Are Bigger Headers Better?

Can you run straight headers?

Yes, you can run open headers if you wish with no harm to your engine.

I would however take a look at the spark plugs after a few miles to make sure the engine is not running too lean..

How much horsepower does a 350 4 bolt main have?

Stock 350. The four-bolt main 350 with two-barrel carburetor came with 8.5:1 compression, and was good for 145 horsepower at 3,800 rpm and 250 foot-pounds of torque at 2,200 rpm. 350s equipped with four-barrel Quadrajet carburetors produced 170 horsepower at 3,800 rpm and 255 foot-pounds of torque at 2,800 rpm.

Do headers make your car louder?

Headers alone will not make it any louder. Midpipes and mufflers will give you louder exhaust. … Exhaust headers are rarely found stock on vehicles; most vehicles have what is called a standard exhaust manifold. Headers decrease restrictions, therefore increasing horsepower and sound.

How much horsepower do headers add to a 350?

The length of the primary tubing determines the effective rpm range, but headers can be worth 15-20 hp on the right application. Run on our restrictive two-barrel 350, the headers improved the power output to 248 hp and 365 lb-ft of torque, with consistent gains through the rev range.

Are headers bad for your engine?

Headers will not hurt your engine. If anything you actually improve its longevity because you removed the restrictions. Its as if you were running with 5 lb ankle weights as Oem exhaust manifold. Now take those 5lbs off and you are relieving the weight making you more efficient as if you put on headers.

Should you wrap your headers?

Header wraps are designed to keep the heat in the header to improve scavenging of the cylinders. Keeping the heat in the header allows the exhaust speed to remain high. (the right idea) Header wraps, by keeping the heat in the header, also reduces the radiant heat in the engine bay.

Why are open headers bad?

There’s nothing wrong with running open headers. Lack of backpressure may hurt low end torque a little, but it won’t wreck anything or cause the engine to run poorly.

Do header tubes need to be the same length?

It is also very important that all header tubes are as close as possible to the same length. The tubes from the rear cylinders are closer to the collectors and need a few extra twists and bends to be as long as those (tubes) at the front of the engine.” … That’s why primary tube length is significant.

What headers are better short or long?

For shorty headers, the port pipes actually merge into a single exhaust pipe in a much shorter distance. For long tube headers, the exhaust pipes are much longer and merge farther out. … Long tube headers build a ton of power in the mid to high RPM range. They are the best option for high-rev vehicles, and track terrors.

Can headers be too big?

If the headers are too small for the application they will cause restriction and increase heat in the engine. Too large a header will reduce torque output of the engine and increase the possibility of exhaust gas reversion—again increasing heat.

How do you calculate header pipe size?

Multiply your Volumetric Efficiency-adjust single cylinder displacement by 16.38; we’ll call this Figure C. Add 3 to your calculated length from Step 4, then multiply that by 25; this is Figure D. Divide Figure C by Figure D and you’ll have the header tubes’ inside diameter in inches.

Does the size of the exhaust pipe matter?

Manufactures don’t increase exhaust size because it doesn’t universally improve performance or efficiency. The optimal exhaust size is a function of exhaust volume. The greater the exhaust volume, the greater the optimal exhaust size. Exhaust volume increases with engine rpm and fuel delivery.

Can you get 500HP out of a 350?

You “can” get 500HP out of a 350 BUT because it is a small cubic inch engine it IS going to be peaky and won’t have much torque. … As soon as that chain gets stuck, it’ll bog down and stop because it doesn’t have enough “torque” to rip that chain loose to keep cutting.

Does adding headers increase horsepower?

By installing exhaust headers, you are aiding your engine in its ability to push gases through the cylinders. Doing so alleviates excess back pressure in the manifold. … Thus, when headers remove the exhaust, there is a surplus of clean air, allowing the engines to increase horsepower production.

Do headers increase mpg?

While more involved from an installation standpoint, headers in combination with a cat-back system will give you a measurable boost in power. In most cases, fuel mileage will remain the same or improve a bit. Two other components that affect performance and mileage are the oxygen sensor and the catalytic converter.

What do bigger headers do?

Headers are installed because they boost the rate of exhaust flow out of your engine compared to OEM stock exhaust manifolds, which are typically designed to take up as little space as possible. … This means installing larger-diameter, mandrel bent exhaust pipes, and it definitely means using freer-flowing mufflers.

Can you put 400 heads on a 350?

400 heads on a 350 block is a great way to increase your midrange and top end power. The swap is a direct bolt – on deal, you just need to be sure to use 400 head gaskets when you do the swap.

What is the best brand of headers?

What are the Best Exhaust Headers for Increased Horsepower?Doug Thorley Headers.PaceSetter Headers.Hooker Headers.Gibson Headers.Nov 25, 2018

Are headers louder than manifolds?

Headers GENERALLY make your exhaust sound louder, as the headers are thinner in composition than manifolds, and you are moving a greater deal of exhaust gases.

Do shorty headers make your car louder?

Shorty headers are usually a little louder… especially at part-throttle and Idle.

What size headers should I get?

Recommended Header Primary Tube DiameterHorsepower OutputPrimary Diameter200-325 hp.1 1/2 in.275-425 hp.1 5/8 in.400-500 hp.1 3/4 in. or 1 7/8 in.500 hp. or more2 in. or largerMay 11, 2017