| FAQ |
| Members List |
| Social Groups |
| Calendar |
| Search |
| Today's Posts |
|
#1
03-04-2024, 04:16 PM
|
|||
|
|||
headers size for 68 Firebird
What size headers would be required to support a 750 hp engine? Round port.
Looking at a set of Doug's 1-7/8" for a 68 Firebird. Also wondering if they will fit a 68 Firebird? Thanks |
|
#2
03-04-2024, 05:09 PM
|
||||
|
||||
|
|
|
#3
03-04-2024, 05:20 PM
|
|||
|
|||
|
Posted for conversation...
https://www.motortrend.com/how-to/he...s-performance/ Note on the graph it states "inside" diameter. Take note of the tubing used on the headers involved, are they based on a popular 16 gauge or 18 gauge materiel. Example if 16 gauge: .062" thick x 2 sides = 0.124" .
__________________
'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 ) Old information here: http://www.hotrod.com/articles/0712p...tiac-trans-am/ Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine) 5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension https://www.youtube.com/watch?v=qDoJnIP3HgE |
|
#4
03-04-2024, 07:22 PM
|
||||
|
||||
|
Quote:
Meaning, if the cam is not correctly spec'd would larger headers add more power. |
|
#5
03-04-2024, 08:28 PM
|
||||
|
||||
|
I use 2" tubes on my car at around 700 Hp.
__________________
1967 Firechicken, 499", Edl heads, 262/266@0.050" duration and 0.627"/0.643 lift SR cam, 3.90 gear, 28" tire, 3550#. 10.01@134.3 mph with a 1.45 60'. Still WAY under the rollbar rule. |
|
#6
03-04-2024, 08:30 PM
|
||||
|
||||
|
Handy chart.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
|
#7
03-04-2024, 10:17 PM
|
|||
|
|||
|
The handy chart above, again based on the inside diameter.
.
__________________
'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 ) Old information here: http://www.hotrod.com/articles/0712p...tiac-trans-am/ Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine) 5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension https://www.youtube.com/watch?v=qDoJnIP3HgE |
|
#8
03-05-2024, 08:58 AM
|
||||
|
||||
|
Quote:
|
|
#9
03-05-2024, 01:15 PM
|
|||
|
|||
|
I believe 1 7/8 would work fine. I used a set of Doug's recently and had to clearance them on the idler arm and power steering box . These were round ports. The mad dog headers fit well I hear if you can get a set.
__________________
Be carefull of the feet you step on today.They may be attached to the a$$ you kiss tomorrow. |
|
#10
03-05-2024, 01:49 PM
|
||||
|
||||
|
We tried some 1 3/4-1 7/8 step-real short 1 3/4 section and about as big as port on a friend's 650 HP 462 E head roller motor and lost 40 HP and a lot of TQ vs the 2" he had. Used some modified GTO Hookers to fit his 63 Tempest.
__________________
Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
| Reply |
|
|
The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.
Linear Mode
