Headers on 355 - Ever Revised?

No sir, even if purchased new from Ferrari themselves, the fate would be the same. Later generations were not excused from header issues either. 360 and 430 owners have had similar experiences with headers cracking. The material used is simply not strong enough, thin metal coupled with high exhaust temperatures equal failure.

 

Ferrari must have started the practice of "build 'em cheap and sell 'em steep."

I too thought I read somewhere that the headers were changed or maybe it was the cats?

 

Not the cats either. The headers only had a slight revision to the air injection ports. That is unrelated to the headers melting. Melting... they don't crack they melt.

 

YEAH! MORE GOOD NEWS...

 

I'm hearing the same, its just not a 355 issue as these cars keep getting the bad rap for.

 

Guys, sorry to chip in, and this isn't a nah, nah, n, nah, nah comment, genuinely interested. Why don't we suffer from melting headers? I know you guys rev quicker but unless you're red lining it on every change I can't see that making a difference yet 348 headers seem ok. What's the difference?

 

It's true you never hear about issues on the 348 headers, as anyone done a side-by-side comparison?

I heard one theory that the way the exhaust air flows out of a 355's exhaust system design is what causes excessive heat and premature damage to the headers. It can make sense as a theory but who knows????

 

Reasons the headers fail have been discussed in many threads. Poor quality 409s/s was used. It is 1.2mm thick. Place a thin piece of poor quality s/s between two pieces of s/s(heat shields) and add insulation around the primary tubes. Primary tubes are also entwined, unlike most headers on an American V8. Add a hot running and high revving engine making 380 HP in a 3.5L 8 cylinder engine.

 

A quick check on 409 steels is that this kind of steel begins to supper from scaling at 1450dF, yet the cats on the F355 do not register as being too hot until 1472dF (WSM).

<Hint> The cats are quite some distance from the place in the headers where most of the heat problems are.

304 remains useable at 180dF above that of 409
321 remains useable at 265dF above that of 409

 

The cats are not bad in the 355 by any means. The problem is 355's running rich. Excess fuel being burned by the cats for years. That is why the cats are known to fail. This excess fuel being burnt contributes to excess heat being trapped in the headers and bad stuff happeing.

Why does the 355 run rich? See Dave Helms Gold Kit for what he is trying to solve and see what Goth's coolant temperature poll thread is all about.

 

I just had an engine-out service done on my 97 355.

I grilled my shop, which is highly renowned in this area, about the need to change exhaust headers while the engine was out. Their answer: if they're fine, leave them alone. They smoke tested them, and there was no leakage.

I realize that the exhaust headers are a weak point on the 355; however, is this problem really overdone? Why would a shop, who works on multiple 355s at a time, and has done so for years, tell me not to worry about the stock exhaust headers?

 

imho.. there is no real solution to the problem.

shielded solutions including the originals will fail again (particularly if the restrictive cat/exhaust is not improved.)

and nonshielded solutions eventually fry ancillary components.

It is difficult for a shop to recommend a change that is not an improvement or a fix.

 

Actually the catalysts were improved. Somewhere in the 1999 production they started using metal catalysts. I found one on Ebay (same part number as the earlier ones) and it is very obvious when looking inside as to the difference in the matrix. They guy I bought it from said it got them from the local dealer back in 2010 or 2011, when FNA had the "special" where you could get two new catalysts installed for around $3500. He only needed one, and sold me the other.

 

I have replaced many oem ceramic catalysts on my car. They fail due to the ceramic cores being poorly secured inside the stainless steel housings. Engine and chassis vibration (and according to Mark Glenwood at FoS) perhaps the engine pulses, cause the cores to work loose. Once loose, they start to rotate and move around, and crumble. In other words the failure is physical, not from rich running. Every thread on Fchat can confirm this, as people post pictures of the physical damage, they look just like every cat I have removed from my car.

 

If your shop is not already well versed on the change Ferrari made to the 355 exhaust manifolds (or lack there of), I would question their overall knowledge on the cars...

 

The problems with 360 and 430 exhaust manifolds is different and not nearly as common....but I am not an expert...

 

Deal Wit It!

 

my f355 2.7 was running rich for approx 3mths ,i replace the oxy sens,then i decided to drive it to my mechanic ,suddenly the temp went up ,upon arrival and their shop d/side cat was glowing red hot ,i was lucky the car didnt, have any fuel leakage as i just filled the tank up previous day,anyway mechanic pulled out both cats,d/side one had crumbled inside,both were purchase by me previous (cheap one approx usd400)from u.k. to comply the car here,lucky i still have original ferrari one here,however i fitted straight pipes yesterday.the car seems to run at normal temps on the freeway,but i little higher now in traffic,i would like to hear your comments please

 

We've come up with a blanket design that blocks a significant amount of radiant heat without "suffocating" the metal underneath. It fits most headers offered for the 366 & 360, including factory. While we haven't had problems with premature failures of ancillary components in the past, we understand heat management is important to component longevity.
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Are those shown on the website yet? I've been looking for the price and can't find it.

 

Not on the website yet, you'll have to call in to order, but they are $1495 for the pair of blankets.

 

Do not want to start something but many mechanics think if its not broke why fix it. I agree sometimes and not others. I think to say question their knowledge is a bit harsh. One would need to know all the reasons. Maybe they know how to change them with the motor in the car in less than an hour, I don't know.