Head Flow & Intake Choice

[nivvy]

I read an article in Jan. 07 Mopar Muscle Mag. and it listed flow#'s from a MW Ported EZ head that flowed 351 @ .700 lift but when they strapped on the best MW ported intake the flow dropped to 339 and from 351 to 295 with the victor standard port intake ... thats like a 100HP loss going through the intake with the victor??? is MW ports the only way to go

[Chryco Psycho]

with big inch & or high RPM engines the MW port certainly helps , Especially on short rod ratio engines

[moper]

You need to stop racing flowbenches. Every flowbench will record a huge drop in cfms when you bolt on the intake and the carb. That is how things should be tested, but you dont get huge numbers that way, and it adds more inequality to trying to compare results from one bench and operator and another. The only way to compare two parts is to flow them on the same bench, by the smae guy, withing very close times of each other. Otherwise the results will seem skewed. You are combining accepted generalities (like twice the cfm=max HP) and they aren't meant to be compared like that. You use cylinder displacement, minimum cross section, and projected power peaks to choose what you need. MW size is great on a 440 " engine being raced in a very small rpm window (drag racing), and on a 528" street engine that operates over a wide range of rpms. So really, which is better? every engine build is unique. Approach things that way, and use the general info to make choices based on your setup.

[nivvy]

I totaly understand that mopar ... but what im saying if you drop less flow with a MW ported intake then why not run a MW head/intake combo ... granted I have a 499 CID roller motor ... 

If im gonna pay $3500 for indy ez heads why not go a little extra with the MW setup for more power 

[Chryco Psycho]

Assuming the engine can Actually use the Extra CFM then I totally agree use the best intake to work with the heads , using a better intake is one of the basic upgrades 

[moper]

And what I'm saying is you are not using the data as it's intended. All intakes drop a certain amount when tested against a clay or plastic radius entry. Because you are adding restrictions from surface friction, and turns, and limiting the access by the limited amout of air that test bench can pull in. So the numbers you are reading do not directly translate into how that setup will behave on your engine. There is no way to preform a test and see exactly how a head will perform on a real engine. We cannot duplicate the environment  accounting for everything that effects things in there when it's running. The formulas for minimum cross section, curtain area, and average velocity are all used to more accurately predict what the heads and intake will do on your exact engine. The flowbench simply gives numbers for a situation your engine will never be in. The formulas give a prediction for a specific rpm for your engine. On a 499, a MW port opening on an RPM head VS an Indy -1 is a huge difference. CFM numbers give 1/2 the possible story. Overall volume (not incluing the iontake runner section) adds another larger percentage. A race engine, you tend to go with the larger volume, and higher flow numbers for a higher peak number for a given cubis inch. On a street engine, you tend to go with the smallest volume, and higher low and mid lift numbers for a given cubic inch. Very general..but that's all flowbenchs are anyway.

[moper]

And what I'm saying is you are not using the data as it's intended. All intakes drop a certain amount when tested against a clay or plastic radius entry. Because you are adding restrictions from surface friction, and turns, and limiting the access by the limited amout of air that test bench can pull in. So the numbers you are reading do not directly translate into how that setup will behave on your engine. There is no way to preform a test and see exactly how a head will perform on a real engine. We cannot duplicate the environment  accounting for everything that effects things in there when it's running. The formulas for minimum cross section, curtain area, and average velocity are all used to more accurately predict what the heads and intake will do on your exact engine. The flowbench simply gives numbers for a situation your engine will never be in. The formulas give a prediction for a specific rpm for your engine. On a 499, a MW port opening on an RPM head VS an Indy -1 is a huge difference. CFM numbers give 1/2 the possible story. Overall volume (not incluing the iontake runner section) adds another larger percentage. A race engine, you tend to go with the larger volume, and higher flow numbers for a higher peak number for a given cubis inch. On a street engine, you tend to go with the smallest volume, and higher low and mid lift numbers for a given cubic inch. Very general..but that's all flowbenchs are anyway.