Wahey Posted June 26, 2004 Share Posted June 26, 2004 What is this Windage thing that people keep going on about. I know it has something to do with oil starvation but I need to know how you tell if it happens and how to go about stopping it? What do sump baffles do too and how do I know if I have one? How do I fit one? Cheers Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 26, 2004 Share Posted June 26, 2004 Windage is when the whirling crank hits the oil in the sump. This loses energy into the oil (the oil gets hot, the crank is decelerated), so it costs you power and that power gets dumped into the oil. All wet sump Ks with shallow sumps have windage issues. It is reasonably difficult to baffle a K series shallow sump because there is hardly any depth - the webbing that contains the main oil gallery and the fastening for the through bolts protrudes beneath the main bearing ladder. While baffling is difficult it is not impossible, although I do not know of anybody who has achieved it to good effect. Sahf London; every 1st Wednesday from 19:30 at The Duck just around the corner from Clapham Junction station Link to comment Share on other sites More sharing options...
Wahey Posted June 26, 2004 Author Share Posted June 26, 2004 Nice one Peter. Thanks Rich Link to comment Share on other sites More sharing options...
Chelspeed Posted June 26, 2004 Share Posted June 26, 2004 Windage to me is the resistance on rotation of the crank from any fluid that resists it's turning. In a car it is primarily the oil as Peter says, hence the use of windage trays to keep the oil away from the crank. But the air in the crank case will also resist the crank turning. At work we fill big generators with hydrogen rather than air because the windage losses from spinning the generator rotor in low pressure hydrogen are lower than for one filled with air. In a car you can oversize the dry sump scavenge pumps and pull a small vacuum in the crankcase so windage losses of the crank spinning in low pressure air are lower than for one spinning in ambient pressure air. Small difference though. Link to comment Share on other sites More sharing options...
Myles Posted June 26, 2004 Share Posted June 26, 2004 Blimey Chelspeed - haven't you heard of the Hindenberg??? Keep BC free and open for ALL. Membership No. 43xx Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Myles Posted June 26, 2004 Share Posted June 26, 2004 Serious question though - I slightly overfilled my engine at a Curborough test-day a few weeks back (by accident - the oil level was too low - but I obviously overdid it). My OTs are peaking 5-7 (ish) degrees higher than normal... ...but I've also been convinced that the car is feeling slightly lifeless. The former is obviously due to windage - I wonder if the latter is too... I guess I should empty the apollo (only) and the top-back up to the correct level. Keep BC free and open for ALL. Membership No. 43xx Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Fibrepro Posted June 26, 2004 Share Posted June 26, 2004 My wife suffers from serious windage 🙆🏻 Link to comment Share on other sites More sharing options...
Bare Posted June 26, 2004 Share Posted June 26, 2004 Hindenberg?? Saw something recently that the Infamous Airship Burned .. because of the Aluminum Powder Coating on the Skin Fabric.. not the hydrogen itself.. Ali Powder is seriously danerous.. and a seriously stupid material to but on a hydrogen gas bag. Seemingly it would have made little or no difference if the Gas employed was Helium. Static discharges ignited the Aluminum and the rest is on Film. In actuall fact no one was actually burned by the hydrogen itself, those that were burned were by Debris and mostly the Diesel fuel for the Engines... Another bit of useless fact . Link to comment Share on other sites More sharing options...
Mick Day Posted June 26, 2004 Share Posted June 26, 2004 Myles The oil drains from the Apollo back to the sump when you switch off; so only need to drain from the sump. Can anyone answer this one: if I let the oil level get too low (wet sump with Apollo) the oil pressure goes up slightly? Mick Edited by - Mick Day on 26 Jun 2004 18:04:35 Link to comment Share on other sites More sharing options...
Myles Posted June 26, 2004 Share Posted June 26, 2004 Mick - not entirely... If you do an oil-change, you will find a good pint or so in the Apollo... ...to be honest, I can't recall if I've ever done a 'cold' oil change (i.e. I usually run the engine to thin the oil and persuade as much as possible out of the engine - so my experiences with the amount left in there might be exagerated - but there is definitely some oil in there... Keep BC free and open for ALL. Membership No. 43xx Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Chelspeed Posted June 26, 2004 Share Posted June 26, 2004 > haven't you heard of the Hindenberg??? There's 22kV and 1000's of amps in the windings of the generator. There's high pressure oil in the bearings. There's 500degC, 60 bar steam in the turbine next door that drives it. If that lot lets go there's serious carnage, a bit of hydrogen is neither here nor there...... Link to comment Share on other sites More sharing options...
Simos Posted June 26, 2004 Share Posted June 26, 2004 The 660 Mega-watt turbo alternators at Drax are also filled with hydrogen. Additional properties are that it is 'dry' and non-conductive which is important 😬 with such currents in the beastie. Seem to recall there is positive pressure to ensure no air gets in. Link to comment Share on other sites More sharing options...
Bafty Crastard Posted June 26, 2004 Share Posted June 26, 2004 Yep Windage is definitely a condition related to beer and curry ☹️ R300 nut (my nut's have gone again) Link to comment Share on other sites More sharing options...
Mick Day Posted June 27, 2004 Share Posted June 27, 2004 Myles If you've overfilled it doesn't really matter where the oil is drained from as the sump & Apollo are part of the same system. However it's easier to drain from the sump. When you switch off oil will drain from the Apollo to the sump at a rate proportional to the airbleed from the cam cover. That's assuming you haven't fitted a one-way valve. Link to comment Share on other sites More sharing options...
Myles Posted June 27, 2004 Share Posted June 27, 2004 Well, I guess I'll see shortly... I only want to drain a bit off - not perform a full oil change (it isn't due by a long-chalk). So, my plan is to jack the front of the car up and drain from the Apollo to try and reduce the amount lost with the engine cold. I reckon from experience that if I crack the sump-plug, I'm going to lose far too much oil. It wouldn't be so bad, but my sump-plug doesn't have a washer and so needs blue Hylomar to help seal it. I'll report back later Keep BC free and open for ALL. Membership No. 43xx Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Mick Day Posted June 27, 2004 Share Posted June 27, 2004 Myles wrote: "It wouldn't be so bad, but my sump-plug doesn't have a washer and so needs blue Hylomar to help seal it." Good time to fit a washer *thumbup* Link to comment Share on other sites More sharing options...
Myles Posted June 27, 2004 Share Posted June 27, 2004 Yeah, I suppose so. Next time then I've performed the partial drain as described (from the Apollo with the engine cold - hadn't been run for two days, front jacked up)... ...and I can confirm that there is a 'lot' of oil in the apollo at rest... Actually, it showed no obvious desire to slow down when I removed the plug and waited for 30 secs or so - so I put the plug back in, but a bit of fresh oil in, ran it up to temp and then added oil every so often until the level came up. I've just done a 30-40 min blat and peak OTs are down by 5-7 (ish) degrees as expected (it's always a bit hard to compare due to differing weather conditions, but it's fairly warm, and I ran the engine hard). So that's that then, FWIW.... Keep BC free and open for ALL. Membership No. 43xx Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
rich_em Posted June 27, 2004 Share Posted June 27, 2004 More useless facts The hydrogen in a large generator is there for its superior heat transfer charactersics otherwise helium would be used and as long as no oxygen present then it cannot burn Link to comment Share on other sites More sharing options...
Myles Posted June 27, 2004 Share Posted June 27, 2004 Shame - just imagine the fun you could have had with the helium when it is discharged... Mind you, nitrous oxide would be even *more* fun... Keep BC free and open for ALL. Membership No. 43xx Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Subaru Blue SV Posted June 28, 2004 Share Posted June 28, 2004 Mick day says above that oil flows from the apollo back to the Sump when car is stopped. Q1. If this is the case presumably it needs to fill back up when the car is started. Does this short space of time lead to oil starvation issues. Q2. Where does the apollo fit in the oil system - eg before the oil pump and is it fed by suction or, is it filled from oil flowing back down the galleries. Q3. if it flows back to the sump is the oil level above the crank oil seal level, and if it is, does/can this lead to oil contamination of clutch/flywheel area. Link to comment Share on other sites More sharing options...
Subaru Blue SV Posted June 28, 2004 Share Posted June 28, 2004 Mick day says above that oil flows from the apollo back to the Sump when car is stopped. Q1. If this is the case presumably it needs to fill back up when the car is started. Does this short space of time lead to oil starvation issues. Q2. Where does the apollo fit in the oil system - eg before the oil pump and is it fed by suction or, is it filled from oil flowing back down the galleries. Q3. if it flows back to the sump is the oil level above the crank oil seal level, and if it is, does/can this lead to oil contamination of clutch/flywheel area. Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 28, 2004 Share Posted June 28, 2004 A1) This does cause about 10 seconds of low oil pressure running, but at idle this does not cause problems. A2) The Apollo is on the pressure side of the pump, so gets fille dup on first start if it has been allowed to drain. A3) No. This is what the crank "seal" is for. Link to comment Share on other sites More sharing options...
Myles Posted June 28, 2004 Share Posted June 28, 2004 if it has been allowed to drain ...and as my experience shows - even after two days non-running rest, it does *not* completely drain... With my (accurate, digital) SPA oil/oil gauge, I'd say the 0-normal pressure build-up is in the Keep BC free and open for ALL. Membership No. 43xx Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
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