ALFAGTV6.COM

Mezevenf wrote:

Scott in MN wrote:The owner of an exhaust shop that did work on my 164 claims that mandrel bending is not worth the cost. He races sprint cars and does a lot of work on dragsters and hot rods. He acknowledged that it makes a difference, but claims it is miniscule and not worth it on a street car. His machine results in a smooth bend but ovals the pipe slightly.

This may be true from the cats/collectors and back but the headers themselves need to be mandrel bent.

Anyway, the cost of getting mandrel bends here is minimal.

On a street car, good press bends is way over the "good enough" limit. I'm not sure the difference is more then a few HP and you can lose LOTS more by messing up the shape of the system or choise in dampers/mufflers.

Well as promised, Daniel and I got together on the week end and had a bit of fun remaking the model for the primaries template.

Now remember, you have to do your homework about internal tube sizes and tuned lengths for your pupose. The point here is just to give you and idea of how to get started.

Tip: the vacuum hose you select should be as cheap and as compliant as possible. It will make the job easier to bend to shape.

When it's done, have some fun with it and not only bend it but twist it too and see that you can make quiete a variety of solutions. It may even inspire you to do other projects.

If you are also thinking of building a collector, you could join it at the primary flange as per the model.

Party time..get your play dough out kiddies..

Endeth part ONE

Starteth part TWO..

Once you cut the holes in your timber manifold faceplate, insert the tube and staple inside to retain it.Three staples is enough. Use some contact glue before hand if you intend to be rough in handling this item later.

BTW. Don't let me catch you even thinking about using real fexible pipe for your actual headers unless you want me come around and smack you on the back of the head with a borrowed KIWI thong for being a bird brain. You need SMOOTH internals man..

That was fun Daniel. Hope it inpsires a few out there to have a go.

As you can see, the V6 does not need a spaghetti weave going around the moon and back to work. It is one of the simplest there is. Don't let anyone charge you the earth to make it.

very nice guys!! that's a very good idea and i'll be putting it in use hopefully in a short time

thats god to be one of the best informative DIY posts I have ever seen. Well done guys Well done.

BRILLIANT!!!
v

Not to steal your thunder Duck man,but you gotto do this in the car to check clearances...That nice 3 way flange of about 50mm dia.?Dem pipes gotto clear little space between engine and body...

Otherwise,bloody well done..(For an Aussie )


Hey,I like your floorpan/tunnel mod for the exhaust pipes...

MD,

is it OK to use another color for my headers.
I tried the blue tubes but they melted. Maybe I need to use thermo-tec but how do I get it inside instead of outside as it normally is?
The new headers are much lighter than the steel ones so this is a big plus!


PS! what type of plastic canister would you recommend as catalytic converter

It's a good idea but I dare you to find ready made twisted bends like that...

Micke wrote:PS! what type of plastic canister would you recommend as catalytic converter

Tupperware makes some high quality plastic containers Micke. Some models are high flowing units.

Seriously this is a good idea. But clearence may be an issue if this is not built with the chassis.

When Larry (APE) built headers for the 24V he had just the engine bay of a gtv6 with the 24V in there. Of course being the owner of an Alfa wrecking yard, he has an advantage.

You guys have to remember, even exhaust shops have mandrel benders in Australia. This is unlike any other place in the world, so bends may not be an issue in Australia.

Ah you're all whacked !! Is it any wonder I like you guys.

Micke, I stick with blue cause it goes with the colour of my eyes.

Bazza, I originally did mine in the engine bay and that's when this technique really shines cause you can weave your way around all the stuff in there. That's how I worked out the route past the starter motor that needed some mods to the floor.(remembering I also had to deal with the steering shaft. RHD).

Mats, you can get a whole variety of donut tube of varying radius to make your bends from and just weld them together. I know you know this and you are just having a crack like the rest of the guys. I say this for the benefit of readers who may not know that.

Tupperware -the killer header..

Flat bends yes but judging fron the pics you need helical bends, i.e. twisted bends like a spring.

Zamani wrote:You guys have to remember, even exhaust shops have mandrel benders in Australia. This is unlike any other place in the world, so bends may not be an issue in Australia.

This may sound a bit stupid... but where else would you find a mandrel bender if not an exhaust shop? lol.

I guess we have it easy here.

I don't mean to rain on anyones parade, but has anyone done a dyno comparison of the stock manifolds to the headers/extractors?

Granted I'm new to Alfas, but the stock iron manifolds look to be pretty good as is. I can see a weight benifit to headers, but if the hp gain is only 5hp then it sounds like a really expensive exersise (putting headers on) that comes with a bunch of headaches (heat, clearance, etc.).

just my .02

Scott