Highest HP 4g63 engine (from 2007)
Newbie
Joined: Aug 2011
Posts: 87
Likes: 0
From: Kennewick WA
The welds where filler was used aren't too pretty.. It's like the welder didn't leave any gap between fittings. So there may be lack of penetration and what not. But the lower autogenous welds look good, but I can do that..
However, definitely looks like a nicely engineered unit.
Also don't like how the fittings are cast pieces of pipe, but extruded tube is used for straight sections.. But I'm nit picky..
However, definitely looks like a nicely engineered unit.
Also don't like how the fittings are cast pieces of pipe, but extruded tube is used for straight sections.. But I'm nit picky..
Last edited by gasolinebaptism; May 8, 2012 at 11:59 AM.
Thread Starter
Former Sponsor
Joined: Apr 2008
Posts: 282
Likes: 0
From: Athens, Greece
The welds where filler was used aren't too pretty.. It's like the welder didn't leave any gap between fittings. So there may be lack of penetration and what not. But the lower autogenous welds look good, but I can do that..
However, definitely looks like a nicely engineered unit.
Also don't like how the fittings are cast pieces of pipe, but extruded tube is used for straight sections.. But I'm nit picky..
However, definitely looks like a nicely engineered unit.
Also don't like how the fittings are cast pieces of pipe, but extruded tube is used for straight sections.. But I'm nit picky..
Newbie
Joined: Aug 2011
Posts: 87
Likes: 0
From: Kennewick WA
How? Let's say you have two 1.5" 90* elbows you're welding together.. it doesn't make sense to weld inside and out, even if it is possible, the time and equipment required to get into the tight spaces would make these pieces very expensive.
So we're talking about schd. 10 fittings.. That's not thick, a 0.109" wall thickness. It wouldn't even take a bevel to get full penetration if you're welding hot enough.
I mean, it's obvious that things like the v-band flanges are welded inside and out, and probably the other flanges as well, but I said those welds look fine, it's the welds on the fittings that I'm not impressed with. It seems lower quality than some that I can buy from punishment racing or from STM, but you're asking for more money..
And okay, they may be using 304 fittings and filler, but this is a low stress member (i.e. not structural) so it doesn't need to be able to withstand large forces, it simply needs to be able to withstand the same stress throughout it's life, going through thousands of heat cycles, and I don't see a reason to use 316 over 304, other than the fact that 316 is more expensive..
And in reality, 304 is as strong if not stronger that 316, and has a higher chromium content. So IMHO, not only is 304 cheaper, but would fit the bill for an exhaust manifold better.
$0.02
So we're talking about schd. 10 fittings.. That's not thick, a 0.109" wall thickness. It wouldn't even take a bevel to get full penetration if you're welding hot enough.
I mean, it's obvious that things like the v-band flanges are welded inside and out, and probably the other flanges as well, but I said those welds look fine, it's the welds on the fittings that I'm not impressed with. It seems lower quality than some that I can buy from punishment racing or from STM, but you're asking for more money..
And okay, they may be using 304 fittings and filler, but this is a low stress member (i.e. not structural) so it doesn't need to be able to withstand large forces, it simply needs to be able to withstand the same stress throughout it's life, going through thousands of heat cycles, and I don't see a reason to use 316 over 304, other than the fact that 316 is more expensive..
And in reality, 304 is as strong if not stronger that 316, and has a higher chromium content. So IMHO, not only is 304 cheaper, but would fit the bill for an exhaust manifold better.
$0.02
Evolving Member
Joined: Feb 2011
Posts: 115
Likes: 0
From: Toronto
I agree!!
How? Let's say you have two 1.5" 90* elbows you're welding together.. it doesn't make sense to weld inside and out, even if it is possible, the time and equipment required to get into the tight spaces would make these pieces very expensive.
So we're talking about schd. 10 fittings.. That's not thick, a 0.109" wall thickness. It wouldn't even take a bevel to get full penetration if you're welding hot enough.
I mean, it's obvious that things like the v-band flanges are welded inside and out, and probably the other flanges as well, but I said those welds look fine, it's the welds on the fittings that I'm not impressed with. It seems lower quality than some that I can buy from punishment racing or from STM, but you're asking for more money..
And okay, they may be using 304 fittings and filler, but this is a low stress member (i.e. not structural) so it doesn't need to be able to withstand large forces, it simply needs to be able to withstand the same stress throughout it's life, going through thousands of heat cycles, and I don't see a reason to use 316 over 304, other than the fact that 316 is more expensive..
And in reality, 304 is as strong if not stronger that 316, and has a higher chromium content. So IMHO, not only is 304 cheaper, but would fit the bill for an exhaust manifold better.
$0.02
So we're talking about schd. 10 fittings.. That's not thick, a 0.109" wall thickness. It wouldn't even take a bevel to get full penetration if you're welding hot enough.
I mean, it's obvious that things like the v-band flanges are welded inside and out, and probably the other flanges as well, but I said those welds look fine, it's the welds on the fittings that I'm not impressed with. It seems lower quality than some that I can buy from punishment racing or from STM, but you're asking for more money..
And okay, they may be using 304 fittings and filler, but this is a low stress member (i.e. not structural) so it doesn't need to be able to withstand large forces, it simply needs to be able to withstand the same stress throughout it's life, going through thousands of heat cycles, and I don't see a reason to use 316 over 304, other than the fact that 316 is more expensive..
And in reality, 304 is as strong if not stronger that 316, and has a higher chromium content. So IMHO, not only is 304 cheaper, but would fit the bill for an exhaust manifold better.
$0.02
Newbie
Joined: Aug 2011
Posts: 87
Likes: 0
From: Kennewick WA
Not trying to flame on Spyros or anything.. But is there an advantage to using 316 over 304? It seems that the higher chromium in 304 would make it more resistant to rust after it's gone through a thousand heat cycles or so..
And okay, they may be using 304 fittings and filler, but this is a low stress member (i.e. not structural) so it doesn't need to be able to withstand large forces, it simply needs to be able to withstand the same stress throughout it's life, going through thousands of heat cycles, and I don't see a reason to use 316 over 304, other than the fact that 316 is more expensive..
And in reality, 304 is as strong if not stronger that 316, and has a higher chromium content. So IMHO, not only is 304 cheaper, but would fit the bill for an exhaust manifold better.
$0.02
And in reality, 304 is as strong if not stronger that 316, and has a higher chromium content. So IMHO, not only is 304 cheaper, but would fit the bill for an exhaust manifold better.
$0.02
Manifolds actually can have HUGE internal forces on the material due to thermal expansion. The design alone can greatly improve the situation there and a material alone won't make up for a bad design. Also, at the operational temps encountered, these material lose a HUGE amount of their strength and fatigue becomes a major concern as even the loads on a well designed piece can easily go above the endurance limit of the material...neglecting corrosion...which brings us to 316 stainless.
With regards to 304 being stronger, 316 stainless is more resistive to inter-granular corrosion then 304 stainless. Because exhaust gas has caustic elements in it, 316 actually is the better material here for long term durability. Exhaust gases will attack and corrode from the inside out on stainless steel long before you would see any issues on the outer surface.
Sorry, if you are going to attempt to attack somebody else work, you should have a better idea of the actual reality behind what they are doing.
Newbie
Joined: Aug 2011
Posts: 87
Likes: 0
From: Kennewick WA
I'm not attacking anyone. If you notice I simply stated an opinion, and asked Spyros "is there an advantage to using 316 over 304?"
Your answer in interesting and may well have some basis, but I'm not asking for your answer. I want to know what Spyros has to say on the subject.
And of course there will be loads from thermal expansion, that's a given. That's one of the reasons very good welds with full pen are important.
And if we're realistic, these cars aren't built for the long term, one of these manifolds will almost never see 50,000 miles.. Probably an average of more like 10-20.
Your answer in interesting and may well have some basis, but I'm not asking for your answer. I want to know what Spyros has to say on the subject.
And of course there will be loads from thermal expansion, that's a given. That's one of the reasons very good welds with full pen are important.
And if we're realistic, these cars aren't built for the long term, one of these manifolds will almost never see 50,000 miles.. Probably an average of more like 10-20.
I'm not attacking anyone. If you notice I simply stated an opinion, and asked Spyros "is there an advantage to using 316 over 304?"
Your answer in interesting and may well have some basis, but I'm not asking for your answer. I want to know what Spyros has to say on the subject.
And of course there will be loads from thermal expansion, that's a given. That's one of the reasons very good welds with full pen are important.
And if we're realistic, these cars aren't built for the long term, one of these manifolds will almost never see 50,000 miles.. Probably an average of more like 10-20.
Your answer in interesting and may well have some basis, but I'm not asking for your answer. I want to know what Spyros has to say on the subject.
And of course there will be loads from thermal expansion, that's a given. That's one of the reasons very good welds with full pen are important.
And if we're realistic, these cars aren't built for the long term, one of these manifolds will almost never see 50,000 miles.. Probably an average of more like 10-20.
I'm not attacking anyone. If you notice I simply stated an opinion, and asked Spyros "is there an advantage to using 316 over 304?"
Your answer in interesting and may well have some basis, but I'm not asking for your answer. I want to know what Spyros has to say on the subject.
And of course there will be loads from thermal expansion, that's a given. That's one of the reasons very good welds with full pen are important.
And if we're realistic, these cars aren't built for the long term, one of these manifolds will almost never see 50,000 miles.. Probably an average of more like 10-20.
Your answer in interesting and may well have some basis, but I'm not asking for your answer. I want to know what Spyros has to say on the subject.
And of course there will be loads from thermal expansion, that's a given. That's one of the reasons very good welds with full pen are important.
And if we're realistic, these cars aren't built for the long term, one of these manifolds will almost never see 50,000 miles.. Probably an average of more like 10-20.
I would disagree on the idea of these manifolds not going 50k miles. Sure, those "1500 HP" setups will never make it there. But there are lots of AMS turbo kits for example that are still out there and probably have 100k miles on them.
That said, sure, if you are using schedule 40 pipe, as long as you have good penetration on the weld, you would probably be fine even with any stainless steel pipe...
Not everybody wants a 20 pound manifold though and thinner material means you need better material. Even if it's simply dropping to schedule 10.
Newbie
Joined: Aug 2011
Posts: 87
Likes: 0
From: Kennewick WA
Okay, well if this thread is about the best, and we're talking stainless manifolds, they need to be coated on the inside first thing. And okay, I was wrong, 316 is superior to to 304 because is has higher operating temp. But that won't matter as much with a good coating.
And we also need to bring 321 SS into the picture. -That is, if we're talking about the best.. (Short of inconel or titanium of course.)
And we also need to bring 321 SS into the picture. -That is, if we're talking about the best.. (Short of inconel or titanium of course.)
