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1 5/8 equal vs 1 3/4 unequal shorty's

7K views 34 replies 15 participants last post by  Ed Curtis 
#1 ·
I want some new headers for my 331, currently have 1 1/2 equals. I am going to go with ceramic coated, so need some input. I'm thinking the sound might change some from the two, but more worried about flow.
 
#4 ·
Ya I knew someone would bring of long tubes, more money more work, if I was starting fresh I would. The bbk 1 5/8 and 1 3/4 unequal coated are about the same price, do you still have the plug wire problems with the 1 3/4
 
#5 ·
You have 1 1/2" equals or 1 5/8" equals? I know they made the 1 1/2's for a little while. I used to prefer those over the 1 5/8 equals for a mostly stock motor. However, I would say, regardless, the equals are going to give you a better scavenge effect and flow more efficently (especially if you have 1 5/8"). So, I would say stick with the equals. I bet there would be a negligible difference, if any, compared to a larger diameter UN-equal header. My bet is the power curve would be better with the equals for sure, even though there might be a slight tippy top RPM HP gain with the larger Un-equals. That's my $0.02. I am sure if you Googled it there are plenty of old tests with similar motor combos. Enough to make your own call.
 
#7 ·
Oh, okay. The title says 1 5/8". I wanted some equal length shorties for my current combo, but stumbled on a really great deal on some ceramic coated 1 5/8 UN-equal length's. I guarantee you I would make more power with the EQUAL length 1 1/2". I can't say that the ceramic coating does much except make the engine compartment look really nice and they haven't changed color yet like the chromies do!
 
#9 ·
My suggestion would be don't worry about the equal length unless you are going with a long tube style. I think in theroy they are better but I found them to raise my under hood temp a lot more than the unequal one (this was uncoated in both styles). My spark plug and wire access was horrid.

Some food for thought, you could always get your headers coated. There is a place in missouri that quoted me 80 bucks to do myne.
 
#12 ·
Brand makes a difference. The exhaust openings on my JBA 1-5/8" shorty's are bigger than the openings on my FRPP 1-3/4" Z headers I had. I'll be damned if the runners weren't about the same size as well. They are an awesome shorty. The BBK's I replaced, which were also a 1-5/8" were an absolute joke compared to the JBA's.

But, I guess for the price they should be.
 
#18 ·
Here is Mac 1 3/4 stock good cheap header that works... collector is puny compared to mid length and even the cheapo BBK LT



BBK 1 3/4 LT modified for a much better design..



don't mean to take things over here but i went thru a similar scenario before.
from one upgrade to another .

Bigger exhaust will not hurt as long as engine parts are chosen carefully cam/intake/exhaust and gears etc
 
#24 ·
well powder coaters coat things with powder coat which is not a thermal coating. some powder coaters do "ceramic" coating but it is the same as the "ceramic" coating the header mfgs use and will likely cost you more in the end.

one of the better colored coatings is called "jet hot" but it is not a thermal coating like the swaincoat i posted.

ceramic is white

.
 
#26 ·
So all these headers that come with ceramic coating won't reduce heat,besides the fact that they state the do, that's really my main goal, not really appearance. Ever since putting this 331 in and the fact I painted the headers with high temp paint, its really hot under the hood. I've read that taping causes the pipes to rot away .
 
#28 ·
thats what i said . they exagerate . . greatly lol . . swain coat or the other mentiooned or wrap them .. no they will not rust away quickly but will rust faster in some environmeents . . a higher flow rad fan will also reduce engine temps as well as unning your engine cooler etcm
 
#27 ·
^In addition to "Swain" and "Jet Hot", there is also "Cerakote".

Ceramic coated headers will help reduce under hood temps by reducing the amount of heat emitted from the header... its still going to be very hot if you shoot it with a temp gun.

Going to an unequal length header will lower underhood temps as well as there is less pipe to physically emit heat into the engine compartment.

Lastly, a larger primary pipe should run a lower temp as well... exhaust restrictions tend to increase EGTs.
 
#31 · (Edited)
anything you wrap, will trap heat and moisture, and cause accelerated failure of header as compared to same header unwrapped.

Jet hot has two thermal coatings, a pretty "silver" one good to about 1100 degrees, it does protect the header, and when done on NEW headers they actually warranty the header. OR used to... The coating is inside as well as outside, so it protects the steel from moisture, it also allows far less heat to penetrate the header and more heat ends up further down exhaust system, or dumped out.. if running open headers.

They also have a rather dull blue that's good to 2400 degrees or so.. better for turbo and forced induction applications, or those who are prone to LOTS of N20 and some eleveated EGTs.....

adding to what ED and Buddy already illustrated.. which header is better comparisons are only valid on a single combination. Just swapping from a 1 1/2 or 1 5/8 header to a 1 3/4 or 1 7/8 on an engine might have some improvement. But to really see the maximum performance, the whole combination should be assessed and addressed. A cam with huge exhaust bias based on a restrictive stock exhaust, is going to rob an engine of performance potential when that exhaust is replaced with a free flowing header/turbo muffler combination.

Its akin to bolting on one great aluminum head, then leaving the factory iron one on the other side, and all else equal bitching that the head didn't live up to the promise of performance improvement.
 
#33 ·
Damn, what happened to the pics, just when I need to eyeball accufab midlengths, gotta see if they'll fit a ranger V8 swap.
 
#34 ·
Get the cheapest of the two and be done with it!!!!
Header length and diameter importance is way over rated.
I guarantee you can't feel the difference between the two! You may THINK you can but .....think about it!! A1/4" increase in diameter on an engine that is more than likely pretty "sorted out" to begin with.
You're wasting money...time..and brain cells trying decide if your engine NEEDS and increase of 1/4" diameter!!
Trust me brother....you won't be able to tell the diff.
6sally6
 
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