Cathedral vs ls3 test on a 408
11 Second Club
Joined: Mar 2012
Posts: 1,541
Likes: 15
From: South Florida
It's called Minimum Cross Sectional Area. If you don't have enough, or if you have too much, you won't make much power. MCSA is limited by your valve size. The 317 casting has 2" intake valves but the 821 and AFR heads have 2.165" intake valves.
So it's a lot like trying to breathe through a coffee stirrer versus a paper towel roll. The rectangle port makes good power just because it has more adequate MCSA. To get the same MCSA out of a cathedral head, you need to do a lot of work to an OEM casting or start with an aftermarket casting.
I'm sure you understand this, but carry on with your troll posts.
So it's a lot like trying to breathe through a coffee stirrer versus a paper towel roll. The rectangle port makes good power just because it has more adequate MCSA. To get the same MCSA out of a cathedral head, you need to do a lot of work to an OEM casting or start with an aftermarket casting.
I'm sure you understand this, but carry on with your troll posts.
11 Second Club
Joined: Mar 2012
Posts: 1,541
Likes: 15
From: South Florida
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with ya.....
It's called Minimum Cross Sectional Area. If you don't have enough, or if you have too much, you won't make much power. MCSA is limited by your valve size. The 317 casting has 2" intake valves but the 821 and AFR heads have 2.165" intake valves.
So it's a lot like trying to breathe through a coffee stirrer versus a paper towel roll. The rectangle port makes good power just because it has more adequate MCSA. To get the same MCSA out of a cathedral head, you need to do a lot of work to an OEM casting or start with an aftermarket casting.
I'm sure you understand this, but carry on with your troll posts.
So it's a lot like trying to breathe through a coffee stirrer versus a paper towel roll. The rectangle port makes good power just because it has more adequate MCSA. To get the same MCSA out of a cathedral head, you need to do a lot of work to an OEM casting or start with an aftermarket casting.
I'm sure you understand this, but carry on with your troll posts.
