Gbody shorty headers

Status
Not open for further replies.

Texas82GP

Just-a-worm
Apr 3, 2015
7,981
18,676
113
Spring, Texas
Aren't 1-1/2" primaries a little small?
 

Dinosport

G-Body Guru
Jul 20, 2015
557
146
28
Ct
You know I really don't know. To be honest I haven't looked into what I should have for tubing sizes or anything like that. In fact I don't know the tuning size the s10 headers are. Im just not going to pay 1000 dollars for a set of headers and don't want to be bothered with beat and fit. If I were looking for every horse I could get maybe but it's just going to be a fun street car I could put the kids in and take a ride. If somebody knows of a set of long tubes that cost 2-250 that will fit in the Gbody with Holley mounts im all ears.
 

UNGN

Comic Book Super Hero
Sep 6, 2016
3,048
3,264
113
Southlake, TX
Aren't 1-1/2" primaries a little small?

Here a Tube Diameter Formula from the internets:

Tube Diameter

To decide on the right primary tube diameter, there are numerous formulas used in the design of race headers, but for a street car, Don Lindfors of PerTronix (makers of Doug’s, Patriot, and JBA headers) says the following is a great rule of thumb: 200-325 hp look for 1.50-inch diameter primaries, 275-425 hp use 1.625 inches, 400-500 hp use 1.75 to 1.875 inches, and 500 hp and up look for 2 inches or bigger. If you’d like to get more specific, keeping in mind that smaller diameters set a lower limit on peak torque, a 300hp motor could use 1.5- or 1.75-inch primary depending on whether you want the torque at a lower rpm, or to allow it to keep moving higher at a higher rpm. Just a .25-inch increase in primary diameter will push the torque peak up by about 700-800 rpm.

We know many hot rodders like hard numbers, so if you’d like to get as specific as possible and try to size your primary tubes to work effectively within a specific rpm range, try these formulas out:

Primary Pipe Area (PPA) = (peak torque RPM ÷ 88,200) × 1 cylinder ci

To find the PPA, we use A=πr²
For a few common header sizes, this is:
1.5"=1.55
1⅝ = 2.07
1¾ = 2.19
1⅞ = 2.53

For example, for a 350ci engine with a peak torque goal of 5,000 rpm:
PPA = (5,000 ÷ 88,200) × 43.75 ci
PPA = 2.48

To see what the theoretical peak torque rpm of a certain set of headers is for your particular engine, just rearrange the formula:
Peak torque rpm = (PPA × 88,200) ÷ 1 cylinder ci
1⅝ (2.07) = 4,175
1¾ (2.19) = 4,415
1⅞ (2.53) = 5,100

So theoretically, our fairly high-winding 350 with a peak torque of 5,000 rpm should run a set of 1⅞-inch headers. But if your street-oriented 350 makes peak torque at a more typical 4,000 rpm, a set of 1⅝-inch headers would make more sense
 
  • Informative
  • Winner
Reactions: 5 users

motorheadmike

Geezer
Nov 18, 2009
8,976
27,522
113
Saskatchewan, Truckistan
That is not a bad deal at all awdblazer. How well do they fit with the holley mounts. Has anybody with the Holley mounts tried these?

They need mods, but will work.
 

Dinosport

G-Body Guru
Jul 20, 2015
557
146
28
Ct
Dam are there a set of shorties with bigger primaries. The 1 1/2 are kind of small. I really feel like buying a set of headers to modify them to fit. Why cant there ever just be an easy solution that works.
 

Injectedcutty

G body LS mafia
Nov 24, 2014
6,057
22,807
113
Louisville, KY
Dam are there a set of shorties with bigger primaries. The 1 1/2 are kind of small. I really feel like buying a set of headers to modify them to fit. Why cant there ever just be an easy solution that works.
Unfortunately the "easy" solution headers are the costly $800ish type!
 
  • Like
Reactions: 1 user

Dinosport

G-Body Guru
Jul 20, 2015
557
146
28
Ct
I guess Im going to have to get the fbody long tubes and will have to call on a favor from a customer. Easier to do that than to 800 bucks. And as soon as I do it somebody will start selling a set for 300bucks, Im going to have to have the exhaust modified to attach to the shorties I cant imagine it be much more to make the long tubes work now that I really think about it.
 
  • Agree
Reactions: 1 user
Status
Not open for further replies.

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor