What do you prefer to use for head flanges on turbo manifolds. From what I can tell CRS 1018 mild is a popular choice for high end manifolds. The are the pros and cons of using stainless or mild?

Regards,
Justin

 

Stainless expands a lot more and can result in cracking, I use mild for all my head and turbo flanges.

 

When welding stainless to mild I've read that 309 and 312 are good fillers to use. Anyone?

 

I typically use 309.

 

If you look at the material properties of stainless and mild steel you will see that they only slightly vary. Steel in general expands alot with heat but the difference between the two isnt much to worry about in my opinion.

 

Why does Full-Race, Lovefab, JG fab ect all use mild 1018crs flanges? From what Geoff has stated in the past, the mild steel head flanges are actually stronger when properly stress relieved compared to using a stainless head flange.

Regards,
Justin

 

my buddy has a love-fab manifold and i hate how they use mild steel flanges. its like why spend soo much money on a bling bling manifold to have the flanges nice and rusty a few months later. i perfer to have rust free for the price im paying. i would pay extra to make sure they were stainless flanges.

for mild to stainless, i used 309

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k24em2 &raquo;</TD></TR><TR><TD CLASS="quote">I typically use 309.</TD></TR></TABLE>

i use 309L. i'm not sure the difference, but i was told to use this rather than plain 309.

 

You already made a post about this about 6 months ago.

https://honda-tech.com/zerothread?id=1381644&page=1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90DALS &raquo;</TD></TR><TR><TD CLASS="quote">my buddy has a love-fab manifold and i hate how they use mild steel flanges. its like why spend soo much money on a bling bling manifold to have the flanges nice and rusty a few months later. i perfer to have rust free for the price im paying. i would pay extra to make sure they were stainless flanges.

for mild to stainless, i used 309</TD></TR></TABLE>

Because a manifold not cracking is more important then it looking nice.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90DALS &raquo;</TD></TR><TR><TD CLASS="quote">my buddy has a love-fab manifold and i hate how they use mild steel flanges. its like why spend soo much money on a bling bling manifold to have the flanges nice and rusty a few months later. i perfer to have rust free for the price im paying. i would pay extra to make sure they were stainless flanges.

for mild to stainless, i used 309</TD></TR></TABLE>

Becuase it's better to use mild steel than stainless. Cody is certainly not about cutting costs at all.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin Olson &raquo;</TD></TR><TR><TD CLASS="quote">What do you prefer to use for head flanges on turbo manifolds. From what I can tell CRS 1018 mild is a popular choice for high end manifolds. The are the pros and cons of using stainless or mild?

Regards,
Justin</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nowtype &raquo;</TD></TR><TR><TD CLASS="quote">You already made a post about this about 6 months ago.

https://honda-tech.com/zerothread?id=1381644&page=1</TD></TR></TABLE>

To Mr. Olsen-You already know the answer. Its going to be the same from damn near everyone and you know it.

Are you just trying to stir up trouble?

 

maybe he's bored, or he only has a short term memory.

 

That old thread had a bunch of controversy, and I just wanted to here what the fabricators in here thought. Sorry for the repost

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18bEKcoupe &raquo;</TD></TR><TR><TD CLASS="quote">If you look at the material properties of stainless and mild steel you will see that they only slightly vary. Steel in general expands alot with heat but the difference between the two isnt much to worry about in my opinion.</TD></TR></TABLE>

Well stainless expands at about 1.5 times that of carbon steel.

 

So from my understand by having a mild flange it is less likely to move the runners around in relation to the exhaust ports. Since the head flange doesn't move around so much it isn't pushing and pulling the runners around as much. This would help in keeping the collector from cracking I would think.

Regards,
Justin

 

I like 1018 Cold Roll Steel.

Stainless expands way too much. A flange with tight clearances around the bolt holes will break studs off the head as it expands and is bolted down. Not only that, but when the rest of the manifold is stainless, it has the tendency to warp out and not come back.

I've fixed countless disaster stainless steel log manifolds. There have been times where I have said "let me make you a new one in mild, cause my repair bill is going to be more than I would charge you to duplicate this and it's bound to crack again"

1018 flanges, mild piping, sand to a bright finish and let rust. If you hate rust, send to ceramic coating.

 

Would SS flanges work for an N/A header? Or would it still get too hot?

 

Say you cut the stainless head flange between each port after fabing up the manifold. Having a flange per cylinder out of stainless would help with the overall thermal expansion, but are you likely to warp the flange still?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin Olson &raquo;</TD></TR><TR><TD CLASS="quote">Say you cut the stainless head flange between each port after fabing up the manifold. Having a flange per cylinder out of stainless would help with the overall thermal expansion, but are you likely to warp the flange still?</TD></TR></TABLE>.

Cutting the slots will help but I don't feel like its efficient enough. Besides the flange expanding on the head, the flange is going to want to pull in all sorts of directions causing the runners to either expand with it or crack.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by danielm3 &raquo;</TD></TR><TR><TD CLASS="quote">Would SS flanges work for an N/A header? Or would it still get too hot?</TD></TR></TABLE>

I believe the head is going to get just as hot, so I would say no.

Just my opinion though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by weiRtech &raquo;</TD></TR><TR><TD CLASS="quote">i use 309L. i'm not sure the difference, but i was told to use this rather than plain 309.</TD></TR></TABLE>

Yea mines 309L too. Just forgot the L.

 

The problem isn't necessarily the heat, it's variances in heat. The head flange is bolted to the head, which is aluminum and always acts as a heat sink. Even when the head is 250°, it's still pulling heat from a 1500° manifold. The turbo collector area absorbs all the heat and is bolted to the turbo, which in essence eats all the EGTs. Because stainless expands so drasticly, the difference in temperature levels between the collector and the head flange cause the whole manifold to expand and contract unequally. If the whole thing expanded equally, there would be no cracks. However, the head flange and start of the runners remain drasticly cooler than the turbo flange and collect area during normal boosted use. This causes warp and cracks.