How to select the right header...

[geoklass]

There are many types of headers available for your FOX chassis car. There are shorty headers, long tube headers, mid length headers, front exit headers, and maybe some I can't think of. Our company (RCI Headers) manufactures Long Tube Headers, Mid Length Headers, and Front Exit Headers, in primary sizes from 1 3/4" up to 2 1/4". The first consideration is, "what am I going to do with the car?" Is it a street car, or a drag car, or a street/strip car? The majority of people that call me on the phone tell me they have a street/strip car, or at least, they think they do. I ask them, "How many miles do you drive your car a year?" The average is 6,000 to 7,000 miles. Then I ask them, "How many times a year do you race your car at the drag races?". Answer, "Oh, maybe four or five times a year." My next question is, "And on the average, how many passes do you make when you go drag racing?" Answer, "Maybe about six passes." So, with that information we now understand that this enthusiast runs his car at the track maybe five times a year and averages six passes each time. Those six passes (at a quarter mile per pass) equal 1 1/2 miles, multiplied by five times a year, for a grand total of 7 1/2 miles of racing, and maybe 6,000+ miles of street use.

Folks, that is not a street/strip car. That is a street car that is used for racing a few times a year. Does he need an all out race header or a high performance street header? Some of you guys probably think that an all out race header will work great on the street. But think about it, an all out race header is designed to make horespower above 6,000 RPM, or 7,000 RPM. A well set up drag car leaves the starting line at the drag strip at about 5,000 RPM. They have no interest in mid range torque (3,000 to 5,000 RPM) because the drag car does not operate in that RPM band. But that's where a good running high performance street machine operates. Most street racers rarely exceed 6,500 RPM very often, so why buy a header that is designed to function best in that range, at the expense of making power in the RPM band that the street car typically operates in?

Like almost everything else in life, header design is always a compromise. As the Marketing Manager at RCI Headers, I would like to discuss this stuff and get some feedback from you. I have been the Marketing Manager at Accufab for the last 16 years. We manufactured Throttle Bodies but we also offered RCI headers to our customers (using the Accufab name). I have retired from Accufab but am now working with Craig at RCI. I'm a "header guy". I started in this industry at Kaufmann Products in the 1980's, where we offered RCI headers. From there I started a company with Stormin Norman Gray, and offered RCI headers. I then opened up Pro Mustang Performance, and offered RCI headers. I sold that to Coast High Performance, and while I was there, offered RCI headers, and then to Probe Industries, where we offered RCI headers, and moved to Accufab in 2002, where we offered RCI headers. Over 30 years I have been working with Craig, the founder and owner of RCI headers, and now I'm working exclusively for RCI headers.

There are a lot of thing about headers that people are not familiar with and if you are interested, let's share some knowledge together, and maybe make something useful out of this thread.

George Klass

 

[89ripper]

Well for starters your company doesn't offer anything for my application. 1 3/4 seems kinda big for a 5.0
I run 1 5/8 long tubes right now

 

[geoklass]

I hear you, and for a lot of guys, 1 5/8" headers are the right call. To be honest, we do offer some of our headers in 1 5/8". We don't advertise them primarily because they are the same price as the 1 3/4". But if someone is interested in the 1 5/8" primary Long Tube headers, we will be happy to make them. Personally, with a mild engine that runs in the 13's in the quarter mile, especially if they have an automatic transmission, I feel that a 1 5/8" header is a good choice.

 

[89ripper]

I hear you, and for a lot of guys, 1 5/8" headers are the right call. To be honest, we do offer some of our headers in 1 5/8". We don't advertise them primarily because they are the same price as the 1 3/4". But if someone is interested in the 1 5/8" primary Long Tube headers, we will be happy to make them. Personally, with a mild engine that runs in the 13's in the quarter mile, especially if they have an automatic transmission, I feel that a 1 5/8" header is a good choice.

Ok lol i feel better about my choices. What are your opinion of shorty versus long tubes as far as racing performance goes? I know the debate has gone on for a long time but id be interested to hear your opinion.

 

[geoklass]

The first problem with most shorty headers is that the flanges are not set up to accommodate cylinder heads with optional bolt patterns (like the AFR 205's, etc.). The second problem is that even the 1 5/8" are terrible, where they weld on to the flanges, the "dent" they put on both sides to be able to get the spark plugs in is huge. The tube is squished in so much on both sides there is barely 1 1/4" diameter right near the flange. Also, most of the shorty headers I have seen have separate little flanges, one per cylinder. Once you take the header off, good luck ever trying to re-install it, there is nothing in the flange area to keep the header from warping. But in my opinion, the worst thing about the shorty headers I have seen is they don't have a real collector. They use the "ball and socket" set up, which is a horsepower killer. Our Mid Length headers use a real competition style collector. In fact, it's the same collector we use on the Long Tube headers. Finally, I have seen some shorty headers that are called "equal length" shorties. First of all, the tubes are not actually equal length (which is not that big of a deal), but the sharp bends and tight radius are terrible. In simple terms, most shorty headers suck.

I am not that big a proponent of Long Tube headers for a lot of street runners, I prefer the Mid Length headers, first for price, and also for ease of installation. When running a full exhaust system (H-pipe or X-pipe and mufflers). the difference in primary length between the Long Tubes and the Mid Length does not seem to make much difference. I would say that on a 300 to 350 horsepower engine, the difference between the two is probably less that 7 or 8 horsepower. We have all out drag cars (bracket cars mostly) that use the Mid Length headers, and run them open, with no exhaust system or mufflers (we offer the Mid Length headers with up to 2" primaries). The only real difference between the Mid Length header we make and our Long Tube header is the length of the primary tubes. There is no "perfect" length for primary tubes. Most long tube headers have a primary length between 32" and 34", and even that is just a compromise. If you only ran your engine under full power to 6,000 RPM, it would be possible to build the perfect length primary for that engine, but the length would NOT be perfect below 6,000 RPM or above 6,000 RPM.

 

[89ripper]

The first problem with most shorty headers is that the flanges are not set up to accommodate cylinder heads with optional bolt patterns (like the AFR 205's, etc.). The second problem is that even the 1 5/8" are terrible, where they weld on to the flanges, the "dent" they put on both sides to be able to get the spark plugs in is huge. The tube is squished in so much on both sides there is barely 1 1/4" diameter right near the flange. Also, most of the shorty headers I have seen have separate little flanges, one per cylinder. Once you take the header off, good luck ever trying to re-install it, there is nothing in the flange area to keep the header from warping. But in my opinion, the worst thing about the shorty headers I have seen is they don't have a real collector. They use the "ball and socket" set up, which is a horsepower killer. Our Mid Length headers use a real competition style collector. In fact, it's the same collector we use on the Long Tube headers. Finally, I have seen some shorty headers that are called "equal length" shorties. First of all, the tubes are not actually equal length (which is not that big of a deal), but the sharp bends and tight radius are terrible. In simple terms, most shorty headers suck.

I am not that big a proponent of Long Tube headers for a lot of street runners, I prefer the Mid Length headers, first for price, and also for ease of installation. When running a full exhaust system (H-pipe or X-pipe and mufflers). the difference in primary length between the Long Tubes and the Mid Length does not seem to make much difference. I would say that on a 300 to 350 horsepower engine, the difference between the two is probably less that 7 or 8 horsepower. We have all out drag cars (bracket cars mostly) that use the Mid Length headers, and run them open, with no exhaust system or mufflers (we offer the Mid Length headers with up to 2" primaries). The only real difference between the Mid Length header we make and our Long Tube header is the length of the primary tubes. There is no "perfect" length for primary tubes. Most long tube headers have a primary length between 32" and 34", and even that is just a compromise. If you only ran your engine under full power to 6,000 RPM, it would be possible to build the perfect length primary for that engine, but the length would NOT be perfect below 6,000 RPM or above 6,000 RPM.

I appreciate the detailed response you have given. As of now my block is stock with over 180000 miles and i will have to upgrade someday. I may have some follow up questions in the future. I think a good many of us starting out tend to slap exhaust on without considering the science behind it.

 

[geoklass]

I'm not so sure that "science" is the correct word, I like the word "logic" better. Think about it, 95% of the Small Block Ford aftermarket cylinder heads have an exhaust valve measuring 1.60" in diameter. Tubing diameter is measured on the outside of the tube (versus water pipe which is measured on the inside of the pipe). A 1 5/8" primary tube has an outside diameter of 1.625", but exhaust does not go on the outside, it goes inside of the tube. This means that the inside diameter of 1 5/8" tubing is about the same size as the outside diameter of the exhaust valve. Does this make sense to everyone? But let's also remember that the exhaust does not flow through a 1.60" hole going into the exhaust port, because of the valve seat, which probably measures about 1 1/2" in diameter, plus, a valve stem is also in the way. This is where the primary exhaust restriction is on the SB Ford heads. This is why, in my opinion, a 1 5/8" header is fine for a car in the 300-350 horsepower range, and for more power than that, the 1 3/4" header will be a benefit. We have plenty of race car customers making 900 horsepower with 1 3/4" RCI Headers.

I hope I'm not messing up anyone's head with all of this.

 

[mikestang63]

are you an authorized vendor on Stangnet?
I've used Ford SS Ceramic shorty headers on many cars with excellent results and both Kooks and BBK LT headers

 

[geoklass]

Sorry, I don't know what that is.

 

[a91what]

Sorry, I don't know what that is.

An authorized vendor is allowed to advertise products on the site. Without being a vendor here selling or pushing a product is off limits. This is to keep spam to a minimum and for other obvious reasons.

 

[General karthief]

You appear to be offering technical advice and thats ok, from your posts you must have a vast knowledge on this subject.
how do you feel about back pressure?
i'm kinda old school and run long tube headers, street car that needs the low end torque.
header technology, like everything else has come a long way, even the crappy tube headers that come on fox cars from the factory are better than the old cast iron stuff from the past.

the back pressure thing is a on running joke around here.

 

[geoklass]

I was offering technical advice, trying to create a dialog on the subject, but at the moment I'm confused. I guess I can't do that as I'm not an authorized vendor nor do I know what that is or how to become one. When I registered for the site last week, I listed my email, etc., but nobody told me that discussing technical issues was off limits and what I had to do to be permitted to do that. I would appreciate if someone connected to the management of this site could contact me and tell me what I need to do, via email.

[email protected]

 

[General karthief]

No,no,no, don't misunderstand, your technical ability is what is being appreciated and commented about, we are just making sure and I am sure you understand about the 'no selling' outside the classified forums. Never once did you even hint at a sales pitch so do carry on with giving us you header technological expertise.
Exhaust systems can be a very misunderstood part of building horse power in the area an engine is built to work.

 

[geoklass]

I'm learning about this site as I go, thanks. I have no intention of stepping on any toes. I do want to find out what an Authorized Vendor is, and how to become one. I did reach out to the site management through their "Contact" page, have not heard back yet.

I know that I mentioned the name of the company I'm working at, but I was careful not to list any contact information, like phone number, email or website. I figured that might be against the rules, as it is on most sites. I think at this point I will just see if I can answer questions that folks may have, and not post up any general header tech.

George

 

[General karthief]

Give it time.

 

[Rcdgl]

So, good stuff there, George. I have some really old Blackjack almost longtube headers on my carbed 82. Got them in 85 or so. They require a pipe with a 45 deg turn up to mate. They fit ok, but are somewhat of a pain to remove and install, and make r and r of the engine a pain. Not sure what tube size, but they have old fashioned connectors. I have 2 1/4 pipes to Super 40 mufflers, no tailpipes.

From what you said earlier, these may be a pretty good setup for a 325 hp carbed car, C4, 2500 stall, 410 car. Barely in the 12s most days.

I keep wanting newer shorties because of the ease of removal. Should I keep them?

 

[geoklass]

I'm not familiar with the Blackjack "almost long tubes" but they may be better than any shorty header. You didn't say what the diameter of the primaries were, hopefully they are at least 1 5/8". The 2 1/4" exhaust pipes might cramp your power a little, I kind of think that 2 1/2" should be the minimum, with 2 1/2" in and out mufflers to match. People have to understand that shorty headers are not "bad", it's just that you are giving up horsepower when you use them. It all depends on the horsepower you are putting out. The more HP your engine is capable of making, the worse the shorty headers are, in my opinion. An engine is really not much more than an "air pump" when you think of it and if you cramp the amount of exhaust (old air) your engine can put out, you are also limiting the amount of new air you can get in to it. An engine runs more on "air" than on gasoline. Fuel (air and gasoline) is typically around 11 or 12 parts air and 1 part gasoline, regardless of whether it has a carb or is EFI..

 

[geoklass]

The exhaust systems on most of the newer cars are pretty good these days. In fact, some of them are very good. Have you ever wondered how that all came about? Let's start at the beginning. In 1932 Henry Ford introduced the V-8 engine. Although he was not the first to offer a V-8 (Chevy had one in 1918), the Ford was a large production vehicle which brought the V-8 into the mass market. The good old flathead Ford, I learned about engines and hot rodding with that engine.

 

[geoklass]

Of course, this was not a "header", this was an exhaust manifold. Not too slick, obviously. If you wanted to hop up the old flathead, you had to get some headers.
This is what real nice flathead headers looked like. Basically a single tube with two other tubes flowing into it in a nice smooth manner, which was a HUGE improvement. (the center exhaust port on the flathead engine was siamesed, meaning that the center cylinders had two exhaust ports flowing into one).

 

[geoklass]

That basic style header configuration lasted many years, and not just with the Ford flathead. The early OHV engines (like the Cadillac and the Oldsmobile) used a very similar configuration. The next major change we saw was what became known as a "Tri-Y" header, or sometimes called a 4 into 2 into 1 design. This design typically followed the engines firing order, to promote some scavenging. This became quite popular in the late 1950's and early 1960's with hot rodders, and they were very effective.