Exhaust Manifold Cracks

[thepowertowin]

Quote: Originally Posted by turbojack

OK, sorry for the opinion, I'll stop

I do appreciate the opinion... but I do think you're being a slight bit unreasonable. But that's opinion... take it or leave it.

Didn't really mean to come off condesending... (sp?)

Cracks will be common unless we use a different medium for casting the manifolds. A different medium that no one else has found yet. Obviously cast iron is the most common, and will continue to be from the manufacturers.

[Simon.Starkie]

So getting back to welding the manifold...that does seem quite risky, especially if it increases the probability of producing more cracking. So perhaps it really is better to leave it alone until it fails hard and then if it does, replace it with something else.

[thepowertowin]

I guess it's going to be personal choice. I like the idea of what DCR is doing though... the ramp is a good idea. I'm sure they have enough experience to at least know what they're doing there. I myself am happy w/ what I've got.

[ptcruzin42]

I'm willing to bet that just about any Service Manual for ANY turbo car has a section about acceptable and unacceptable cracks......

Why would those sections be there? Probably because cracks are normal.

[Simon.Starkie]

Quote: Originally Posted by ptcruzin42

I'm willing to bet that just about any Service Manual for ANY turbo car has a section about acceptable and unacceptable cracks......

Why would those sections be there? Probably because cracks are normal.

You would win that bet.
The Neon, SRT-4 manual says:
INSPECTION - TYPICAL TURBOCHARGER
Visually inspect the turbocharger and exhaust
manifold gasket surfaces. Replace stripped or eroded
mounting studs.
(1) Visually inspect the turbocharger for cracks.
The following cracks are NOT acceptable:
² Cracks in the turbine and compressor housing
that go completely through.
² Cracks in the mounting flange that are longer
than 15 mm (0.6 in.).
² Cracks in the mounting flange that intersect
bolt through-holes.
² Two (2) Cracks in the mounting flange that are
closer than 6.4 mm (0.25 in.) together.
(2) Visually inspect the impeller and compressor
wheel fins for nicks, cracks, or chips.
(3) Visually inspect the turbocharger compressor
housing for an impeller rubbing condition (Fig. 12).
Replace the turbocharger if the condition exists.
(4) Measure the turbocharger axial end play:
(a) Install a dial indicator. Zero the indicator at
one end of travel.
(b) Move the impeller shaft fore and aft and
record the measurement. Allowable end play is
0.038 mm (0.0015 in.) MIN. and 0.089 mm (0.0035
in.) MAX. If the recorded measurement falls outside
these parameters, replace the turbocharger
assembly.
(5) Measure the turbocharger bearing radial clearance:
(a) Insert a narrow blade or wire style feeler
gauge between the compressor wheel and the housing.
(b) Gently push the compressor wheel toward
the housing and record the clearance.
(c) With the feeler gauge in the same location,
gently push the compressor wheel away from the
housing and again record the clearance.
(d) Subtract the smaller clearance from the
larger clearance. This is the radial bearing clearance.
(e) Allowable radial bearing clearance is 0.326
mm (0.0128 in.) MIN. and 0.496 mm (0.0195 in.)
MAX. If the recorded measurement falls outside
these specifications, replace the turbocharger
assembly.