I have a 1971 xy 302 windsor i recently transplanted and dumped the six , It is stock, rebuilt 5000 ks ago, used the old radiator but got it 3 cored, tried running a 16 inch thermo got over three qtrs hot so went back to old fan, fitted shroud and high flow thermostat yesterday but still sits between half and three qtrs hot! Is this normal? Tried going with no thermostat for 2 days and went great always half but mechanic told me NO GO, will end up cooking it! What am i doing wrong? any help would be greatfully appreciated
YES definetly check with mechanical gauge first. it may be fine, does it push loads of water out of overflow? use a 82C/180F thermostat, check temp coming out of motor is holding within 10F of this. check with radiator shop that radiator has correct fins per inch for V8 falcon. use a fan shroud. preferably use 302a/con/351/GTstyle radiator. hope this helps. cheers
Hi, spoke to local radiator shop and the guy(owner) reckons i can run the car without a thermostat I have had a 160 deg thermostat, hi flow thermostat, had the original 6 cyl radiator recored, timing is ok but still runs between half and three qtrs on the temp gauge? He said he had done a trip out west years ago in a fairlane running a clevo and had never had a problem, it's only when your in colder temp that you have a problem! Still unsure yet today it did the job, as soon as i took it out it was between qtr and half
I hear so many conflicting arguements from different mechanics on this but it seems to work here in bris in 30+ deg heat
Has anyone done or heard the same thing or would recommend against this?
ok, this is why you need a thermostat,, and for general street use you really should use 82 degC at the lowest. ,, (71-74degC for straight LPG),, when petrol enters the engine it is in a fairly well misted/ vaporised condition, it then relies on engine heat to complete the vaporisation process, if the thermostat is too cold or removed, the intake track/manifold/ports and cylinder walls will not get to a suitable temp to complete vaporisation completely, this causes small ammounts of fuel to condense on the entry into the engine, causing, the lubricating oil on the bottom of the intake valve guides/stems and the cylinder wall and ring faces to be washed off, this creates extra wear, it does happen slowly but will drastically reduce the service life of your engine, Also the slightly incomplete combustion means you need a richer air fuel mix to achieve smooth running and correct power so you use a little more fuel, the incomplete combustion( as small as it is) will cause the exhaust valve face/ stem to run hotter due to some after combustion occuring in the valve port due any unvaposised/burnt fuel then igniting from the exhaust port heat, this will wear your exhaust valve stem faster and cause valve seat recession over time. Now onto cooling efficiency! the thermostat also alloes the engine to warm up quicker therefore better thermal efficiency is achieved earlier due to the fore mentioned effects on fuel and combustion., it also regulates engine temp to a fairly steady point so that the engine is then tuned correctly for that temp range,( the air/fuel ratio required for smooth running and power delivery is far different in an engine running at 70degC compared to one running at 90degC) keeping the engine at a steady temp means a more accurate tune can be held which means better econony, power and engine life. the thermostat also provides a restriction to water flow which stops the water form passing thru the radiator too quickly, the water needs time in the radiator to dissipate heat into the air flowing over it, if the flow is too fast, the water will not lose enough heat to sustain high engine revs/and or load, so the hot water then just runs back into the motor, so on a fine 25-30 degC day the engine may cope or atleast seem to cope fine but when you start to give it a hard time or get a hotter day, all that water that is not getting cooled enough just goes right back into your engine making it run hotter and you will find it will continue to then get hotter until you stop or the day cools off! there is more but im sick of typing now!!! i hope you now see why designers spent a lot of time designing and putting a thermostat in the system, im sure if it was not needed that car makers of every liquid cooled vehicle out there could of saved billions of bucks over the last 100 years by leaving them out!!!!! i have over 20years experience in the engine reconditioning/mechanical industry for standard and performance engines so i just took 30 min out of my day to give you first hand advice so that you dont need to spend more money with someone like me 100,000km+ sooner than you otherwise would. personally, and every other quality engine builder is the same(ring around), i do not cover warranty on an engine that has had a compromised cooling system. If i did not know what the thermostat really does or if i just did not know how to solve your temp problem, i too may be tempted to just say "shee'll be right mate, mine was the same" and send you on your way. but that is wrong and bad advise that WILL cost you MONEY. not if but when. i hope you get it sorted(befor the first 35+degC day!!! i am willing to give you more advice to help you out. cheers
Thank you craig,
I now know what it does and why, i have had a lot of coolant loss (via overflow) so got the guy to check it and did a test with some die that if i had a blown head gasket it would change colour, not sure the name but you would. The motor was reco'd 5000ks ago and bored out 30thou (do you know what that would make it)? Anyway got the original 6 cyl radiator recored to a 3 row new sender unit, if i havent changed the temp gauge in the car would it be reading wrong? Will install new thermo tommorow would drilling 3 small holes help me?
Thanks for all your advice so far
hi. i hate to say it but a .030" over bore makes it about a 308! t be honest i think the first thing would be to make sure your temp gauge is correct, even if you temporarily fit a mechanical gauge just to be sure what temp it runs at. in all my experience with early falcons the 6cyl radiator, even with a good 3 core is only just good enough for a stock motor. you really need a radiator with more surface area, eg, the air/cond 351/GT radiator. or you can fit the later crossflow radiator if you're not worried about keeping it looking origional. are both the head gaskets on the correct way? you can tell by looking below the front outter head bolt where the head and block meet, if correct you will see a small tag of head gasket protruding out, check this on both sides of the motor. one thing you can do on a windsor is put a restrictor inside the radiator bypass hose, that is the 90deg bent hose that runs from the thermostat housing to the water pump, make a plug that fits inside this hose and drill a 5/16" hole in it , doing this will restrict the ammount of coolant that bypasses the radiator and goes directly back into the block, note, do not completely plug this hose, you need some bypass for when the t/stat is shut. some 289 and 302 heads had a problem with casting flash in the water jacket behind the core plugs in the ends of the heads. if this was not removed under factory program ( there are still some heads with the flash inplace) you will never get it to run at the correct temp unless its winter! you need to remove the core plugs to see if it is there and then remove it if it is. no need to drill holes in the t/stat, all it will do is take longer to warm up, it wont help your cooling, remember you need the restriction of the t/stat to keep the water in the radiator long enough for it to cool. a stock thermostat with no mods flows enough coolant to keep a hi comp 460 with the correct radiator running at the right temp all year round. my ZB with 460 and XY GT/air/cond style 2core radiator ran fine, with a stock 82degC t/stat. XD460 with aircon and power steer ,3core XD radiator, stock 82degC t/stat, fine,. XR 302w with 289heads 10.5:1 comp XYGT radiator stock 89degC t/stat fine, . the problem is not your t/stat. believe me! let me know when you have fitted a mech gauge and let me know what fan, shroud, pulley diameter(water pump and crank) and space between your fan and radiator. dont drill your t/stat!!!!!!!!! cheers, craig.
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