| Author |
Message |
magoo (Magoo)
Advanced Member
Username: Magoo
Post Number: 2652
Registered: 2-2001
| | Posted on Thursday, April 25, 2002 - 1:23 pm: | |
Ok Jeff,I didn't think it would be a simple job in completely removing it. |
Jeff 77 GTB (Jbk)
Junior Member
Username: Jbk
Post Number: 80
Registered: 4-2001
| | Posted on Thursday, April 25, 2002 - 6:15 am: | |
Without the heat shielding, I can just barely sneak the front header in with the tank still in place. Have to remove the alternator and AC compressor plus mounts though. |
'75 308 GT4 (Peter)
Intermediate Member
Username: Peter
Post Number: 1823
Registered: 12-2000
| | Posted on Thursday, April 25, 2002 - 12:20 am: | |
No Magoo, he means removing it (been there). |
magoo (Magoo)
Advanced Member
Username: Magoo
Post Number: 2627
Registered: 2-2001
| | Posted on Wednesday, April 24, 2002 - 4:13 pm: | |
Burnell, You mean re-positioning the gas tank don't you, not removing it. |
Frank Parker (Parkerfe)
Member
Username: Parkerfe
Post Number: 819
Registered: 9-2001
| | Posted on Wednesday, April 24, 2002 - 3:54 pm: | |
Header wrap/tape does give a little more hp per the racing crowd. By retaining the heat in the header you get better flow is the theory. But, it will cause the headers to wear out quicker. |
Paul Newman (Newman)
Junior Member
Username: Newman
Post Number: 151
Registered: 12-2001
| | Posted on Wednesday, April 24, 2002 - 2:34 pm: | |
Hans, I would avoid the wrap because these headers crack without any help as it is. The wrap has cracked aftermarket headers(seen this myself) because the extra heat makes them brittle. I would coat them if you are concerned about heat. |
Burnell P. Curtis (Burnell)
New member
Username: Burnell
Post Number: 12
Registered: 4-2002
| | Posted on Wednesday, April 24, 2002 - 9:26 am: | |
Removal of the headers is not easy but can be done with the engine in the car. Remove both rear wheels and inner fender covers. Sit in the fender opening with your arms extended to the headers and remove the nuts from the engine. It is slow but can be done. After all of the nuts are off, I think the front header can be removed by removing one of the gas tanks. the rear header comes out ok. A few of the nuts can be removed by using a very long extension and a socket wrench. all nuts are 13 mm.
BE PATIENT! |
Mark (Markg)
Junior Member
Username: Markg
Post Number: 177
Registered: 2-2001
| | Posted on Wednesday, April 24, 2002 - 9:16 am: | |
Try this site: http://www.designengineering.com/ for wraps, blankets etc. |
David Jones (Dave)
Junior Member
Username: Dave
Post Number: 120
Registered: 4-2001
| | Posted on Wednesday, April 24, 2002 - 8:08 am: | |
I had my 308 headers coated by HPC and have been very pleased.... |
Jeff 77 GTB (Jbk)
Junior Member
Username: Jbk
Post Number: 79
Registered: 4-2001
| | Posted on Wednesday, April 24, 2002 - 6:33 am: | |
I just stripped the stock insulation off the headers on my 77 since they were stained and looked cr****. I like the look of the bare headers painted with silver high temp paint. I'm just fabricating removeable heat shields from some stainless sheet similar to what is depicted in the parts book for the euro versions. One to protect the starter, and another that will shield the firewall side from radiant heat. Another benefit is I can install/remove the headers with the engine in place now. |
Ben Lobenstein 90 TR (Benjet)
Member
Username: Benjet
Post Number: 570
Registered: 1-2001
| | Posted on Wednesday, April 24, 2002 - 1:18 am: | |
just to trying to add something to the discussion, a couple other coating places are:
http://www.jet-hot.com
and my personal fav (since my entire exhaust system, except the headers) have been done here:
http://www.hpcoatings.com/
The difference is VERY noticable.
-Ben |
'75 308 GT4 (Peter)
Intermediate Member
Username: Peter
Post Number: 1820
Registered: 12-2000
| | Posted on Wednesday, April 24, 2002 - 12:32 am: | |
Hans, I forgot to mention to you in my email (from the Ferrarilist) that the headers are stainless. |
Ric Rainbolt (Ricrain)
Junior Member
Username: Ricrain
Post Number: 69
Registered: 2-2002
| | Posted on Wednesday, April 24, 2002 - 12:12 am: | |
In general, US headers are stainless (on cars with cats) and Euro headers are mild steel. A quick test is to see if a magnet sticks (the SS is alloy 304, non-magnetic).
I have ceramic coated both types and noticed no ill effect on the headers. Neither of my 308's had cats, BTW.
|
magoo (Magoo)
Advanced Member
Username: Magoo
Post Number: 2622
Registered: 2-2001
| | Posted on Tuesday, April 23, 2002 - 11:17 pm: | |
Also I wonder what affect it would have on the Cats. Pumping hotter gases into them. It can cause premature overheating and trip the sensors plus not be good for the catalyst. Just throwing these things out for thought. |
Bill Sebestyen (Bill308)
Junior Member
Username: Bill308
Post Number: 190
Registered: 5-2001
| | Posted on Tuesday, April 23, 2002 - 10:58 pm: | |
Magoo,
Yeah, I'd be hard pressed to do an analysis showing much gain here. I guess the only way it would make any measureable difference is if the exhaust gases were used to drive a turbo charger. In this case, you'd want to retain as much exhaust heat (energy) as possible to drive the compressor section. This would allow you to use a smaller engine to get a given power output. For a normally aspirated engine, any additional heat retained by insulated headers, may cause the engine to run a little hotter, by conduction from the headers to the head (and this is not a particularly effective conduction path because there are insulating gaskets between the headers and head), but might be offset by cooler engine bay temperatures. In any event, if you weren't running at the limit of the cooling system, the thermostat would just open a little wider and engine temps would be pretty much the same. Still the hotter you can run an engine, the more efficient it will be. One way this would show itself is as more miles per gallon. |
magoo (Magoo)
Advanced Member
Username: Magoo
Post Number: 2615
Registered: 2-2001
| | Posted on Tuesday, April 23, 2002 - 10:19 pm: | |
Bill, wouldn't you say though that the headers are after the fact in engine efficiency? Internal combustion has already taken place and the headers really don't affect anything but engine bay temps. Even with the bay temps down your intake gets its air from the airbox which is rammed with outside air from the scoop. So it wouldn't affect air temps to the intake. Just a thought. |
Bill Sebestyen (Bill308)
Junior Member
Username: Bill308
Post Number: 188
Registered: 5-2001
| | Posted on Tuesday, April 23, 2002 - 9:21 pm: | |
Jay,
I don't know about your GT4, but my 78 308 GTS has stainless steel headers, covered with the factory heat shields, which are aluminum. The shields seem to loosen up and rattle with age. This may be the reason the previous owner removed them.
I don't think wrapping or shielding the headers does anything beneficial for gas flow, but they do help control engine bay heat and, in theory, increase engine efficiency. All else being equal, the hotter you run your engine, and in fact any engine, especially turbines, the more efficient they become. Of course there are practical limits like oil break down, that limit acceptable temperatures.
|
Hubert Otlik (Hugh)
Junior Member
Username: Hugh
Post Number: 61
Registered: 1-2002
| | Posted on Tuesday, April 23, 2002 - 9:02 pm: | |
Magoo,
You are right, in theory, wraping the header exposes the material to greater thermal strain, and can-the operative word-fatigue the metal to a greater degree. However, I have know people w/ heat wrapped turbo exhaust manifolds-which see EGT temps much higher than NA cars- and NA headers for years now w/ out incident.
Also, in my passing comentary, the fatiguing is more prone to appear w/ the ceramic headers over the stainless steel.
However, I have never heard of thermal coated headers fatiguing any more quickly than standard headers.
Hubert |
magoo (Magoo)
Advanced Member
Username: Magoo
Post Number: 2605
Registered: 2-2001
| | Posted on Tuesday, April 23, 2002 - 8:57 pm: | |
Guys just a question, Not to throw a monkey wrench in to this, but hasn't ther been a problem with some of these headers cracking? By holding in the heat won't they be more prone to do so? Not knocking just asking for opinions. |
Hubert Otlik (Hugh)
Junior Member
Username: Hugh
Post Number: 57
Registered: 1-2002
| | Posted on Tuesday, April 23, 2002 - 7:53 pm: | |
Hans,
If your headers a shiny w/ blue discoloration, then I would assume they are SS, w/out seeing them. Also, yes, the ceramic coated headers-when wraped, in my experience-have weathered worse than their SS counterparts.
W/out seeing your car, I would hasten to make an estimate as to how hard removal would be. But, I can assure that the use of power tools will make any job of that sort much easier, not to mention a lift. Lastly, wraping them now, and coating them later is also a good and inexpenisve way to get engine bay temps down in the interim.
-Hubert |
Hans E. Hansen (4re_gt4)
New member
Username: 4re_gt4
Post Number: 3
Registered: 4-2002
| | Posted on Tuesday, April 23, 2002 - 7:46 pm: | |
Thanks, Terry.
I wasn't so much worried about moisture while driving, but rather with condensation while parked. I guess I shouldn't worry too much, the car doesn't sit still much, as it seems I live in it. |
Terry Springer (Tspringer)
New member
Username: Tspringer
Post Number: 17
Registered: 4-2002
| | Posted on Tuesday, April 23, 2002 - 7:43 pm: | |
For what its worth, I have used the wrap several times and had very good luck. Once on an E-type Jag and it made a noticable difference to engine bay heat and it did not cause any problems with the headers. The tape does not really retain that much moisture because the heat dries the tape so quickly and thoroughly when the road becomes dry...
Terry |
Hans E. Hansen (4re_gt4)
New member
Username: 4re_gt4
Post Number: 2
Registered: 4-2002
| | Posted on Tuesday, April 23, 2002 - 7:42 pm: | |
Hubert:
Slightly confused by the wording of your (very helpful) answer. Are you saying that wrapping ceramic coated (or perhaps just high temp paint) will accelerate rust, but not the case w/SS?
My headers *look* like stainless, but I really don't know for sure. Shiny with blue heat discoloration, no hint of corrosion.
I was figuring on trying to wrap them on the car. How hard are they to remove?
I'm now considering Choice #5: Wrap now, and have them coated this fall or winter if they aren't too hard to R&R.
Thanks. |
Hubert Otlik (Hugh)
Junior Member
Username: Hugh
Post Number: 56
Registered: 1-2002
| | Posted on Tuesday, April 23, 2002 - 7:31 pm: | |
Hans,
You have a few choices. 1). Run the headers w/ the header wrap, the wrap may accelerate the corrosion of the header, but this is predominantly the case w/ ceramic coated headers, not so much w/ the stainless steel headers. And, 2). like Ric mentioned, have the headers professionaly thermal coated, look up:
http://www.airborncoatings.com/
they do top notch thermal coating.
Also, not only will this reduce engine bay temps, but it will have the added and more beneficial effect of making your headers a bit more effiecent, since the insulation will maintain a higher operating temp w/in the header, the result is faster flowing gases. This is the primary reason why people wrap/coat headers, to increase the flow efficency of the header by retaining higher interior temps.
Hope this helps,
-Hubert |
BretM (Bretm)
Intermediate Member
Username: Bretm
Post Number: 2445
Registered: 2-2001
| | Posted on Tuesday, April 23, 2002 - 6:55 pm: | |
You could make your own shields, all they are is a simple piece of tin or something like that, not a big deal. But you should definitely have something. |
Ric Rainbolt (Ricrain)
Junior Member
Username: Ricrain
Post Number: 66
Registered: 2-2002
| | Posted on Tuesday, April 23, 2002 - 6:18 pm: | |
Choice #4.. the one I've used and liked:
Remove the headers and have them ceramic coated. |
Hans E. Hansen (4re_gt4)
New member
Username: 4re_gt4
Post Number: 1
Registered: 4-2002
| | Posted on Tuesday, April 23, 2002 - 6:01 pm: | |
Hi, FerrariChat newbie here.
Pr Owner removed the heat shields from the exhaust headers of my '75 'GT4. The firewall is now aptly named, as it is way to hot to touch. The metal fuel tank-to-fuel tank pipe and the carb fuel hose are *very* hot.
So.... Choices:
1. Get the OEM shields (least favorite)
2. Apply high-tech racer-type insulation to firewall and plumbing.
3. Header tape.
Choice 3 is my favorite, but I'm concerned it may cause corrosion, via moisture that may condense there.
Comments? Please, no flames. (Couldn't resist that pun.) |