Hybrid_From_Hell Posted March 31, 2011 Share Posted March 31, 2011 Yes I know its similar to the other thread, which I am still trying to get a definative answer re thermostats, but this is different. Can we all agree that to drop the overall heat of an engine an oil cooler of the right type and stylee etc will have a dramatic effect, and assist the rad in dumping heat ? If so then hurrah and I am now asking for thoughts around oil coolers The 5.2 V8 has a remote filter, which is plumbed into the timing cover which JED Modifies, so the world (oil cooler wise) is me oyster etc. What are the most efficient oil coolers vs size / costs etc, is a thermostat needed for a cooler ? best place(s) to mount, if I shoved a cooler in the back with a dedicated fan(s) would a crank driven pump be man enough to control flow, as with the extar tubing the oil volume would also be increaded ? And any other thoughts. Nige Quote Link to comment Share on other sites More sharing options...
q-rover Posted March 31, 2011 Share Posted March 31, 2011 Take your pick here or a trip to a scrappy may turn something up. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 31, 2011 Share Posted March 31, 2011 Yes to a thermostat, but no, personally I wouldn't run it all the way to the back, especially as you are running 20w50 oil, it's unnecessary strain on the pump if you ask me. A nice big one where the rad used to be would be ideal (assuming you are moving the rad to the back). Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted March 31, 2011 Author Share Posted March 31, 2011 Take your pick here or a trip to a scrappy may turn something up. Erm, just to mention that fitting a second hand ex scrappy oil cooler is not often a good idea, as will most likely contain carbon sludge and debris, next to impossible to clean out, on any engine a bad plan if engine is in good nick on my new rebuilt unit t'would beabsolute madness Nige Quote Link to comment Share on other sites More sharing options...
Davedef90 Posted March 31, 2011 Share Posted March 31, 2011 May not be a good idea to fit a second hand unit but a look at the scrappys will let you see what is on the market. A quick blitz round with a tape and then off to the auto factors to order a new one. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 31, 2011 Share Posted March 31, 2011 Nige - I'd have thought a soak in your parts washer tank of lost souls should be enough to shift anything Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted March 31, 2011 Share Posted March 31, 2011 washer tank of lost souls So he's given up on Land Rovering and turned to fixing shoes now has he? Quote Link to comment Share on other sites More sharing options...
Daan Posted March 31, 2011 Share Posted March 31, 2011 Can we all agree that to drop the overall heat of an engine an oil cooler of the right type and stylee etc will have a dramatic effect, and assist the rad in dumping heat ? I dont think it is going to make a blinding bit of difference if I am honest. Maybe if you have piston cooling, it might just help, but if your radiator is too small, an oil cooler will do 2 tenths of very little in my experience. I can only think that if you have a plumbed in water-oil cooler ( like a TDI has) it might improve things, but by very little. Even in this case, I would not disconnect it, since the cooler has the added effect to heat up the oil on startup. My 2p worth anyway. Daan Quote Link to comment Share on other sites More sharing options...
pitmole Posted March 31, 2011 Share Posted March 31, 2011 Daan is bang on there,given that you want to run in the plop and keep a nice expensive motor alive, then spend the time and money on fitting a nice big rad with lots of overcapacity, give it good ducted airflow and lots of fan so it has the airflow to stay cool, maybe, fit an oil to water heat exchanger and oil stat so the oil warms nicely as well as stays cool, and then, as long as your rad has overcapacity, you can fit a stat to run it at any temp you want. Nicked this, but it simply shows where your fuel energy is going, and that the radiator has to be in it's way, as powerful as your engine! Energy Losses (Heat Balance) Only a part of the energy supplied to the engine is transformed into useful work whereas the rest is either wasted or utilized for heating purposes. The main part of the unutilized heat goes to exhaust gases and to the cooling system. In order to draw a heat balance chart for an engine, tests should be conducted to give the following information. (i) Energy supplied to an engine which is known from the heating value of the fuel consumed. (ii) Heat converted to useful work. {Hi) Heat carried away by cooling water. (iv) Heat carried away by exhaust gases. (v) Heat unaccounted for (radiation etc.) It is expected that the heat balance results of CI engine must differ from that of petrol engine due to much higher compression and expansion ratios in the former. The higher compression ratio results in lower exhaust gas temperature and also lower flame temperature that in turn causes lower heat loss to the cylinder walls in CI engines. The utilization of the fuel’s heat energy is also higher in CI engines because of its higher compression ratio. Although the actual value of heat utilization is dependent upon a number of factors like compression ratio, engine load, fuel injection quantity, timing etc. some average figures for heat Spark Ignition Engine Heat converted to useful work (i.p.) 25 to 32% Heat carried away by cooling water 33 to 30% Heat carried away by exhaust gases 35 to 28% Heat/noise unaccounted for 7 to 10% Total (= Energy supplied) 100% Quote Link to comment Share on other sites More sharing options...
tacr2man Posted March 31, 2011 Share Posted March 31, 2011 Oil coolers are very effective, thats why usually they are not that big , (see VW engines ) MOCAL do a very good range have a look on ebay just put in oil cooler . They are best fitted with a stat, so that engine gets up to temp before you start cooling it (another mocal option). HTSH Quote Link to comment Share on other sites More sharing options...
zoltan Posted March 31, 2011 Share Posted March 31, 2011 Maybe an overlooked point but oil coolers cool the oil and keep it in the right temperature range where it will do its job of lubrication. I don't know how many people have oil temperature gauges fitted or have any idea what their oil temperature is? Keeping it cool is as important as warming it up. Another <like> for oil coolers! Quote Link to comment Share on other sites More sharing options...
Tom A Posted March 31, 2011 Share Posted March 31, 2011 Nige, oil is for lubrication; water is for cooling - its specific heat capacity wins every time. If you've got a correctly designed cooling system, the only thing an oil cooler really does is create additional opportunities to rapidly lose engine oil and destroy an engine! You might need to consider one for the poor transmission that's got to handle this engine though..... Quote Link to comment Share on other sites More sharing options...
zim Posted April 1, 2011 Share Posted April 1, 2011 Yes I know its similar to the other thread, which I am still trying to get a definative answer re thermostats, but this is different. Can we all agree that to drop the overall heat of an engine an oil cooler of the right type and stylee etc will have a dramatic effect, and assist the rad in dumping heat ? Nige Sorry Nige, but i don't agree with this. The flow rate of the oil compared to water is nothing. I run a thermostat with my oil cooler. G Quote Link to comment Share on other sites More sharing options...
B reg 90 Posted April 1, 2011 Share Posted April 1, 2011 My view is that water is for maintaining a constant engine block temperature and oil is primarily for lubrication, but we also use it to maintain a constant temperature in smaller components such as bearings. Calling either system a 'cooling system' is misleading in my opinion as it implies 'the cooler the better'. Sticking with the water system: It is there to maintain an constant and even temperature through out the engine so that: 1/. Components don't get to hot and melt, bend, change properties, etc. 2/. Warm enough that the oil heats up and is not to viscous, but not hot enough that the oil carbonizes and degrades 2/. Even/temperature through engine so that thermal growth is unform and clearances between components are as the designer intended Oil system - Lubricates. However to do this it needs to be at the right viscosity. This is temperature dependant. Therefore we want it to get up to temp as quickly as possible, then keep it there by removing the appropriate amount of heat. The interactions between the two systems are complex and both systems can't be maintained at the appropriate temperatures by the other. Therefore you need a thermostat and cooler of appropriate size on each system. The water system removes the majority of the combustion heat. The oil system removes some conbustion heat and the friction heat from the bearings, cam, etc. One thing that I have noticed on bigger V8's in 90's is that people tend to fit big radiators and fans so that when the rad is 1/2 blocked the system can still keep the engine cool. The fan system then cycle's on and off quite quickly. In my mind in this situation the thermostat opens. The massive rad and fan over cools the water in the radiator which goes into the engine in a 'cold' (it's relative) temperature subjecting it to a thermal shock until it gets to the outlet from the engine and cools the thermostat and hence closing it again. Constant temperature changes/shocks such as this are not good for machinery/engines and will reduce life span/reliabilty. Variable speed fans or twin fan set ups where one comes on before the other seem a good idea to limit the teperature cycling. Adrian Quote Link to comment Share on other sites More sharing options...
SteveRK Posted April 1, 2011 Share Posted April 1, 2011 My 2 pennies worth (as I'm no way experienced in his area)is that the source of the heat is the top of the cylinder/head area where there is no oil flow to speak of so unless you can increase the surface area of the cooling chambers in contact with the heat source you might look at increasing the surface area of the external engine area by way of aluminium fins, thinner walled rocker covers with fins etc. along with a couple of small supplementary cooling fans and rear facing funnel on both sides of the bonnet above each cylinder head. Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted April 1, 2011 Share Posted April 1, 2011 LR themselves decided an oil cooler was necessary, it was optional on the 3.5 and standard on the 3.9. Given that you already have "extra" pipework in the remote filter I wouldn't suggest having the oil coler too far away, the extra drag of long pipes won't help the oil circulate and it moves much faster than the water in your rad. OIl needs to be in a quite narrow temperature band to work properly, an engineer at Dunton once told me "anything below 130degrees and it's too cold", it needs to be hot enough to thin out and to "dry out" any condensation. As said most mechanical parts are specc'ed to fit properly at running temprature and not when cold. The Ali V8 warms up quite quickly and it made sense to use an oil to water heat exchanger in the "cold" end of the radiator. Firstly I'd ask why your new engine needs any more oil cooling than standard? or is it not possible to keep the original radiator? I fitted a Kenlowe to my auto box, they are just as good for oil and it might be worth a chat with their application engineers (they aren't salesmen BTW) I found them very helpful. I'd think a thermostat would be a very good idea, your engine wil of course fair better if the oil is as close to optimum temperature most if not all the time. Have you also considered a bypass oil filter system whilst you are at it? Noy seen your other post yet BTW Quote Link to comment Share on other sites More sharing options...
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