Tom Pickering Posted June 24, 2002 Share Posted June 24, 2002 With the engine temp at 80deg (normal) and the oil at the correct level I've noticed that under heavy straight line breaking that the oil pressure guage will go right down to zero, then the pressure guage takes a second or so to come back up to normal operating pressure (between 1.5 - 3.5 depending on engine speeds)when I power on again. It's a little disconcerting when it happens. Is this normal - or am I worrying about nothing. Can any one throw a little light on this for me. Tom Link to comment Share on other sites More sharing options...
Jam Mad Posted June 24, 2002 Share Posted June 24, 2002 doesn't happen to me... but as to why it may be happening... i'm sorry but i can't help. j Link to comment Share on other sites More sharing options...
R2D2 Posted June 24, 2002 Share Posted June 24, 2002 With the oil hot 3.5 bar at 6000rpm would seem to be quite good. At idle you may do quite well to have about 0.75 bar depending on the gauge. Electronic gauges/sensors can be iffy at low pressure and I use to have one which gave a zero reading. I checked it with a mechanical gauge and was getting around 1 bar. Are you sure that oil pressure only drops to zero when you brake heavily rather than just come off the throttle. If it only happens under braking you may have serious oil surge and you do need to worry. Link to comment Share on other sites More sharing options...
Tom Pickering Posted June 24, 2002 Author Share Posted June 24, 2002 Chris Sometimes on roundabouts too, usually large ones that can be taken at high speeds with the rear just starting to slide out (no not really officer). Tom Link to comment Share on other sites More sharing options...
John Hughes Posted June 24, 2002 Share Posted June 24, 2002 Isn't the oil pickup at the rear end of the sump ? Under braking is all the oil forced to the front of the engine ? Prob more likely with the slope fronted sumps as opposed to those which are step shaped / modified escort or cortina sumps ? john Link to comment Share on other sites More sharing options...
Roger King Posted June 24, 2002 Share Posted June 24, 2002 This is oil surge and can occur quite often in a Caterham, depending on the individual sump that you have, the tyres and the brakes. If you have sticky tyres and good brakes this will make things worse. The full answer is to convert the engine to dry-sump which is designed to eliminate the problem completely. Failing this, drop the sump and check that the pick-up pipe gauze is as low as possible without actually touching the bottom of the sump. If it is too high, you should be able to bend it to sit lower, but make sure that nothing else then fouls before you refit the sump. Link to comment Share on other sites More sharing options...
ashaughnessy Posted June 24, 2002 Share Posted June 24, 2002 What about making sure you have a properly baffled wet sump? I have to try VERY VERY hard to get serious enough oil surge on my xflow that my oil pressure warning light comes on, and that is set for 20 or 30 psi (I think). I have the standard caterham wet sump. Anthony Link to comment Share on other sites More sharing options...
R2D2 Posted June 24, 2002 Share Posted June 24, 2002 I have a 711M based engine with an aluminium wet sump which has been baffled and "trap doored". I don't suffer any oil surge on the road but I have fitted an oil pressure warning light (1989 car, not fitted as standard) just in case. I think that if I stared to do any track days I would certainly fit a dry sump. I have a 7 psi switch as the standard pressure, high flow pump that I use only gives about 10 psi at idle when the oil is warm. I am still surprised that there is bad surge with a standard car, are you sure that the oil level is correct and that you have the right dipstick etc. Link to comment Share on other sites More sharing options...
Tom Pickering Posted June 24, 2002 Author Share Posted June 24, 2002 The oil level is correct as I checked this the first time I noticed it. I do have the slope fronted sump fitted, also AO32(s) tyres and uprated brake pads, so I guess it is oil surge. I have considered dry sumping but don't know much about the fitting and costs of this. I will look at the sump as Roger suggests first. What's involved with the baffling system, can you buy baffles to insert. But ultimately I think dry sumping is the answer as I do enjoy track day's. Cheers Tom Link to comment Share on other sites More sharing options...
def843t Posted June 25, 2002 Share Posted June 25, 2002 I have lost all pressure a couple of times blasting down a local downhill twisty bit. Mines an 1800 X/F wet sump. Goodyear F1 tyres. I,ve nver been happy with the oil level. Too full and it ends in the catch tank and to low...... Link to comment Share on other sites More sharing options...
Tom Pickering Posted June 26, 2002 Author Share Posted June 26, 2002 def843t I know what you mean about the oil level. I'm always checking the oil level, topping it up and emptying the catch tank before every run (perhaps I worry too much about it). I wonder if a dry sump system would be better for the engine and cure me of my phobia. A few years back I owned an 84 1760 Xflow and was unaware about the different dipsticks and the oil level (I don't think the previous owner was either, he did'nt tell me if he was) so I kept overfilling it. The under side of the car was always dripping with oil and on one occasion I was asked to leave the Nurburgring because of it. I have the level marked now so I know where it should be. Tom Link to comment Share on other sites More sharing options...
Roger King Posted June 26, 2002 Share Posted June 26, 2002 Yes, dry sump is wonderful (apart from paying for it of course). You get much more reliable lubrication and as a bonus, improved ground clearance. Once fitted, you can relax on track days. Link to comment Share on other sites More sharing options...
Tom Pickering Posted June 26, 2002 Author Share Posted June 26, 2002 Roger Do you know where the best place would be to enquire about dry sumps and how much the system would cost to buy? Is the installation difficult? Cheers Tom Link to comment Share on other sites More sharing options...
Roger King Posted June 26, 2002 Share Posted June 26, 2002 There are a lot of detail differences that can be specified on a dry-sump system so the price can vary a bit. As a rough guide, the parts would cost £600 + VAT - tank, hoses, unions, pump, sump, oil filter assembly, oil cooler, etc. Fitting can be done DIY if you are competent. You may need to shorten the passenger footwell to accept the tank too. Some chassis are like this from manufacture and others need modifying, but it's not so difficult as it sounds. It is possible to obtain a tank that will fit without shortening the footwell, but we haven't tried one ourselves, so I can't really comment on their effectiveness. Bear in mind that tank design is crucial to good lubrication. We (and others) can supply parts as necessary, but DON'T use a kit that leaves the oil filter hanging from the sump as the lowest point. We've seen engines ruined when the filter gets knocked off or holed. Link to comment Share on other sites More sharing options...
James Arnold Posted June 26, 2002 Share Posted June 26, 2002 Tom (or anybody) How do I work out the right level for filling the oil on my Xflow. I have tried to nail this issue before and failed. I have no idea where the sump came from. For a track day at brands I filled the oil to the max. in a 20 min session the catch tank went from emtpy to overflowing (over 1 litre). I then ran the oil just above the minimum for the rest of the day. No sign of oil starvation on the gauge and only a little blown out into the catch tank. However this isn't good for my nerves, becuase I know if I see oil starvation it probably too late! Whilst obviously different sumps changes the amount of oil, I fail to see why it should affect the level of the surface below the block. Therefore the dip stick should be the same? How high should be surface of the oil be? Should I take off the sump and fill it up to a certain height and measure the required volume? J Link to comment Share on other sites More sharing options...
Tom Pickering Posted June 26, 2002 Author Share Posted June 26, 2002 Roger Thanks for the info on dry sump. My Caterham is alredy fitted with an oil cooler so I'm assuming that this will cut down on the costs, that's also assuming that there is no need for any specific kind of oil cooler to go with a dry sump. I'm reasonably competent with a spanner (having rebuilt 4.2 Jag engine and petrol to diesel conversions in Landrover). What might concern me most is how I would know if the passenger footwell would need shortening. If as you say the tank design is crucial,I would prefer to shorten the footwell, but this would be the the area that I would need most guidance on. I have a short cockpit 1990 ital live axle model. Tom Link to comment Share on other sites More sharing options...
John Posted June 26, 2002 Share Posted June 26, 2002 I have a barely used X/Flow dry sump pan for sale if required. Email if you are interested. Also have a tank a dry sump rocker cover. John Link to comment Share on other sites More sharing options...
ashaughnessy Posted June 26, 2002 Share Posted June 26, 2002 I believe it is fairly obvious whether your passenger footwell needs shortening. On the "short passenger footwell" versions, the passenger footwell ends square with the bulkhead chassis rail. On the longer versions, it protrudes by several inches towards the exhaust. If you have the shorter version you should have an obvious not-used space between the footwell and exhaust just asking to have a dry-sump tank (or battery!) in. Otherwise, you'll look at it and think "how the hell do you fit a dry sump tank in there". I might not have described it too well! Perhaps others can have a go :-) Anthony Link to comment Share on other sites More sharing options...
Tom Pickering Posted June 26, 2002 Author Share Posted June 26, 2002 John Where are you and how much for the items. I could do with a full list of the essential items I need for the dry sump conversion. I can then organise the purchase of these items from yourself/Roger king (obviously I want to get everything at the least cost). Anthony Just had a look and yeah it is obvious. At the moment the space (roughly 10" square - I did'nt have a ruler with me) houses the windscreen washer bottle, which could be moved (can't remember the last time I used it anyway. If I did away with it altogether it would cut weight down) and the oil catchment tank , which would be redundant anyway. cheers Tom Link to comment Share on other sites More sharing options...
Old Septimus Posted June 26, 2002 Share Posted June 26, 2002 Isn't the washer an MOT requirement? Link to comment Share on other sites More sharing options...
Tom Pickering Posted June 26, 2002 Author Share Posted June 26, 2002 Old Septimus For MOT purposes I could always do a Blue Peter job with a Fairy liquid bottle and a hose from inside the cabin. "Just squeese that for the washer". "That's fine, here's your MOT Sir". "Cheers". What do you think? Tom Link to comment Share on other sites More sharing options...
John Posted June 26, 2002 Share Posted June 26, 2002 Yep, dry sump is the way to go. Although not to sure about ditching the washer bottle. Relocation would be better. Email me about the parts I have. IMHO, always best to buy a new pump for peace of mind but tanks and sumps etc are OK secondhand. John Link to comment Share on other sites More sharing options...
AndyA Posted June 26, 2002 Share Posted June 26, 2002 Oil surge - (first hand knowledge) - Mallory Park Gerrards bend in the Caterham Grads race just over a week ago! Oil filled correctly, catch tank full after qualifying & oil all over the place then topped up. During the race (lap 5) exit Gerrards - smoke, oil pressure and power drop off - end of race. Currently sourcing 1600xflow crank and rebuild - next race 6th July. BU**ER Link to comment Share on other sites More sharing options...
Tom Pickering Posted June 26, 2002 Author Share Posted June 26, 2002 John you have e-mail Andy Sorry to hear that bad news That's what I worry about. I'm off to Oulton on the 5th and I don't want the same to happen to me. Wondering if I can get the bit's I need for dry sumping and fit it up before then. Anyone any idea how long it takes to do the job Tom Link to comment Share on other sites More sharing options...
Anthony Posted June 26, 2002 Share Posted June 26, 2002 Hi Tom, I have fitted a dry sump to my X-flow and Roger kindly supplied the parts ( as well as building the engine ). The conversion of the footwell is straight forward and both the plate upon which the tank sits (once foot well is shortened ) and the panel to cap-off your footwell are available from Tony/Darren at Caterham. The foot well panels come off very easily and you just need to drill out the rivets, put the new panel in and rivet ( along with silicone sealent ) As Roger advises you can then consider the lubrication "done". I have left the oil-cooeler in the circuit, but fitted a thermostatic by pass. On a track day the cooler does get used. Any queries on the footwell give me a call/mail Best regards Link to comment Share on other sites More sharing options...
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