Big power for the S4 just got a bit further away

[Mike159]

I was needing to sell my other toy before I could spend any money on the new s4. I thought the headgasket had gone the other day after the fans failed to kick in and it overheated. I left it at home until yesterday when I went to fix it.

First sign something was wrong was when I couldnt get a spark plug out.

When I took the manifold off and a bent £450 valve dropped out I knew it wasnt going to be good.

I had some serious money in this engine (I could of driven out with an mrc 500 on the s4) and I was planning on selling it to fund big power in the audi to get some power with control.

I did have some good times with it, couple of trips to the ring and lots of bald front tyres. It was one serious sleeper. Standard looking apart from big intercooler behind r32 bumper. But even if you saw that you wouldnt expect it have 500bhp

Ive got a few saleable parts from it, I will put them in the classifieds just incase anyone else has a 20v turbo toy on here.

[Doug_S2]

why is hte manfifold chopped?

[jimbo1234567]

snap. this happened to me a few weeks ago.

[Mike159]

The manifold had cracked around the weld from where the downpipe has been rattling on the floor. It would be nice to think a £600 downpipe would fit but never mind! That bit decided to drop off as I unbolted the manifold lol.

Has the end of the valve dropped off in that pic? That is what happens to standard valves run over 350bhp apparently. The reason behind me fitting the uprated supertech ones. But I cant work out what has gone first. The head might have cracked at the point in the port where there is a chunk out of it. Letting in water which has done the valve in. Or the end of the valve might have dropped off first?

[quattronutter]

the valves are only fricition welded as is the case of most manufacturers original valves,inspect very carefully when rebuilding or replace with new or uprated

[Doug_S2]

was the broken runner on the same cylinder that has been messed up?

that manifold looks like it has 5mm wall thickness runners?

[quattronutter]

looks like scaffolding tube..

[Mike159]

No the broken runner is on the 1st cylinder and the damage is on the 4th

The manifold is this one http://www.tig-art.com/inc/sdetail/558 and has since been coated for heat insulation

[jc..]

It looks like Sch10 1.5" welded tube which is pretty common for tubular manifolds. but.......
poor quality blow up of your photo but that manifold has barely been welded. it looks like they have run a cap weld over square butted joints, if I was speculating they haven't run enough heat though it either.
not $1200 worth of manifold. compare that to Full Race who (IIRC) have a lifetime warrnty on weld cracks.

I would be speaking to Tig Fart if that was my mani.

[Mike159]

Someone I know who is a top notch tig welder has repaired it for me. And he commented on the lack of penetration

[jc..]

lack of penetration is never a good thing!!