2 part question. Firstly what everyone opinions on header sizes? When do you need a 1 3/4 tube header for a SBC versus a 1 5/8? This leads me to my second question. Has anyone ever used or tried to use circle track headers? I see them advertised for G Body street stocks. Reasonably priced, but im not sure if they would work in an actual stock car. Just curious. Thanks in advance.
Header questions
- Thread starter stubnosebrock
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Header tube diameter is determinded by the engine build and size. A smaller tube header works better on a smaller engine and/or more mild builds. A header sized too big hurts the headers ability to scavage the cylinders ( especially at lower RPM's ). Usually people use headers that are just too darn big, but sometimes ( like in my case ) it's because you have no choice due to what's available. If the Olds exhaust ports weren't so damn big and a smaller tube header could bolt up to it without over lapping the port, a 1 5/8" header ( or maybe even 1 1/2" ) would work better for me.
Header tube length and collector size/shape also factor into how a header will function on a particular engine. Remember, a headers primary function isn't to flow lots of exhaust gas. It's main job is to scavage the cylinders. If a headers main job was to just be a big low restriction tubular manifold, then a bigger header would always be better, but that's not how headers really work.
Header tube length and collector size/shape also factor into how a header will function on a particular engine. Remember, a headers primary function isn't to flow lots of exhaust gas. It's main job is to scavage the cylinders. If a headers main job was to just be a big low restriction tubular manifold, then a bigger header would always be better, but that's not how headers really work.
DoubleV said:
So of couse, the next question is....why dont they make smaller tube headers for Olds engines?
+1 to doublev
you are fine with the standard size headers of 1 5/8. once you start getting into a race motor then you bump up to 1 3/4 or like me who is pumping out some serious power and track only you spend the cash and go with a 1 7/8 to a 3.5 collecter
you are fine with the standard size headers of 1 5/8. once you start getting into a race motor then you bump up to 1 3/4 or like me who is pumping out some serious power and track only you spend the cash and go with a 1 7/8 to a 3.5 collecter
bill said:
Because most people think ( erroneously ) bigger is better, so these companies market bigger headers knowing they will sell more because that's what everybody will buy. Also, they can keep the costs down by making only 1 size header that would 'work' on various levels of performance builds.
Also, the Olds exhaust ports are so freakin big, you can't really fit a header smaller than 1 3/4" anyway!
bill said:
For a G-body? None unless you count Sandersuck shorty headers. Either Heddman or Hooker had a set for older A-body's but I don't know if those are still around or not.
I cant see why it would be that difficult to make a header for an Olds engine that had 1 5/8ths tubes....just takes a bit thought and design. After reading this post, I have decided it makes little sense to consider going with any available header on my SBO stock set up.
A 1 5/8" is a good size for a stock( ish ) 350, but for an OLDS, they would just have a severe port mismatch. Look at the size of an Olds 350 exhaust port and then look at the inlet size of a set of small tube headers. Not a very good match to say the least.
Also, the manufactures simply don't care about building a small tube Olds header becayse they wouldn't sell. Companies only care about profit, not making a small fraction of their customers happy.
With that being said, even an oversized ( 1 3/4 ) set of headers would be better than manifolds, but for a stock 350, it wouldn't be the night and day difference many others have made them out to be. Lots of yahoo's out there unfairly compare the stock manifolds w crossover and crap factory size/style crinkle bent sh*t exhaust to headers and a nice mandrel 2.5" exhaust and say 'wow, these HEADERS made a huge difference'. People can be so stupid sometimes.
For a stock smogger 350, a set of 1 3/4" headers would roughly knock off about .2 seconds and give you about 2 mph at the track IF you're running the same exhaust system. On a hotter setup, those numbers would increase dramatically.
Also, the manufactures simply don't care about building a small tube Olds header becayse they wouldn't sell. Companies only care about profit, not making a small fraction of their customers happy.
With that being said, even an oversized ( 1 3/4 ) set of headers would be better than manifolds, but for a stock 350, it wouldn't be the night and day difference many others have made them out to be. Lots of yahoo's out there unfairly compare the stock manifolds w crossover and crap factory size/style crinkle bent sh*t exhaust to headers and a nice mandrel 2.5" exhaust and say 'wow, these HEADERS made a huge difference'. People can be so stupid sometimes.
For a stock smogger 350, a set of 1 3/4" headers would roughly knock off about .2 seconds and give you about 2 mph at the track IF you're running the same exhaust system. On a hotter setup, those numbers would increase dramatically.
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