around 1200 and it seems to like it there. I have 71 jets. thinking of going up one step just so it will not lean out. I am happy with it mostly. Still has a bit of stutter just off idle when I hit throttle. but I am not driving it just off idle, as Big E mentioned. I think I will try this. thanks for all of your help. I used a little bit of everything. I love 4m net.

[let-r-eat]

Double check your transfer slot placement and make sure you don't have the butterflies open too far at idle. The butterfly should make the slot square..........not a rectangle *about. .030 down on slot*This picture illustrates a transfer slot exposed too far:

[let-r-eat]

If you need to open the throttle blades that far to get the engine to idle then you need to drill the throttle plate hole a little larger to allow the butterfly to close some.

[dannyracer6]

thanks, I will check that.