Header size question

[rt/10stew]

Hi I am looking at buying some headers the seller tells me that the I.D is 1 5/8" and the O.D. is 1 3/4". So my question is what size are these ? as I do not know if headers are sized by the O.D. or I.D.

Thanks Stew

 

[RTTTTed]

My experience has been that the size measured is the ID. 1 5/8" is not 1 3/4" OD a the tubing is smaller than 1/16. This is not always true and there are differences between steel and SS, etc.

Superhcharged engines (like mine) need 1 3/4" headers and if they are the Belangers 5>2>1 the pickles must be removed for the headers to make power.

Normally aspirated can use 1 5/8" OR 1 3/4" headers. Highly modified n/a engines also need the 1 3/4" headers for a slightly better performance (gas mileage and/or hp).

1 5/8" headers are best for stock. 'Tuned' (read expensive) headers are the best for all applications, but the difference in hp is often not worthy of the much higher cost.

Ted

 

[rt/10stew]

Thanks for the reply Ted. But I am still unsure of how these are measured. I am looking for 1 3/4" as I am planning on adding a supercharger. So are 1 3/4" headers an O.D or I.D measurement ?


T.I.A. Stew

 

[RTTTTed]

What kind of headers?

Unless they're a cheap/chinese/junker set they should be 1 3/4" if that's what they're listed at. What brand name?

Here's my Belangers 5>2>1 with pickles removed. 1 3/4"

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[RTTTTed]

OD measures 1.735" so if you want to get technical, they aren't 1 3/4" on the outside either, but I'd guess that the bends make the tubing larger and smaller and the measurement is different in different places so it is kind of irrelevant anyway. .015" isn't worth mentioning either so I guess we could say the 1 3/4" must be the outside measure.

I'd recommend just don't buy cheapo. Stick with brand names.

Ted

 

[rt/10stew]

OD measures 1.735" so if you want to get technical, they aren't 1 3/4" on the outside either, but I'd guess that the bends make the tubing larger and smaller and the measurement is different in different places so it is kind of irrelevant anyway. .015" isn't worth mentioning either so I guess we could say the 1 3/4" must be the outside measure.

I'd recommend just don't buy cheapo. Stick with brand names.

Ted

Thanks Ted that is what I wanted to know

Stew

 

[RTTTTed]

Thanks Ted that is what I wanted to know

Stew

You're welcome.

 

[ViperTony]

Just call Lou Belanger for the measurements, if you're looking at Belanger headers. Belanger Headers : Producing The Highest Quality of Specialized Exhaust Systems

 

[viperbilliam]

I believe advertised header tube sizes are generally ID.