[Brewman]

Can anyone explain the root cause of 355 CATS overheating ? Do 348's have this problem ?

Thanks, Brewman

[Brian]

The one and only reason a cat can overheat in any car is that they are exposed to an excess amount of unburned fuel.

A 355 in correct tune will not overheat its cats any more than any other car.

They were far more sensitive to proper cam timing than any car Ferrari built prior and many people working on them did not appreciate that fact so did not take proper steps to insure correct cam timing.


It is a problem those of us in the business have been dealing with since the 4 valve motors started and really since the TR. While the TR and 348 are not as bad as the 355 for cam timing sensitivity they were a large step worse than their predecessors. The better a cylinder head breaths the more sensitive it is to this problem.

[Brewman]

Originally Posted by Brian

The one and only reason a cat can overheat in any car is that they are exposed to an excess amount of unburned fuel.

A 355 in correct tune will not overheat its cats any more than any other car.

They were far more sensitive to proper cam timing than any car Ferrari built prior and many people working on them did not appreciate that fact so did not take proper steps to insure correct cam timing.


It is a problem those of us in the business have been dealing with since the 4 valve motors started and really since the TR. While the TR and 348 are not as bad as the 355 for cam timing sensitivity they were a large step worse than their predecessors. The better a cylinder head breaths the more sensitive it is to this problem.

Brian,
Thanks for this info. I've seen contradictory posts as to how to time the 355 engine when it's in the car. Can you comment on this ?

Thanks, Brewman

[Brian]

I have seen contradictory posts as to the existence of gravity.


Cams cannot be timed in the car but you are welcome to not believe me if you promise to not get your information from the internet where everyone is an expert. I will have done my job if I can just get people to get their information from real live people who have some expertise rather than some numbnuts with a keyboard and internet access.

[Granucci]

oh, Brian, I truly just love your answers.

[Shane]

Brian said numbnuts.....

[Markp]

Originally Posted by Brian

I have seen contradictory posts as to the existence of gravity.


Cams cannot be timed in the car but you are welcome to not believe me if you promise to not get your information from the internet where everyone is an expert. I will have done my job if I can just get people to get their information from real live people who have some expertise rather than some numbnuts with a keyboard and internet access.

Brian,

What is the likelihood that the cams move out of spec during a major maintenance interval? Clearly there is a reason why the motor gets dropped during a major, which of course makes it much easier to do all these tasks.

Thanks.

Mark

[Brewman]

Originally Posted by Brian

I have seen contradictory posts as to the existence of gravity.


Cams cannot be timed in the car but you are welcome to not believe me if you promise to not get your information from the internet where everyone is an expert. I will have done my job if I can just get people to get their information from real live people who have some expertise rather than some numbnuts with a keyboard and internet access.

Brian,

Because of your response it's obvious I was not clear. I am in no way questioning what you are saying. In fact I very much appreciate your help. You're correct that anyone with a computer and keyboard can portray themselves as an expert. Because there are so many "experts" out there it gets very confusing and difficult to filter out the BS.

I've owned many, many cars (TR6 and Porsche), over the years, do my own maintenance, and am now ready to move up to a Ferrari.

To get to the point I prefer the F355 (styling/performace/creature comforts) but am concerned with all the posts that indicate it is prone to problems (cats/headers/and resultant engine damage) more so than the 348 series that I am now leaning toward. Hypothetically speaking what are your thoughts as to the reliability of both models assuming a equal level of condition, maintenance, mileage, etc.

Thanks,

Brewman

[Brian]

Originally Posted by Markp

Brian,

What is the likelihood that the cams move out of spec during a major maintenance interval? Clearly there is a reason why the motor gets dropped during a major, which of course makes it much easier to do all these tasks.

Thanks.

Mark

From probable to great.


Thats why we do it this way.

[Brian]

The first picture is of a Ferrari cam with the timing perfectly set. The second picture it is off by 6 degrees, more than enough to overheat a cat.


The third picture is the degree wheel I really like. It is huge, that's a Testarossa motor it is mounted on. The single degree marks are about 1/8 inch apart, even Stevie Wonder can see them.. Now reduce that to 1 inch in diameter. Even if the marks were correct how are you going to see 1 degree? Thats the chances of doing it correctly without degreeing them.

[Brian]

Originally Posted by Brewman

Brian,

Because of your response it's obvious I was not clear. I am in no way questioning what you are saying. In fact I very much appreciate your help. You're correct that anyone with a computer and keyboard can portray themselves as an expert. Because there are so many "experts" out there it gets very confusing and difficult to filter out the BS.

I've owned many, many cars (TR6 and Porsche), over the years, do my own maintenance, and am now ready to move up to a Ferrari.

To get to the point I prefer the F355 (styling/performace/creature comforts) but am concerned with all the posts that indicate it is prone to problems (cats/headers/and resultant engine damage) more so than the 348 series that I am now leaning toward. Hypothetically speaking what are your thoughts as to the reliability of both models assuming a equal level of condition, maintenance, mileage, etc.

Thanks,

Brewman

I know you weren't, I just hate all the disinformation that is spread by self professed experts on internet chat rooms and I do believe we would in many ways be better off without them. Either that or people without bona fides should be forced to shut up and listen. Snake oil salesmen are one thing but people that don't know scheise are another.


I try very hard to keep my clients out of 355's. It will bite their bank account hard and I hate to be the bearer of bad news. They have caused many people to turn their back on what I consider a very good make. If you want a 348 get a 93 or 94. I personnaly prefer either the 328 or 360 though.

[Brewman]

Originally Posted by Brian

I know you weren't, I just hate all the disinformation that is spread by self professed experts on internet chat rooms and I do believe we would in many ways be better off without them. Either that or people without bona fides should be forced to shut up and listen. Snake oil salesmen are one thing but people that don't know scheise are another.


I try very hard to keep my clients out of 355's. It will bite their bank account hard and I hate to be the bearer of bad news. They have caused many people to turn their back on what I consider a very good make. If you want a 348 get a 93 or 94. I personnaly prefer either the 328 or 360 though.

Brian,

Thanks for your guidance. You've confirmed what I had concluded.

Regards,

Brewman