header tube size

Wade_Owens · 11-20-2011, 08:02 PM

Quote:

Originally Posted by chassis1

Wow, Wade you sound like a real header builder......lol...but you forgot to tell him about the steps in the header and what purpose they serve....

1.625 is the way to go and when you measure that exhaust port, I bet it is really close to that size.....

Chassis1

Lol, I've wasted enough money on headers and hardly ever see a gain. Use the KISS method.........

Wade O

chassis1 · 11-21-2011, 12:35 AM

for the combination you run, there are very interesting ways that are not simple to make the small engines move more air then ever thought. Believe it or not, it is done with the 4 into 1 and not the tri-y because of the cfm of the smaller heads......sometimes you can speed the air up too fast and the smaller engines do not like it.....

Chassis1

Wade_Owens · 11-21-2011, 01:27 PM

Quote:

Originally Posted by chassis1

for the combination you run, there are very interesting ways that are not simple to make the small engines move more air then ever thought. Believe it or not, it is done with the 4 into 1 and not the tri-y because of the cfm of the smaller heads......sometimes you can speed the air up too fast and the smaller engines do not like it.....

Chassis1

Jeff Teuton · 11-21-2011, 05:31 PM

Here is what we got; 360 motor wedge 1 5/8 to 1 3/4 to 1 7/8 with merge collector, 370 motor hemi; same size one runs to 7k, the other past 8k, the 370 liked a 1 3/4 to 1 7/8 about 5 better one made 540, one made 660.

Ed Wright · 11-21-2011, 05:56 PM

Strangely, mine doesn't appear to like step headers. Been running them (1 3/4" to 1 7/8") since last year, but I have never even had the thing on a dyno until recently. Bought them on the recomendation of someone I really respect. The step headers only appear to help down around 5000 RPM. Past that straight 1 7/8" picked it up everywhere. If I were foot braking they might be worth more. Wonder what I'm doing wrong, that it doesn't appear to like them, when everybody else runs them?

Thinking about trying a set of 2" primaries? My old, original-1975-rules-292" C/SM Camaro loved 2" headers. But, it was a stick car leaving over 8000. This is a 358" LT1 trans brake car, the converter hits about 6000.

chassis1 · 11-21-2011, 06:05 PM

1.750 is way too big for the lt1 first step.......measure the ports one of the heads, I think they are more D shaped and barely over an 1.500.....

and remember, just because it is a step header does not mean the steps are correct......

Chassis1

Ed Wright · 11-21-2011, 06:13 PM

Quote:

Originally Posted by chassis1

1.750 is way too big for the lt1 first step.......measure the ports one of the heads, I think they are more D shaped and barely over an 1.500.....

and remember, just because it is a step header does not mean the steps are correct......

Chassis1

The 1 7/8" are even bigger, yet made more power 5500 + up.

MEXJOE · 11-21-2011, 06:34 PM

BOY! You said it !
I've got a bunch of expensive stuff I'm gonna make into wind chimes and try to sell on E-BAY.
"Tune around what you have" is the best advice I ever got.
KISS method.........

Quote:

Originally Posted by Wade_Owens

Lol, I've wasted enough money on headers and hardly ever see a gain. Use the KISS method.........

Wade O

chassis1 · 11-21-2011, 08:07 PM

everyone seems to forget that the cam is still the brain of this deal when it comes to headers. most of the time, off the shelf STOCKER cams are still very old designs and are not made to be as efficient as some headers are built or bought, no matter what your engine guys chooses.....truth is most engine guys miss on the cam and go to what they call, " ol' reliable cams...." but yet the racer seems to think better than the engine builder sometimes...and looks at his WHOLE combination......

Chassis1

K Stubbs · 11-22-2011, 12:44 AM

I know a racer that ran a 69 Camaro 350/255 auto stocker. He had a set of Kromer (sp?) step headers that were 1/12 - 1/58 - 13/4. He blew out a tube at a race and put on a straight 13/4 on that side and did not affect performance one bit. He ran it like this for a couple of years and won class many times including Indy. Like Wade said, unless you are way out in left field there is probably not a big performance difference in them.

11-21-2011, 12:35 AM	#2
chassis1 Junior Member Join Date: Nov 2003 Location: drag city, ne Posts: 92 Likes: 1 Liked 9 Times in 3 Posts	Re: header tube size for the combination you run, there are very interesting ways that are not simple to make the small engines move more air then ever thought. Believe it or not, it is done with the 4 into 1 and not the tri-y because of the cfm of the smaller heads......sometimes you can speed the air up too fast and the smaller engines do not like it..... Chassis1

11-21-2011, 05:31 PM	#4
Jeff Teuton VIP Member Join Date: Jan 2002 Location: Houma, LA Posts: 2,717 Likes: 2 Liked 325 Times in 50 Posts	Re: header tube size Here is what we got; 360 motor wedge 1 5/8 to 1 3/4 to 1 7/8 with merge collector, 370 motor hemi; same size one runs to 7k, the other past 8k, the 370 liked a 1 3/4 to 1 7/8 about 5 better one made 540, one made 660. __________________ Jeff Teuton 4022 STK

11-21-2011, 05:56 PM	#5
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: header tube size Strangely, mine doesn't appear to like step headers. Been running them (1 3/4" to 1 7/8") since last year, but I have never even had the thing on a dyno until recently. Bought them on the recomendation of someone I really respect. The step headers only appear to help down around 5000 RPM. Past that straight 1 7/8" picked it up everywhere. If I were foot braking they might be worth more. Wonder what I'm doing wrong, that it doesn't appear to like them, when everybody else runs them? Thinking about trying a set of 2" primaries? My old, original-1975-rules-292" C/SM Camaro loved 2" headers. But, it was a stick car leaving over 8000. This is a 358" LT1 trans brake car, the converter hits about 6000. __________________ Ed Wright 4156 SS/JA

11-21-2011, 06:05 PM	#6
chassis1 Junior Member Join Date: Nov 2003 Location: drag city, ne Posts: 92 Likes: 1 Liked 9 Times in 3 Posts	Re: header tube size 1.750 is way too big for the lt1 first step.......measure the ports one of the heads, I think they are more D shaped and barely over an 1.500..... and remember, just because it is a step header does not mean the steps are correct...... Chassis1

11-21-2011, 08:07 PM	#9
chassis1 Junior Member Join Date: Nov 2003 Location: drag city, ne Posts: 92 Likes: 1 Liked 9 Times in 3 Posts	Re: header tube size everyone seems to forget that the cam is still the brain of this deal when it comes to headers. most of the time, off the shelf STOCKER cams are still very old designs and are not made to be as efficient as some headers are built or bought, no matter what your engine guys chooses.....truth is most engine guys miss on the cam and go to what they call, " ol' reliable cams...." but yet the racer seems to think better than the engine builder sometimes...and looks at his WHOLE combination...... Chassis1

11-22-2011, 12:44 AM	#10
K Stubbs Member Join Date: Aug 2008 Location: Benton, Arkansas Posts: 402 Likes: 0 Liked 20 Times in 3 Posts	Re: header tube size I know a racer that ran a 69 Camaro 350/255 auto stocker. He had a set of Kromer (sp?) step headers that were 1/12 - 1/58 - 13/4. He blew out a tube at a race and put on a straight 13/4 on that side and did not affect performance one bit. He ran it like this for a couple of years and won class many times including Indy. Like Wade said, unless you are way out in left field there is probably not a big performance difference in them.