Teebags Posted January 7, 2008 Share Posted January 7, 2008 I'm looking to stick an Oil Pressure gauge on my 4.0 EFI 50th 90 and have a small selection of questions. 1> Electric or Capillary, is there any particular advantage of one over the other? I'm thinking electric is likely to be a lot easier to fit but is there a much advantage in capillary that would make the extra work worthwhile? 2> Looking through a few different companies that sell gauges I see you can get them rated to different pressures. What should the nominal pressure be on a 4.0 efi V8? 3> Fitting the sender unit? Any suggestions on a good spot, or should I look to replace the existing sender with some kind of dual system that can do both the dash light and the gauge? 4> The reason I want to install an Oil Pressure gauge is that my 90 was fettled by Overfinch a few years prior to my buying it. As it's running beyond it's original remit and getting a little long in the tooth (10 years and 80k miles) I'd prefer to keep a closer eye on things rather than reply on just the warning light. Should I also be keeping an eye on Oil Temperature? I've seen a few gauges that combine both Pressure and Temperature, is it worth the extra £30-£40 to display both? Any advice or comments would be appreciated. Quote Link to comment Share on other sites More sharing options...
Jon White Posted January 7, 2008 Share Posted January 7, 2008 Electric. Do you really want hot oil dribbling down the back of your dashboard when the pipe cracks? Been there done that.........it makes a hell of a mess......... v8 will probably not make more than about 60psi at best - more likely less. I'd go for a guage that goes to 80psi. You'll probably find there is a spare blanked off outlet on the oil pump base that you can use. If not replace the existing switch with a dual sender/switch whish i was I've done. VDO do some nice ones. I wouldnt bother with oil temp personally. If you've a reliable coolant temp gauge, and the oil cooler is plumbed in as it should be its not necessary. For gauges I'd recommend the VDO cockpit range. Suppliers wise try http://www.egauges.com - I found them to be alot cheaper than this side of the pond, and were on my doorstep the day after ordering (yes really!). Jon Quote Link to comment Share on other sites More sharing options...
Teebags Posted January 7, 2008 Author Share Posted January 7, 2008 Thanks for the reply Jon. The www.egauges.com website looks excellent and as you say considerably cheaper than any UK suppliers I've seen. Lots of good info there too. Quote Link to comment Share on other sites More sharing options...
Boothy Posted January 7, 2008 Share Posted January 7, 2008 Teebags, A good V8 will usually when reving run at about 40psi, mine hits 60psi when its cold and I overev it a bit, but bearing in mind they are not a high pressure unit and usually high pressure on a V8 will result in leaks all over the place. I would not hesitate but to fit a good quality mechanical gauge, it will only ever tell the truth and will also do it underwater if need be, and the modern plastic pipes rarely fail and if they do tie a bleedin knot in it. Boothy Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted January 7, 2008 Share Posted January 7, 2008 And from the other camp I have a capillary one on mine, I just want to be 100% sure that if I have a reading its correct, ie if there is some electrical fault and it says I have pressure <Gulp>, whereas with capillary if the gugae says yes or no its 99% certain to be correct, but the comment re squirty oil is a valid one ! I have a 0-5 bar, does it for me, nicest ones I have seen (but spendy) are the racetech ones, can't remember what mine is maybe a VDO from memory, didn't wnat a real cheapy one for all the above reasosn There you go, now thats confused you ! Nige Quote Link to comment Share on other sites More sharing options...
Mark90 Posted January 7, 2008 Share Posted January 7, 2008 For the reasons mentioned above I like mechanical guages for water temp and oil pressure. The more trick the engine the more inclined I'd be to use decent quality mechanical guages. Had Racetech mechanical guages in the 90 (water temp, oil pressure, oil temp, gearbox oil temp), oil pressure plumbed in pipe with proper swaged connections and stainless overbraid for added bling. Quote Link to comment Share on other sites More sharing options...
istruggle2gate11 Posted January 7, 2008 Share Posted January 7, 2008 I too prefer the mechanical type, but totally understand the reasoning of electrical senders. I have broken the oil line twice, once through fretting of the pipe through the bulk head (grommit moved) and once by crashing the axle into the pump head (on a hybrid build). I tried the electrical ones, but they do tell lies when water gets involved, in the end, I resorted to always carrying a spare standard pressure switch which could be fitted to blank off the connection if the pipe did split. A good rule of thumb for a V8 is 10psi per 1000rpm, yes they are a volume pump, but any half decent engine will attain 30psi at 3000rpm. Its not unusual to see the RV8 with a tickover pressure of 5psi, the engines do happily run, but it is indicating the begining of the end for the engine, new shells at the very least! Quote Link to comment Share on other sites More sharing options...
Teebags Posted January 7, 2008 Author Share Posted January 7, 2008 Thanks for all the excellent info. The chances of me ever getting round to trying to waterproofing this beast are extremely slim so I've gone down the simpler electrical route. I've gone for an 80psi VDO gauge with a Sender that has additional contacts for a warning light. Cheers Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted January 7, 2008 Share Posted January 7, 2008 In that case......... Consider doing the other mod I have done to mine. Add a buzzer or beeper unit to the oil pressure light, then you get an audible sound (drives Jon W mad so double bonus ( Jon) so that you KNOW that its trying to tell you somethingisn't as it should be ?? An old trick from my racer days, destroyed an engine when the sump was damaged lost oil and pressure and didn't see the light or guage until it was far to late, a diddle diddle diddle noise would have got my attention - or my case when JW says "That Bl**dy thing" Works for me though - this way I have an oil fed guage and an electrical warning sounder Nige Quote Link to comment Share on other sites More sharing options...
Mark90 Posted January 7, 2008 Share Posted January 7, 2008 Buzzer would be bugger all use in my mates racer. With a 4.0 TVR lump just behind our heads and a Milner transfer box howling by our legs you wouldn't hear a buzzer. Without the intercom we can hardly hear each others shouting. Find a set of decent sized warning lights on the center of the dash work well. When it wasn't running properly it would stall under braking (auto box) and we would spot the lights come one even before the engine fully died. Got it down to a fine art, driver slipped it in to neutral as I hit the starter button and we'd hardly loose any speed/time. Quote Link to comment Share on other sites More sharing options...
Jon White Posted January 7, 2008 Share Posted January 7, 2008 Thanks for all the excellent info. The chances of me ever getting round to trying to waterproofing this beast are extremely slim so I've gone down the simpler electrical route. I've gone for an 80psi VDO gauge with a Sender that has additional contacts for a warning light. Cheers Are you sure that sender is the correct thread? I've no idea what a V8 one should be, I'm just a little surprised that it would be metric?? Jon Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted January 7, 2008 Share Posted January 7, 2008 Buzzer would be bugger all use in my mates racer. With a 4.0 TVR lump just behind our heads and a Milner transfer box howling by our legs you wouldn't hear a buzzer. Without the intercom we can hardly hear each others shouting.Find a set of decent sized warning lights on the center of the dash work well. When it wasn't running properly it would stall under braking (auto box) and we would spot the lights come one even before the engine fully died. Got it down to a fine art, driver slipped it in to neutral as I hit the starter button and we'd hardly loose any speed/time. On the racer I have a rear brake light too on the dash Sad thing was after splitting the sump open and losing everything (inc engine nice 5.7 chevy ali heads and loads of special bits..............BANG ) I fitted the guage / buzzer / Big Foff Light to everything since and erm never had the need to say "Oh I am so chuffed to have done that" Nige Quote Link to comment Share on other sites More sharing options...
Mark90 Posted January 7, 2008 Share Posted January 7, 2008 Isn't that always the way Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted January 7, 2008 Share Posted January 7, 2008 O Yep, .....isn't it ever the case Quote Link to comment Share on other sites More sharing options...
Teebags Posted January 7, 2008 Author Share Posted January 7, 2008 I've also been shopping for a "Mudpod" today in which I'm planning to stick a duplicate light cluster from a standard Defender dash. I've a motolita steering wheel which obscures a few lights already so wanted duplicate it all anyway. I'm just a little surprised that it would be metric?? Yeh, I doubt it's metric too, but I'll stick a converter on it all being well. Quote Link to comment Share on other sites More sharing options...
Jon White Posted January 8, 2008 Share Posted January 8, 2008 I've also been shopping for a "Mudpod" today in which I'm planning to stick a duplicate light cluster from a standard Defender dash. I've a motolita steering wheel which obscures a few lights already so wanted duplicate it all anyway.Yeh, I doubt it's metric too, but I'll stick a converter on it all being well. In which case go for the 1/8" threaded senders as they're alot cheaper! Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted January 8, 2008 Share Posted January 8, 2008 On the pre-serp engines (pre 1994) the sender thread is 1/2UNF ……….. I can’t see that Rover would change this for the later engines…………… Up until recently I always used capillary gauges due to the fact that electrical gauges costing reasonable money were always of dubious accuracy. Another reason was that 270degree electrical gauges were very expensive. However, all that has changed considerably over the last 5 years or so and electrical gauges from reputable manufacturers are as good, if not better, that the capillary equivalents……. I use autometer ……. http://www.autometer.com/cat_gaugeseries.aspx The exact models being from the ultra lite metric range.... http://www.autometer.com/cat_gaugeop.aspx?sid=11 As the gauges are of USA origin the senders are standard 1/8npt ………….. gauges and 1/2UHF-1/8NPT adaptors can be got from here ………. http://www.realsteel.co.uk/ On a good RV8 the oil pressure should be 2.1 to 2.8 bar (30 – 40psi) @ 2400rpm with the oil temp at 80C………… idle should be no lower than 20psi Mine at idle (750rpm) is 30psi and 50 – 55 psi @ 2500rpm with the oil temp @80C HTH Ian Quote Link to comment Share on other sites More sharing options...
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