exhaust manifold vs. header--is there a difference?



hey, i have a question--is there a difference between an exhaust manifold and a header? im just kinda wondering. im wanting to put some stuff on my car (its all hand-done, even the paint) so i saw on the clifford site that it had a single outlet header. would that part do anything towards performance? can yall give me a couple of quick, bolt-on type, not that time consuming, add-ons for some power. i know people ask that so freakin much, but please just answer it for me yall.
Howdy CustoMustang:

A header will make a significant difference if you are willing to tune to take advantage of it.

A header is probably not the most cost effective mod on a stock engine, and is seldom a simple bolt-on.

What year and engine are you working with? What tranny? what's your budget? What's your goal?

Adios, David
hey, im working with a 1966 200 cube I-6. Im just looking for some extra UMPH out of the little powerplant. Money really isnt an issue at the moment, since its only costing me $2000 to totally redo the car. That included all the interior stuff, CD player and speakers, battery-in-the-trunk relocation kit, new carb, distributor, wheels off a datsun Z car, homemade exhaust system, paintjob done by my dad, rebuilt power steering system, electric fan, custom radiator, homemade ram-air system, and i bet some more stuff i cant even remember! the transmission im using is the tried and true C4, which is the only thing we are not doing by hand, because its sort of a time issue, and it only takes the shop a day to rebuild it. Plus, putting in a shift kit. So, in total, all this is costing us about $2000, which is a damn good deal for a pristine-condition restoration done by dad and I. any other questions? just post a reply.
Howdy back CustoMustang:

It sounds like you're quite a ways down the rebuild road already. Probably the best and 1st performance modification is to reset the initial advance at about 5 degrees more than stock calls for. It's too bad that we didn't talk before you purchased a new carb and distributor. Ideally, you'd do yourself a favor by upgrading to a newer distributor that has both centrifugal ancd vacuum advance built into it. If you think you might want to consider a better, later distributor let me know, in the mean time, consider a bolt in electronic unit called a Petronix Ignitor. It converts your point distributor to an electronic unit. Add the compatible coil, add a set of new plugs one step colder, gapped at .050" and enjoy increased performance and economy.

Make sure that your carb linkage is adjusted to get wide open throttle when the pedal is fully depressed

What are you doing with your torque converter? Are they rebuilding? Replacing? If possible, when rebuilding it have them trim the stator fins and change the angles to get a little more stall rpm.

When you get ready to do the head, that's another area where you can help yourself to better performance.

That should get you started.

Adios, David
Hey CustoMustang,

Please go to http://www.headersbyed.com

I ordered and recieved his Header InfoPak, and it's worth it if you're really serious about a header. I've played with cars for over 20 years and what he says makes a lot of sense.

Good Luck! :D
Speaking from experience...

Recently fitted (ancient and well-loved) Pacemaker headers to a 200 six; stock otherwise. Noticed exhaust sounded quieter (!), slightly smoother acceleration.

Then installed (six weeks later) rebuilt full electronic ignition/distributor (Bosch, as we're in Oz). Car started more readily, had MORE POWER, smoother engine and should have been better on juice. Fuel economy was down because "more power" was too tempting! :eek: Still on stock timing, didn't even regap the plugs!

Regards, Adam.
hey yall. CZLN6 i do have a petronix ignition in my car right now. dealing with points are a pain, tell me what distirbutor you were talking about, i wanna know cause im all for more performance. i cant put the dual outlet headers on my car, since its impossible to have a car w/o AC in texas. whats probably the best performance single outlet header? so having them do that to the torque converter will really help? i dont know yet if we are gonna opt for a new one or just have them rebuild the old one. what mods are you talking about for the head? i wanna know, im all for more UMPH. also, is there any such thing as a rear disc brake kit for the 6 cylinder mustang? i dont think one exists, but wouldnt it be nice? im planning on doing the front disc conversion, just to make the car safer. any other questions? post a reply
HowdyBack CustoMustang:

A '68 - '72 distributor will give you both centrifugal and vacuum advance and you may be able to use your current Ignitor in it.

I prefer the DuraSpark II electronic system used by FoMoCo from about '77 ot '82/ It includes the electronic distributor, the module and the coil, as well as the connectoing harness.

Know that your stock 1966 Autolite 1100 carb and Load-a-matic distributor are designed to work together. It is possible to change one without changing the other, but it requires some fiddling and adapting. You may want to step up to a Carter YF carb from an early '70 200 or 250, to match the 1st distributor option, Or and early Holley #1946 from 1980 for the DSII. Both of these carbs are more sophisticated than the Autolite 1100. The Holley offers a slight increase in cfm at 195, the YF from the 250- 195, compare to 187 for the Autolite. Both the YF and the Holley offer a source for ported vacuum for the distributor, a better idle system, accelerator system for smoother transitions, and a slightly better top end.

You didn't say what head you're using? I assume it is stock. What are your goals? Is staying stock important to you?

The modified torque converter allows the engine to rev a little higher before it couples or stall, which allows a slightly higher torque multiplication. What is your rear-end ratio and rear tire diameter? Short of converting to an OD trans, a slightly looser converter helps get out of the hole and maintains a decent cruising rpm. It is worth considering.

You have several options in the head area. But I'd like to hear what your goals for this engine are first. Is a head rebuild/valve job in your future?

Adios, David
from what i know, its the stock head. now, i dont really know what to do with it, but what are some small changes or alterations, nothing too extreme cause i dont want it to mod'ed. where could i find one of those distributors that you are talking about? ok i got a question about exhaust right now--if all i have is glass packs on my exhaust, no cat converter, is it as free flowing as it can be? will adding an actual exhaust system like a dynomax 1 in 2 out make it sound better, but reduce HP? emissions laws here in texas are good, so my mustang is free from emissions laws :D . i am gonna consider doing that work to the torque converter, sounds like a good power boost. any more questions? post a reply.
Howdy Back:

You can modify your stock '66 head when you do a valve job. that means removing the head. Have a three angle performance valve job done including installing hard seat inserts. Have the machinist back cut the intake valves, and mill the head .025" to provide a flat mating surface and maintain stock compression- due to the difference in OEM steel shim head gasket thickness and the composite type aftermarket gaskets. This is also the time to get and install a center exhaust port divider. The valve job gasket set will include new valve stem seals. Be sure to install them. If the stock springs are up to specs, reuse them, but shim them up .030".

Or, you can find a later '78 or '79 head, which will have larger 1.75" intake valves, larger port volume, hardened seats and a larger 1.75" carb hole. Do all of the above mods to this head with 2 exception; there is no need to do seat inserts as this head already has them, and mill this head .075" to reduce the combustion chamber volume from 62 to 52cc and to compensate for the difference in gaskets mentioned above.

The distributors that I mentioned in previous post are available rebuilt, through most parts houses, or at your local recycle yard. If you find a likely candidate in the junk yard, check for shaft wear. There should be very little side to side ore up and down movement, and it should turn freely. Get everything from the coil to the plug wires to simplify the swap. You may be able to swap your petronix into the '68 - '72 ignition system- I don't know for sure. I think the DuraSparkII system is the way to go. Same choices on this one.

On the exhaust, the inner diameter is as important as the components. If your head pipe and tail pipe are stock, they are most likely 1 3/4" or 1 7/8" od. For giggles figure out the difference in area between a 1 7/8" circle and a 2" circle. It only sounds like an 1/8 of an inch, but the increase in area is suprising. The glasspack is likely an improvement over a stock muffler, but you'll damage your hearing in the long run. Personally, I like the DynoMax, and If you were to add the 2" system to a 1 in 2 out turbo muffler, like the DynoMax, you'd free up the exhaust and some HP and save your hearing in the process. This system would porvide a great foundation for future mods.

Adios, David
Those mods you're suggesting sound very nice. One question, though, how much will they all cost in the end? More specificly, isn't the DSII kit kind of pricey? I'm just about in the same boat as CustoMustang and am interested in about how much money I should store up for the engine mods...any ideas?
The D-II setup can be had quite reasonably if you're not abject to visiting your local self serve wrecking yard. I pulled one from an 80 something Fairmont and the distributor, cap adapter, cap, plug wires, coil wire, module, and associated harness was under $30.

If you go to the parts store and specify you want a rebuilt distributor, cap, cap adapter, coil, & ignition module it will be quite a bit more. Some guys here have paid around $200 for new parts.

The only risk you take with the junkyard parts is the distributor may have too much end play and need to be rebuilt. So far, the Ford module is working just fine in my '62 and I have no plans to change it. All I did was clean everything up, replace all the plug wires, installed a new cap, and fired it up. Here's what it looks like in my '62:

Down at the local AutoZone you can get the DII dizzy for 49.99$ (no core) The stock for ignition module can be gotten from them for 15$. You will also have to find a dist to cap adapter, the best price I found for this was Advanced Auto $6.50 then cap and rotor $15, the cheapest plug wires that Checker has for a '78 Fairmont 3.3L $15.

under $100
the local yard around here wants $25 for the dizzy, and $15 for the ignition module.

Unless a new coil is required and I dont have a price for that.

A while back I missed the opportunity to buy a '80 Fairmont head because the wrecking yard crushed it, even after I asked them to hold it for me. That yard gets $50 per head with a guarentee for a new one if it is cracked.
When I bought my '74 250 head I took it to a shop right away to have it checked and that shop told me $180 for a valve job, around $380 to put in hardened seats, and $40/hr for machine work (about 60$ to have it milled) Stock replacement valves were $6-$7 each if you need to get any.

Will he need to get an adjustable rocker assembly and the older style cup pushrods? ($25 from the local guy out of a 170)

These are all prices I got from people when I went shopping around to upgrade my buddy's '66 200, but it should get you in the ballpark. Make sure to add some to each item then round up a couple $$

i have heard of using a late 70's head on an old block, or just getting a getting, say a '77 block, and using that. is it that hard to find an old head from those years? i dont know where a local junkyard is, but would it be hard acquire? if i were to find and purchase a good condition one, would i have to have the stock one machined off and have the new one welded on? if that is the case, then it sounds like a lot of work. also, is it hard ot find a machinist? plus, could anyone give me a ballpark on getting the head machined? would i just be able to find the 1 in 2 out muffler at any local autozone or pep boys? is dynomax one of the best choices for it? does borla make a muffler like that? im a big fan of borla. any questions? post a reply.
Howdy All:

Redstang- You would do well to start inquiring from your local machine shops on prices and willingness to work with you. Prices on a typical valve job vary as to price and what they include, based on the condition of the head you bring them. I'm blessed with several very willing and high quality machine shops. A typical basic performance valve job, at $180, includes cleaning and inspection of the head I bring them. It includes a valve job gasket kit that, seperatley runs about $60, and includes the new valve stem seals. They check all parts for specs. If their reuseable they clean and prepare them for reassembly. It includes a clean up mill cut of about .010" to get a flat mating surface. Most importantly it includes a three angle valve and seat cut. If you need new valves or other parts or more milling, that is extra. I usually end up paying closer to $300. That includes welding in the exhaust port divider, back cutting the intake valves, shimming the springs .030 and extra milling.

I usually take it back after clean up and dissassembly to do some grinding on it. I smooth the exhaust ports considerably and match them to the exhaust gasket, I clean up the intake valve pockets- especially the transitions from casting to machined surfaces, I round the transition from the carb hole into the log in both directions and I polish the combustion chambers. Probably none of this is critical, but every little bit may help. It takes time and would cost a bundle if I had the Machine shop do this stuff.

If you use a C7XX or later head, you can save the cost of valve seat inserts and installation. I have never paid more than $40 for heads and got most for much less.

I use junk yard DSIIs also and so far, so good. Usually pay $40 or less for the whole works.

Ron- The adjustible rocker from the early 144/170 solid lifter/pre hydraulic lifter engines are nice and help with tuning, but are not necessary.

One of the nice things about improving your Ford Six is that you don't have to do it all at once. It is best to have a realistic plan with the proper sequence so that you don't end up doing something twice.

CustoMustang- it sounds like you need some basic mechanical knowledge. Get a good Manual and read up. The head on our engine is a bolt on process. No welding is required. It is quite involved and detailed. Finding a good mechanic/machinist is always an adventure. Most, who appreciate our adventure, have more than a few gray hairs, or were born 50 years too late.

Enjoy the journey.

Adios, David

You mentioned you were in Texas...where?

there are quite a few of us on here.

TxAgs66 - Houston
Inliner - San Antonio
46Stude - Rockport
MThad - Orange
LBones - Alvin
and someone who's handle I can't remember is from Corpus.

Let us know!
i am a fellow houstonian. haha. isnt it the intake manifold thats integrated to the block? does installing a new head require any additional tune ups, like tuning the engine to handle more of something? is it just a simple bolt on, or is it not? ok this is another question about exhaust (im just a fan of exhaust parts--i love the sound of it) isnt the main goal of a car is to get the MOST free flowing exhaust? so in what ive done to my car, its SEEMS to be at maximum flow. heres my setup (in order)--it starts at the end of the exhaust manifold, then pipe, then glasspack, then pipe, then another glass pack, then pipe, then the tip and out the exhaust goes. Can it get MORE free flowing than that? my system is pretty much straight through, no baffles, you could shine a light through it and it would come out the end. isnt that free flowing? any more questions? post a reply.
ok im gonna lay out all the things ive done to my car--petronix ignition, new holley one barrel, electric fan, way oversized radiator, manual fan switch(my car will never overheat), electric fuel pump, smaller A/C compressor, new power steering unit, custom air intake system, battery-in-the-trunk relocation kit, most free flowing exhaust ever, C4 with a shift kit. what so you think my power figures would be with all this stuff done? and someone please make an attempt to answer this, or at least just reply, i hate it when i ask this question and it goes unanswered. also, how fast do the drum brakes on the front of the mustang (new) take you wear down? how much more affective are the front disks? im thinking about making the conversion sometime soon, i just wanna know how much better the disks are than the drums. also, i have blacklights in my mustang (one under the drivers side of the dash, and one under the passengers side of the dash), think its a nice touch? any more questions? post a reply.
As I understand it you have a 66 200 with Holley 1bbl, but I didn't pick up on which one. I assume you have the stock head so it would be the Holley used with the 1.5" intake bore, I assume. This is not a performance carb, although it is better than the 1100 that came on the car.

Ignition. You have Pertronix. You didn't say which one, Ignitor or Ignitor II. Did you change the coil? If so, what are you using? What distrbutor, Load-o-matic (dual vac) or late dual advance ('68 - '73).

Header is good. Did you install the port divider?

Intake, ignition and exhaust can be done several ways, i.e., in several combinations. If you are still running a stock carb, a Load-o-matic, and header you have improved reliability and feel (throttle responce), but HP would not be materially different. I'd guess 10% based mostly on the header. The stock 66 200 was rated at 120HP at 4400 rpm. This was a gross number achieved on an engine dyno under test conditions. That is the way it was done in the 60's. Since 1972 HP is stated as a net number, i.e., in the car at the flywheel. The 1972 200 (same engine - slightly lower compression but better carb and ignition) was rated at 91HP at 4000 rpm. Your mods have probably raised that to 100 assuming you have a solid motor (good compression and well tuned).

The balance of your mods certainly add to the pleasure of owning / driving the car but don't add HP, although the shift kits sure feel like they do. Actually, they might in that they add efficiency to the drive train, which probably does get power to the rear wheels. That is to say that the well documented rear wheel HP of the stock engine is 65-67, or 73%-74% of the flywheel number. The shift kit probably improved the efficiency a few points.

A performance carb on an adapter (Holley 5200, Weber 32/36, Motorcraft 2100 - 1.08), and a dual advance dizzy with Ignitor II and Flamethrower2 would qualify as performance upgrades to match the header (with port divider). With these adds you can reasonably expect a 25% increase in HP without pulling the head.

If you don't already have one get a copy of the Falcon Perfromance Handbook. It is a great tool.

Have fun with your project.
hey steve, i was wondering if it is hard or not to mount the 2 barrel adapter plate? also, is the holley 5200 the most reliable 2 barrel for this application? where did you acquire your dynomax 1 in 2 out muffler? since im in texas, and its impossible to live without A/C, i cant use a dual outlet header. so i think the 1 in 2 out is a great idea. i love seeing those dual pipes coming out of the rear end of a car. i have a ignitor II, a flamethrower coil, and i think the stock distributor from 1966. so if i do the carb thing, find a more high performance distributor, and get a port divider for the header, i will gain some HP? any more questions? post a reply.