Alfa Romeo Owners Club of Australia Forum

Racing => Rear Wheel Drive => Topic started by: MD on September 19, 2022, 08:38:36 PM

Title: Homebrew Exhaust Header Flange
Post by: MD on September 19, 2022, 08:38:36 PM
Hi Guys. Not sue how many of you make your own competition headers nor what problems (if any) you have to obtain the necessary flange to make the start. What I am posting here are some examples of flanges I have made by a small business next to my workshop. (Handy that).
The flanges are 10mm thick, mild steel and cut by a milling machine. Very accurate fit.
He charges $100 plus postage which is under 2kg. Same price for either flange.
His contact details are here: https://mmes.com.au/ (https://mmes.com.au/)

Cheers, MD
Title: Re: Homebrew Exhaust Header Flange
Post by: festy on October 13, 2022, 01:04:29 PM
That's a very good price!
About 10 years ago I drew up a dxf for an Alfetta header flange and got a few laser cut in 10mm mild steel, and IIRC just the setup cost was over $200.
And I still had to finish mill the exhaust ports because the laser couldn't cut them on an angle  :-\
alfetta_header_flange.png
Title: Re: Homebrew Exhaust Header Flange
Post by: MD on October 13, 2022, 03:24:52 PM
Hi Festy,

That's interesting. About 10 years ago I paid about $150 and like you I had to finish it to fit. Those headers I am still using BTW !
I am currently building a complete new racing engine and this one is a Nord and wouldn't you know it, my spare TS flange doesn't fit. So my neighbor came to my rescue and made one for me for a $100 which I figured was a good price. So I pushed my luck a little and asked if he would do the same for Club members and he said yes. That's what prompted me to create the post.

I get no financial benefit for making the posting it's only there to assist anybody doing their own project.
Title: Re: Homebrew Exhaust Header Flange
Post by: Vne165 on October 19, 2022, 12:06:30 AM
MD, thanks for the heads up.
1 x Nord header flange ordered today, bound for Perth and a sprintex blown 2L (eventually).

Vne
Title: Re: Homebrew Exhaust Header Flange
Post by: MD on October 19, 2022, 08:22:15 AM
Hi Vne,
Ha,ha. Small world. Max spoke to me yesterday to say he had received your order and  I think he is planning to fit your job in if not today then this week.

I run an SC5-210 Sprintex on a 8v Twin Spark with water meth injection. The figures quoted on the American web site for maximum output pressure of 36PSI is fanciful in my opinion. Mine makes 17.5 PSI @ maximum rated speed of 15 000rpm and when you take into account 2.5PSI losses through the intercooler, you get 15 in the plenum.

BTW if your project is not for racing, be sure to fit the throttle body before the intake  as these guys make a VERY loud whine. Impresses the crowd, they think I am running  a crashbox !  ;D

Best wishes for your project.
Title: Re: Homebrew Exhaust Header Flange
Post by: Vne165 on October 19, 2022, 10:18:42 AM
MD, appreciate the sentiments and advice.

The car languishes, safe and sound inside a nice dry hangar at Jandakot, awaiting my attention but life gets in the way mostly.
Have just been collecting parts for the last few years, like teh one I just ordered from MadMax.

I did have an interlude a couple of years back with a 916 series twin-spark that I rebuilt, and during the process, I happened to try fitting the cylinder head onto a spare Nord block I have. Surprisingly, bore centers and head stud spacing were very, very close. Bit of judicious relieving and some pocketed head nuts and we might have a goer for a 16V, Frankenstein's monster engine. Then there's the issue of cam belt drive, front timing cover/oil pump drive, so we'd launch into dry-sumping the bugger. A poor mans F3 Novamotor of a kind. Nice to dream.

One question re the blower motor you have - did you manipulate your CR, or is it standard?

Rgds
Vne

Title: Re: Homebrew Exhaust Header Flange
Post by: MD on December 18, 2022, 08:46:04 AM
Apologies Vne for my late reply.

I overlooked your last question. The engine runs forged pistons and original compression ratio (10:1). The water meth solves the detonation issues.It's a UK product from Aquamist .
Title: Re: Homebrew Exhaust Header Flange
Post by: Storm_X on November 04, 2023, 10:13:00 PM
Quote from: MD on September 19, 2022, 08:38:36 PMHi Guys. Not sue how many of you make your own competition headers nor what problems (if any) you have to obtain the necessary flange to make the start. What I am posting here are some examples of flanges I have made by a small business next to my workshop. (Handy that).
The flanges are 10mm thick, mild steel and cut by a milling machine. Very accurate fit.
He charges $100 plus postage which is under 2kg. Same price for either flange.
His contact details are here: https://mmes.com.au/ (https://mmes.com.au/)

Cheers, MD

Unfortunately the photos you loaded up dont show for me. Is anyone else having this issue ¿
Title: Re: Homebrew Exhaust Header Flange
Post by: MD on November 14, 2023, 08:55:01 AM
Neither my photos or the ones from festy are loading.