ChadSpeierRacingHeads wrote: ↑Mon Nov 28, 2022 8:56 pmI wish I could get my 350/360hp Super Stock engine at 11" total. The E is the only manifold that fits under the hood. So I'm at 5.140 head and 5.000 manifold, But it has a ton of taper from 3.500in at plenum to 1.95 at head opening and 1.85 at PR. I shrink the manifold and it kills power. These peak at 7300 and trap at 8800 with 10.140 total.Lloyd klem wrote: ↑Mon Nov 28, 2022 8:43 pmI will give you my opinion on where I would be if trying to peak say 7500 and run out to 8000ish.If mine I would have intake valve about 52 percent of bore being used.I would leave my throat 91 to 91.5 of that valve.I measure my runner length from valve seat to say about 3/8" back from radius in plenum opening.So imo for that rpm I would be wanting right at 11" total runner tract.So if head port average is 5.5" then that leave same 5.5" avr of runners in intake manifold.This is my opinion and just something to think about and look at.If you had say 2.55" csa at upper runner area in head I would be looking at about 3.6" on my long runner in plenum for csa and 3.25ish on my short center runners.This can be changed with other variables as cam events etc used .Again this is just where I would be and roughly what I have used in that similar area.I like 2" 4 hole radius into open spacer for general tuning.I like to have carb blades away from floor of manifold etc.steve cowan wrote: ↑Mon Nov 28, 2022 2:15 am
Lloyd,
Really appreciate your input and photos etc,you do really nice work.
I have a question for you or anyone else who wants to answer -
My engines are 550 - 600hp 383 sbc stuff I run
Street/ strip car 3600 pounds.
I have done a few single plane intakes
Vic Jr
300 - 25
SV
and I have several others.
When I size a intake and decide on what I think is close I make the CSA of both runners the same only length is the governing factor.
I always open carb pad and have lots of spacers.
The question regards keeping the intake manifold runners the same size.??
I currently run at 6000 - 7500rpm window but one combo will go 8000rpm next year hopefully using the big trickflow intake manifold.
Thanks in advance
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That is great info.Nice of you to explain and share that..