Header or no header?

7

72maverick

Well-known member
Is it ever better to not use a header? With a header back pressure is lost, right? Which results in a loss of low end torque? I want to do my exhaust once my engine function correctly so I'm curious. I'm not looking for a race motor. I would want a good street motor and I'm wondering if headers would effect that at all

Current mods include:
DSII, weber 32/36, bore .40, 1.6 rockers

Future things I want:
Cam 364/364 110*, flat top pistons, and dual timing chains

Thanks
 
Headers reduce back pressure , yes , BUT no Engine Needs Back Pressure , what an Engine Needs is scavenging , and port velocity , think of it like a siphon , the smaller the hose the easier it is to get a siphon effect , BUT a very small hose moves very small amounts , be it a fluid or a gas , a good tuned header of the right size primary's utilizes the pull of a previous cylinder to grab and pull on the next one exhaust pulse to induce the flow " scavenging ", it is a rare instance that any header hurts flow ( other than Zoomies ) but they also have their use , usually on a Blown application or a High RPM Injected combo
 
THIS reminds me, Faron, how does the C.I. header stack up in scavenging abilities for the average 200/250 engine?
and even a modified engine such as mpgmustang`s mustang engine? ( since that's a fairly average stage build on this site, being 2bbl, cammed lightly)
 
While I have NOT used CI's Header it is a good Compromise on fitting and power adding , and could only help even a STOCK 6, A Factory Manifold's result of putting all the exhaust into one outlet is convenient for packaging , but terrible for power , OR torque production , if you are thinking about a Header upgrade , it is Second on my list for The Small Six after Ignition
 
The Duraspark is great , but so is a pertronix and a 68 up points / Vac adv Dist , both need recurved to get the most from them , it all depends on the combo and your wallet , keep in mind most combos are all done by 5000 , build the car to how you drive it 80% of the time
 
Well I have both readily available so ill drop each in and test them. Easy to wore between both the way I have them set up. Thanks for the info
 
awesome. I was just curious since it is a one size fits all system, but I never did any measuring and lost track of all my exhaust documents.
 
Another question,

I was looking at either a arvinode single exhaust or the "imposter" exhaust. I like the idea of both; however, it says the imposter can install with the stock manifold and the arvinode needs a header. WOuld it be a noticeable difference with a header on my current set-up? And can the imposter exhaust be refitted to a header if I get a header at a later time?

Thanks
 
The best results are with the recomended pacakge as a whole, but you can do as you please. In 1979, Ford's 250 six got a 18% improvment on peak power with the Perry headers Classic inlines used to use. Compared to the stock single outlet cast iron exhast header, it got 13% better fuel millage too. But if the combo isn't readjusted to suit, sometimes, you can loose midrange torque when the headers are used, and in EFI and applications where underhood heat isn't controlled properly, headers can create heat soak which hurts on road torque and peak power. Using the right igniton and carb settings allows you to use any exhast header and get the best results. As for me, I'll take the odd ball foot ball header used from 1980 to 1983. With a port divider, it flows as well as any other exhast, and doesn't suffer heat soak.
 
"...foot ball header used from 1980 to 1983..."

I've not heard of that 1 B4. Got a pic?
OEM for the 250? what model vehicles (some "headers' don't fit all models, even w/same engine)?
If you cite it it must have some advantage....
:thumbup:
 
With a cast iron head USA made I would use the Hooker header which has a 1 1/2" primary long tube vs the shorty header with 1 5/8" header.
The Hooker also aligns to the USA iron head.
The shorty classic inlines header is designed for the aussi head where the center exhaust ports are vertical same as the aluminum head.
Using the aluminum head you have to use the classic inlines header so the exhaust ports on the center cylinders match.
On a 250 engine the larger primary pipe would be a plus. On the 200 engine it may cause a loss of mid-range torque.
Theory only need track proof.
 
So for a street engine would it just be beneficial for me to do the exhaust and just use the stock exhaust manifold, at least financially?
 
I'd do both. The headers first, then price out and do the rest of the system as you can affort it.Only do what you can affort, as you can afford it.

Headers are an easy addition. I''m not sure the 4.25" exhast is the easiest to work around, since its a strange diameter, and it needs a plate to split the two branches, then to a dual pipe. It ends up little like the 4.9 EFI F150 truck exhast that slept with a stock system. Any time you put headers where the stock single out 2" iron header was, same deal, its a 18% performance, 13% economy deal. The exhast then flows good. Cast iron technically helps heat soak protection, but the stock pre 1960 to 1979 exhast headers are costing you power, torque and economy even if the car is tuned to suit.

For off the topic info, or as an intermediate step, the mods to foot ball converter header haven't been shown by me, but the header itself has.


cb732838-0f76-4d49-a4a9-22812c1d641c.jpg


http://vb.foureyedpride.com/attachment. ... 1326208798




viewtopic.php?f=22&t=69396

xctasy":1nwxx8mi said:
Yep, its the standard item you'd find on an I6 3.3 Fox after 1980. Thats what I use for my turbo and supercharged engines. It can be divided back up the 4.25" diameter drain to form a dual outlet exhast for a blown applications, and sized to suit a nice new ball besaring turbo like it is for my turbo application.


http://i1215.photobucket.com/albums/cc5 ... G_6861.jpg
http://i1215.photobucket.com/albums/cc5 ... G_6824.jpg
http://i1215.photobucket.com/albums/cc5 ... erhead.jpg
Click to expand...
 
I guess my next question is do headers bolt up to the stock system? I have really been considering the arvinode from.classic inlines or the imposters
 
I will tell you. I have the arvinode exhaust on my baby and she is loud, it does not give the best sound either. very high pitched and buzzy...

I'm about to replace it with a super 44 and some resonator tips to seed what that sounds like.

you can get the headers to work with the stock, but they do not bolt up. it will take a bit of welding and a y pipe at least.
 
so maybe not the arvinode.... Ha. I wanted aggressive but not loud or a low rumble. How about the imposter? I also saw on classic inlines it has a side exit kit? I think I will save up for both and have them ship at the same time
 
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