TR5tar Posted October 14, 2016 Report Share Posted October 14, 2016 Having a quick drive out earlier today, I pondered on how sometimes the engine feels sweet as a nut ... it runs smooth, it sounds smooth, and all is well with the world. And then on other days, it sounds a bit rough and feels a bit lumpy. It's not that something is going wrong with the car on those days it feels a bit rough, because the following day it can feel perfect. What makes the difference of course is the weather. If there's a bit of moisture in the air and it's not extremely hot my car seems at its best. I never note such differences in a modern car; I suppose that's down to onboard computers adjusting things so the engine runs smoothly whatever the weather conditions. Darren Quote Link to post Share on other sites
Motorsport Mickey Posted October 14, 2016 Report Share Posted October 14, 2016 Answered your own question, late summer drives when the atmosphere is damping down is great. Mick Richards Quote Link to post Share on other sites
RogerH Posted October 14, 2016 Report Share Posted October 14, 2016 Hi Darren, cooler air is always a good thing. Damp air can help also. Hot dry days give less oxygen. If the engine is finely tuned then it will react to more things. Roger Quote Link to post Share on other sites
Peter Cobbold Posted October 14, 2016 Report Share Posted October 14, 2016 (edited) Darren, Those water droplets are as a good as adding octane to the fuel. Its a clue that on dry days the engine might be knocking very slightly and inaudibly, and possibly only on one cylinder. It will feel slightly rough. To cure this try retarding the static timing a degree or two. It's because water slows combustion. You are right about moderns, they retard the spark every time knock is detected. At full throttle they would knock all the time so the electrickery then retards the sparks considerably. This is one way to run with compression ratios of around 14:1 on 95RON. Peter More on water and its effect like high octane here, the Kindle book and pdf from WWII aircraft studies are useful: https://supertrarged.files.wordpress.com/2016/01/tr6se-35-water-injection-revisited.pdf Water injection looks like being a new add-on trick for moderns, although the knowledge is decades old: https://techxplore.com/news/2016-09-bosch-fuel-saving-bonus.html Edited October 14, 2016 by Peter Cobbold Quote Link to post Share on other sites
Dave Larnder Posted October 15, 2016 Report Share Posted October 15, 2016 Darren The only thing I notice when it rains is, that I get wet! and the car gets filthy, especially the wire wheels. Having hit rain in Switzerland and France recently, it takes me two hours to clean one wheel. Dave Quote Link to post Share on other sites
Ben Freer Posted October 15, 2016 Report Share Posted October 15, 2016 (edited) Darren The only thing I notice when it rains is, that I get wet! and the car gets filthy, especially the wire wheels. Having hit rain in Switzerland and France recently, it takes me two hours to clean one wheel. Dave Dave you should see the state of my wheels after the RBRR - and it barely rained! Its mostly brake dust............ The car ran really well on the Run until we filled up with some dodgy fuel (I suspect Tesco's at Land's End). Full power was resumed once we filled up again with good juice. I suspect lots of short TRips doesn't help good running. I can recommend a 2000 mile blast it sorts all issues out (and potentially finds ones you didn't know you had! Edited October 15, 2016 by Ben Freer Quote Link to post Share on other sites
TR5tar Posted October 15, 2016 Author Report Share Posted October 15, 2016 My original post was more of a musing than anything else, on just how cosseted and cocooned we are in modern cars, divorced from the sound and feel of the engine and the road. It's those sounds and that feel, along with the smell of oil and petrol, that I love most about driving the TR. It was interesting to read what you said about water droplets being as good as adding octane to fuel, Peter. Before you added the detail about what some manufacturers are doing with modern cars in this respect, I was thinking along the lines of - Wouldn't it be possible to add some sort of device to the engine that created water vapour. Two hours on one wheel, Dave! I reckon I take about 30 minutes on each of my wires and I thought that was bad enough. What does your routine involve that takes that long? Out of bed, Ben! Quote Link to post Share on other sites
TR 2100 Posted October 15, 2016 Report Share Posted October 15, 2016 What's the problem ? Your car has a character of its own. Sometimes it's happy, sometimes it's grumpy. Like most of us. Why else would you drive a classic ? AlanR Quote Link to post Share on other sites
Peter Cobbold Posted October 15, 2016 Report Share Posted October 15, 2016 I came across a TR6 that had an after-market steam injection kit fitted. IIRC a small pump pushed water through a coil wrapped around the exhaust and the steam was squirted into the intake manifolds. Dont recall how it was controlled, maybe by a throttle switch. Perhaps at full throttle the cold mixture condensed the steam to droplets that would then re-evaporate during the compression stroke when the 'octane' effect of water works best. Peter Quote Link to post Share on other sites
TR5tar Posted October 15, 2016 Author Report Share Posted October 15, 2016 What's the problem ? Your car has a character of its own. Sometimes it's happy, sometimes it's grumpy. Like most of us. Why else would you drive a classic ? AlanR No problem Alan, just an observation ... I don't mind grumpy car, but I like it best when it's happy. Wouldn't have it any other way. Quote Link to post Share on other sites
Guest ntc Posted October 15, 2016 Report Share Posted October 15, 2016 Fit a winter stat. Quote Link to post Share on other sites
iain Posted October 15, 2016 Report Share Posted October 15, 2016 IIRC Neil Revington experimented with water injection (combined with twin Webers)on his TR2 years ago. No idea what the result was .....I am sure someone will recall. Iain Quote Link to post Share on other sites
Peter Cobbold Posted October 15, 2016 Report Share Posted October 15, 2016 There maybe overskimmed heads with compressions of 12.5....13:1 that became unusable when pump fuels became mandatory for racing. WI would allow them to be run without knocking holes in pistons. But until the last year or so finding how much water to inject was not easy, it was buried in the WWII research literature. TG for the www. Peter Quote Link to post Share on other sites
Nick Jones Posted October 16, 2016 Report Share Posted October 16, 2016 They definitely do have "moods" and definitely related to atmospheric conditions - partly external and partly under-bonnet. Back in the day when the Vitesse still ran Strombergs and clockwork dizzy it was was quite moody. When when she was good she was very, very good (cool damp air, near sea level) and when she was bad, she was horrid (hot day, in traffic etc). When on song there was a particular crisp note to the exhaust sound and eager edge to the engine - the happy sounds. Maybe 30 - 40% of the time. The first primitive incarnation of engine management extended the sweet spot and the happy sounds were more frequent, but still probably only 60 - 70% of the time. The improved engine management (still pretty primitive by modern standards), which saw the addition of barometric sensing (so atmospheric pressure is constantly being allowed for) and feedback from a wideband O2 sensor, made a pretty big difference and we now get the happy sounds 90% of the time, even at 2,700m up an Alp. Very hot weather and traffic remain problematic due to under bonnet temperatures and heat soak. The first car I remember being utterly consistent was our 1996 Golf GTI 8v. My previous K-jet Audis andGTis (including Digifant engine management) still had moods, albeit slight. The 5 pot Audis usually responded well to a good caning though! Nick Quote Link to post Share on other sites
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