I read somewhere that a rule of thumb for choosing header tube diameter was 10% larger than the exhaust valve.

Anyone have experience with this guide and, if so, does it have merit? Any reason it wouldn't apply to turbocharged applications?

 

I'd like to know also

 

I don't think that is applicable on our cars.

stock b series exhaust= 28mm
+ 10% of 28= 30.8mm
30.8mm= 1.21in header tube diameter

maybe small block chevy's who commonly see 1.94"-2.08"
= 2.00in
+10% of 2in= 2.2in header tube diameter

so figure most v-8 headers are 1 7/8in-2 1/4in primaries would fit the forumula.

 

maybe 10% larger volume than surface area (or *open* area) of valves?

 

There are more factors then just exhaust valve size gentlemen

 

of course, but i can see how the relashonship may provide for a good rule of thumb.

 

mmm yes and no the exhaust valve maybe too small and then your not taking into account other things such as the cam shaft, bore and stroke of the motor etc exhaust is really a black art

 

A black art that, when modeled correctly, can be completely expressed in mathematical terms.

So yes, you can have an equation. However, it will be a tad more complicated than just exhaust valve diameter. A fluid dynamics book will help you in your search.

 

Since were on the subject, what size pipping should be used for our cars (B series mainly) when making a header or turbo manifold?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicross &raquo;</TD></TR><TR><TD CLASS="quote">A black art that, when modeled correctly, can be completely expressed in mathematical terms.

So yes, you can have an equation. However, it will be a tad more complicated than just exhaust valve diameter. A fluid dynamics book will help you in your search. </TD></TR></TABLE>

Well yes and no thats where we sourced alot of our information from, at the same time the formulas are not exact and do not account for a lot of variables hence our extensive R & D and testing put into the development of our program


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Luserkid &raquo;</TD></TR><TR><TD CLASS="quote">Since were on the subject, what size pipping should be used for our cars (B series mainly) when making a header or turbo manifold? </TD></TR></TABLE>


It's gonna vary from app to app i wouldn't use anything larger then an 1 3.4" OD 16 ga. tube

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eLusive ek4 &raquo;</TD></TR><TR><TD CLASS="quote">Well yes and no thats where we sourced alot of our information from, at the same time the formulas are not exact and do not account for a lot of variables hence our extensive R & D and testing put into the development of our program

It's gonna vary from app to app i wouldn't use anything larger then an 1 3.4" OD 16 ga. tube</TD></TR></TABLE>


Agreed, lots of R&D is always key to help refine and increase the accuracy of your models, so you don't have to make so many prototypes.

 

You guys do know that Burns Stainless will design you one for free, right? (or at least they did until recently.) Their payback is that they hope you will buy the tubing from them.

 

NO NO NO not for free hehehehhe we give nothing away!@!!!!! nothing!!!!
\
75.00 dollars

or free with the purchase of merge collector

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eLusive ek4 &raquo;</TD></TR><TR><TD CLASS="quote">NO NO NO not for free hehehehhe we give nothing away!@!!!!! nothing!!!!
\
75.00 dollars

or free with the purchase of merge collector</TD></TR></TABLE>

My work bought two 5-1 merge collectors from Burn's. We weren't offered the X-design service at all. I'm guessing it would have been pointless for the application we're using them for but it'd be nice to have your input on the design anyways (Dodge Ram SRT-10 - Vortech supercharger).

Like what primary length/size. For full exhaust would a crossover help? Blah blah blah.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by backpurge &raquo;</TD></TR><TR><TD CLASS="quote">

My work bought two 5-1 merge collectors from Burn's. We weren't offered the X-design service at all. I'm guessing it would have been pointless for the application we're using them for but it'd be nice to have your input on the design anyways (Dodge Ram SRT-10 - Vortech supercharger).

Like what primary length/size. For full exhaust would a crossover help? Blah blah blah.</TD></TR></TABLE>

MY apologies you weren't offered the imput did you speak with me if so were you set on a predetermined size?

We always recommend a cross over or Y with a tailpipe car

and dont forget to fill out the Race Engine spec form completly

*not trying to advertise for my company just trying to answer questions sorry for previous price post*

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eLusive ek4 &raquo;</TD></TR><TR><TD CLASS="quote">

MY apologies you weren't offered the imput did you speak with me if so were you set on a predetermined size?

We always recommend a cross over or Y with a tailpipe car
</TD></TR></TABLE>

We weren't aware of the X-design program until after ordering from the paper catalog. Probably just didn't notice it in the catalog, I know it's on your site though. No biggie, we already determined primary length and size. For sure we wouldn't be able to do full length headers because we wanted them to bolt up to the stock exhaust. I did some math before hand and figured primaries should have been around [insert random # here]" with 1 7/8" piping on the stock motor with the headers being made for peak power around 5500 rpm. With the supercharger the lengths were to be shorter, but still we had to sacrifice performance for fitment and made the primaries much shorter but still equal length. Longer and the headers would be too close to the aftercooler, firewall, wheel wells and other crap.


Modified by backpurge at 3:27 PM 1/19/2005

 

That V-10 is A 10 cyl. 383 mopar.Same bore and stroke as the old 383 wedge.The primaries should be about 36 to 40" long .No longer than 40". With out a supercharger.With A S.C. I would say no longer than 35".I did a set for Roger Mears in a truck that Dodge gave him to race Pikes Peak.Dodge gave them A new
Viper motor to put in the truck.That was in 1993 or 94.But they were twisting it 6800rpm.And I did the headers The magic number 30".


Modified by RMF at 2:56 AM 1/19/2005

 

Some things are better left unsaid.

And ummmmmm...

Mopar 383 V8
Bore - 4.25"
Stroke - 3.38"
CID per cyl - 47.9"

Mopar 505 V10
Bore - 4.03"
Stroke - 3.96"
CID per cyl - 50.5"


Modified by backpurge at 3:38 PM 1/19/2005

 

&lt;cough&gt; back on topic &lt;cough&gt;

You can also buy a header design from http://www.headersbyed.com

It runs around $30, and you have to fill out a form for all aspects of your engine, but it's a good service. Much better then guessing. "Ed" is a real guy, very much from the old school and pretty strong opinions, but we all do...

I used the recommendations from him and Burns Stainless for my own header.

 

hehehe who is this ed

Sultan of stainless &gt; ed

lol jack was dubbed that title by popular hot rodding so hilarious!

sorry of topic i will look at this ed and report back with my humble opinions

 

I hate headers. such a secret. Got to buy some and coppy them. I guess $75.00 from burns is cheaper though