DCF Posted October 15, 2003 Share Posted October 15, 2003 Airation of the tappets generaly does not result in permanent damage to the tappet. If you have a faulty tappet it is extremely difficult to identify which of the 16 it is. Measuring the clearances might give an indication.The only foolproof way I know of checking if damage has occurred is to replace the tappets with new ones - very expensive Link to comment Share on other sites More sharing options...
GTD Posted November 18, 2003 Share Posted November 18, 2003 This is all really interesting - thanks. Can someone explain why some people say that a dry sump gives you more BHP? How much more - and why? G 4 Geoff Link to comment Share on other sites More sharing options...
Paul McKenzie Posted November 18, 2003 Share Posted November 18, 2003 Crank's not flailing around in oil. Couple of bhp if you're lucky Link to comment Share on other sites More sharing options...
GTD Posted November 18, 2003 Share Posted November 18, 2003 So not really worth 2 grand!! G 4 Geoff Link to comment Share on other sites More sharing options...
dino ferrana Posted November 18, 2003 Share Posted November 18, 2003 Not for power gains but definitely worth it for engine protection. Link to comment Share on other sites More sharing options...
danwhiley Posted November 19, 2003 Share Posted November 19, 2003 2 grand spent and Andy B will still be faster ☹️ 😬 Link to comment Share on other sites More sharing options...
Pierre Gillet Posted November 19, 2003 Share Posted November 19, 2003 Is it confirmed that fitting an Appollo means fitting also a Laminova? Pierre Link to comment Share on other sites More sharing options...
CharlesElliott Posted November 19, 2003 Share Posted November 19, 2003 It doesn't. I have an Apollo only. Charles --- My Caterham Academy 2004 Diary Link to comment Share on other sites More sharing options...
Chelspeed Posted November 19, 2003 Share Posted November 19, 2003 And the Apollo is sometimes called an anti-cavitation tank, but it isn't. Cavitation is where the pump turns so fast that little vapour bubbles from in the low pressure areas behind the pump impellor. These bubbles immediately collapse causing local damage to the blades, they can also reduce flow as the pump can't pump vapour. So anti-cavitation is nothing to do with preventing entrained air entering the pump it's to do with preventing cavitation from vapour bubbles formed in the pump. So really it's a de-aerating tank not an anti cavitation tank. And just to get really technical it's called an Apollo because it's shaped like a space rocket 😬 Link to comment Share on other sites More sharing options...
thinfourth Posted November 19, 2003 Share Posted November 19, 2003 is there anything inside an apollo tank is it just a plain clyinder member of the club because of blatchat Link to comment Share on other sites More sharing options...
CharlesElliott Posted November 19, 2003 Share Posted November 19, 2003 Plain cylinder. Charles --- My Caterham Academy 2004 Diary Link to comment Share on other sites More sharing options...
Englishmaninwales Posted November 19, 2003 Share Posted November 19, 2003 Chelspeed - Anticavitation. You are absolutely correct. This term has bothered me for a while, as I thought it was being used incorrectly. I even asked an ex-submariner. And he knows a thing or two about cavitation and propellers! The Russians used to chase him because of cavitation. Link to comment Share on other sites More sharing options...
Chelspeed Posted November 20, 2003 Share Posted November 20, 2003 A submariner!! All we need now is for someone who knows an Astronaut to check that I'm right about the Apollo and we're 100% confident. Anyone? Link to comment Share on other sites More sharing options...
GTD Posted November 20, 2003 Share Posted November 20, 2003 Dan - Ah yes, so I don't think I'll bother! Mind you he's racing with the bigger boys next year - see you in December! G 4 Geoff Link to comment Share on other sites More sharing options...
Pierre Gillet Posted November 20, 2003 Share Posted November 20, 2003 Charles, I have an Appolo too. But after having 'vitrified' the sump foam during a track day last summer, I am considering fitting a Laminova , and what Peter is writing seems to confirm the need for it. Pierre Edited by - Pierre Gillet on 20 Nov 2003 08:29:45 Link to comment Share on other sites More sharing options...
Bob Corb Posted November 20, 2003 Share Posted November 20, 2003 Cavitation can occur at several locations in an engine and can be a serious problem for big end bearings in high speed engines. The oil in an engine always has a certain amount of air dissolved in it. The amount of air which can stay in solution depends on the pressure at which the oil is held at. Typically at atmospheric pressure an oil can hold up to 9% by volume. This rises to~ 45% by volume at 4Bar (this is traight from SAE paper 940792 if your interested). If a high speed SI engine is consuming a reasonable/high amount of oil then a figure of 30% aeration may be expected. 30% aeration would normally be okay except possibly in the crankshaft... When oil is forced into the crank against the centrifugal forces due to its rotation the oil pressure will drop significantly. At the crank centreline it can often be low enough to force the air out of solution (same as opening a bottle of carbonated drink and getting a fiz) - this is called psuedo cavitation as the vapour coming out of solution is usually air not oil vapour. This air will then sit in the centre of the crank and prevent oil from passing through to the big ends. If the engine speed is held high for long periods then the oil in the crank webs leading to the big ends will drain away and then the big end bearing will be starved - crunch. The appollo/anti cav tank will remove any free air which is very bad for the crank but hopefully it will try to centrifuge the oil such that the less dense oil (which contains more air) will stay in the centre and eventually rise to the top whilst the denser oil sinks to the outlet. I'm not sure the density difference is high enough to do this but it may have a minor effect. I'd really like to test one here at work with an aeration meter.... Anyway, must crack on... BC Link to comment Share on other sites More sharing options...
Chelspeed Posted November 20, 2003 Share Posted November 20, 2003 So you are agreeing that it is primarily a deaerator? But by deaerating it can prevent pseudo-cavitation. So describing it as an anti-cavitation tank could be a little bit right after all? I suggest we start calling it an anti-pseudo-cavitation tank..... No? OK stick to Apollo. Link to comment Share on other sites More sharing options...
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