| Author |
Message |
Frank Parker (Parkerfe)
| | Posted on Sunday, January 27, 2002 - 7:24 am: | |
Shields may hold more heat in the headers which is a good thing. You get better flow and thus more power the hotter your headers are. That's why professionals use header tape to keep more heat in the headers. |
'75 308 GT4 (Peter)
| | Posted on Sunday, January 27, 2002 - 1:51 am: | |
I don't think so. Shields or no shields there is ALOT of heat passing through those pipes and it wouldn't make much of difference. If they've cracked, its from manufacturing defects.
From what I know, Mike the Pipe (Mike Randall of Wallington, Surrey, UK), uses mandrel bends (formed by dies) and are smooth all around. The heating process forms wrinkles on the insides of bends and does s--- for flow (which unfortunately, is a feature of the headers off of the GT4) |
magoo (Magoo)
| | Posted on Sunday, January 27, 2002 - 12:30 am: | |
So Peter, Could the shields be holding in too much heat and causing the manifolds to crack? Just a thought. |
Brian stewart (Eurocardoc)
| | Posted on Saturday, January 26, 2002 - 7:38 pm: | |
The headers are made by heating and bending the tubing as the metal stretches on the outside of a curve it can become very thin. Hard to find anyone doing it that way anymore, used to be a place in London, Mike the Pipe, who was an artist in exhaust. |
'75 308 GT4 (Peter)
| | Posted on Friday, January 25, 2002 - 7:16 pm: | |
Brian, many have posted at the Ferrarilist of cracked headers (Mondial, 308's). I have repaired GT4 headers (the bends are poorly made, the outside surface of the bend from forming got so thin, the heat just blew a chunk right off. The metal was paper-thin, no exaggeration). |
Brian stewart (Eurocardoc)
| | Posted on Friday, January 25, 2002 - 4:59 pm: | |
Best as I know the problem with the header meltdown is peculiar to the 355. |
magoo (Magoo)
| | Posted on Friday, January 25, 2002 - 4:14 pm: | |
Just a thought for comment. In the past there have been reports of the manifolds cracking. I wonder if these shields hold in too much heat and cause that. It seems to occur more than just seldom according to the comments on F.C. . |
Richelson (Richelson)
| | Posted on Friday, January 25, 2002 - 1:14 pm: | |
Bret, I don't have my heat shield and it is fine. I think it maybe a little louder but that is fine. Your cats will be gone too so, you should be fine. |
Gerrit Visser (Gerritv)
| | Posted on Wednesday, January 23, 2002 - 6:19 pm: | |
Hi,
the Euro ones are indeed without an attached heat shield around the headers but there are definitely heatshields there in another format. On my 308GT4 there are shields around the starter, behind the alternator, between the front header and firewall, above the exhaust pipe from front header to muffler and above the rear header. There is also (missing on mine at the moment) a shield below the rear header, this one is more like an air deflector though.
All of these serve to keep heat away from various parts of the car. |
BretM (Bretm)
| | Posted on Wednesday, January 23, 2002 - 1:20 pm: | |
Does the heat shield do anything important like protect the engine compartment or anything? If you take it off a US car it wont do anything bad? |
Brian stewart (Eurocardoc)
| | Posted on Wednesday, January 23, 2002 - 5:49 am: | |
The heat shield serves two purposes, one to carry the heat through into the cats for more efficiency and two for noise and heat protection. The Euro headers are identical but sans heatshield, you can remove it entirely if need be. |
magoo (Magoo)
| | Posted on Tuesday, January 22, 2002 - 11:09 pm: | |
Hey, Hope it works. Keep us posted. Magoo |
C. Smith (Italianauto)
| | Posted on Tuesday, January 22, 2002 - 9:55 pm: | |
Thanks Magoo....seems like that might be a good fix. |
magoo (Magoo)
| | Posted on Tuesday, January 22, 2002 - 9:53 pm: | |
If this is the shield around the exhaust manifold, I would use a large "C" clamp with two small thin pieces of wood on each side of the clamp and slowly add pressure, trying it occasionally until the noise is gone. |
C. Smith (Italianauto)
| | Posted on Tuesday, January 22, 2002 - 9:04 pm: | |
308 carb GTB...anyone have a fix for a rattling heat shield.....previous owner put metal tape on it but this is unacceptable. |