Another rattle

[kanujunkie]

I'm not talking HP fluids or gases, I'm talking metal and how it reacts when heated especially welding. It's all about using the right base material and the suitablity of that materail for the use intended, so for the sake of "peace of mind" it's worth doing. Remember from little acorns grow some very large trees - now theres an old saying  s:wink: :wink: s:wink:

read the context of what i said again, i said "if you were talking HP fluids or gasses then i'd agree". But were not, were talking about thermal expansion of metals when subjected to high temps and i very much doubt that an invisble crack when cold will suddenly appear, were looking at a visible crack, or more beleivable a failed gasket

The best solution to eliminate the manifold from future problems either to have one cast in steel or have one made by a professional company - not an exhaust company - someone who does it for a living, the downside to this is the cost, you have to be talking over a £1000+ for decent job.

we know where to get a cast manifold for the C2, makes me wonder wether it would work on the PE kit as well, obviously it would require some pipe work but could be worth a look see

WTS (at least I think it was him) just gave a good advice how to find out leaks. Just block your exhaust and put compressed air in the intake. Then listen to hisses.

add to that some really soapy water and you've got a perfect fault detection system

[Tem]

Thanks Tem. I think I'll just run the manifold to destruction now .... we're in talks to get an equal-length tubular made up. It won't be £1000+ but it will be the work of a time-served stainless weldererer.

Have you thought how a metal manifold would affect intake temperatures? I'm not sure, but I don't think it has much, if any, airflow around it and it will surely heat soak from the engine heat.  s:? :? s:?

Don't forget that the intake temp is measured before the manifold, so any heating that happens there is something the ECU won't know about.  s:? :? s:?


...and the +500whp MWR car is still running the stock plastic manifold, so it can't be that bad.  s8) s8)

[spit]

I think we might be at crossed purposes Tem....we're discussing the exhaust manifold.....

[Anonymous]

OK Stu got the wrong end of the stick  s:oops: :oops: s:oops:  

But a small crack when heated / vibrated will travel, so surely for the sake of a small test it's worth eliminating it from the equation, also when it's been welded how can you establish that the crack has not moved to another part of the existing weld, it will be interesting to see if Spits pressure drops even more as he uses it.

Cast steel is the best solution - tough and strong, not sure about stainless on a turbo manifold it can be prone to cracking, especially if you use the wrong grade.

[spit]

I'll keep an eye on it and let you know.

I'm depending on my stainless expert to find the right grade and compromise between thin wall and structural integrity (? 321 stainless). With beefed up bracing the stresses on the runners will be significantly reduced.

The 8mm flange plates at each end will be mild steel due to their low thermal expansion properties. My current flanges have always been slightly banana'd from new (although I'm as sure as I can be that the pressed gaskets effect a decent seal).

I haven't ruled out a cast manifold just yet, but the equal length "downward firing" stainless manifold appeals to me more at the moment. If Gas comes forward with a cast option for me I might take that on instead. I fear a significant amount of helicoiling and studwork'll be required though  s:cry: :cry: s:cry:  ...not to mention the exhaust re-working  s:? :? s:?

[kanujunkie]

OK Stu got the wrong end of the stick  s:oops: :oops: s:oops:  

no worries Rob

But a small crack when heated / vibrated will travel, so surely for the sake of a small test it's worth eliminating it from the equation, also when it's been welded how can you establish that the crack has not moved to another part of the existing weld, it will be interesting to see if Spits pressure drops even more as he uses it.

agreed and as part of that im going on the hunt tonight for some dye and developer  s:wink: :wink: s:wink:

[Tem]

exhaust manifold.....

  s:oops: :oops: s:oops:    s:lol: :lol: s:lol:

[Anonymous]

agreed and as part of that I'm going on the hunt tonight for some dye and developer  s:wink: :wink: s:wink:

Stu

If you get stuck let me know, we use it all the time at work I should be able to borrow the set. Cleaner, dye and developer.

Are you in the fab / welding business as well then?

Rob

[kanujunkie]

If you get stuck let me know, we use it all the time at work I should be able to borrow the set. Cleaner, dye and developer.

Are you in the fab / welding business as well then?

Rob

Cheers mate but i managed to get Ste some. will post it later. And no i'm not in the welding business, i'm in the Aerospace industry, i'm a licenced engineer working for BA