[vinniekq2]

I plugged in a few numbers to that calculator
Calculate Required Induction Airflow CFM
Use to determine how large a carb or throttle body to run
Engine Displacement (cubic inches only): cubic inches
Manifold type: Dual Plane Single Plane IR (no plenum)
Volumetric Efficiency @ red line: %
Red line RPM: RPM
Required CFM: 716 to 896 cfm (calculated)
so what carb do I use? rofl?650? 900? that was using a mild 355 at 93% VEjust over 6k redlin

[E.Furgal]

Originally Posted by vinniekq2

I plugged in a few numbers to that calculator
Calculate Required Induction Airflow CFM
Use to determine how large a carb or throttle body to run
Engine Displacement (cubic inches only): cubic inches
Manifold type: Dual Plane Single Plane IR (no plenum)
Volumetric Efficiency @ red line: %
Red line RPM: RPM
Required CFM: 716 to 896 cfm (calculated)
so what carb do I use? rofl?650? 900? that was using a mild 355 at 93% VEjust over 6k redlin

now do it at a more real 80% v/e

[vinniekq2]

If your engine runs at 80% efficiency then fix it

[bygddy]

Originally Posted by vinniekq2

If your engine runs at 80% efficiency then fix it

Funniest thing I heard today......

[E.Furgal]

Originally Posted by bygddy

Funniest thing I heard today......

not really, as most don't get anywhere near 90%

[bygddy]

All I know is,
350,
Alum heads, 10.5:1
525/525
Air gap
Long tubes
It ran fantastic with a BG 650
I swaped to a BG 750
It went 2 tenths faster
Consistantly..
Yes it gave up some low speed response.
But it went 1.6 MPH faster almost every time.....

[bygddy]

Originally Posted by E.Furgal

not really, as most don't get anywhere near 90%

I wasn't arguing its merit as admittedly its over my head......it was funny tho....you gotta admit.....and if his combo is figured out and needs, and makes more power with a big Carb....then the bottom line is, on the whole....the bigger Carb will outperform the littler one!

[E.Furgal]

358cids with 390 carbs, made so much power they added plates to slow the cars..
there is tons more to it than just stabing a 750 on a 350 and calling it good.

[vinniekq2]

390 carbed roundy round cars used longer duration on the intake side.non restricted engines in the same cars made a lot more horse power. My slightly larger carb on my engine works well,even though I only use 3.5 gears and probably too big of cam in most peoples opinions

[chevy302builder18]

Thanks for the responses, im definatly going with a 750 on my 406 cubic inch. it that doesnt make 87% V.E what other alternatives would there be?

[ap72]

Originally Posted by chevy302builder18

Thanks for the responses, im definatly going with a 750 on my 406 cubic inch. it that doesnt make 87% V.E what other alternatives would there be?

a 750 carb on a mild 406 is typically just fine. If its a street engine consider running vacuum secondaries.

[chevy302builder18]

Originally Posted by ap72

a 750 carb on a mild 406 is typically just fine. If its a street engine consider running vacuum secondaries.

Thats exactly what im thinking now that this virtual dyno i have does the V.E calculater. the carb im looking at is quick fuels slayer 750 model

[E.Furgal]

thread started with asking about a 350 now it's a 406?

[chevy302builder18]

Originally Posted by E.Furgal

thread started with asking about a 350 now it's a 406?

Well if you look at the first post it was a friend, and i was confused about his tail of a 570 carb on a 350. and he said somethings pertaining to cfm size and you guys went on and forgot i still have a block sitting, still in current construction of a 406. Theres been many delays on this engine build, been waiting patiently and id like to have it built by this upcoming spring. LOL if it wanst for my stupidity, i wouldnt have to get this thing line honed and line bored. As you can see im still learning each and everyday and the thirst for knowledge is instilled based off the laws and phsysics of every piece of the engine and what it does. so you can say im a big newton fan. And a guy looking to have some fun by the end of the build.
Ive also noticed something very intresting, what Techinspector has pointed out and many other dyno guys on this site, is on the kinda of engine were talking about and big block chevy,(idk if this is true for other engines like ford, dodge ect.) that at 5252RPMs peak torque meets horsepower. intriuging as it is id like to save that topic for another thread involving V.E and other things that could cotribute to this rule of horsepower and torque 5252 rpms

[E.Furgal]

thats because hp that we think of is nothing more than a math formula..
not what that engine can do..
I'm willing to bet a 160hp engine can't pull 1/3rd what 160 horses could..
if it could you'd snap the chain(most front drive cars) or gear teeth everytime it shifted gears at wot at hp peak..