Inlet manifold runner length

[Clare Snyder]

The throttle body may be anywhere along the lenth of the runner. The runner
"runs" from the valve to open air - in your case, the plenum. On a carb/cyl or
Hilborn injection system, the "stacks"above the carb become part of the runner
length.

Stuart Bunning wrote:

> Thanks Bruce
>
> But this doesn't help me.
>
> I have a program called ENGINE ANALYSER that will tell me the runner length
> for whatever application or tell me HP/Tor for different runner lengths but
> my question is where exactly to I measure the runner length. valve to plenum
> or valve to throttle body ????
>
>
>
> At 08:38 PM 27/9/98 -0400, you wrote:
> >
> >-----Original Message-----
> >From: Stuart Bunning <stuart at kenelec.com.au>
> >To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> >Date: Sunday, September 27, 1998 8:08 PM
> >Subject: Inlet manifold runner length
> >
> >
> >>I am in the process of making a custom EFI inlet manifold for a straight
> >six.
> >>I will be using a common plenum and a single throttle body or possible two
> >>throttle bodies not sure yet.
> >>Can anyone tell me the correct way of calculation the inlet runner length.
> >
> >At the bottom of the DIY_EFI home page is an area for calculations,
> >and one of them is for runner lenghts.
> >>
> >>I assume inlet valve to plenum. Or is it inlet valve to throttle body this
> >>calculation will add a extra few inches as the plenum is usually a few
> >>inches wide. After the throttle body there will be a length of about 20
> >>inches of ducting to a airbox. I assume this is not relivent.
> >>
> >In some testing I did was best to keep this volume .5 to .75 engine
> >displacement.
> >Bruce
> >
> >
>
> Best Regards,
>
> STUART BUNNING
> SALES ENGINEER
> KENELEC PTY LTD
>
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>
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