Dave The running temperature of 95 to 97 on the road seems rather high to me. I would expect it to be around 85 to 90 with an 88 Deg thermostat fitted. I think the cap on the expansion tank is the most likely culprit, but also be aware of the head gasket issues on Rover V8s, there can be a gas leak from cylinder to coolant without any effect on the oil. Also check the temp gauge readings if you can , they are notoriously inaccurate.
There is another "fix" that I have heard used , go for the lowest temperature thermostat you can (75 Deg?) , this will open earlier so the running temperature should be lower and therefore there is more margin before it starts to climb in traffic. The downside of this can be that the engine run too cool and the oil will not attain full operating temperature. The optimum coolant operating temperature for a Rover V8 is 85 Deg C , the later cat equipped cars are run hotter to keep the emissions down. Regards Andy >________________________________ > From: Dave Ager <[email protected]> >To: mogtalk2 <[email protected]> >Sent: Tuesday, 17 July 2012, 22:24 >Subject: Re: [mogtalk2] Plus eight water pump. Technical > > > > >On 17/07/12 21:07, Andy Garlick wrote: > >Dave >>Before going down such a route consider some (debatably) easier options: >> >> >>1 Is the car chipped?YES Optimax, This will richen the mixture slightly and >>help it run cooler. Is the air filter clean?YES Are you sure it is allowing >>the engine to breathe sufficiently? Try a K & N type? Fitted Are you sure >>there are no air leaks allowing the engine to lean off? Will Check >> >>2 Is the alloy radiator larger than the original , or the same size? My >>Mulfab one is deeper by several cms. Techniques Larger >> >>3 Are you sure you don't have any air locks in the cooling sytem? Reasonably >>sure, on the road engine nicely stable at 95-97 C >> >>4 Have you changed the expansion tank cap recently, they can age and allow >>the water to boil at a lower temperature.No but see previous >> >>5 Have you backflushed the system recently , crud in the bottom of the rad >>can affect water flows a lot. Backflushed no, Rad fitted 18months annual >>change of coolant with pre rinse through >> >>6 Is the number plate or anything else impeding the air flow into the >>radiator core? No I am paranoid about anything in front of the grill, no >>badge bar even >> >>7 Are you positive that you don't have any head gasket issues? Checked 8 >>years ago, no issue on the road, just in traffic, but perhaps will check. >>However oil always clear as new when changed. No sign of oil in coolant. >> >Thanks Andy >Problem only occurs when stationary in traffic or slow moving. The radiator is clear and the Spal fan works OK. >As above engine runs at a steady 95-97 when on the move except on very hot days e.g. LeMans 2010 air temp 104F+ >Regards >Dave > > >> >> >> >> >>>________________________________ >>> From: Dave Ager <[email protected]> >>>To: mogtalk2 <[email protected]> >>>Sent: Tuesday, 17 July 2012, 20:43 >>>Subject: [mogtalk2] Plus eight water pump. Technical >>> >>>Hi All. >>>My plus eight has the normal problem of getting hot when stationary. >>>I have opened the rear of the bonnet 40mm and fitted an aluminium rad. >>>Still have a slight issue. >>>Before fitting an oil cooler a guy at LeMans suggested fitting a smaller pulley to the water pump to draw more water through the system. >>>With a standard 97 3.9 hotwire I believe I may have room on the pump to try this, engine doesn't rev as high as a worked 4.6. >>> >>>However before I start machining a billet I would like to check the pump characteristics to ensure I don't end up with cavitation in the pump. >>>Currently toying with a 10-15 % speed increase. >>> >>>Now the point . Can anyone provide a spec for the water pump, preferably with characteristic curves. >>> >>>Thanks in advance. >>>Dave >>>97 plus 8 >>> >>> >>> >>> >>>------------------------------------------- >>>View posts on The Mail Archive >>>http://www.mail-archive.com/[email protected]/ >>>[http://www.mail-archive.com/[email protected]/] >>> >>>Modify Your Subscription: https://www.listbox.com/member/?&; >>>Powered by Listbox: http://www.listbox.com >>> >>> >>> >>View posts on The Mail Archive >>http://www.mail-archive.com/[email protected]/ >>Modify Your Subscription > > >View posts on The Mail Archive >http://www.mail-archive.com/[email protected]/ >Modify Your Subscription > > ------------------------------------------- View posts on The Mail Archive http://www.mail-archive.com/[email protected]/ [http://www.mail-archive.com/[email protected]/] Modify Your Subscription: https://www.listbox.com/member/?member_id=22459785&id_secret=22459785-4a39ddf8 Powered by Listbox: http://www.listbox.com
