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Header pipe temperatures

Discussion in '348/355' started by eulk328, Apr 5, 2010.

  1. eulk328

    eulk328 F1 Rookie

    Feb 18, 2005
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    #1 eulk328, Apr 5, 2010
    Last edited by a moderator: Sep 7, 2017
    After letting my car (355) warm up by idling for about 20 minutes (fans cycling on and off) I measured the header pipe temperatures using an I.R. thermometer.

    Temp. readings in photos are shown where they were taken on the pipes. Pipes have Swaintech ceramic coating.

    The much higher temp. of cylinder 1 concerns me. Cam timing and fuel pressure problems should affect all the cylinders on the bank. So what is left? Poorly flowing injector on cylinder 1?

    I would expect somewhat higher temps. on cyl. 1 and cyl. 2 pipes since they are close to reflective heat shielding but the difference still seems quite large. I would also expect cylinders 1 and 8 to read higher because the measurement point is at the shortest length of the pipe compared to the others (in other words the point I measured is closer to the heads than any of the other pipes).

    I BELIEVE I have the cylinder numbering correct. for all eight cylinders. If someone knows different let me know. In any event the temp. readings are in the correct locations on the photos.
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  3. 2NA

    2NA F1 World Champ
    Professional Ferrari Technician Consultant Owner

    Dec 29, 2006
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    Idling isn't really the best example. A better test would be to drive a few miles and check immediately.

    An IR gun is a handy tool but it's kinda tricky to get precise measurements on odd shaped rather small targets. The laser beam aiming device is subject to parallax problems up close (where the dot is pointing isn't always the area being measured). Great for comparing right bank to left, trickier doing individual pipes.
     
  4. eulk328

    eulk328 F1 Rookie

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    #3 eulk328, Apr 5, 2010
    Last edited by a moderator: Sep 7, 2017

    I agree that a drive would be best but it would be hard to do quickly. For these photos and tests I had to have the wheels off, the wheel well liners removed and the back of the car jacked up a bit.

    It's a pretty decent I.R. gun and I measured all temps with the gun 8 inches from the pipes (where the beams converge to measure a 1/2" spot - according to the manufacturer anyway).

    I should add that when I unshielded the headers recently (OEM with 35,000 miles) the cyl. 2 pipe had damage from overheating (deformation). All other pipes were okay. There are no holes in pipe 2 but it actually touches header pipe 3 in a small area. They may even be a bit "welded" together.
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  5. UConn Husky

    UConn Husky F1 Rookie

    Nov 11, 2006
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    Lower temps than I've seen; but it's tough to draw any conclusions because there's sooo many variables. For one is emissivity of the Swain Tech vs. the aluminum - ceramic coating I have (but I fully expect the Swain is a better insulator). Then there's cooling rate of each tube location; that's affected by how (and when) the cooling fan kicks on, pulling air over the radiators while blowing on the headers (a somewhat shielded tube would be hotter).

    And probably most important...distance from the block. Further downstream the exhaust has more chance to cool.

    Having said that...I still love the IR gun, I'm always zapping different engine parts just for fun :D
     
  6. eulk328

    eulk328 F1 Rookie

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    #5 eulk328, Apr 5, 2010
    Last edited: Apr 5, 2010
    Swaintech do claim their coating is thicker and better than other coatings which I tend to believe. Silver looks prettier but they think of it as more cosmetic than anything else. Also, I would imagine it's harder to get a good reading off the shinier silver.

    I made LH measurements with the radiator fan off. The RH fan stayed on almost constantly so I shielded the headers and gun from the fan with a clipboard while making the measurements.

    I measured cylinders 3,4 and 5,6 right at the thermocouple tests caps to have a consistent point of reference on those. Would be nice to have a "proper" tester that utilizes the ugly test ports (okay, they're not that ugly until you take off the surrounding heat shielding!).

    Did you write down your temp. measurements?
     
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  8. eulk328

    eulk328 F1 Rookie

    Feb 18, 2005
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    I also measured the ceramic coated test pipes (within a couple seconds of each other) very close to the thermocouple locations and and came up with:

    LH = 270 degrees F

    RH = 250 degrees F
     

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