I have read about head flow for years,But?????
Moderator: Team
-
- Guru
- Posts: 3285
- Joined: Wed Jun 25, 2008 1:46 pm
- Location: NC
Re: I have read about head flow for years,But?????
...
Last edited by Warp Speed on Thu May 03, 2018 7:47 pm, edited 1 time in total.
-
- Guru
- Posts: 3285
- Joined: Wed Jun 25, 2008 1:46 pm
- Location: NC
-
- Expert
- Posts: 816
- Joined: Fri May 18, 2007 6:46 pm
- Location: Crane, Texas
- Contact:
Re: I have read about head flow for years,But?????
Airflow is not the be all end all in making power. You need air flow sure, but the runner size and shape and fuel handling is just as important.
Abbott Racing Heads and Engines
Re: I have read about head flow for years,But?????
IIRC, 4-bbl carbs are rated at 1.5 inches of vacuum and 2-bbls at 3".
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
Studebaker-Packard V8 Limited
Obsolete Engineering
Re: I have read about head flow for years,But?????
What do they flow a single throttle body at? Thanks, Charlie
Servedio Cylinder Head Development
631-816-4911
9:00am - 9:00pm EST
631-816-4911
9:00am - 9:00pm EST
Re: I have read about head flow for years,But?????
I'm just saying that if you rated a carb at 28" the cfms would be a lot more than what they are rated at. What would the 300 cfm intake port flow at 1.5" of vacuum? The restriction is not at the carb because the intake isn't drawing all 8 cylinders at the same time. I didn't quite understand the point you were getting at regarding a 300cfm intake port and 800 cfm's at wide open. Not arguing I'm just trying to understand.
Re: I have read about head flow for years,But?????
Sinc he has a supercharger it should be real simple.
The runners are short enough you can just go by size. The carb needs to match the draw of the supercharger.
The runners are short enough you can just go by size. The carb needs to match the draw of the supercharger.
Re: I have read about head flow for years,But?????
1 bbls carbs were also rated at 3.0" Hg.
EFI throttle bodies are a relatively recent development (compared to 1 or 2 bbls.) and with no fuel mixing duties, can be sized for less WOT restriction, so regardless of barrel count (3 on the 1990-95 Corvette ZR1...) an aftermarket manufacturer would almost certainly rate them at 1.5" Hg.(20.4 H2O).
OEMs? Who knows unless they list it...
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
- Stan Weiss
- Vendor
- Posts: 4823
- Joined: Tue Feb 20, 2007 1:31 pm
- Location: Philadelphia, PA
- Contact:
Re: I have read about head flow for years,But?????
Jay,Warp Speed wrote: ↑Thu May 03, 2018 6:39 pm Why does a port need to flow 300cfm, when the engine running full song doesn't pull 800 total?!?
How much will that port flow in 3 Milliseconds?
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
-
- Guru
- Posts: 3285
- Joined: Wed Jun 25, 2008 1:46 pm
- Location: NC
Re: I have read about head flow for years,But?????
Kinda my point...........I think?!? LolStan Weiss wrote: ↑Fri May 04, 2018 12:01 amJay,Warp Speed wrote: ↑Thu May 03, 2018 6:39 pm Why does a port need to flow 300cfm, when the engine running full song doesn't pull 800 total?!?
How much will that port flow in 3 Milliseconds?
Stan
-
- Member
- Posts: 133
- Joined: Mon Jun 27, 2005 10:22 pm
- Location:
Re: I have read about head flow for years,But?????
You need velocity
Stephen Johnson #2162
Horace Johnson #2167
SS/D 427 Ford Fairlane NHRA-IHRA
Ex-Jim Van Cleve
1985 Mustang GT N/A 331
Horace Johnson #2167
SS/D 427 Ford Fairlane NHRA-IHRA
Ex-Jim Van Cleve
1985 Mustang GT N/A 331
Re: I have read about head flow for years,But?????
The CFM that an engine consumes at X RPM is one thing.
The CFM that a head flows at a certain no of inches water is something completely different.
As is the no of CFM that a carburettor flows at x inches Hg,
3 completely different things with nothing in common apart from "CFM".
The CFM that a head flows at a certain no of inches water is something completely different.
As is the no of CFM that a carburettor flows at x inches Hg,
3 completely different things with nothing in common apart from "CFM".
Re: I have read about head flow for years,But?????
Isn't the carb rated in inches of mercury vs cyl heads in inches of water (i.e. using manometer) the numbers would all have to be taken at the same depression, using the same measuring device to in any way correlate the cfm of the carb vs the port.
Re: I have read about head flow for years,But?????
Sorry I just saw Joe mentioned the same thing I did.