[lambretta_ash]

hello all i have a question for your opintions and or help

now ive spend alot on my engine and it only seems right to make a big bore exhaust i seen some on ebay witch are £168 i think but i can make it for £60 so im gonna go for it

so my question is
is it critical where the two 38mm branch pipes join to the 51mm outlet IM COPYING FROM A SPORTEX EXHAUST and going by measurements on the listing heres the picture and sizes thanks

primary pipes length 35mm to 45mm (size 38mm) main pipe size 51mm

 

[MikeS]

I know that there is a optimum length and diameter for headers but didn't know how to calculate this; so I found this on Google Primary Header Tube Length and Diameter Calculator or this, which seems a bit easier to use Bowling's Exhaust Header Length Computation

 

[lambretta_ash]

is there any others im shaw there is

 

[vince-305]

I did mine mate .................. Pure guess work (what would fit within the confines of the space in both the car and my wallet) and what i thought was pleasing to my eye ................ :tup:

If i was going into it for more of a competitive sport (other than my own enjoyment) then im sure there are right n wrong ways of doing it (price up tri chevy fenderwells :shake

 

[lambretta_ash]

I did mine mate .................. Pure guess work (and what would fit within the confines of the space in both the car and my wallet) and what i thought was pleasing to my eye ................ :tup:

If i was going into it for more of a competitive sport (other than my own enjoyment) then im sure there are right n wrong ways of doing it (price up tri chevy fenderwells :shake

COUGH n half if im honest i think i have the measurement there i think the one primary is 35cm and other 45cm so i think <<< THINK its fairly easy just need my flaming engine back been there 3-4weeks now

 

[vince-305]

I think that if your running 35CM primaries i got a feeling that they will flow real well ........... im using 45mm (1.75") on my bigblock ................. :tup:

 

[lambretta_ash]

well thats the size of the exhaust port seems daft to block some of the size right gonna order some pipe and ask someone to bend the pipes when i figure where to bend them and how much haha but i do know dont to go straight down let them go out abit so it flows easy

 

[JackGriffin]

Have you got a tube bender that is suitable for thinwall tube? Most will just kink it or squash it flat.

 

[vince-305]

Hey Ash i think i through you a lil bit ................... 1cm = 10 mm and your using 45CM .........450mm :lol:

(well i was trying to be funny :lol

 

[lambretta_ash]

Hey Ash i think i through you a lil bit ................... 1cm = 10 mm and your using 45CM .........450mm :lol:

(well i was trying to be funny :lol

eermmmmmm SHAT UPPPP :lol: yes i think it will go super fast if i was talking bore sizehaha

the size is 38mm pipe but the Length of the pipes is 35cm and 45cm on the primarys so jokes on you haha

i dont have a pipe bender no but think i no someone i can ask

 

[bigyellataxi]

I bought bends from a local motor factors, flanges from PaulG @ Whengparts and made mine meself...

Lengths are whatever fit and that's about it...

Changed the flanges for supertraps...

Get on with it mate...!!!

 

[45bobber]

Have you got a tube bender that is suitable for thinwall tube? Most will just kink it or squash it flat.

iam guessing the hydrulic type you can get from most hire centres, may not be any good then? thinking into the future as was going to have a go at making an exhaust in a few months.

 

[JackGriffin]

iam guessing the hydrulic type you can get from most hire centres, may not be any good then? thinking into the future as was going to have a go at making an exhaust in a few months.

I think that you need a mandrel-type bender to make nice bends on thinwall tube. The Hilmor/Record electrical conduit and copper pipe hand bender might work with smallish diameter tube, but it might be hard work actually pulling the bends. The hire centre ones are usually for water pipe, airline and scaffolding, i.e. thick walled, and just push the centre of the tube between two guides: guaranteed wrinkles and/or flattened thin tubes.

 

[45bobber]

I think that you need a mandrel-type bender to make nice bends on thinwall tube. The Hilmor/Record electrical conduit and copper pipe hand bender might work with smallish diameter tube, but it might be hard work actually pulling the bends. The hire centre ones are usually for water pipe, airline and scaffolding, i.e. thick walled, and just push the centre of the tube between two guides: guaranteed wrinkles and/or flattened thin tubes.

cheers, il do a bit of homework between now and when i need one.:tup:

 

[vince-305]

Ive heard that you can pack thin wall pipe with sand and then use that type of bender but it has to be packed solid with sand

It maybe worth giving barry the bender a pm on here http://www.rodsnsods.co.uk/forum/members/barry-the-bender

Ash he maybe able to offer some advice too :tup:

 

[bigyellataxi]

We have a mandrel tube bender at work, and it doesn't do thin wall exhaust tube.

Mind you, we don't have the mandrels for thin walled tube, so that might not help...!!!

 

[lambretta_ash]

so theres the right side

 

[lambretta_ash]

 

[Lee]

Looks good Ash.

 

[spanners]

is it a spider,,,:lol: ,, or what sort of tune will it play :lol:
only joking,, just been playing with the headers and side exhausts on ,,EMILY,, my austin ten pick-up 52mm primary,s 4into 1 95mm side exit ,,olds 260 v8 engine,,sounds nice :tup: