Don't kid yourself...it didn't just start all of a sudden and then let go...this has been a progressive failure for a few years...it just finally gave out. I bet the tubes were deformed and partially collapsed for months if not a year. Check on this site for pictures of what they look like...
Why not remove the heat shields now and examine the headers? But take your time and remove the shields carefully so that they can be re-used (should you decide to have the headers rebuilt). And post photos.
Right now I am going to install a good (tested and non leaking) used one. Then I can still drive the car at least for short term. I am fully aware that the used one may fail at any time. However, this will give me a short time to consider brand new replacements or overhauled QV or JP headers or equivalent. I called both QV and JP for quotes, warranty info etc. Price is fair at about 500 to 580 pounds (British currency) each side. Shipping time to UK via FedEx return plus time to repair means I will have to drive with the used header for about a month maybe 6 weeks. Apparently they are very busy at the moment. That will get me back on road, at least temporarily. I'm OK with that. So I have some questions. Has anyone used the rebuilt units for a long time and noticed any problems? They have lifetime warranty. Has there been any testing done regarding flow or general performance? Dyno test? Lots of other brands get tested for performance, sound, durability etc. Has anyone used non shielded brands, applied heat wrap, and run them for an extended time and mileage? Does the heat wrap retain too much heat causing premature failure? As far as taking apart my bad one, I am hesitant to do this because if I decide to get them rebuilt, I need the existing heat shield kept in good condition. I must admit it is very tempting to open it up and see just how bad the damage really is. I know Tubi have the heat shields in place. Can anyone shed light on some current pricing for Tubi headers? Gary
I think you are right. I don't think the failure was sudden. I should rephrase. The header seemed to fail suddenly. If I could see through the shielding it would be easy to diagnose an imminent failure caused by deformed, cracked and split tubes. Since all of the failures seem to be inside the heat shields, it seems obvious to me the headers are simply running to hot. Removing the shields may save headers, but at sacrifice of various components, such as alternators, motor mounts, etc. High engine bay temps lead to all kinds of driveability(sp?) issues. High engine bay temps cause real problems with fuel/air delivery systems. I don't have experience on Ferrari, but on other makes I have experience with fuel pressure regulators giving grief under high temperatures. Does anyone know of an NDT (non destructive test) method to inspect the headers. I am referring to gama ray, x ray or maybe some form of ultra sound that could be used to inspect while still installed on the vehicle? NDT methods are used routinely to inspect welds, thickness, cracks etc. Gary
Here you go, now coated by Swain Technologies: http://www.ferrarichat.com/forum/showpost.php?p=138655371&postcount=17
Several friends and I have had ours for anywhere from 3 to 4 years now...no problems. I have over 17k miles on them. Never heard of anyone dyno testing, since the tube diameter is the same, and QV London claims the bends are the same as oem as well. Edit, I do recall one friend having a problem with a single weld of one tube to the flange on the head. His mechanic was able to repair it pretty easily without removing them.
Does anyone know who Ferrari's OEM supplier for these headers was? It is my understanding that they recently (past few years?) changed suppliers. Also, I would think that any competent fabricator would be able to repair these headers fairly easily. I would think the most difficult part of the job would be removing and reinstalling the heat shields.
i have been told it was ANSA, as well as the muffler. Exactly. In fact, the shields are such a pain to get off that I dont know how you could put them back on. Mine were welded 360 around each test port, just for starters. jay
Does the ECU actually allow that much correction.. enough to wash bores and burn valves? Sure I could believe a lean signal could be generated from a header leak.. but I need help understanding what happens in such a case. I am no expert, but my feeling is that the lean signal would generate a rich correction, which should be enough to eventually overcome the lean signal the O2 reads. But is it enough correction to cause the drama everyone claims?
Ansa...they make the 360 and 430 ones which are also occaisionally failing now...though I hear there is an updated exhaust manifold from Dec 2007 forward on the 430.
The ECU will allow fuel correction up to 25%. I do not agree with Speedmores hypothisis but the fact is a bad header will take out a motor.
I hve take them off and anyone who can get them off fast enough in a condition they can be reinstalled, get the header repaired and do it for a commercially acceptable price gets my vote. The do not cut well and have a few hundred spot welds. What a PIA.
Maybe a bit off topic as non-335, but headers failures in general, so, here goes. 1. We used to use a, name escapes me, 'paint' chemical to metal, especially Alum. to detected cracks. Used them a lot in the Navy for boat boom hoists etc. Is there not a similar product for these metals? I like daves oil drip approach, but there might be something better? 2. 'other' models are experiencing failures too. Older, not many, 12 cylinder models are seing failures. They look completely burned in the interior, and not much showing on the exterior at all. Have one that failed, Rifledrive gave me, and someday, when my garage doesn't take bread crumbs to navigate about, I'm going to open that baby up and show all to see: looks terrible. 3. So, what is the cause on the 'other' models failing. 456's are 'tame' unless injecting pure nitro in there so doesn't seem to be a fuel issue for 'older gents' car. The 550/575's might be a different issue? rik
For what its worth I had both of mine rebuilt by QV with a turnaround of about 1& 1/2 weeks. I asked about doing an exchange to speed up the process. They said the only ones they had were ones that the owner removed the shields and basically really tore them up. Moral of the story reads "Don't let curiosity get the better of you" Let someone who does this do it right. FYI - I'm at 1300 miles so far, so good but obviously time will tell.
Inspecting by many methods would be a piece of cake if it were not for the heatshields. As it is, either a smoke test if it is on the car or a pressure test if it is off the car works well. The problem with either is it will only show a failed header. It will not warn you if it is only circling the drain. I have even used a bore scope on them and it is damn hard to tell much. They are all failing for the same reason it is just that the 12's have an easier life so don't go south as often. There are factors which can speed things up but the short version is they were just not made from good enough materials to cope with the exhaust heat the motors generate. Lots of cars over the years have had manifold troubles. Mercedes Benz had trouble with manifolds for years. Probably as bad a Ferrari but no one really cared because they were not expensive. When a component has a pattern failure, and all makes go through that, it just isn't all that big a deal but when it happens to a Ferrari it is and only because it costs so much to fix. If 355 manifolds were $200 each we would not be having this conversation.
So.. essentially that means going from say 12.5:1 AFR to 10:0? Thats rich alright but it doesn't strike me as bad enough to ruin an engine. I wonder what process is at work to take out a motor? Perhaps this is a question to be posted on: http://www.gofastnews.com/board/engine-technology/
That has nothing to do with it. It has been discussed here countlees time before in the countless threads on the subjects of failed headers and compression loss in 355 motors. It is such overworked territory I am sure a cursory search will yield a great deal. Don't trip over the hundreds of timing belt threads on your way there.
Thats the problem Brian.. SO much discussion, but its hard to find anything specific. Basically most discussion seems to be: cause=leaky manifolds, effect=ruined engine. I could simply accept that fact, but being an inquisitive, anal, engineering type, want to know more.. ie: what process is at work. If anyone has some idea where I could find such info, please tell me. J
I believe it goes this way: Header leaks mean (relatively) cold air is pulled through the manifold leak past the exhaust valve on the intake stroke. This unmetered extra air results in a lean mixture on each power stroke. Lean = Hot, which results in burned valves. Also, the exhaust valve is first seeing a lean, hot exhaust pulse, immediately followed by colder air being pulled across the valve. Seems this would cause more severe thermal stress on the exhaust valve, at least compared to normal, and exhaust valves will see early failure. Hopefully Brian or other techs who have seen lots of these failures can verify and correct me if necessary.
Being an engineering type consider this: Motronic 2.7 and 5.2 have no ability to modify fuel or spark for individual cylinders. The engine damage is not motor wide or an entire bank, it only strikes individual cylinders. That leaves anomalous flow issues, either fuel, intake, or exhaust, or pure coincidence. When it happens in conjunction with a bad exhaust manifold it is when the car has been operated for some time with a bad exhaust manifold and the damaged cylinder also has the damaged pipe. We know these motors have significant gas reversion on the exhaust side under some operating conditions.
I'm going to jump into the quagmire here(crap Brian I can't believe you have stuck your neck out hear on the preverbal chopping block on this beat up topic hahaha). I have been involved with Brian a few times on this subject, not a pro as RD but as an owner/head mechanic on my own 355 for 7 years of ownership. On that note I will pass along my experiments and gained info. My 355 is an ex challenge care that had 6500 race miles on it when I bought from FoBH in '02. Within a year or so I stumbled across a leaking RH header(this was before much discussion on the topic). When I removed the header and then the shielding I was stunned at the condition of the tubes: warped, what I would call bubbles in the tubes and holes. 2 of the tubes were distorted, as if heated to the point of being fluid. There was no replacement available except Ferrari parts. My conclusion at the time was there was to much stored heat. What I did at the time was buy a new RH one from Ferrari, removed the LH side(it was ok) and it's shielding had them both ceramic coated. Did not replace the shielding, removed the cats, there is no muffler because it being a challenge car and there are no upper cats or bypass valve. ie; no heat sinks in the exhaust system. I put heat shields on the alternator and around the brake lines that are close to the headers. in the 6 years and 1000's of miles later the headers are fine shape and had no problems with heat. The conclusions I made have been: over time there is to much heat in the exhaust for the inferior tubes to stand up to and it has been determined there is a reversionary process going on that has contributed to the engine ingesting itself ie; cat and tube material. If you remove the heat factor you seem to remove all the problems. I don't need any comments on this please it is my opinion based on personal experiance. Of course my car is unique that I like the noise it makes so I am fine with the open exhaust. It isn't driven on the street(low traffic county roads/intestates only) where it can't bother anyone other than the poor bastard that might happen to be behind me at some point hahaha. Altho sometimes they love it as much as I do and will follow to listen If you like to learn more about the subject search out RD's and Dave Helms comments on this subject. I would try to avoid everyone else because most is not based on actual knowledge, not to offend anyone it's just that there is a lot blabbering on the subject
I appreciate all your input.. Its my nature to learn and become intimately knowledgeable with my cars, (and reverse engineer them ) hence all my prying questions. Ill seek out the pros..thanks By the tone of your opening statement, Llen, it is sounds like it can risky business offering a direct opinion on this forum.. if thats the case, its a shame.. For years I have been into Lotus Esprit tuning. At one point, outside the Esprit forum, befriended a super knowledgeable guy in CA. We have a good relationship with some seriously great technical discussions, free of all the chatter and backtalk that forums often have... -------------- I would think that an ECU with individual cylinder correction capability, an O2 sensor would be required on each primary for the function to work dynamically? The per-cylinder concept makes total sense. An unbalanced cylinder, operating over time, makes sense to me. I get a sense now that it is likely a diluted, contaminated, or air enriched charge that works, over time, to reduce the service life of exhaust valves. Failure over time, not necessarily immediate? I guess the 355 has a fair amount of lift and cam overlap? I guess that's to be expected with 110hp/L. Do you know if there are cam profile chart available for the 355.. or would I need to plot the data from the OM? I like the idea of dealing with the packing and heat shields. In high heat turbo applications thin-wall 304 is NFG. With all the packing and shields, along with EX heat the 355 must generate, its no wonder they have issues. Ive seen pix of the damage you describe..thats not good. I wonder if the 355 manifold remanufacturers use 321? That would be ticket. thanks again .. Jan
QV London/JP Exhausts use 304, one gauge thicker than oem. The oem manifolds are made from cheaper, thinner 409. 321 would be better still, but their solution seems to be working so far (several years now).
good info here... http://www.burnsstainless.com/TechArticles/Stainless_article/stainless_article.html http://www.azom.com/details.asp?ArticleID=969 http://en.wikipedia.org/wiki/Stainless_steel
