ALFAGTV6.COM

Kevin,

That sounds pretty good. If you are going to that much trouble you may as well include a goilet termination of the primaries into the collector. This will maximise the smooth flow of the gases within the collector. Now I know every kid on the block will want to know wtfk this is.

Well, the best I can do at short notice is a shitty pencil drawing which I hope gets the message across.

You could flange fit the collector or wrap it around the primaries depending on space available. For ease of servicing, I would go the flange route.

I must be dyslexic nor can I spell in french. The word is goilet not goiter. Had you all off the scent for a while ha ha..

Note the one on the right is a venturi collector type which causes gases to speed up at this point an supposedly create a vacuum behind it.

Hi,
I have a 24v conversion in my 85 gtv6 and having problems with exhaust header leaks. Does anyone know of after market headers for these?
Thanks

goiter termination .. what the hell is this is this merge collector?

Yeah Baz agreed but sometimes you just gotta let it all hang out don't ya?

MR Turbo. You are on the money ! Exactly. Now I guess the theory is that the actual collector volume needs to represent the volumes as I have previuosly said to allow the gases to expand at that point and create a vacuum in the primaries behind it. This causes "slugs" of gases from each cylinder to move in rapid succession corresponding to the RPM much like machine gun fire. In doing so , it will create a negative pressure behind it helping to move these exhaust gases out.

It is why the correct name for headers, primaries is the term extractors. It is also why it is so important to match the length and inside diameter of each primary pipe to the nature of the use the engine will be put to eg. towing work, 4 wheel drive work,general street use, rally, or tarmac racing.

So you can see that when somebody says, oh yeah, I think I am going to fit a set of headers the response is -here we go again. All is well but one has gotta do the homework and build the entire sytem to achieve what it is the modifications are needed for.

Good ferreting by the way getting that pic.

and optimal merge collector with improoved scavenging is venturi trasition one ...

dan668s wrote:Thanks for all the feedback guys!
I've ordered the CSC headers last night as that was the best system I could find for a reasonable amount of money. I got a qoute for a custom made system, but that would cost me 3 times as much as the CSC-system, so I figured it wasn't worth it.
MD, the CSC system are supposed to have primary pipes with equal lengths, so it should be better than the IAP-headers I posted a picture of earlier.
I ordered the CSC kit complete with all gaskets and bolts and the price was only £385,- from EB Spares (www.ebspares.co.uk).

welcome to the club.
you will see, its a good invest for a gtv6/75(milano); sounds cheap/effectivefull (however because of that is cheap; it means machine bended..ect so the quality is not great like a pure hand made exhaut...but this should cost much much more).

i buy ones 4 years ago(headers only), and have some feedback to share:
-sound is great.
-??? need a few nuts and bolts somewhere...nothing cost but annoying, good tips is to fit studs(M8 *1.25) and nuts instead of bolts beetwen sections.
-there is no seal beetwen sections, so need to put a thin exhaut paste sealant.
-the paint go away after few hours but the exhaut dont rust. just a little little bit on solders after long years.
-the first start, and for a 0.5-1 hour the paint smokes and it smelts like sewers ! .....just hang on.

- in europe we are numberous to buy these by the past. and i know a lot of people that get trouble (me to) to fit the left header (coil side):
it looks like that the part is badly bended at the cylinder 4, and then you had to enlarge bit the hole or rebend it a bit.

when i buy my ones i send an email to csc, and they said that they will modify them jig...perhaps we get a answer whit your ones.

MD, My dad made up sets like this on Formula Ford car(many years back) with the seven degree venturi in the collector box then coming back out seven deg into the secondry pipe which proved to be the best then , however he did not worry to much on the amount that the collector box held as the extraction came purely from that venturi effect. The collector probably did hold close to twice that of one cylinder but that was just a product of getting the angles correct.
Back to GTV. Im going to give it a try but space is going to be my problem.
Thanks for those pics.

Smithy, where are the leaks coming from as you can just use the original 24v gaskets if its at the the head, with good silicone, copper nuts and spring washes.

Could anyone here please post a picture of a Porsche collector and the other type so I can understand what the whole thing is about???

Try this site for info but I would encourage you to read others for balance.

http://www.popularhotrodding.com/tech/0310phr_burns/

wow... burns stainless. pretty cool.
v

I would like to make one more contribution here. I am sorry I didn't make any photos of it at the time so you will have to perservere with a text discription. To do it all again, I would need a spare V6 on an engine stand so it isn't going to happen too soon.

How to design and fabricate a model of your own Primary Pipes (Headers, Extractors).

1 Pick a tuned length, say 450mm
2 Obtain some swimming pool pump vacuum hose of around 38mm I.D. you need 6x450mm=2.7metres of it. Cut six pieces of 450mm. This is your equal length pipes.
3 Obtain some timber that you can make a manifold faceplate out of and a coupling flange at the other end. Drill the mount holes to the head and cut out holes in the timber that correspond with the exhaust ports.
4 Insert 3 tubes into the port outlets you have made in the timber manifold faceplate. Fix with contact adhesive and staples.
5 Insert the other end of the tubes into the coupling flange and fix in the same way.
6 Plug up the exhaust ports with some rag tightly. Position the assembly onto the engine head and lightly bolt up the timber/tube manifold. You now have three swimming pool pump tubes hanging off the the engine head. They look like corrugated headers.
7 Play around with their shape by simply moving them around until you have the smoothest flow curve and one that fits around all components around the engine bay.
8. Once you are happy with the shape and location, fixed them in place with anything handy, wire, zip ties etc.
9 Using some expandable foam in a spray can, insert the foam into each tube and seal it.
10 Wait for the foam to set.
11 Once set. Carefully remove the assembly by unbolting from the head.
12 You are now holding a model of your future headers that will clear everything, fit your engine bay, have the outlet positioned exactly where you want it and they are a tuned (equal) length !!
Take it along to your exhaust shop and get them to quote you a price for making up the real thing in any material of your choice. You can ceramic coat them prior to mounting if you so chose.

Remember this is an execise in principle. So for you chosen exhaust specifications, you will need to modify the tube lengths and ID to suit you needs but the method of making the model is the same.

Once the fabricator sees your model in hand, they are less reluctant to have a go at making one as invariably they are very simple being only 3 pipes each. Keep the flow simple and DONT make a spaghetti weave !!

great idea MD, I like.

I will have to give it a go - I have Barry's majical ex manifolds for the 24v, now just have to play around with the rest of the exh system - maybe when the engine gets finalised.

MD, that's brilliant! The only thing I would add is to get the curved stainless pipes before you start. Otherwise you may end up designing a system with bends that can't be duplicated by a muffler shop.