Stuart Faulds Posted May 12, 2003 Share Posted May 12, 2003 As above for a K-Series - anyone know the part no (Rover, QH or whatever)? I've seen GTS1102 mentioned, but Rover assure me that's an 88c item. Stuart Link to comment Share on other sites More sharing options...
V7 SLR Posted May 12, 2003 Share Posted May 12, 2003 Hmm, my GTS1102 is definitely a 78 degree item (pretty sure it's not a 76 jobbie). You can tell when it opens up and the Spa water temp gauge is pretty accurate. It was off a diesel Rover of some description. Then again, the thermostat is one side of the engine and the temp sender the other. BUT this would only mean the thermostat opening up even earlier... nope, I'm cinvinced it's a 78 degree item. Bought it from Halfords. Genuine Rover part for 2/3rds of the price from a Rover dealer. Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Edited by - V7 SLR on 12 May 2003 14:55:20 Link to comment Share on other sites More sharing options...
Steve-B Posted May 12, 2003 Share Posted May 12, 2003 definitely 76-78 as V7 says.....the parts counter guys will get it confused with the exact *next one on the list* so they need to be mroe careful....as i've got one in my car now and it does what it says.. Steve 210Bhp Sinister Version-VHPD here Link to comment Share on other sites More sharing options...
Stuart Faulds Posted May 12, 2003 Author Share Posted May 12, 2003 Cheers for that, I'll have another go. Stuart Link to comment Share on other sites More sharing options...
PeterS Posted May 12, 2003 Share Posted May 12, 2003 Please excuse me if this is a dumb question. If the thermostat opens at 78 degrees, and the temperature sender is on the "hot" side of the engine, what temperature do you expect to see on your guage once the engine is up to normal? Having recently replaced the thermostat it is reading rather hotter than I expected on the guage. Link to comment Share on other sites More sharing options...
Jason Plato Posted May 12, 2003 Share Posted May 12, 2003 The opening temp of the thermostat is marked on the actual body of the thermostat . 1102 = 78 C dave Link to comment Share on other sites More sharing options...
V7 SLR Posted May 12, 2003 Share Posted May 12, 2003 Peter, I'm going to have a go at this one... (is this a test?). The temperature gradient across a K head should be fairly minimal. At least that's the desirable "state". If there is a large temperature gradient then you run the risk of the all alloy engine warping. Therefore, the gauge ought to read 78 degrees when the thermostat opens. OK, in practice it may read slightly above that, but I doubt it is much. Based upon my newly installed Spa gauges I can say that the temperature when thrashing around country lanes, sitting at 100mph on motorways and stationary in traffic remains between high 60's and low 80's. The only time it went into high 80's was when being thrashed on the RR. As the thermostat is a 78 degree jobbie and I've a large radiator, I'd say I'm quite pleased with that. The only wierd thing is the oil temp which only got above the water temp on the RR. My laminova definitely helps to bring the oil temp up quicker but the oil temp was consistently below the water temp except on the RR. The oil temp was never more than 12 degrees from the water temp though... which was nice. Haven't tried it on a track yet though. Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
PeterS Posted May 13, 2003 Share Posted May 13, 2003 V7 SLR Thanks for that, and I understood the logic. No, it wasn't a test, just me trying to understand why my temperature which used to read 80 now reads 100 despite new temperature sender, thermostat and radiator. The search continues. Link to comment Share on other sites More sharing options...
Peter Carmichael Posted May 13, 2003 Share Posted May 13, 2003 Nig, have you got a reason why with a 78degree thermostat you have seen running temps of "high 60s"? Genuine question cos I don't have a definitive answer either. Link to comment Share on other sites More sharing options...
V7 SLR Posted May 13, 2003 Share Posted May 13, 2003 Not sure but the dry sump is probably the cause of the oil temp being a good 10 degrees lower than the water temp. The laminova ties the 2 together pretty well so I guess the water temp is being held low by the low oil temp. Remembering that my water temp sender is just after my laminova too... well, it's just after the head outlet. The water temp leaving the head may in fact be higher, but as it's immediately mixed with whatever comes from the laminova (which has been cooled by the lowe temp oil) it might give a lower reading than what's really happening. I ought to see if there's a difference between the water temp at the Spa sender and the ECU sender. They are either side of the head outlet on mine. Just need to calibrate them somehow. If they read the same then this theory is crap. Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
Miraz Posted May 13, 2003 Share Posted May 13, 2003 You've got confused about the direction of flow in the bypass line....the coolant passes through the Laminova on the way down to the thermostat housing.... Link to comment Share on other sites More sharing options...
V7 SLR Posted May 13, 2003 Share Posted May 13, 2003 I think I'm less "confused" than utterly wrong then. I'll have another think about things... I still think the dry sump cooling the oil and the laminova cooling the water has a part to play though. Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
PeterS Posted May 13, 2003 Share Posted May 13, 2003 Let me see if I've got this right. If the water temperature is less than 78 degrees, the thermostat stops the flow and there is no flow through the radiator. The engine should then get hotter. When the water gets above 78 degrees, the radiator is allowed to perform its role of cooling the engine. So I presume that under normal running conditions, one would expect the radiator to be involved, and the water temperature to be a minimum of 78 degrees as it enters the engine. Whilst passing through the engine, the water will get hotter, by an amount which doesn't cause differential stresses, and will have its temperature assessed by the sender as it exits the block. So the guage should read at least 80 degrees(say). The Laminova happens downstream of the temperature sender, so shouldn't have an effect on the exit temperature in normal running. Link to comment Share on other sites More sharing options...
Rob V Posted May 13, 2003 Share Posted May 13, 2003 I have just replaced a faulty thermostat on my R300. It deffinately reads 88 on the bottom of it. I drilled a small (2.5mm) hole in the thermostat tomake it easier to bleed the system when filling. It worked a treat and doesnt seem to affect the running temperature. Link to comment Share on other sites More sharing options...
V7 SLR Posted May 13, 2003 Share Posted May 13, 2003 RobV, we know the standard thermostat is 88 degrees. We're talking about the GTS1102 variety which is a 78 degree variety. PeterS you are assuming a binary condition, which isn't true. The thermostat opens anywhere between zero and fully open depending upon the temperature. It starts to open at 78 degrees, gently mixing cool water from the radiator with hot water from the radiator bypass circuit and passing the resultant 78 degree water into the engine. The hotter the engine gets, the hotter the bypass water gets, the more the thermostat opens allowing a greater percentage of cold water from the radiator to mix with the hot bypass water thus KEEPING the water entering the engine at 78 degrees. The only time the engine should exceed the thermostat temperature is when the thermostat is fully open and the water coming from the radiator is hotter than the thermostat rating. Then you need a bigger radiator. I've got the triple-pass version which appears to be more efficient than strictly necessary. It has enough heat dissipation capacity to dissipate heat from the water system AND the oil system. The laminova dumps heat from the oil system into the water system. The only way "out" is via the radiator which appears to cope well. A bit too well on cool days. Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
PeterS Posted May 13, 2003 Share Posted May 13, 2003 V7 Thanks for the explanation of the radiator by-pass. However, if the water inlet temperature is maintained at 78 degrees, and there is only a hot engine between that inlet and the exit where the temperature is measured (for the guage), then the guage must show at least 80 degrees (say) under normal driving (i.e. not especially hard, or stationary, or on a hot day), and couldn't possibly be less than 78 degrees. The Laminova isn't involved between inlet to the engine and outlet from the engine. Link to comment Share on other sites More sharing options...
fordy Posted May 13, 2003 Share Posted May 13, 2003 I changed my thermostat just recently. I asked for a standard 1.4 K thermostat at the Rover factors and I got an 88°C one. The one I replaced was an 82°C. I checked with Caterham and they told me the 88°C was the correct one. Whats with that? Problem is since that time I've had temps upto 105°C, generally around a 100°C on a blat though. This seems too high and I've been messing about with bleeding the system ever since. Still not sure if its because of the new stat or because I've not got to grips with the bleeding process properly or not. Link to comment Share on other sites More sharing options...
V7 SLR Posted May 13, 2003 Share Posted May 13, 2003 PeterS, you're right, although in practice I think you generate more heat as you work the engine harder, therefore the flow of water through the engine increases, therefore the temperature gradient across the head ought to remain pretty much the same. As you say though, the temperature as measured will never be below that of the operating temperature of the thermostat. What that is in absolute values though I cannot say. Depends upon the accuracy of the thermostat, and accuracy of the gauge, the temp gradient across the head and whether your inlet cycles at all (Elises have exhibited a hysteresis in engine temp owing to the remote location of the radiator). Fordy, I am of the opinion that the 88 degree stat is to allow for better emissions. Caterham appear not to be able to map engines very well (citing the recent and on-going problems with the R300 and R400 models) so this might be the way to generate reasonable emissions readings to compensate for poor mapping. Then again... Anyway, for power, it's better to go lower. There's a few other benefits too, not least in increased component life. To run over 100 can't be a good thing. Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours Link to comment Share on other sites More sharing options...
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