New Manifold?
#1
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New Manifold?
I'm considering a new manifold, but I'm trying to decide if it's worth it.
The one I have now is home-made out of stainless (except the flange), and it keeps cracking. Apparently the guy I had weld it for me wasn't as good as he claimed. So far I've been pulling it off and having it fixed every time but that is getting old.
I have an offer from a friend who works at a very good machine shop to weld me a new one (just like the old one, so the turbo wouldn't move) for the price of materials (I supply the materials and he turns them into a manifold for free).
So far it sounds like a no-brainer.
I don't intend to keep the car for too much longer, so a shiny new manifold just doesn't seem worth it. I also don't like having a cracked manifold either.
I guess the basic question is what would you do in this situation? My options as I see them are:
1. Continue to have the old manifold repaired every couple months as it develops new cracks - Free but a pain in the ***
2. Have a new manifold built out of stainless - $200ish
3. Have a new manifold built out of mild steel - $179 or less
At this point I am leaning toward option 3 and seeing if I can get the parts a little cheaper. Thoughts?
The one I have now is home-made out of stainless (except the flange), and it keeps cracking. Apparently the guy I had weld it for me wasn't as good as he claimed. So far I've been pulling it off and having it fixed every time but that is getting old.
I have an offer from a friend who works at a very good machine shop to weld me a new one (just like the old one, so the turbo wouldn't move) for the price of materials (I supply the materials and he turns them into a manifold for free).
So far it sounds like a no-brainer.
I don't intend to keep the car for too much longer, so a shiny new manifold just doesn't seem worth it. I also don't like having a cracked manifold either.
I guess the basic question is what would you do in this situation? My options as I see them are:
1. Continue to have the old manifold repaired every couple months as it develops new cracks - Free but a pain in the ***
2. Have a new manifold built out of stainless - $200ish
3. Have a new manifold built out of mild steel - $179 or less
At this point I am leaning toward option 3 and seeing if I can get the parts a little cheaper. Thoughts?
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I'm working on it. Had an interview on Wednesday at a place that will pay roughly 3x what I make now. You may have heard though, the job market isn't great for those of us fresh out of college.
#6
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How is making a quality manifold out of mild steel selling a car with problems? Aren't most of the cast manifolds around here something other than stainless? The $200 price was an estimate, I don't think either of the flanges from JGS are stainless, and those tend to be tough to find. Is a SS manifold with MS flanges a bad idea?
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I believe he was referring to option 1, "Continue to have the old manifold repaired every couple months as it develops new cracks" on the premise that it would continue to develop new cracks after you had sold the car.
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How is making a quality manifold out of mild steel selling a car with problems? Aren't most of the cast manifolds around here something other than stainless? The $200 price was an estimate, I don't think either of the flanges from JGS are stainless, and those tend to be tough to find. Is a SS manifold with MS flanges a bad idea?
A few quick questions about the previous manifold.
1. Thickness
2. Did the "good" welder back purge while welding?
3. What welding process did he use?
4. Did he get full penetration?
5. What filler rod?
6. Where does it crack?
1. If its thin **** it is more prone to crack than say schedule 40 pipe
2. Without a back purge you are burning the chromium out of the metal creating the *sugaring* which will in turn cause stress risers and crack.
3. Im just curious on this one
4. Without full pen the pipe will already have stress risers in the weldment and be more prone to failure.
5. Im assuming your using 304 base metal since thats the cheap **** everyone buys (it works great for this crap) Important to know what kind of filler rod he used. I use 308L which is low carbon rod which aids in preventing martensetic. Martensitic is a property of alloys that allows them to be hardened but the downside it takes away from ductility.
6. If the crack started at the weld then most likely the stress riser gave way. We all know about thermal expansion and you add 1 flaw... time makes fools of us all right?
Last edited by SKMetalworks; 06-14-2009 at 04:09 AM. Reason: wording
#9
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sbkcocker, sorry, I don't know the answer to many of those questions. The thickness of the pipes was something pretty decent. I want to say it was sch. 40 but don't quote me. I don't know about back purging, he was using a mig with gas to weld, no idea on the penetration. I almost doubt it in most places because the weld only shows from the front. Don't know about the filler rod, and it cracks on the welds where the Ls meet the Ts. So far it hasn't cracked where either of the flanges meet. The first crack was on the top side and the second and third cracks have been on the underside.
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So I'm leaning toward a new manifold out of mild steel because I had forgotten how expensive/hard to find SS flanges are, and I don't really feel like having it made out of two materials. Doesn't matter, most manifolds are MS anyway.
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But then you run into the possibility of the dissimilar metals expanding and contracting differently causing unnecessary stresses... so far nobody has mentioned a single reason not to just make the entire mani out of MS...
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