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Block hugger headers vs Long tube headers

45K views 15 replies 14 participants last post by  4 Jaw Chuck 
#1 ·
Hey guys looking for some input here. What is the advantages/disadvantages between block hugger headers and long tube headers?? I know hugger headers are very common (espeically on SBC's) but I am curious as to any HP or torque altering differences between the two.

Thanks,
Keith :)
 
#4 ·
it depends on the engine setup.

On a high hp 350 sbc (400+) you will lose 30 hp with block huggers and 60hp with stock manifolds when compared to full length headers.

On a stock engine, the losses will be 10 hp with block huggers and 20hp with stock manifolds when compared to full length headers.

The huggers are about 1/2 way between full length headers and stock manifolds.
 
#5 ·
Its no different than intake runners. Large, short primaries support high end HP and smaller, long primaries support low end torque.

having said that, the long tube headers are almost always superior in both HP and Torque. Most block huggers are small primaries because of space concerns. BUT, in most situtations, the worst block huggers are better than the best manifolds.

Fullest benefits will be realized when using a properly sized, full-length header.
 
#6 ·
454C10 said:
it depends on the engine setup.

On a high hp 350 sbc (400+) you will lose 30 hp with block huggers and 60hp with stock manifolds when compared to full length headers.

On a stock engine, the losses will be 10 hp with block huggers and 20hp with stock manifolds when compared to full length headers.

The huggers are about 1/2 way between full length headers and stock manifolds.

WOW! those must be some magical long tube headers or super super crappy manifolds...
 
#7 ·
No magic. headers are just that much better than manifolds.

Like I said. it all depends on the cam.
Long duration cams lose a lot more than a stock cam when using manifolds.
stock cam don't lose that much power.

Check out this website: http://www.chevyhiperformance.com/techarticles/49178_headers_power_increase/index.html

The website tells a story pretty much what I said. Gained 70hp with a big cammed 350 and 16 hp with a stock 350 using long tubes over manifolds.

Then I remember seeing a 7 header and 1 manifold comparison test on a hot 350 and remember (very well) the block huggers were about 1/2 way between the manifolds and long tubes. I have the original write up somewhere in my magazine collection and can't seem to find it on the web, but I'm still looking.
 
#8 ·
If you are building a race, or modified engine it makes all the difference in the world. Shorties are better than a cast iron log style or ram's horn but fall short of a proper length header for the specific application. Sure, most folks just buy what fits but this is not 'the way' in the Zen of headers Tuned headers are not just equal length or whatever. Consideration must be given to the engines design, combination of parts and desired RPM as well as usage. I don't care what it is, if it's mine it gets headers. Some get block hugger tyupe because the chassis or model is only going to get them to fit without modification. For instance, on a '94 S10 with a 404ci sbc w/angle plug heads, it NEEDS block huggers without cutting. JMO
 
#9 ·
Keith, your question is to general....

what is the car and motor combo and how do you plan to use the car???
a cruiser....,
street/strip....
strip/street....
full race???

don't forget that "everything needs to match" to get the benefits that a better exhaust "can" produce....

read 454's magazine link very very carefully,
the stock motor did gain 16hp "at" the peak rpms with headers...what's are those headers worth at the strip...2 tenths quicker...that's 2 quick eyeblinks

to get the 6 tenths quicker simulation with the strong motor they had to change the convertor and gears to shift at much higher rpms due to the cam which alot more cfm thru the motor...

maybe smarter to re-word your question as "how much real world ET difference is there between block hugger and long tubes" with more info about your ride and motor....(that's really what you want to know?)
 
#10 ·
If you are worried about fitment, make your own, cheaper, and you can extract as much power out of it by not going with some "universal block hugger". "universal" normally means the designers had to sacrifice good engineering just so it can fit in many different applications.
 
#11 ·
probably none

1. On a typical crate-motor-street-driven engine with a full exhaust system, there is very little seat-of-the-pants difference.
2. On a radical-barely-streetable-pro-built-Saturday-special, where everything is coordinated and uncapped at the strip, a big difference.

The long tube headers let more noise into the cockpit than do the block-huggers.

thnx, jack vines
 
#12 ·
sexypizzaman said:
Hey guys looking for some input here. What is the advantages/disadvantages between block hugger headers and long tube headers?? I know hugger headers are very common (espeically on SBC's) but I am curious as to any HP or torque altering differences between the two.

Thanks,
Keith :)
For the most part either is a great improvement over cast manifolds both in terms of weight and performance.

Long tube headers are usually better tuned to the street strip RPM range of the typical engine. But the tuning comes in specific peaks which while add an amount of power at exact RPMs based upon a prime tuned frequency and subsequent harmonics, you've got to be on those RPMs for any benefit. Most of the rest of the time long tubes are doing nothing more than short tubes to effect power.

You can modify short tube header performance which tends to be above where the typical street/strip engine is usually working, by adding length to the collector, though not as totally effective as long tube header wave tuning, you can considerably close the power gap at certain RPMs.

Get your eyes on this "The Scientific Design of Exhaust and Intake Systems" by Phillip H. Smith, he gets into wave and particle movement and theory and puts in a bunch of formulas you need to compute the correct size, at least as a starting point as the math craps out pretty early and cut and try takes over. All sorts of things get in the way from temperature variations down the tube to an unnoticed blob of weld tripping a return wave before the expansion hits the end of the pipe.

Bogie
 
#14 ·
For the most part either is a great improvement over cast manifolds both in terms of weight and performance.
You can modify short tube header performance which tends to be above where the typical street/strip engine is usually working, by adding length to the collector, though not as totally effective as long tube header wave tuning, you can considerably close the power gap at certain RPM

Bogie
How can you modify the collectors to add length on a set of short tube headers? For example do you add a foot long 3" section (assumed diameter of collector) of exhaust pipe by bolting it in at the collector and then fixing that to the rest of the exhaust system on both sides of the car?
 
#13 ·
Another place ot pick up some information (albeit buried in a lot of advertising) is headers by Ed. Ed has a lot of information on his web page, and sells a package of information as well.

Pat
 
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#16 ·
Ten year old thread BTW.

Bogie can you explain how an expansion chamber in the exhaust system improves power? Basically you are describing creating an expansion chamber and I've never seen this work.

All the research/testing I've seen with increasing collector length/diameter has been on heavily modified engines that needed the volume because off the shelf headers were not big enough and this only worked on the dyno since putting a full length exhaust with mufflers negated the effect. Basically it only works on open header exhaust systems like circle track cars where changing length of the pipe before it hits atmosphere affects wave tuning.
 
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