A recent thread here prompted me to ask a similar question, only in connection with my BBC project.
I am doing a low budget 454 Gen IV with stock heads, RPM Air Gap intake, mild cam - not settled on that yet, but it will be approx 220ish give or take, on 112 lsa. 5500rpm max, going in a heavy, tall geared daily driven vehicle.
I bought a nice used set of Hooker long tube headers from a gentleman who told me they were 1 7/8. My bad..... got home and put my calipers on them and they are 2".
Since low rpm torque and decent fuel efficiency are priorities, what do you guys think? Run them, or sell them and buy some smaller headers?
Headers too big? (BBC 454)
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Re: Headers too big? (BBC 454)
You need 1 3/4 by 3 inch headers for your application. The 2 inch will cost some low rpm torque.
Re: Headers too big? (BBC 454)
Thanks for the replies.
Just realized I need to brush up on my Roman Numerals...
It's a Gen VI Vortec 454, not that it would make a huge difference to the replies, just thought I should clarify.
I guess the question is, how much low rpm torque loss are we talking using these 2" primaries vs a set with 1 3/4?
Just realized I need to brush up on my Roman Numerals...
It's a Gen VI Vortec 454, not that it would make a huge difference to the replies, just thought I should clarify.
I guess the question is, how much low rpm torque loss are we talking using these 2" primaries vs a set with 1 3/4?
Re: Headers too big? (BBC 454)
Not sure where you are measuring the tube diameter, but if they are 2" OD size the ID will be about 1-7/8". The tube length in your use will be actually more important than the actual difference between 2" and 1-7/8". The longer the tubes the better for your torque needs. If the headers have primary tubes let's say 28" or longer the 2" or 1-7/8" will be fine. Make sure you spec. a cam that optimizes your torque needs at lower rpms.
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