Hello V8 People. I am considering buying Headers for my 71-455 the ballpark cost is 600-800 bucks, what is the benefit versus cost ? Anyone regret buying/adding headers ? why ? thanks in advance
Yes....I have regretted them on some my street cars. They usually have more than enough power and sound with good exhaust system WITHOUT headers. Headers tend to sound tinny, leak and rust out..... But for the track it's easy horsepower.....
Normally headers are harder to install, sometime on certain motor they can make the plugs harder or easier to change. My stk 2 headers go is easier than my stage 1 but the plugs are easier on the stage 1. Use a good gasket like remflex, not that paper stuff or you will be doing it again. Some headers have ground clearance issues
Is there a noteworthy gain to be had on a stock or mild street engine? $700 for 5 hp is probably a regret but many would probably pay that for 25 hp.
99% of the time , headers increase hp and torque, not just 5hp , depending on whats done to your engine, can be 10 -20 hp usually 20-40 hp. compared to stock exh manifolds, I'm talking non computer cars here, rear wheel dyno tests, show average 20hp increase, but 20+ ft lbs of torque and over a broader rpm range, all this means more efficient, headers scavenge adjoining primary tubes, something cast exh manifold cannot do! creating better cyl filling of the intake charge , me, 100% yes, but, there not for everyone, yes tightening of the header bolts is common, in over 50yrs of using headers, I've never had headers rust out, but... I've always lived in the south west, (no snow)
If your serious about power, yes to headers If you wanna choke off any upgrades for power, like intake, higher comp. pistons, bigger cam, ported iron or aluminum heads, then yes to iron manifolds
If you go with headers, spend the extra bucks for Jet hot coating. That adds to the price, but the under hood temperatures are much cooler and is better for everything under the hood. The air is cooler going into the carb and makes more power as well as subduing detonation. Even the paint on your hood may like the cooler temperature. Your face will like it too when you raise the hood and not feel scorched. About stock manifolds....... How about Jet hot coated or ceramic iron manifolds. Coat them inside and outside. First, die grind the carboned area to match your heads for better flow. The carbon builds up where the manifold ports are smaller than the head port, so grind those areas till they are slightly larger than the head port. Lay the manifold on a surfacer for a few seconds to remove any warpage, and the manifolds will never leak. No gaskets needed. Use an efficient muffler. Any variety of Walker ultraflow mufflers will not rob horsepower from iron manifolds. Use about 1 or 2 feet of 2.5" exhaust pipe from the manifolds, then slide a 3" system over it with H or X pipe will also help iron manifolds do the job. Let the 2.5" pipe extend a few inches into the 3" to help stop reversion. If your at 450 horsepower or less, headers will not be worth the trouble and expense.
Headers are a foundation piece for performance. While I certainly have built some stout engines over the years with modified exhaust manifolds, you really have to work at that.. Even for a near stock engine, headers show substantial gains in torque, when properly sized. For the vast majority of Buick 455 builds the 1 7/8 primary with 3 or 3.5" collectors is the proper sizing. Here are a couple of examples.. Near stock 70 455.. with just mild cleanup on the heads, and a 212 cam.. dead stock shortblock.. 9-1 ,measured compression.. With manifolds And with headers ON much more modified stuff, this difference will grow dramatically.. to nearly 60 HP on the 600 HP street stuff. The downside of headers is cost, hassle(installation and blown gaskets, fitment and ground clearance) and the "not stock" look. Personally, if I was building a street cruiser, in which the throttle will barely be beyond half throttle most of the time, with a mild engine build, I would prefer manifolds.. but serious performance cars typically wear headers, and if your going to pound on it, or race it, then the choice is pretty simple. Good luck, JW
for now just a street car, so the cost wouldn't be worth it to get headers. Thank you V8 good information from the members
Wow, that's a consistent 20ish ftlbs of torque and 10-15hp. You have to remember your engine is just an air pump, the easier and more effect air moves in and out, not only will it make more power, but it will get better mpg, with more torque you will need less pedal to do the same work, when an engine breathes better the air and fuel mix better, yet again resulting in more complete burn, more power, less wasted fuel, better emissions. Yes they are not cheap to buy new or ship, but good used or new thats been sitting around can be found. To me headers are like proper gearing, its using the most of what you already have. Why build more power with other parts when you have it freely right there just waiting to be picked
