chrisb Posted February 6, 2003 Share Posted February 6, 2003 Tis me again! Having looked at fitting a dry sump, and decided that I need to do a bit more saving up first, is there anything else I can do to reduce oil surge? At present, I only have to stop quick, and the oil pressure drops alarmingly for a moment 😳 Is there likely to be a problem in the sump, or is this rapid drop in pressure normal. Thanks Chris PS It doesn't drop under moderate braking. Link to comment Share on other sites More sharing options...
Chris K Posted February 6, 2003 Share Posted February 6, 2003 The sump in my 84 spec xflow has never shown me any serge (TOUCHES WOOD) and thats with Yoko21s.. OK Im not the fastest out there by some margin but Iv never even seen a flutter on the gauge. Chris minus 10 outside and over a foot of snow.. Link to comment Share on other sites More sharing options...
Anthony Posted February 6, 2003 Share Posted February 6, 2003 Does not sound normal. Assume oil level correct and sender connections/sender all OK. Could it be a relief valve ? Obvious concern is that it does not take long to run a set of bearings... Anthony VX the real way sideways Link to comment Share on other sites More sharing options...
Peter T Posted February 6, 2003 Share Posted February 6, 2003 As Anthony says, worth investigating further. Are you reying on the oil pressure gauge in the car? How do you know that it is accurate? First thing i would do is substitute that gauge with one that is known to be ok! Other than that i have not heard or oil surge to this extreme, unless on a racing track. If all else fails, check in sump by dropping it to see if the oil pick up pipe has been bent or broken or loose, or the strainer is blocked! Power Freak member! Link to comment Share on other sites More sharing options...
chrisb Posted February 6, 2003 Author Share Posted February 6, 2003 Not sure about the accuracy of the guage, but it hasn't given me any reason to beleive it is faulty. When cold, above 2K RPM pressure at 5, during idle this drops to approx 3. When oil is hot, pressure remains 4.75 - 5 on the guage above 4K, 3- 4 down to about 2k, and 2 during tickover. The pressure drops right down if I stop quickly, and then shoots back up. This is what I would expect if the oil pick-up is right at the back, and slopping about like water in an ice cream tub! Chris Link to comment Share on other sites More sharing options...
Peter T Posted February 6, 2003 Share Posted February 6, 2003 Yes, but most Caterhams sumps are fairly well baffled, is it alloy or steel sump? Power Freak member! Link to comment Share on other sites More sharing options...
chrisb Posted February 6, 2003 Author Share Posted February 6, 2003 Not sure what sump is on the car. It does look like it has met with a speed bump or two in a previous life (Large dent in the front leading edge) Link to comment Share on other sites More sharing options...
Graham Perry Posted February 6, 2003 Share Posted February 6, 2003 If the car was made from a kit, it might hve had the engine sourced elsewhere and not have the Caterham sump, which was pretty good for most roadgoing applications Link to comment Share on other sites More sharing options...
chrisb Posted February 6, 2003 Author Share Posted February 6, 2003 The car was built with a new engine. The engine has been to Roger King a couple of times for some major work, and lots of power 😬 (Before I bought it) So I guess it has a Caterham sump. Link to comment Share on other sites More sharing options...
Peter T Posted February 6, 2003 Share Posted February 6, 2003 Pick up pipe is at the back, when you say large dent, how large? 😳 Power Freak member! Edited by - Peter T on 6 Feb 2003 12:43:11 Link to comment Share on other sites More sharing options...
chrisb Posted February 6, 2003 Author Share Posted February 6, 2003 Can't remeber exactly. But I would say a good 1/2" x 3.5" long If pick-up is at the front, I can't see how the pressure drops as I brake surely it would drop as I accelerate hard Link to comment Share on other sites More sharing options...
Peter T Posted February 6, 2003 Share Posted February 6, 2003 Sorry, will engage brain first, pipe is at the back Does your dipstick look like someone has Hacksawed a line on it to indicate the oil level in the sump, if so it is possible that your oil level is far to low! Have you ever measured the amount of oil you put in your car? Power Freak member! Link to comment Share on other sites More sharing options...
chrisb Posted February 6, 2003 Author Share Posted February 6, 2003 Can't say that I've noticed any saw marks in the dipstick. Only had the car since September. Sent it to John Noble motorsport just after I got it. They carried out a major service, and converted the head to unleaded, and assured me it was bolted together properly. Just wanted to know it was right before I started tinkering......... Now I'm learning more and more, and getting more adventurous with a spanner Link to comment Share on other sites More sharing options...
Peter T Posted February 6, 2003 Share Posted February 6, 2003 Good on yer *thumbup* It wont bo long before upgradius grabs yer! 😬 😬 😬 Power Freak member! Link to comment Share on other sites More sharing options...
chrisb Posted February 6, 2003 Author Share Posted February 6, 2003 Too late Infected already Link to comment Share on other sites More sharing options...
Roger King Posted February 6, 2003 Share Posted February 6, 2003 If the sump has taken a few hits, it is possible that the pick up pipe has been partly blocked by the sump itself. There is not a great deal of clearance between the pipe and the bottom of the sump when all is correct, but if the sump is bashed it is not unknown for it to end up touching the pipe. The Caterham wet sump is a little prone to surge, but it is normally OK for road use. What you describe sounds like there is a problem. That said, dry sump is a good investment. Link to comment Share on other sites More sharing options...
chrisb Posted February 6, 2003 Author Share Posted February 6, 2003 OK, so if I go down the route of a dry sump, I'm not sure I would want to fit it myself all seems a little complex for a novice like me. How much should I look to pay to have one fitted? I've also heard rumours that dry sumps offer a little bit more power 😬 - not that I need it or anything..... Link to comment Share on other sites More sharing options...
Peter T Posted February 6, 2003 Share Posted February 6, 2003 Only worth thinking about if you are going to go racing on Track days and like, or your going to uprate the engine, putting a dry sump on a standard engine will not release much power in terms of power to money ratio! ☹️ Power Freak member! Link to comment Share on other sites More sharing options...
chrisb Posted February 6, 2003 Author Share Posted February 6, 2003 Engines already chucking out about 170 bhp (1800 X-Flow) And yes, I do want do track days 😬 Link to comment Share on other sites More sharing options...
DaveMorris Posted February 8, 2003 Share Posted February 8, 2003 Chrisb Don’t know where you are, and what your next moves are but your problems got me to thinking. Thinking – my oil pressure is REALLY low at times and I think my engine may be kn******d. I have a low pressure switch (separate from the pressure gauge) the setting of which was unknown + standard caterham pressure gauge.. SO I checked everything out. Took pressure switch and had it checked vs national traceable standard. Found that it goes off at EXACTLY 400mbar. (i.e. VERY LOW pressure – but there's no damping so this light can come on and go off again without the in-car pressure gauge flickering below 2 bar). Bought and calibrated (again to a National traceable standard) a 0-11bar gauge. This is what I found. (I don’t really know what it says about my engine – possibly someone will tell me – but I do know what it says about the standard fitment gauge) Car gauge (bar) Calibrated Gauge (bar) COLD Tickover (750rpm) 2.9 3.1 2000 rpm 3.1 4.2 3000 rpm 4.5 6.0 4000 rpm * 7.0 ~10.2 HOT ** Tickover 1.5 2.1 (and no surge when throttle blipped) 2000 1.8 2.75 3000 1.9 3.5 4000 2.0 4.25 * don’t normally rev it to 4000 when cold ! ** Fan running after a 5 mile blat and 5 minutes sitting in garage. The standard gauge appears massively damped, and more inaccurate as the engine bay warms up, (WHY ???) and almost a waste of dashboard space. My next step is to buy a ¼” NPT “T” piece and a 2.0bar switch. To compliment the 0.4 bar “oh b****r” switch currently installed. Note – I can get the 0.4 bar switch to activate – heavy breaking, no throttle, right hand bend (the one just before home!!!). If someone wants to comment on these pressures then please do - on Forum or via e-mail. Link to comment Share on other sites More sharing options...
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