Exhaust manifold casting

[arguti]

Have a wee problem on my Alfa 75 Turbo Evo in that the exhaust manifold is cracked inside - see photos below.

Trying to get hold of a replacement is like trying to get hold of a hen with square teeth and I am toying with the idea of getting a small run cast as I wish to keep the car original. 2nd option is to go down the tubular manifold route if getting a OE replacement is not possible.

Amy recommendations as to:
1) What the best metal for casting
2) Any companies that may do this and
3) Likely costs of the two options.

I was thinking of doing a run of 10-20 and selling some on if the cost was not too prohibitive.

The problem!



What it should look like

[arguti]

Thanks but I already spoke to Goos last week - he has none in stock and has been waiting for 12 months for their Italian supplier to make up another batch.

There are one or two people who also have a spare manifold but, for obvious reasons, do not want to sell.

[arguti]

TheRealFingers99 said:

Can't speak for the owner. I hope none at the moment. But if a shard of cast iron breaks off it will destroy the turbo almost instantly.

This, manifold was taken off as turbo was damaged, this was probably the cause when you look how much of the vane has eroded over time compared to the original

Edited by arguti on Friday 29th August 18:26

[arguti]

Thank you everyone for the comments and suggestions; Mike from Boosted has got back to me saying it is possible but he has to have the original in order to estimate costing, etc.

Going down the tubular route is the other option yet understandably no one will guarantee against cracking especially in a turbo application.

Flatinfourth, I take your comments yet I seem to recall a thread on the Guy Croft forum about comparing the Alfa 155Q4/Lancia Delta Integrale OE exhaust similarly, is a crude looking thing and comparing the actual gas flow versus some aftermarket tubular manifolds and establishing that the OE manifold came out best.

I cant find the specific thread but here is a similar one

http://www.guy-croft.com/viewtopic.php?f=6&t=2...

In fact it was only recently I saw on his forum that there is now one aftermarket manifold that he endorses but it is around £2000!

http://www.guy-croft.com/viewtopic.php?f=7&t=2...

Some of Guy Croft's thoughts on exhaust manifolds (he posts under GCRE) for educational purposes. I have no connection Guy other than saying his book on modifying the Fiat/Lancia engines is absolutely fantastic!

http://www.fccuk.org/forum/ubbthreads.php?ubb=show...


thank you

Edited by arguti on Friday 29th August 18:27

[arguti]

If you look at the pictures of the new manifold versus the current state of mine there is a large crack but more importantly with time, the dividing vane has effectively been eroded away by heat and my concern is that is is this particulate matter which I believe has led to the damage to the turbo

The car is a 1987 model with only 69,000 km on the clock and the boost is factory standard with power at around 155bhp - the standard pistons, crankshaft etc are apparently strong enough for up to 400bhp so it's not like the engine has been particularly stressed. Just heat and age have taken their toll.

My preference for going down the casting route is that I am thinking of getting a second 75 turbo and I don't want to have to go through this again.