Very convoluted infirmation.
Using Dyno CFM reading for carb sizing
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Re: Using Dyno CFM reading for carb sizing
I always complete my tuning with out the air turbine.
It seems to have an effect on carb metering and booster signal.
It seems to have an effect on carb metering and booster signal.
Adger Smith
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Adger Smith Performance Engines
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Re: Using Dyno CFM reading for carb sizing
Hi Adger,Adger Smith wrote: ↑Sat Sep 04, 2021 12:11 am I always complete my tuning with out the air turbine.
It seems to have an effect on carb metering and booster signal.
A honeycomb element in the tract will help with that tremendously.
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
-Carl
Re: Using Dyno CFM reading for carb sizing
I’ve never seen a eddy carb perform as good as quickfuel.
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Re: Using Dyno CFM reading for carb sizing
A 383 cuin engine, running at 100%VE, will require a specific amount of air volume, depending on rpm.eric8 wrote: ↑Thu Sep 02, 2021 2:03 pm This seems like the most obvious metric for determining an engine’s true cfm needs, so it has me wondering. My mild 430 hp 383 SBC on a Superflo dyno had a cfm rating of 592 at 5,900 rpms. A 650 cfm carb should in fact be plenty, no? Just thinking out loud. Am I missing something?
5000rpm...554 cfm
6000........665
7000........776.
The air volume is dependent on whether the air contains fuel vapor or not. The air mass will depend on air density.
Re: Using Dyno CFM reading for carb sizing
CID x RPM / 3456 = CFM for 100%VEeric8 wrote: ↑Thu Sep 02, 2021 2:03 pm This seems like the most obvious metric for determining an engine’s true cfm needs, so it has me wondering. My mild 430 hp 383 SBC on a Superflo dyno had a cfm rating of 592 at 5,900 rpms. A 650 cfm carb should in fact be plenty, no? Just thinking out loud. Am I missing something?
383 x 5,900 / 3456 = 654 CFM.
Mike Jones
Jones Cam Designs
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Jones Cam Designs
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http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
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Re: Using Dyno CFM reading for carb sizing
Just a WAG as to what might be.
Stan
Stan
Code: Select all
_______STPPwr__STPTrq___BMEP_____Fuel___BSFC___UnCorr_UnCorr_Correct___A/F______Air
__RPM____CHP___Clb-ft____PSI___lbs/hr__lb/hph____HP___Torque__Factor__Ratio____SCFM____VE%
_5900___430.0___382.8__150.8___208.53__.4850___430.0___382.7__1.0001__13.00___591.9___90.6
Stan Weiss/World Wide Enterprises
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Re: Using Dyno CFM reading for carb sizing
Sorry for the delay. Here’s the dyno sheetStan Weiss wrote: ↑Sat Sep 04, 2021 2:39 pm Just a WAG as to what might be.
Stan
Code: Select all
_______STPPwr__STPTrq___BMEP_____Fuel___BSFC___UnCorr_UnCorr_Correct___A/F______Air __RPM____CHP___Clb-ft____PSI___lbs/hr__lb/hph____HP___Torque__Factor__Ratio____SCFM____VE% _5900___430.0___382.8__150.8___208.53__.4850___430.0___382.7__1.0001__13.00___591.9___90.6
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Re: Using Dyno CFM reading for carb sizing
Stan,Stan Weiss wrote: ↑Sat Sep 04, 2021 2:39 pm Just a WAG as to what might be.
Stan
Code: Select all
_______STPPwr__STPTrq___BMEP_____Fuel___BSFC___UnCorr_UnCorr_Correct___A/F______Air __RPM____CHP___Clb-ft____PSI___lbs/hr__lb/hph____HP___Torque__Factor__Ratio____SCFM____VE% _5900___430.0___382.8__150.8___208.53__.4850___430.0___382.7__1.0001__13.00___591.9___90.6
When calculating carb CFM, what allowance is made for fuel vapor, if present?
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Re: Using Dyno CFM reading for carb sizing
David,David Redszus wrote: ↑Tue Sep 07, 2021 7:53 pmStan,Stan Weiss wrote: ↑Sat Sep 04, 2021 2:39 pm Just a WAG as to what might be.
Stan
Code: Select all
_______STPPwr__STPTrq___BMEP_____Fuel___BSFC___UnCorr_UnCorr_Correct___A/F______Air __RPM____CHP___Clb-ft____PSI___lbs/hr__lb/hph____HP___Torque__Factor__Ratio____SCFM____VE% _5900___430.0___382.8__150.8___208.53__.4850___430.0___382.7__1.0001__13.00___591.9___90.6
When calculating carb CFM, what allowance is made for fuel vapor, if present?
That CFM would be like what is measured by the dyno air turbine. When I do carb CFM calculations I ignore the fuel vapor.
Stan
Stan Weiss/World Wide Enterprises
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV