Hello everybody!
Just getting ready to give my new motor its first start, and I realized my 1-4 tubular exhaust manifold has the dreaded v-crack! (It's the earlier model with a reinforcement tab, not the whole sleeve like the later ones)
There's a guy just up the street with a set of cast iron early manifolds on the local "want ads", but he seems to be away for the holiday weekend (it's not Memorial Day in France, but it's a 3 day weekend), so I'm thinking of of trying to run a weld up the crack, and at least bolting up a temporary exhaust just to get that first start and first oil change done.
NC944er mentioned in one of his videos that he switched over to an early cast iron manifold. I thought I'd ask the forum if any members have done this and if they've noticed any difference in performance or sound between the cast iron manifold and the tubular SS manifold?
Cracked exhaust manifold
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Tom
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Paging @NC944erOringojin wrote: Sun May 24, 2026 1:40 pm Hello everybody!
Just getting ready to give my new motor its first start, and I realized my 1-4 tubular exhaust manifold has the dreaded v-crack! (It's the earlier model with a reinforcement tab, not the whole sleeve like the later ones)
There's a guy just up the street with a set of cast iron early manifolds on the local "want ads", but he seems to be away for the holiday weekend (it's not Memorial Day in France, but it's a 3 day weekend), so I'm thinking of of trying to run a weld up the crack, and at least bolting up a temporary exhaust just to get that first start and first oil change done.
NC944er mentioned in one of his videos that he switched over to an early cast iron manifold. I thought I'd ask the forum if any members have done this and if they've noticed any difference in performance or sound between the cast iron manifold and the tubular SS manifold?
On paper, the cast iron exhaust manifolds weight 8.4 pounds more than the stainless steel tube design. In general, the steel tubular manifolds are a bit smoother, with less restrictive air pathways and they dissipate heat more quickly. That said, I did not dyno test the car before and after the manifold swap, but my bet is the that performance difference is nominal, certainly not something I have felt behind the wheel.
As for sound, the thinner-walled stainless tubes produce a slightly louder, sharper exhaust note than the thicker cast iron ones, which dampen the sound and produce a slightly deeper, subdued note. Again though, the difference is barely discernable. The primary benefit of the cast iron version is that they handle heat cycles more reliably and rarely crack.
As for sound, the thinner-walled stainless tubes produce a slightly louder, sharper exhaust note than the thicker cast iron ones, which dampen the sound and produce a slightly deeper, subdued note. Again though, the difference is barely discernable. The primary benefit of the cast iron version is that they handle heat cycles more reliably and rarely crack.