B16B and B18C headers, what's the difference?

[Joshm88]

Ok, so I have been reading some very mixed things with regards to the differences between B16B and B18C headers......

If the blocks are exactly the same, which they are, and the sumps are exactly the same.....why is it that there is this stigma that seems to come with B18C headers that they hang lower than B16B headers?

I have raised this question a couple of times in the past week or so in various threads and again recieved mixed response.

I have done some searching on and come across this from older threads:

http://www.ek9.org/forum/air-intake-exhaust/4556-difference-between-ek9-dc2-header.html

Guys,

Do any of you know what the difference between the fitment of these two headers is? I've been told that its simply that the mounting bracket is about 3mm out, and that it can easily be cured by using a few washers to space it out.

Is this correct?

Cheers olly. I was thinking more in terms of aftermarket header though. After a 5zigen this month, but the only place I can find only has the DC2 fitment headers in stock.

If the difference is literally a 3mm gap between the lower fixing bracket, i'll go for it. Just dont wanna get a DC2 fitment 5zigen & find that any other clearance is affected.

It will fit without any issues, it'll just hang lower, nothing to worry about unless you have your car lowered too much

http://www.ek9.org/forum/air-intake-exhaust/5606-itr-stock-421-header.html

Hi Mates, a friend of mine is selling his Stock JDM ITR-DC2 4-1 Header (spec 98, 2.5" collector) and i thought of buying it for my ek9 (since i have b16a 4-2-1 headers), I have a 2.5" exhaust line... I think it'll be a good mod, what do you guys think?

Cheers
Enrique

good mod if your car is not too low to the ground.

As said, the ek9 4-2-1 manifold is the same as he 96 spec ITR manifold.
The 98 ITR 4-1 mani doesnt hang low at all though.

TODA has one for the B16 and B18. The B18 has larger pipes, not good for the B16. But I'm tempted for one thats available locally..

however its not much difference...

18100-DC2-960 ø45 ~ ø50 ~ Taper ~ ø60mm INTEGRA-R(DC2/DB8) 96spec
18100-DC2-980 ø45 ~ ø50 ~ Taper ~ ø60mm INTEGRA-R(DC2/DB8) 98spec
18100-EK9-000 ø45 ~ ø48 ~ Taper ~ ø60mm CIVIC-R(EK9) 98spec

So what exactly is going on here? Do they hang lower or not?!

I can understand the piping diameter difference due to the larger stroke?? Does this mean that there is a distinct design difference in length wise between the two?

Obviously it's a difficult question to answer since aftermarket manifolds vary in their clearance due to design, and the stock headers are different (minus the 96 spec DC2 and oem EK9).

But for instance, why do Mugen have the same product codes for 4-1 header for 96 spec DC2/EK9, but a different one for 98 spec DC2???? Is it just piping diameter?

 

[Accessory Zone]

Cant speak for an aftermarket header but the stock B16b header bolts right onto the
b18c no probs. Everything lined up just fine.

 

[Joshm88]

Cant speak for an aftermarket header but the stock B16b header bolts right onto the
b18c no probs. Everything lined up just fine.

Yeh I have heard that they all bolt up fine, and the B16B bolts up to the B18C no problem since they use the same block.

But is there any truth in the fact that B16B and B18C headers give different ground clearances?

 

[Accessory Zone]

I think you'll find that most b18c headers will be fine. I am running a DC sports on my
b16b and it was for a b18c and it fits fine.

 

[Joshm88]

I think you'll find that most b18c headers will be fine. I am running a DC sports on my
b16b and it was for a b18c and it fits fine.

I'm not planning on purchasing a B18C header or anything, I'm just generally curious since I've heard a lot of conflicting views lately, got me thinking lol

If there is a difference in height/clearance, one would assume there is a slight (however minor) in flow as well....

 

[rvm]

The 4-1 header hangs a little low because of its design.

4-2-1 design:

4-1 Header

If you see in the 4-1 design you can obviously assume that it'll hang a little lower because you can see the 2 more tubes just before the exhaust that connects to the catalytic converter.

 

[rvm]

B16B OEM 4-2-1 Header Clearance

 

[Joshm88]

Thanks RVM but I already knew that 4-1 designs hang lower than 4-2-1. Is this the only reason people perhaps claim that DC2 headers hang low???

If that's the case I can understand where it may have come from....with people putting the 98 spec 4-1 on the B16B, replacing the identicle 4-2-1 oem header on the 96 spec teg/ek9.

However, this doesn't explain why Mugen and most other aftermarket manifolds producers have the same product codes for both their 4-1 and 4-2-1 designs for the ek9/96 spec DC2, but different ones for 4-2-1 and 4-1 for the 98 spec DC2??

If they were all the same, wouldn't they just all have the same product code? Or is it something to do with different oem exhaust fitment on the 96 and 98 spec DC2's?

 

[Joshm88]

B16B OEM 4-2-1 Header Clearance

Wow, nice pic, it does give extremely good clearance! Not so good on gas flow though

 

[RagingAngel]

However, this doesn't explain why Mugen and most other aftermarket manifolds producers have the same product codes for both their 4-1 and 4-2-1 designs for the ek9/96 spec DC2, but different ones for 4-2-1 and 4-1 for the 98 spec DC2??

If they were all the same, wouldn't they just all have the same product code? Or is it something to do with different oem exhaust fitment on the 96 and 98 spec DC2's?

It is because the 98spec OEM header uses a different header hanger on the collector than that of the 96spec and EK9.

 

[blinx9900]

I have never seen proof that a header made for a dc2-r hangs lower than the same header made for an ek9, furthermore i have never seen proof that a header made for an ek4 (or any other car with a b16a) sits higher than the same header designed for a dc2-r.

But i do think it is possible that a headers for b18c hangs slightly lower than header for b16 only because the b18c (and b16b) use a crank girdle which requires the oil pan to be a bit deeper in the area the header travels under.

I did at one point own ever Edelbrock header made for every B series equipped car in the US and i found a few things:

-All of them mount to the head the same
-Depending on the car it was made from the 2-1 section may be longer, have an extra bend in it, or have a different flange clocking angle.
-To my surprise the one that had the best ground clearance was designed for a a car with a b18c1 (aka b18c4) which was a USDM Integra GSR that also uses the crank girdle mentioned above so my own theory is nullified.

 

[Joshm88]

It is because the 98spec OEM header uses a different header hanger on the collector than that of the 96spec and EK9.

I see, didn't know that!

I have never seen proof that a header made for a dc2-r hangs lower than the same header made for an ek9, furthermore i have never seen proof that a header made for an ek4 (or any other car with a b16a) sits higher than the same header designed for a dc2-r.

But i do think it is possible that a headers for b18c hangs slightly lower than header for b16 only because the b18c (and b16b) use a crank girdle which requires the oil pan to be a bit deeper in the area the header travels under.

I did at one point own ever Edelbrock header made for every B series equipped car in the US and i found a few things:

-All of them mount to the head the same
-Depending on the car it was made from the 2-1 section may be longer, have an extra bend in it, or have a different flange clocking angle.
-To my surprise the one that had the best ground clearance was designed for a a car with a b18c1 (aka b18c4) which was a USDM Integra GSR that also uses the crank girdle mentioned above so my own theory is nullified.

Thanks for the input guys, I think that pretty much wraps it up then

It seems that any actual difference that there may be, accounting for the different product codes, is almost negligible! Would still love to see something like a B16B Mugen 4-1 and a B18C Mugen 4-1 together in person, but don't see that happening anytime soon! lol.

Glad I've finally got an answer to this, now I can carry on deciding what header I actually want lol!

 

[nismo.racing.23]

so lets just say u have an em1 (2000 honda civic si) and swapped the b16a2 motor with a b16b motor.. i would want to buy the b18c header due to the crank girdle which in turn makes the oil pan a bit larger... so by buyin the b18c header it will fit around the b16b's oil pan perfectly? correct?

 

[NZ_EK9]

Correct ^

 

[nismo.racing.23]

^ thank you much and ill pry be gettin that toda header!! ill be sure to post pics when its in... also ill be postin pics of the swap as well also do i get the 96 spec or 98 spec? thanks