MADMALC Posted June 25, 2008 Share Posted June 25, 2008 Just lost my second sump on a cats eye, thank goodness for gold pumps and dry sumps. How heigh off the ground does the lowest point on the sump pan have to be to survive? (just higher than any object you run over will not surfice) If anyone who has not lost a sump can do a quick measure for me I would be obliged. Any helpful data would be good. Go on then, any silly stuf as well. Thanks. S7MAD Link to comment Share on other sites More sharing options...
mav Posted June 25, 2008 Share Posted June 25, 2008 minimum is when the wishbones are parallel to the ground, and even then that may be too low. Link to comment Share on other sites More sharing options...
rgrigsby Posted June 25, 2008 Share Posted June 25, 2008 On the road I wouldn't go lower than 75mm and tbh higher if you can, when I went to Spain last year I wound the dampers up so I had almost 100mm of clearance. The handling was "interesting" but I didn't hit the ground 😳 Rob G www.SpeedySeven.com Link to comment Share on other sites More sharing options...
Rowland Cook Posted June 25, 2008 Share Posted June 25, 2008 I lost a VX ali sump (£250 worth - ouch!) on a cats eye and started a small claim against the road company. However I wasn't able to find any regulation that specified a mnimum ground clearance. When I contacted Caterham they stated that 70mm was as low as they'd recommend and as I was running at 45mm at the time everything fell through. It was a BUMMER !! (well.... very nearly). I'd set the hight to clear a lump hammer lying flat, on the basis I'd see and steer to the side of anything bigger. I hadn't counted on a worn bend where the ouffside lorry ruts were the same width as the front wheels and the wear had crowned the centre and pushed up the old cast metal cats eye proud of the surface. Didn't see it coming as I overtook a slow lorry. Ya live and learn ! Regards Rowland Link to comment Share on other sites More sharing options...
Area Representative Richard Price Posted June 25, 2008 Area Representative Share Posted June 25, 2008 minimum is when the wishbones are parallel to the ground, and even then that may be too low. With 175/55-13 CR500's parallel wishbones is a little to low for comfort ❗ Link to comment Share on other sites More sharing options...
Malcolm Posted June 25, 2008 Share Posted June 25, 2008 I've seen a few threads now about sumps hitting cats eyes. My sump is pretty low but never considered a cats eye was high enough to cause a problem, well not unless the rest of the cat was still attached. 😬 Link to comment Share on other sites More sharing options...
Ray Pearce Posted June 25, 2008 Share Posted June 25, 2008 When I am setting the height I use the measuring tools to hand. I set it so that I can roll a beer can under the sump but not a wine bottle. I just measured the diameter of the two and find that I am setting it to between 60 and 70 mm. Is this too low? I have had a few minor scrapes but it seems to cope with most speed humps that I encounter. Ray Link to comment Share on other sites More sharing options...
Johnty Lyons Posted June 25, 2008 Share Posted June 25, 2008 The danger with Cats eyes is real especially on a road with crest if you nose dive over a crest or brake[cancelled overtaking manoveur] then on suspension dip you WILL contact a cats eye Parallel wishbones are absolute minimum but if on low profile [below60] 13s you may well still be in diffs And DONT come to Ireland ever. 😶🌫️ jj N.I. L7C AR 🙆🏻 Membership No.3927. 240BHP 1900cc K Series 40th Anniversary Link to comment Share on other sites More sharing options...
paul jacobs Posted June 25, 2008 Share Posted June 25, 2008 It's all very well talking about the height under the sump and the stiffness of the front suspension, but nowhere has anyone ever said why they are running their engines so low - note I said engines not cars! I know all the guff about keeping the CoG as low as possible, but for road use can anyone really tell the difference if the sump is 45cms or 75cms, unless of course, bouncing off catseyes counts? 😔Go on, there's a challenge Paul J. Loud pipes save lives, but quiet ones save your hearing. Link to comment Share on other sites More sharing options...
Wrightpayne Posted June 25, 2008 Share Posted June 25, 2008 something to do with getting it under the bonnet 😬 Link to comment Share on other sites More sharing options...
alicat Posted June 25, 2008 Share Posted June 25, 2008 Paul I think I would know if my sump was at 45cm or 75cm 😬 😬 😬 I reckon at those heights I would stand a chance in an offroad trial Alicat Link to comment Share on other sites More sharing options...
MADMALC Posted June 26, 2008 Author Share Posted June 26, 2008 Thanks for the help, I particularly like the hammer and beer can approach so I will go for that as a start. A dry sump is now £258.50 plus post and packing, so thick end of £270, ouch, ouch and more ouches. S7MAD Link to comment Share on other sites More sharing options...
rgrigsby Posted June 26, 2008 Share Posted June 26, 2008 Paul in my case the engine has to be that low to get it to fit under the bonnet, even with a modified cam cover. Rob G www.SpeedySeven.com Link to comment Share on other sites More sharing options...
paul jacobs Posted June 26, 2008 Share Posted June 26, 2008 OK, good point, but then why use such low profile tyres? What I'm trying to get at is that for give and take road use, it's very difficult to tell the difference between small details, but it can save a lot of money and hassle to put up with something which is not 'the ultimate' configuration. Paul J. Loud pipes save lives, but quiet ones save your hearing. Link to comment Share on other sites More sharing options...
Simon.Rogers1 Posted June 26, 2008 Share Posted June 26, 2008 I have hit a Cats eye on a cambered road and lost a sump. Again as others have done drove home with good pressure and a hole I could fit my little finger into 4 years ago now. So along with a new sump I fitted 19mm ali spacers under the rubber engine mounts. I still run 65mm under the sump but the wishbones run down from wheel to car 😔 Saying that its rarely on the road these days. Link to comment Share on other sites More sharing options...
Mickrick Posted June 28, 2008 Share Posted June 28, 2008 when I went to Spain last year Tell me about it! 😔 here Academics are seldom any use at engineering. One must have a mistrust of theorists. (Keith Duckworth) Link to comment Share on other sites More sharing options...
CageyH Posted June 28, 2008 Share Posted June 28, 2008 I run 13" CR500's, and now have 80mm under the sump. This was another reason to go for the freestyle pushrod set up. I took my sump plug out on a cats eye just before I came across to Fance. Only dead fish go with the flow....! Link to comment Share on other sites More sharing options...
thinfourth Posted June 28, 2008 Share Posted June 28, 2008 Okay are these heights with or without a person aboard? Autotesting in Scotland tires provided by Skip motorsport services (Well we pull them out of skips) Link to comment Share on other sites More sharing options...
CageyH Posted June 28, 2008 Share Posted June 28, 2008 I set mine to 82mm without, on the theory I should havre at least 75mm when I get in. I used to have 50 to 60mm, and only ever had one problem. Only dead fish go with the flow....! Link to comment Share on other sites More sharing options...
thinfourth Posted June 28, 2008 Share Posted June 28, 2008 Well currently sat at 73mmish with my body double sat in the drivers seat (bin full of water) Autotesting in Scotland tires provided by Skip motorsport services (Well we pull them out of skips) Link to comment Share on other sites More sharing options...
Bilbo Posted June 28, 2008 Share Posted June 28, 2008 Well mines set at 65mm with me in the car and the engine just below the front of the bonnet. Thats with a 15mm rake front to back. I also have a 4mm bit of steel brazed to the bottom of the dry sump pan and its slight lt's thinner now at the front. Ok a it more weight but its a good mod 'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬 1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? engineered by Roger King, on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension. Link to comment Share on other sites More sharing options...
6speedmanual Posted June 28, 2008 Share Posted June 28, 2008 Hey Bilbo, what is your BD's dry sump pan made of with its brazed on bit? A harder skid on the bottom of the K's ali alloy trough would be useful but not sure how it could be attached. P 6SpeedManual *tongue*There's no such thing as too much BHP per Ton 😬 Link to comment Share on other sites More sharing options...
thinfourth Posted June 28, 2008 Share Posted June 28, 2008 I was thinking for a K to get it machined completely flat and then use a very good epoxy to glue on a thin piece of metal to act as a sacrificial skid plate. Titanium being of course the most obvious choice Autotesting in Scotland tires provided by Skip motorsport services (Well we pull them out of skips) Link to comment Share on other sites More sharing options...
CageyH Posted June 28, 2008 Share Posted June 28, 2008 Why not a delrin block, which you could replace easily? Only dead fish go with the flow....! Link to comment Share on other sites More sharing options...
6speedmanual Posted June 28, 2008 Share Posted June 28, 2008 I like the skid idea, Thin. The leading edge could be curved up slightly (like a ski)to help the front of the sump ride over and solid vertical ridges (such as the catseyes mentioned in this thread) rather than just impacting them. Questions are: Where d'ya get a strip of titanium? Howdya bend teh front edge? What 'poxy adhesive? Delrin block also interesting idea. I think a plastic block might wear out too fast and therefore have to be thicker than a thin metal skid. This would further reduce clearance. P 6SpeedManual *tongue*There's no such thing as too much BHP per Ton 😬 Link to comment Share on other sites More sharing options...
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