Exhaust Manifold Cracks - SRT Forums

thepowertowin · 03-30-2006, 10:55 AM

Cracks in a cast exhaust manifold are considered normal, particularly on a turbo car. What people are referring to on the stage 3 is nothing we should be worrying about. This is (yet another) situation where a harmless issue gets blown out of proportion on the fourm.

I recommend a cool-down period or turbo timer to impede their progression.

High heats, and heat cylcles contribute to the high rate of cracks. Tubular steel manifolds have often been used to combat cracks. These, in order to not crack, have to be very thick and just as heavy as the stock cast manifold, but obviously takes a lot more man-power to produce. Obviously, any car manufacturer will chose cast.

This is for info only, and I will delete any negative responses.

**glhs837** · 03-30-2006, 11:36 AM

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(Those are minus signs

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Does this mean I can get my extinguisher for those running around with their hair on fire?

thepowertowin · 03-30-2006, 11:54 AM

Why not let them burn?

thepowertowin · 03-30-2006, 11:58 AM

I see your ----------------------- and raise you +++++++++++++++++++++++

4SRT4 · 04-01-2006, 09:08 PM

Glad somebody cleared that up.

Simon.Starkie · 04-01-2006, 09:21 PM

As I said yesterday in the other thread...

"BEWARE! S3R Manifolds Cracking!" has way too much drama associated with it.

What is there to beware of anyway? Most people have known for a long time that our SRT-4 cast manifolds crack, regardless of whether or not they stock or S3R.

It's cool.

4SRT4 · 04-01-2006, 09:35 PM

There's always more to the story than what you hear initially.

**glhs837** · 04-01-2006, 09:35 PM

Meaning?

dansrt4 · 04-01-2006, 09:39 PM

I just kinda thought it was odd there is only one company fixing them and all the s3r guys were like lets send it to them or we will die hurry hurry. Just sounds a lil fishy.

Simon.Starkie · 04-01-2006, 09:41 PM

Yes, the same thought crossed my mind also...

Dark-SRT4 · 04-01-2006, 09:48 PM

the hair-line cracks aren't much to worry about...but the debris breaking off is something to worry about. many S3 owners have removed the turbo only to see a destroyed turbine wheel (more then likely due to the debris from the cracking).

Simon.Starkie · 04-01-2006, 09:55 PM

Sure hope those damaged turbines wern't due to taking it apart...
mine has never been apart and it's not going to either, unless it fails completely and I have no choice...

Simon.Starkie · 04-03-2006, 01:18 PM

Question that's been bugging the back of my mind...it used to be considered a bad idea to weld brittle cast iron...especially large chunky pieces where the heat from the welding torch concentrated in a small area may cause distortion...leading to further cracking...

So wouldn't you be better off to leaving the crack rather than trying to patch it with a weld that itself may become detached resulting in the demise of your turbine wheel?

thepowertowin · 04-03-2006, 02:09 PM

Quote: Originally Posted by Simon.Starkie

Question that's been bugging the back of my mind...it used to be considered a bad idea to weld brittle cast iron...especially large chunky pieces where the heat from the welding torch concentrated in a small area may cause distortion...leading to further cracking...

So wouldn't you be better off to leaving the crack rather than trying to patch it with a weld that itself may become detached resulting in the demise of your turbine wheel?

This is a nice little read:
http://www.locknstitch.com/CastIronWelding.htm
(make sure you also read about expansion and contraction at the bottom, and that will lead you to further pages full of explanations

)

I don't know what the process people have used on our manifolds, but I know it's a last resort and normally you have to use low heat to perform a weld. This cast part will go through a lot of heat cycles so I don't recommend welding on it. I'm sure there are experts out there that are better equipped to answer the questions... but from what I understand and what I've read, it's not the best idea.

Back-n-Black · 04-03-2006, 02:35 PM

I have heard just tring to match the alloy of the manifolds with a good wire or stick for wielding is a pain. They use an alloy that has a high nickel content and makes wielding a pain. But like Jimmy said there are those that have figured it out. I can only image the stretch and shrinking that take place between cold and orange turbo. Mine has been glowing on a couple occations, and has seen 1800+ degrees celcius EGT's. (stock turbo mine you, not stage 3) That is a lot of change and distortion.
Randy