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Headers - worth it??

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BPS, Mar 10, 2003.

  1. BPS

    BPS Registered Member

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    Have a '90 Blazer and had to upgrade exhaust -(rusted out) thinking of doing headers at the same time. Is there a noticable HP improvement? I added headders to my camaro and likely picked up ~15-20 rwhp. Would the gains be comparable if I did the same to my Blazer?

    Also - if I'm redoing exhaust - any benefit to going to a latger diameter - I'm running a single cat exhaust?

    Thanks
     
  2. XJOSHX

    XJOSHX Registered Member

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    Chances are the motor you have is the same or almost the same as the one you have in your camaro. You should be able to get better flow from the headers. The better the motor breathes the more power it will make because all a motor is, is a big pump.
     
  3. BPS

    BPS Registered Member

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    camaro has an LT1 - bigger heads and aftermarket cam and is known to be exhaust restricted.

    I recall reading a while ago that someone stated that headers on our blazers were not really worth much in terms of performance gains.
    Unlike performance cars not many people do dyno runs of trucjs to measure benefits of engine mods - so i was just curious before zi drop a bunch of money i wanted to make sure that there is a benefit - darn engines aren't that powerful to begin with /forums/images/graemlins/frown.gif
     
  4. XJOSHX

    XJOSHX Registered Member

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    My plan for my motor is; edelbrock torker intake with their offroad carb, new lunati truck cam, 1:7 roller rockers, and headers with true duals. All that should make my motor breath a lot better and have a LOT more power. If I were to do all that work to the motor and put a restrictive exhaust on I will not take full advantage of the engines power. With a motor, what goes in must come out and if the out is blocked, so is your power. I would say go for it. I can garuntee no power loss and 9 out of 10 chances are you will have a power gain.
     
  5. Z3PR

    Z3PR Banned

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    On 4x4's my goal is low end torque. So in my mind, I'm thinking ( coated ) Doug Thorley TRI-Y headers, with a 2.25" dual exhaust system, with a " H " pipe to connect both sides. For mufflers I personally like 40 Series Flowmasters. Well, thats my thoughts for a exhaust system anyways.
     
  6. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Headers will net you more gain for your buck than any other modification, period.

    I recommend 2 1/2" pipe for better sound and then if you go with a bigger motor, you're set. 2 1/4 will not gain you any more low end torque and you may pick up some mid range and top end from the larger pipe.
     
  7. Flexy K20

    Flexy K20 1/2 ton status

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    Yes headers are the biggest bang for your buck mod you could probably do to your engine. I put some Heddman Headers on and am very glad I did. I also have 2 1/2" dual exaust with flowmasters and turn downs. I highly reccomend doing the same type set up. Later
    -fLeXy K20
     
  8. Thunder

    Thunder 3/4 ton status

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    I have Edelbrock headers on my 89. I noticed a nice performance gain after I added headers. When towing, I got a lot more usable power for climbing hills. I am running single 3" Mandrel bent pipe and flowmaster Muff No cat.
     
  9. bryguy00b

    bryguy00b 3/4 ton status

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    is there was way to tell what kind of headers you have? i have headers..but dont know what kind..andi *think* i have a 2.25 inch pipes..(have to double check that) true duals with dynomax turbo's..and thats it..no tailpipes or turn downs..i think i may run some tail pipes out to the bumper though!
     
  10. bajaviking

    bajaviking 1/2 ton status

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    I have true dual exhaust with flowmasters. I had turn downs that dumped right after the rear diff. but after a while I couldn't take anymore, this is my daily driver and the rumble was just to much when sitting still in traffic during rush hour so a couple of month ago I had the exhaust changed to dump by the rear bumper. Still has a nice rumble and now I can be in the truck without getting headaches plus it doesn't lift up dust when on the trail as it did before.
     
  11. HarryH3

    HarryH3 1 ton status Author

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    [ QUOTE ]
    Headers will net you more gain for your buck than any other modification, period.

    [/ QUOTE ]

    Sorry, but a new cam and lifters wins out over headers by a mile when it comes to bang for the buck. /forums/images/graemlins/shocked.gif While it certainly isn't as easy to install a new cam, nothing short of forced induction can make such a huge change in the performance of our rigs. /forums/images/graemlins/thumb.gif
     
  12. BigRed89

    BigRed89 1/2 ton status

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    I agree with Z3PR's suggestion. I have coated Doug Thorley Tri-Y headers on my '89 Sub with 2.5" tubing and a single Flowmaster. There was a noticeable difference in power throughout the rpm range after I had the exhaust done. I highly recommend this set-up, and if you're worried about it, it's all smog legal.
     
  13. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    I gotta agree with HarryH3. Also, I'm not a fan of headers. Heat problems, leaks, noise, fit and interference... Just not worth it for a near stock engine IMO. Now, if your building a sand or mud truck, high rpm and much power, sure... But not for a daily driver or trail rig, the down sides just over power for my preferences...

    [Edit] BTW, if I did go with headers, it would be the Thorley Try-Y without a doubt...
     
  14. 84_Chevy_K10

    84_Chevy_K10 Banned

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    [ QUOTE ]
    Sorry, but a new cam and lifters wins out over headers by a mile when it comes to bang for the buck. /forums/images/graemlins/shocked.gif While it certainly isn't as easy to install a new cam, nothing short of forced induction can make such a huge change in the performance of our rigs. /forums/images/graemlins/thumb.gif

    [/ QUOTE ]

    To truely take advantage of a cam and lifters, headers are an absolute necessity.

    You may or may not be right, depending on how restrictive the stock exhaust is.

    I agree with you that a cam makes a big difference (I'll never have a rig with a stock cam again now that I've had one with an aftermarket one) but I'm going to maintain that on a stock engine with smog controls, exhaust will make more of a difference than the cam, although it'd be close.

    IMO, before you buy a cam, you should already have headers anyway.
     
  15. HarryH3

    HarryH3 1 ton status Author

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    That's OK. You just keep living in that dream world of yours... /forums/images/graemlins/wink.gif The restriction in a stock engine is much greater at the valves than it is at the exhaust manifolds. Headers will certainly help a heavily modified engine breathe easier, but I've never seen a set of headers that could add 100HP to a small block. /forums/images/graemlins/shocked.gif
     
  16. dyeager535

    dyeager535 1 ton status Premium Member

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    I think you've both got good points.

    Do you seriously think 1980's and early 90's trucks motor heads can flow squat? It doesn't matter how far you lift the valve off the seat, the piss poor flow characteristics of those heads are the limiting factor. They were designed for torque, not horsepower. They don't support high flow numbers as cast. There is NO way a set of 1980's truck heads, with no other mods, will see 100HP gain from a cam swap. Nor will it see that kind of gain from a header swap.

    BUT, look at a complete head swap with the Vortecs (just for instance). Thats an easy (and verified numerous times) 30-40hp increase.

    You both know that an engine needs to work together, as has been discussed before, you can't put a wild cam in a motor, do nothing else, and expect it to scream. Likewise, you can't expect open headers without any other mods to make a huge increase in performance. But, put the two together, and you start seeing large gains.

    I think if both of you would say, "you know, with a better cam and headers, the motor would really wake up" you'd be mostly right. But with that said, headers don't require you to open the engine up, they are useable with any later engine (in the same family) that you decide to go with, and you don't have to worry about problems with idle, brakes and so on, if you go too big with them.

    We all know GM made these engines to meet emissions requirements, and thus they don't make gobs of power, but think about it: one of the huge differences between 1970-1980's motors was head design. Not huge cam changes, not huge exhaust changes, it was heads and induction, or better said, technology. Cam and exhaust technology has both changed for the better, but when you restrict yourself with stock crappy heads, it matters less how much technology you put into the cam, intake or exhaust.

    IMO
     
  17. 84_Chevy_K10

    84_Chevy_K10 Banned

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    [ QUOTE ]
    I've never seen a set of headers that could add 100HP to a small block. /forums/images/graemlins/shocked.gif

    [/ QUOTE ]

    You need to inform me what cam is going to make a 100 HP gain on an 8.5:1 motor.
     
  18. RustBuket

    RustBuket 1/2 ton status

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    No kidding!!! ^^^ Specially my 305!
     
  19. HarryH3

    HarryH3 1 ton status Author

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    [ QUOTE ]
    You need to inform me what cam is going to make a 100 HP gain on an 8.5:1 motor.


    [/ QUOTE ]

    Here's a rather mild one that can get ya there: http://www.compcams.com/information/Products/Camshafts/DynoSheets/XE262H-10_001.asp

    That engine has better heads, headers, and a slightly higher compression ratio, but it also made 348 HP. That's nearly 200 HP more than a stock '83 350, and nearly 150 HP more than a stock TBI 350. Adding 100 HP with the stock heads really isn't too tough, though driveability will suffer.

    Some of their hotter cams will make even more, but then you start getting into special valve springs and valvetrain parts that will drive the price up considerably.
     
  20. HarryH3

    HarryH3 1 ton status Author

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    Sorry Dorian, but you missed the entire point of this debate. We're talking about best bang for the buck. You can spend $150 on a cheap set of headers and hopefully pick up 10-20 HP, or you can spend the same $150 on a new cam and lifters and smoke the tires the first time you pull out of the driveway after the job is complete. /forums/images/graemlins/thumb.gif

    I've spent a lot of money putting all the aftermarket goodies on many of my toys over the years. NONE of them impressed me anywhere near as much as a good cam swap.

    While a set of stock heads won't flow nearly as good as any of the aftermarket stuff out there, getting those valves open, and keeping them open long enough, makes a remarkable difference in the performance of the engine. /forums/images/graemlins/cool.gif
     

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