Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by Chumley

  1. Chumley

    Ox sensor cycle time

    Panelman: Well, that depends on who you ask. All O2 sensors are not the same quality. Wrong question though. A better question is, "Considering my 11 year old Audi V6, what is the best value for my dollar that will function properly and "chances are" won't cause any further issues? If...
  2. Chumley

    Rotten Egg Smell in exhaust

    Patprimmer: I just found something interesting about H2S. According to this: http://www.atsdr.cdc.gov/toxprofiles/tp114-c3.pdf H2S has an odor threshold of .5 ppb. (that's parts per billion which is very very low) In another report I found that concentrations over about 100 ppm (parts per...
  3. Chumley

    Ox sensor cycle time

    Panelman: Yep, if your O2 sensors are the originals, chances are they're tired, especially if you have noticed a recent decline in fuel mileage and the engine uses more than about 1 qt. oil per 1500 miles. According to Bosch, they are 100,000 mile maintenance items. Don't wait too long, on V6...
  4. Chumley

    Ox sensor cycle time

    Assuming you mean how often per second the ECU - O2 sensor feedback loop should tweak the mixture lean/rich/lean . . . that causes the O2 sensors voltage swing . . . Older type single wire unheated O2 sensors should cycle at least once per second with the engine at idle provided the O2 sensor...
  5. Chumley

    Rotten Egg Smell in exhaust

    Pat writes: It should be borne in mind that H2S is also quite intoxicating and toxic. You might be wise to look up an MSDS on it. From memory, it initially smells real bad, but as we become affected, the smell reduces, we get a sweet taste under the tongue, and become intoxicated, then...
  6. Chumley

    Tornado test results

    Franz writes: . . . . . . Leave anything out? Franz Yeah. Reality, experience, education, and a conclusive, repeated, demonstrated history of performance. The "Tornado" design team doesn't have any of it. If none of the above, . . . . matters to you, you should invest your life savings in...
  7. Chumley

    Soft Turbocharging

    Careful Pat. If you keep writing like that, you might end up with a reputation like mine! It's not really a problem though. A few months in exile (call it a vacation if you prefer) usually repairs it! Chumley
  8. Chumley

    Rotten Egg Smell in exhaust

    Metalguy. Yeah, that's true. It is the catalytic converter that actually creates and stores most of the H2S and under certain conditions, releases it in quantities that you can smell. Remember that in 1975, that was the industries first shot at getting the converter technology to work. It's...
  9. Chumley

    Rotten Egg Smell in exhaust

    The reduction section in your catalytic converter, the part that changes NOx and some CO (carbon monoxide) back to N2 and CO2, also has the tendency to start absorbing SOx, or oxides of sulfur when its internal temperature drops below about 500°C. As Pat stated, sulfur is a natural contaminate...
  10. Chumley

    what could happen if diesel fuel was ran in a gas engine

    Depending on where in the world you buy fuel, often both #2 diesel and unleaded gasoline are between 20% to 40% identical aromatic hydrocarbons. Gasoline tends to have the remainder of the mix in the smaller C5 to C8 hydrocarbons and up to 15% oxygenates (alcohols, ethers) while diesel fuel has...
  11. Chumley

    do you know the properties of these fuels?

    These links don't have everything you are looking for and they're no substitute for The Blue Book, but, it's a start in the right dircetion: http://www.me.mtu.edu/~slpost/CLASS/hcprop.html http://www.fao.org/docrep/T4470E/t4470e08.htm Chumley
  12. Chumley

    Cambelt pioneers

    Graviman writes: "Funny how a lot of folks are going back to chains. Wonder why?" No, I don't either. Of course, today, with cell phones, OnStar, GPS, the internet, great warrantys, ECU's, ABS, airbags, Homeland Security, HMO's, and Medicare, you can agressively charge out into the world...
  13. Chumley

    Cambelt pioneers

    Smokey: Pontiac I6 engines, Chevrolet (Vega), Ford (Pinto) all used timing belts in the late/early 60's/70's with minimal belt problems. Your're right, belt based blocks and heads aren't "necessarily" longer, but we're not discussing any specific applications. Compare a few similar...
  14. Chumley

    Cambelt pioneers

    Timing belts require no lubrication and don't add wear particulate to the engine oil. Because of that, the front of the engine block and cylinder head(s) can be shortend up by about an inch as opposed to using a timing chain or gears which require sealed lubrication. Timing belts usually...
  15. Chumley

    Intake Manifold Temperature

    Guys, please, lets take a look in reality. turbinator writes to: SBBlue: I think you assumed the expansion across the throttle is isentropic, which is far from the case. A turbine, with high isentropic efficiency will take energy (heat) out of a fluid stream and turn it into shaft work...

Part and Inventory Search