355/360 exhaust manifolds stats

Don't get me wrong, I am one of Ferrari's biggest supporters and love the 355; but is anyone else a little surprised by Ferrari's response to this ongoing problem with exhaust manifolds? I am a little suprised that two things haven't happened...one, that the EPA hasn't got involved since this would certainly appear to be a "emissions issue" since untreated/scrubbed exhaust is reaching the atmosphere directly...and two, that someone hasn't started a "class action" lawsuit to get Ferrari to take car of these cars with a permanent solution. At least before they were replacing them with more crappy manifolds, now they are not even doing that.

Hmmmmm.....

 

From diagnosing literally thousands of running problems on Ferrari's when you have different EGT's from one bank to the other with out fuel or ignition malfunctions, 75% of the time you have a cam timing problem. Even fuel or ignition problems usually don't strike all cylinders of one bank.

If by any means you have introduced enough additional air to cause a change in EGT you will get a corrosponding adjustment of the mixture by the O2. That is exactly what it's job is.

 

hey brian, I know I am getting a little off the thread here but have a question for you on your response about cam timing. If that was the originating problem of my higher temp on the right side do you think I should resolve it now or would it be ok to wait untill I do belt service next january? the car runs fine and when I looked at the exhaust valve color (when I the manifolds off ) all the valves were clean and were a redish brown color on both banks. Am I assumming correctly that the right side would be slightly retarded. thanks.

 

Within limits higher EGT reflects higher power. Usually and that is a big usually, hotter means a better running motor so I would guess the opposite, that the right bank is the better running bank. How much do you intend to drive it until Jan? I would guess it will be Ok but there are a lot of variables.

One of the problems with exhaust components and even some internal components on modern cars is the very high specific power outputs possible due to the engine management systems and the multi valve motors. The motors are making heat, lots of it. We are pushing the limitations of the materials being used. That is a big part of what goes on with 355 engines. Car makers want to keep costs down but those sorts of demands require very expensive materials. I don't think it will be long that Ferrari production cars are going to have to go to Niconel for the manifolds. That is what the F1 headers are made of.

 

thanks Brian for the help vern

 

You're correct. I don't know if that was a slip of the brain or the keyboard.

 

The boss of one of my customers in NJ told me about this manifold issue last week and asked me to look into the threads here.

Does anyone have more pictures of the stock manifolds, off the car, without the heat shields, installed in the car, installed without heat shields, various failures, the complete exhaust system, drivetrain mounting system?

What is the redline of the engine?

Having quickly glanced over most of these posts, I don't pretend to know everything, but some things I'd like to know would be...

Material specification of the stock manifolds
Tubing wall thickness
Has anyone ever recorded EGTs in all the primaries during dyno or track sessions?
Has anyone recorded A/F Ratios on both banks during dyno or track sessions?

Some things to think about for header design (besides the performance side of it)....

The outside of a bend is the thinnest section of the tubing.
Not all material hold up to heat equally well.
Multiple primaries with multiple bends don't expand in the same direction and therefore induce a variety of different stresses in different areas of the tubes.
Some areas where design flaws are present can be compensated by over designing in other areas.
Some areas where the design is correct can be invalidated by poor manufacturing processes.

The majority of my work involves building headers for Acuras and Hondas. Through this I've become acquainted with many different manufacturers. There are a full range of designs and manufacturing abilities. There is a company that builds a header that is somewhat similiar to this 355 header. I like to describe these style of headers, as intestinal headers because of all the bends. This company has had problems with their products cracking also. I have my ideas to why but this isn't a Acura/Honda forum.

But shooting from the hip, with very little data to go on. I'd say these are the areas you folks should be looking into.

Material specification (grade and wall thickness)
Tubing layout for thermal expansion
Engine movement with respect to allowed exhaust movement
EGTs
A/F Ratios
Expansion points in the entire exhaust system
Welding procedures if any of the failures are at weld locations or in the heat effected zone of the weld.

 

The standard failure mode is well represented in the photo in post #66. It almost invariably happens at the first sharp curve.

I agree with the areas of concern you have pointed to. I do not think there is a great mystery to that. What is a great mystery to most is why Ferrari with their experience in the field designed and had built an inferior product and then with the data base that had been generated by the number of cars/miles/failures came out with an improved unit that was still an inferior product. There are aftermarket options so it has been shown that a suitable quality product is not beyond the reach of commercial viability.

All that having been said I do not understand your comment on the items we should be looking into. Maybe Ferrari should be looking into them. If anyone here is unsure of the problem it is them, but I don't think so. I think they are just being cheap.

 

Here are a couple of pic of a coated Manifold that I had fabricated. The old manifold was beyond reapir so all new tubes had to be made. These are made from 304 stainless and are a bit heavier then the OEM units but they will not burn out. These are a rough proto type for right now..let me know what you think..
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login
Image Unavailable, Please Login

 

I am talking with a company now that has made replacement F355 headers because one of their customers headers broke. They are made from thick 304 stainless steel. As far as for warranty, I am not sure as of this time, but they do offer a lifetime warranty on the stainless steel turbo manifolds that they make for us.

They also are able to produce Inconel headers. Would Inconel be the material of choice with these headers? Or would a lifetime warranty with 304 SS suffice, warranty wise?

 

You had 304 sst coated?

I'm not sure what you are doing with those collectors going from a larger diameter down to a smaller diameter with that reverse step?

With the majority of my stuff, I'll use stainless steel and full merge collectors. Any butt welds I do are 100% purged no matter if it's stainless or mild steel, it's the only way to ensure a proper weld with no contamination of the welds. Welds that aren't purged will also be rough on the inside (which induce turbulance) and will crack in time. In most cases the merge collectors I use will be the slip on variety with a bolted tab to hold the connection together, this allows for some flex so stress is reduced.

Here are some pictures of an Acura header I recently built. The primaries are stepped and 3 of the 4 tubes off the flange have butt welds in them. The next weld is where the tubing increases in diameter.





In the following you can see the tab on the secondaries.

 

While warranty is important the choice between SS and Inconel would come down to price/ real world lifespan. I don't know if it would make sense to offer them both ways.

 

As stated these were a prototype set. They were pretty much rushed out the door as the customer didn not want to wait for a good set to be made up. But the pictures are deciving..all the pipes are the same diameter with the olnly larger one being the sigal tube off the end of the collector. I most definatly agree with you on the welds though..a bit on the sloppy side and definatly need improvment. But as I said..the customer wanted his car..did not want to pay 13k for new manifolds from the dealer..so I helped him out. Oh and I myself did not build the units a friend of mine did. And considering the time we had to build them I think he did a good job.

You manifold looks very good..but is not even half as difficult as the 355 set-up.

 

From previous posts, the stock headers are .12" thick of a "semi-stainless steel". QV London rebuilds them using .15" 304 stainless, and re-installs the factory heat sheilds. I would be interested in opinions on the advisability of deleting the heatsheilds.

Tom, what is the approximate thickness you are using? They look like a good option over QV London, if you can be competitive, and have them in stock.

Regards,
Dave

 

Price wise, we can offer the 304 SS headers for $4900, compared to the FoW price for stock headers at $5990. Warranty wise, I am finding that out and as soon as I do I will post up that issue. I am 90% sure that it does have a lifetime warranty, but want to be completely sure.

 

Dave,

Are you sure about those wall thicknesses? From the blow out picture earlier, they don't even look close to .12" wall. I build from 18g (.049") or 16g (.065"). I've seen some truck headers built from 14g (.083). But .12" and .15" now you are talking about turbo manifold pipe, not tube. In over 5 years I've never had a 16g mild or stainless header crack. I've only had one 18g mild steel header crack at a collector and that was on an ITA CRX that had an off track excursion and hit something.

FYI, When I started my comapny I was down in Charlotte, NC. NASCAR country and I know the guy whose business is 90% NASCAR. He builds some stuff from 20g and even 22g stainless.....they don't crack after 500 miles of racing plus practice. They then acid dip them and run them again.

 

I have absolutely no idea if that is correct or not, as I stated in my post, I was quoting from a previous post in this very thread. Perhaps they meant millimeters or something...you can scroll back through the thread to find the post.

Here's the quote:
"What I've learned is that FNA will not stand behind this sort of failure
eventhough all the data points to a design and material error (they made the
manifold out of .12" wall thickness semi-stainless steel that gets too thin
during forming the manifold and its a poor material). The current
international wisdom I can gather from here is that all F355s will experience this problem sooner or later.

I've removed both of my manifolds and am sending them to QV in England to
have them reworked using .15" wall thickness pure 304 stainless. "

 

They can't be .12, they would weigh 100lbs.

Some serious heat barrier of some kind is in order to save as much as possible the non metallic components of the engine comp.

The question was raised about ex temps. I would bet on a long hard pull they will see 1600+

 

Hi Dave..I do have a set made up..but I have to test fit them to a car to make sure they fit correctly. My guy made up a nice jig off of the OEM's that we used for the prototype as pictured. The car I will be using is in the body shop at the momment for some minor stone chip and scuff repaires to the front bumper. Last I heard it should be done with in the next 2 weeks or so. I will keep you updated. As far as price..not to sure yet as they are quite complex to make. And I do ceramic coat them. I really don't want to try and sell these things on the board so if you have any further questions please e-mail me or PM me. Thanks.

If any Mods feel this is inappropriate please let me know. I'm just trying to help out a fellow F-chatter is all..thanks

Tom.

 

what is the correct diameter of pipes to use to repair the manifolds ? I would like to order for some pipes before to remove it from my car...
will make some pics

 

Regarding the VOTING on the manifold poll, it seems to permit us to VOTE only once. Thus I voted 8 months ago when I had to have my driver's side manifold replaced, but NOW I've just had to replace my passenger side manifold as well and want to update my data by voting again.

I think this monitoring of exhaust manifold replacements is really useful and informative so pls. lets allow it to be updated. Also would be great if the replies could be classified according to mileage of the car. I've now had BOTH manifolds replaced at only 17K miles. Plus one cat had to be replaced and you just know the other will pop in the near future. What a SHAM!!!!!!!!!!!!!!!!!!!!

BTW, when advising a new, potential purchaser of a 355, I'd now say, "get a PPI but regardless of how it comes out, expect to replace one or two exhaust manifolds plus a cat or two -- possibly within one year after purchase.


Paul

Paul

 

Paul,
Both sets of exhaust manifolds were covered under warranty on my car in 2001 at 15,500 miles. I am now at 34,000 miles and very concerned, that these are bound to go. For that reason, today I ordered rebuilt units from QV London, which I will install Aug 27th. I figure I am on "borrowed time".

Were your recent replacements covered under any warranty? Even the emission warranty (which in the States runs to 8 years, 80k miles)?

 

Nobody can tell me the correct diameter to use with a view to repair the manifold ?
nico

 

My Drivers side Header needs Replacing @ only 18K Miles.

Great way to start a week.