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Everything posted by Digsy
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If you want to seal the cap to the head, and there are oil galleries formed by sandwiching the two together (as you might get on a VVTi), use an anaerobic like Loctite 518, to avoid blocking up the galleries when it cures. If you want to seal the corner joints between the cap, head and cam cover gasket, use a small amount of silicone RTV along the three-way joint. No need to bond the seal into its housing or pack the seal with grease.
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They just developed their own completely new range of diesel and petrol engines.
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Yeah, that kind of reaction, but it depends what you mean by "better for the environment". Diesels are better for the environment if you are only talking about CO2 emissions and global warming, which is pretty much all anyone has been talking about when it comes to vehicle emissions since 2009 when the framework for the EU CO2 limits was set out. Even though the entire German auto industry said the legislation would put them out of business, once it became clear that Brussels wasn't going to back down, the automakers just got on with it. Thing is, most of the tech that got us to the 2012-2015 limits was already invented and on the bookshelf well before the legislation was even passed - probably by a decade or so. Its just that the automakers had no financial incentives to use it. The threat of fines from Brussels for not meeting CO2 targets cleared all that up. As well as more high tech petrol engines, diesels were a big part of this CO2 reduction strategy because the fines are calculated on an entire fleet basis, therefore selling more diesel cars lowers the entire fleet CO2 emissions. There's no argument that diesels aren't better than petrol for CO2 emissions, so as diesels got more refined, it was an easy sell (even if you're not a "green" less CO2 = better MPG anyway, so its a win-win). Diesel got a bad name overnight because of the VW scandal. However, the latest Euro 6 emissions limits are pretty much already in force and cars are already being phased in with the technology to lower NOx emissions. Particulates had already been steadily reduced and DPFs are pretty much standard fitment now, but there's still much more that can be done - and again a lot of this tech is ready and waiting. The problem is that instead of a properly thought through strategy for year-on-year reduction like we had for CO2, diesels have become a populist issue and the public is demanding the government "be seen to be doing something". What they appear to be doing seems to be having the effect of killing the market for the new, cleaner diesels just as they are coming on the market, which seems a bit back to font to me.
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Public opinion which is being based on knee-jerk reactions and bullshit reporting in the media. They should be encouraging and incentivising the new generation of Euro 6 diesels, not killing them off before they get a foothold and making it more cost-effective for people to simply hang on to older, dirtier diesels for longer.
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Yes, it will be 500 (because of similar triangles).
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Out of interest what vintage is your Outlook? I am still running Outlook 2003 under Windows 7 and I also still apply the monthly updates but I apply them manually. Not had any issues with older MS software failing as yet. FWIW I don't keep any e-mails in the inbox. I archive everything off to various PST's as soon as I have read or sent them.
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Based on a sample of everyone other than you and I... not very.
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Autocad and Solidworks are hardly "simple to use", IMHO, as they are professional CAD suites. I use CATIA v5 to plan and visualise my DIY projects but I wouldn't recommend it to anyone else. Most DIY'ers seem to recommend Google Sketchup even if they have no prior CAD experience. Other than that, PC World and the like usually have DIY-oriented software for home and garden design for a few quid on their bargain software stands, which will also come with instructions, unlike the big software suites which really require you to go on a training course or do a lot of trial and error.
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If you want a cure for insomnia, here is the full report on the "stainless versus copper" cylinders study: https://www.mcdonald-engineers.com/sites/mcdonald/files/copper_v_stainless_research_report_-_small.pdf
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Not sure Chris. Maybe I got the wrong end of the stick. I just saw that stainless steel cylinders were available for about the same cost as copper and thought it was such a no-brainer that I did a quick Google and found the information that stainless was less efficient than copper. I admit I didn't research it thoroughly. Maybe the coil is made from stainless as well, so it doesn't transfer the heat into the cylinder as effectively?
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Well that's a colossal pain in the butt I will have to have a closer look, measure up and compare to some new ones. For info its a single coil with an immersion heater boss and a single take-off. cold in and hot out are both 22mm and the coil connections look like 28mm. I need to add a second take off and gravity loop to feed a booster pump, hence the reason for the surgery.
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Thanks for the feedback. Yeah, that's pretty much what I was thinking. This is part of a complete bathroom refit so in terms of extra cost it's peanuts. My circulating pump is on service valves already, but good call on swapping the motor valve - I will certainly do that too. I have been pointed towards push-fit stuff by several people, including by one professional. I'll give it a go eventually, but not sure about using it on a hot water tank for my first try! Actually, flexible hoses would be ideal for connecting a tank up with minimal hassle but I guess maybe they can't handle the temperatures / pressure? Even though, mine is a vented system, so the only pressure would be from the head of water in the loft tanks... *EDIT* Just Googled and found out that (obviously) the internal bore on flexible hoses is far too small to use on cylinder connections.
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I’ll soon be doing some fairly major plumbing inside my airing cupboard which will be much simpler if the copper cylinder is removed. Question is, do I stump up £150 and just replace it while I am on the job? My first copper cylinder lasted less than 5 years before splitting around the base. This one has been in for about 15 years, and I know most of them only come with a 2 year guarantee. I live in a very hard water area and the tank that split after 5 years was full of limescale when it came out so god knows what this one is like. Also, are the fitting locations for cylinders standardised? I.e. if I buy another 900x450 cylinder with 22mm compression fittings, will it be plug & play when I install it, or will I have to cut the existing connections about? Looking at the cylinder that is in now, I am fairly certain that did not require any changes to the plumbing as the pipes have been painted almost right up to the unions and the is no evidence of this being disturbed from when I had the cylinder replaced the first time. Was also considering replacing with a stainless steel cylinder, but from what I have read they can be something like 30% less efficient due to stainless steel being a much poorer conductor of heat, so even if they need to be replaced more frequently, a copper cylinder will pay for itself in the long run. I am happy to do the plumbing myself, just trying to weigh up the potential size of the job.
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It's not bigger than "dieselgate". VAG were employing a deliberate defeat device in the ECU code to recognize when the car was doing an emissions test, and put the engine into an operating mode which was not available during "real world driving". This is a (albeit interesting) journalism consisting of revisionist history and some selective data. Firstly, the EU directives for emissions (mostly CO2 reduction, which is directly proportional to fuel consumption) have driven real innovation in engine design over the last decade or so. Most of the tech was already on the shelf by the time the march for CO2 reduction started. All the EU had to do was impose a financial penalty on the automakers to suddenly make a clear business case for taking the new gizmos out of the research lab and putting them on to actual production engines. There are two "take-aways" from this: (1) Modern engines ARE more fuel (and CO2) efficient in both emissions tests and real-world driving than their predecessors, and (2) by and large the auto industry won't do anything to improve emissions on production cars unless they are absolutely forced to. Deiselgate, correctly or incorrectly, brought NOx to the fore - and we were already talking about particulates from diesels. DPFs are standard fitment and GPFs aren't far behind as GDi combustion is practically the norm, now. As with CO2 before it, the tech to reduce NOx without cheating was already on the shelf long before VAG got caught with their pants down. I haven't done an exhaustive check, but a quick Google tells me that both the VW Tiguan and Mercedes C250, which are hailed as having "legal" real-world NOx emissions are both available with SCR. This is the tech that reduces NOx in the tailpipe by injecting AdBlue. Another Google suggested that the "dirty" cars (certainly the Qashqai) do not have it. What I will agree on is that the outgoing NEDC test is shockingly bad at representing real-world driving. The new test profile (WTLP) is better, but perhaps not better enough. But it is a step forward. Bit what they both are, is a level playing field and as such the NEDC (and probably the WLTP) have resulted in engines which are optimised to perform well when tested. And this is where the big difference between optimisation and cheating needs to be underlined. Optimisation is like studying for a test. Sure, you may be a gifted pupil and have capabilities above and beyond what is strictly required to pass, but in order to pass the test you must know those things. Now, what if an average pupil was given the option of having private tuition at weekends to learn stuff that would make them more capable, but would not be in the test, or was told they could go out and see their mates instead? No prizes for guessing what most would do. VAG, on the other hand, snuck into the headmaster's office and looked at the test paper the night before. Quite different. So, despite having had a "flawed" test regime, it has resulted in engines which are cleaner, but have become over-optimised for the conditions under which they will be tested. This has come with a compromise. That compromise appears to be that under real world conditions, some newer cars are now less clean than older cars in real-world conditions, but only in ways that public scrutiny / opinion / outrage has not yet fully focussed upon. The "star pupils" in this class are those already using SCR to contain their NOx emissions. So, you can't take a car which has been specifically developed to pass a given test and then test in in a totally different manner and declare it to be illegal. I am 100% certain that the folks at Emissions Analytics have done a sound job, but in a sense Nissan are right, you can't simply derive your own test profile in secret and then claim it to be more representative than another one. Imagine how many different commutes there are, or driving styles, or road surfaces, or traffic conditions. In order to compare apples with apples you have to have a standardised test, and any standardised test will be more representative for some than others. What I am getting from the article is that by and large newer cars are cleaner than older ones, so the legislation to date can hardly be called flawed unless you are taking a revisionist stance. The fact that some newer cars are significantly more dirty in terms of NOx is a shocker, but I guess this is one of those compromises driven by the optimisation for low CO2 on the NEDC drive cycle. 18 times higher than an old Golf it may be, but currently its still legal. Also the industry clearly knows NOx is an issue, because like CO2 previously the tech to reduce it is right there, waiting to be used - when they are forced to do so. This will come at a cost premium in the short term, as did all the CO2 reduction tech, but costs will fall as they become more commonplace. What is a shame is that despite the hge amount of research that has gone into reducing all emissions over the last 20 years or so, legislation and implimentation is so slow. The internal combustion engine could be having its finest hour, but by the time it reaches its full potential, the focus will be totally on EV's, or the petrol will all be gone, anyway.
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If you feed and return from the bottom you may end up with air trapped at the top of the core, meaning it is never full of oil so you never use the full area of the cooler.
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Yes - but that calc is based on a lot of assumptions. However I did recently work on a fairly run of the mill turbo engine (140hp) which needed a pump capable of flowing about 150LPM at full chat, so the maths scales pretty well.
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I'm always very wary of comparing flow figures for electric water pumps with mechanical pumps, as the electric pump manufacturers tend to state the flow at practically zero head. The Davies Craig EWP80, for example, will only flow 80 litres per minute against a maximum of 7.5kPa head. The resistance in an engine cooling system can easily be ten times that. Mechanical pumps have a lot more "oomph" and can flow against a much higher system restriction. OE engines which use electric water pumps like BMW, Volvo and Toyota have their cooling system specially engineered to suit. In fact, I don't really understand how aftermarket electric pumps work at all, as the end user typically will not have access to any of the measurements required to determine if the pump is correctly sized or not. There are no hard and fast rules but a gasoline engine will normally reject about 50% of brake power to coolant at full load / max speed. More if the engine has other water cooled items like turbos, water-oil coolers, cooled EGR, etc, etc. Typically,the pump will be sized so that the difference between bottom and top hose temperatures is about 8 degrees with a fully open thermostat. You can use the schoolboy physics formula Q=m.Cp.DeltaT to work out the required flow. Q = heat flux (in this case 50% - or whatever factor you want to use - of brake power, in Watts). m = mass flow rate of coolant in kg per second (approx 0.0167 kg per second = 1 litre per minute) Cp = specific heat capacity of coolant (about 3600 J/kg.K for 50/50 water / glycol) DeltaT = the temperature rise in degrees C or K So for the 300hp Supra example: Q = 60% (let's say, allowing for turbos and oil cooler) of 300hp = 0.6 x 223.71kW = 134226W Cp = 3600 J/kg.K DeltaT = 8K Q = m.Cp.deltaT , so m = Q / (Cp.deltaT ) m = 134226 / (3600 x 8) = 4.66kg/s mass flow rate 4.66 / 0.167 = 279 litres per minute at full chat.
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Can't access the site but I assume its this?
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This. I gave up 3rd party AV years ago after they all started getting bloaty and seemingly very picky about working nicely with other security software - AVG stopped paying ball with Zonealarm, for example. I have used the built in Windows AV ever since I installed Windows 7 and 8, plus NoScript + common sense in Firefox and never had any issues, even though I stopped applying security updates to my W7 machine well before the Eternal Blue attack this year (but I have patched it since).
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Agree with this but stranger things have happened. Also, Toyota have just launched a new flagship TT V6 which is designed to replace the big NA V8 in the premium models. Not sure it would package well in a car designed for an I6, though.
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This is what the industry calls a "series hybrid". Unfortunately you can't ditch batteries. You will need something to act as a current buffer for the periods when your gen-set is producing more power then you want (i.e. when cruising) and also to act as a temporary current source when it is producing less current then you need (for rapid accelerations). A series hybrid only works if you can run the small gen set at an optimum economical set point, which will be far below the maximum requirements of the vehicle and way above the minimum requirements (although your 2kVa example is probably too small to work). If you somehow plan to modulate the gen set itself to increase or reduce power as and when you need it then you will end up with something less efficient then the normal engine as you will need a gen set as big as the 2JZ for peak performance, with the efficiency losses in between the engine, motor and generator. If by 2kva you mean the output of the proposed gen set, 2kva = 2kW. The bog stock 2JZ as a peak output of 206kW, so you're not really comparing apples with apples. If you really plan to sun a 2kVA gen set then you will need some hefty batteries to store enough energy for when you want to go above 30 mph for a few minutes To put things in perspective, the Chevy Volt, which reverts to operating as a series hybrid when its EV range has been exceeded uses a 63kW engine driving an (up to) 111kW primary motor-generator or a secondary 55kW motor-generator, coupled with a 18.4kWh worth of batteries and has a 420 mile total range (not "electric" range). The BMW i3 Rex uses a far smaller gasoline engine (25kW) and a similar sized motor-generator (125kW) and 22 or 33kWh battery packs, and has a total range of just 180 miles. Obviously, as you pint out, total range depends on the size of the fuel tank tank. You might be able to get "thousands of miles" out of a 2kW generator using the Supra's big fuel tank, but without batteries you will be doing it all at walking pace
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The "Is Born" series were documentaries, not dumbed down TV fodder for people with a 45 minute attention span. I liked WD with Edd but it was utterly contrived, and the product placement got on my nerves.
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Binned Sky years ago, haven't missed it one bit.
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Does Discovery actually screen proper documentaries any more or is it now completely fly-on-the-wall, American family business arguments docu-soaps?