ossett2k2

iTrader: (9)

I'm having a problem getting the RH exhaust manifold to seal!
After a few problems with the bottom end I had to swap it,using my heads,I can't remember seeing any signs of the manifold blowing but never took much notice,I did have a nightmare removing it as the nuts were properly tight.
Anyway long story short,the engine is fitted but I hear a slight blow from the exhaust,on checking I noticed the RH flange was at fault(see pics).
I removed the manifold and checked the flanges,looks like someone has had a botched up attempt to port them!(Only reason I can think it's not flush)
The LH flange is nice and flat but the RH is not,I tried filing it down but failed to get it flat&true,I'm pretty sure it needs to be perfect to make a good seal but I ran out of time and needed the car so just fitted it back up with new gaskets,my mistake as it's still blowing
Do you recon I will be able to get a nice flat surface on the flange? Any tips on how to would be appreciated
Or should I take it somewhere to be machined?
OR I'm I using the wrong settings to tighten it up(35Nm)?




Cheers
Rich

B9SLJ

iTrader: (1)

Just an idea but Did u notice if it's been ported out bigger than the sealing ring on gasket or is it still within the sealing ring ?

B9SLJ

iTrader: (1)

I ported my own and used the gasket as a guide as was pre warned about overdoing it due to sealing issues

ossett2k2

iTrader: (9)

Ooh that looks like you have a nice finish on that
Cheers for the advice,I never thought of checking against the gasket,I'll have a look tomorrow before refitting.
I did put a metal ruler on the straight edge and the LH flange was flat but the RH not,I'll have to try get that flange nice and flat.

I always thought that porting was just working on the opening and not touching the flat part of the flange so I'm not sure what's happened to mine?

B9SLJ

iTrader: (1)

you are correct the porting shud have been just the opening and not touched the flange.
If you can find somewhere to machine it flat it will be easier than trying to get it flat yourself. Local exhaust manufacturers might have a flatbed sander
If they were mine I would probably try a large belt sander with 40 or 60 grit belts as the bed of the sander is flat and bigger than the exhaust flange

ossett2k2

iTrader: (9)

Nice one,I will see if there's anywhere local who can machine it flat,I've got files and an angle grinder and think I'll be pi55ing against the wind if I try and get a nice flat edge.

Henrik

iTrader: (5)

Number 1, step away from the angle grinder. It will score them to hell. IF the flanges are proper banana shaped the you might be able to get them reasonably close with a flap disc, but the stainless will provably work harden... I'd avoid personally, as you will still have to finish by hand.

The process of making something reasonably flat is simple in theory:
Put a straight ruler across the flange from side to side. It will let you see where the high / low spots are, then file away at the high spots, whilst trying not to create more low spots.
if you've got a flat plate (or even a flat glass table etc), you could put some thinned out paint on it (or proper engineers blue), and gently touch the flange on the painted/blued surface. The paint will transfer to the high spots, which you then remove with a file. Rinse and repeat until satisfactory. Note that this process does not fix "plane errors" (one flange tilted in relation to another) but should at least ensure flatness.

Alternatively, give it to a machine shop, but it might be problematic fixing the manifold down in the machine.

ossett2k2

iTrader: (9)

Thanks Henrik
Great tips there,I think my problem last time was I filed the whole flange hoping it would end up with a flat finish.
I will nip down to the DIY store for some decent sandpaper and just work on the raised points with the file and finish with the sandpaper.