Pelico Posted April 1, 2005 Share Posted April 1, 2005 Relaced my sump foam yesterday (which ironically was in perfect nick) with a nice shiny Hellier Baffle plate. The oil pick up pipe fitted back with no problems, the o-ring was ok, there were no blockages in the collector. Just been for a nice 30min blat to check everything out and noticed that the cold and hot oil pressure seems to be about 0.25-0.5 bar lower. (i.e. Hot idle 2.25bar, hot 4000 rpm just over 3.75bar). This is measured with the Caterham VDO type guage. Anyone else noticed this ? Peter Edited by - Pelico on 23 Apr 2005 18:45:46 Link to comment Share on other sites More sharing options...
david nelson Posted April 1, 2005 Share Posted April 1, 2005 I have diffrent oil pressure since putting the baffle in BUT i am not using the same grade oil. I had used 5/50 caterham but now using mob 1 0/40 Have you change oil grade? David Link to comment Share on other sites More sharing options...
Pierre Gillet Posted April 1, 2005 Share Posted April 1, 2005 Exactly the same oil pressure using before and after fitment of the Hellier baffle Motul 300V 5W40, although the new oil is the later formulation. Pierre Edited by - Pierre Gillet on 1 Apr 2005 17:38:36 Link to comment Share on other sites More sharing options...
knowley Posted April 1, 2005 Share Posted April 1, 2005 Under normal driving no, nothing has changed... pressures are exactly the same with the same oil. Link to comment Share on other sites More sharing options...
Pelico Posted April 1, 2005 Author Share Posted April 1, 2005 Same spec of oil, Mobil 1 0w40. I guess I will just keep an eye on it, the pressure does not appear dangerously low for a K with an Apollo + Laminova. Link to comment Share on other sites More sharing options...
Pierre Gillet Posted April 1, 2005 Share Posted April 1, 2005 Yes , I have exactly the same pressures with an apollo and a Laminova , 5W40 oil and the normal Caterham pressure gauge. . Pierre Link to comment Share on other sites More sharing options...
Myles Posted April 1, 2005 Share Posted April 1, 2005 Yep - no drop in general OP - but I took mine round a roundabout or two this evening - hardly definitive testing - and I believe I saw my OP drop from just under 70 psi to 59ish in fairly short-order... More testing is required - I need to set my video-camera up so that I can concentrate on maintaining speed, revs etc. - but it didn't strike me as being wildly reassuring. ☹️ Project Scope-Creep is underway... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Mick Day Posted April 1, 2005 Share Posted April 1, 2005 70 psi is 4.8 bar. 59 psi is 4.07 bar. Isn't that enough ❗ When it comes down to it it's about flow of oil & pressure is just part of the equation. Link to comment Share on other sites More sharing options...
Myles Posted April 1, 2005 Share Posted April 1, 2005 Nope - because the OT wasn't up to normal operating levels (OP normally sits at around 65psi hot - possibly dropping to 60ish)- and any drop around a moderate section of roundabout with the magical Hellier-baffle is a disappointment... Project Scope-Creep is underway... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Nifty Posted April 1, 2005 Share Posted April 1, 2005 I've had 0.5 bar pressure loss from a normal baffle change, using the same grade oil. I think this is a Caterham anomily and it has been suggested it is due to a slight leak on the pickup pipe. I've certainly seen it remedied on someone elses car by applying a little silicon around the O-ring, not that that is necessarily recommended. Keep off the straight and narrow 😬 Link to comment Share on other sites More sharing options...
oldbutnotslow Posted April 1, 2005 Share Posted April 1, 2005 Hi Nifty, Dont let Oily hear the S word in relation to engin internals! Are you going to West Reynham tomorrow? I thought that I may take a drive up to see what the venue is like. Regards Grant Black and stone chip and currently not going ☹️ but waiting to be made better courtesy of Dr. Dave Andrews. - 6 days to go here Link to comment Share on other sites More sharing options...
oldbutnotslow Posted April 1, 2005 Share Posted April 1, 2005 Sorry chaps, I have to say that I am a bit lost here!? How can the simple fact of fitting the baffle affect the Oil Pressure when there was nothing there before? Is the implication that the baffle is actually exacerbating the starvation situation by restricting oil flow to the pickup? Sorry to seem a bit dim here. Grant Black and stone chip and currently not going ☹️ but waiting to be made better courtesy of Dr. Dave Andrews. - 6 days to go here Link to comment Share on other sites More sharing options...
Nifty Posted April 1, 2005 Share Posted April 1, 2005 Grant, Can't make it Working in the morning, playing rugby in the afternoon at Yarmouth ... .....and drinking in the evening 🤔 Keep off the straight and narrow 😬 Link to comment Share on other sites More sharing options...
oldbutnotslow Posted April 1, 2005 Share Posted April 1, 2005 See you on Monday Grant Black and stone chip and currently not going ☹️ but waiting to be made better courtesy of Dr. Dave Andrews. - 6 days to go here Link to comment Share on other sites More sharing options...
oilyhands Posted April 2, 2005 Share Posted April 2, 2005 It's more likely that you have tapped or touched the sender unit for the gauge, they are notoriously unreliable and sensitive, on one particular car I could change the oil pressure reading from 4 bar to 2.5 by just wiggling the connection on the end of the sender... On the issue of dropping oil pressure on a roundabout, and with no intended criticisim of the baffle, but on a point of order, the absolute pressure is relatively unimportant provided it is sensible, but any sudden drop means that the pickup is drawing air as well as oil, aerated/cavitated oil is not good news for bearings and followers. Anyone using silicone inside their engine should stand in the corner with the big hat on.... Oil Link to comment Share on other sites More sharing options...
Nifty Posted April 2, 2005 Share Posted April 2, 2005 It wasn't me and it wasn't my car ....... but it was someone on here 😳 ❗ Keep off the straight and narrow 😬 Link to comment Share on other sites More sharing options...
Pelico Posted April 23, 2005 Author Share Posted April 23, 2005 On Friday took the car on its first trackday since fitting the baffle, and by the afternoon sessions had enough wit to remember to have a look a the Oil Pressure gauge on the tight right-handers. Results are a bit of a worry. On the 180 hairpin at the end of the long straight at Hullavington, with a nice balanced throttle/constant (high) rpm the reading on the gauge fell from 4 (bar? - old Caterham VDO branded gauge) to less than 2 and as low as 1 as I passed the apex cone. Now I know there are lots of potential variables here, including, is the reported pressure anywhere accurate, but I can not help wondering if I have done something wrong fitting the baffle. Dave's test (as described in Low Flying) was very successfull and he would be cornering at much greater 'g' than me, a fairly conservative driver on A021s. Anyone any thoughts, could I have messed up the fitting in some way ? Anyone tried their baffle plate on track yet ? Is such a low momentary pressure at high rpm a cause for panic? I know Oily always reminds us that OP is merely an indicator of what is going on inside the engine ! All the best, Peter Link to comment Share on other sites More sharing options...
Dave McCulloch Posted April 23, 2005 Share Posted April 23, 2005 Peter I have to admit to "holding fire" on ordering a Hellier baffle at the moment, until there's some more feedback. I don't doubt Dave's original findings, but it's slightly worrying that a number of people seem to be finding the same as you. Question is, how much worse (if any?) would it have been without the baffle 🤔. Dave Link to comment Share on other sites More sharing options...
knowley Posted April 23, 2005 Share Posted April 23, 2005 Pelico, you're not alone. I experianced the same thing on a left hander at Croix and all over the place at Keevil. I am planning to drop the sump again, and have a look at what is going on, maybe mine has a problem in the way it was fitted or something? I plan to put new foam back in, mine was in good condition when it was removed (7k+ on CC oil) so am not too worried about it decaying and go to Keevil again and see what happens. Could the problem be that the engine is draining all the oil from in the middle of the baffle whilst you corner and oil isn't getting back in until your on the straight bits again? 7 only day @ Mallory - 06/08/05 R300 Register My R300 Link to comment Share on other sites More sharing options...
Pelico Posted April 23, 2005 Author Share Posted April 23, 2005 Knowley, I feel exactly the same way about dropping the sump to have a look at what is going on. And was considering refitting some foam. Mine was in such perfect condition when it came out (it went in the bin though - I wasn't considering sticking the same one back 😬) Dave, I know you are local to me. If you want to come and have a look-see when I take the sump off again you are welcome to pop round. Thanks for your comments guys. Peter edited for the worst bits of spelling - the rest are left as an exercise for the reader. Edited by - Pelico on 23 Apr 2005 21:07:04 Link to comment Share on other sites More sharing options...
Steve Kirk Posted April 23, 2005 Share Posted April 23, 2005 Not sure what's going on here, this is just a guess really. But if you look under "What it doesn't do..." here, they talk about aeration. If we accept for a moment that aeration is happening in the engine, is it possible that part of the design principle of the foam baffle is that foam assists removal of bubbles from the oil before it gets to the pickup? Something to do with surface area / capillary action I think. It's a principle also used in inkjet cartridges and shock absorbers. If your oil is slightly more aerated now without the foam, this would explain a drop in pressure. Edited by - Steve Kirk on 23 Apr 2005 21:15:46 Link to comment Share on other sites More sharing options...
Myles Posted April 23, 2005 Share Posted April 23, 2005 Urm, are you suggesting that the oil is getting aerated-as-a-moose (OK, mousse) during the course of one corner??? Most of us have Apollo's fitted as well as the Hellier baffle - and I'd doubt (with no proof) that the oil would froth *that* badly aerated, *that* quickly to cause such a drop in OP. My experience has been similar - in a very short - but tight and uphill - left hander, my OP dropped from 60ish psi to just under 30. In no time flat. I also noticed a much less extreme drop in OP on a trackday in a long, sweeping RHander. I'm 100% sure mine is fitted correctly - you really can't balls it up. I really don't want to put foam back in - because that cost me a couple of hundred quid for a rebuild when it dissolved during running-in and knackered my bearings. OK - I've run 18-odd k miles and changed the foam twice without problems before that, but if it is that unpredictable and dangerous, it's not going back in *my* engine. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Edited by - Myles on 23 Apr 2005 23:41:59 Link to comment Share on other sites More sharing options...
Steve Kirk Posted April 23, 2005 Share Posted April 23, 2005 No you're right I wasn't thinking it could happen during just one corner. I was more responding to the opening post's reference to a general drop in oil pressure, rather than the sudden drop during cornering. Wondering if general drop might be due to slight aeration caused by a slight change in oil level on refill, and the absence of foam baffle meaning that aeration not being removed so easily. However, as you say Myles, my theory is probably wrong if an Apollo is also fitted. Just hazarding a guess really - didn't know that these baffles existed until saw this post this evening. I agree with the others above, it's surprising that the Hellier baffle could make difference in pressure, rather than a difference happening due to instrument variation or problem in sealing of pickup pipe. Link to comment Share on other sites More sharing options...
Mick Day Posted April 24, 2005 Share Posted April 24, 2005 Fitted mine a little while ago & OP with Caterham 5W-50 & Apollo is the same as before. I've tried chucking it hard around roundabouts & haven't noticed much movement in my VDO gauge. As mentioned before when I dropped the sump I was surprised to find the foam between the sump & the windage plate with a nice cut-out for the pickup to fit into. The foam was in as-new condition. I don't know how long the foam has been in this position as I've always entrusted my car to a professional service every 2 years with me doing the others. Gary May was the last to do this last June. If OP is a problem I wonder if the solution is to keep the Hellier baffle but put shaped foam fore & aft, so-to-speak, of the baffle. Will check OP at Cadwell on the 3rd. One disconcerting thing though is checking the oil level: without the foam it spits up the dipstick tube making a bit of a mess! Link to comment Share on other sites More sharing options...
Steve Kirk Posted April 24, 2005 Share Posted April 24, 2005 re oil spitting up dipstick tube, I had a XF that used to do that. it also used to chuck oil out the breather by the bucket (via the little separator box on the side of the block). never did sort out why. presume must have been some type of crankcase fume pressure problem. engine was supposed to have been a rebuild so shoudn't have been a blowby problem. hadn't heard of windage back then so maybe that was a contributor (no windage plate). See also the post at the top of this page which talks about how aeration can happen and be prevented generally. This includes priciples of the apollo but also comments on how to reduce aeration. Not sure if these are issues that affect the K, just found it interesting. Link to comment Share on other sites More sharing options...
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