philbey Posted March 1, 2009 Report Posted March 1, 2009 Guys, I took my 5K for a burn yesterday and it got too hot. I got the radiator cleaned out (about 30 percent blocked) and today it still overheated, although it took longer and a much more energetic drive to do so. I've front mounted a davies craig thermo. I'm getting a lot of "blowback", lots of air bouncing off the radiator and pushing forwards. Yes, before you ask the fan is running in the correct direction. Has anyone ever seen a shroud on the front of a rad? I don't like the idea because you lose a lot of open road airflow, but in this case it will definitely improve the fans effectiveness. Any other ideas on how to get the temp down? Quote
Jason Posted March 1, 2009 Report Posted March 1, 2009 (edited) Try venting the engine bay space better, has it got an undertray or a front splitter? You can have all the frontal pressure in the world but if it carnt get any were you know... Edited March 1, 2009 by Jason Quote
philthy30 Posted March 1, 2009 Report Posted March 1, 2009 iv never been a fan of front mounted fans they seem to block too much airflow. I would personally mount the fan on the other side and make sure its turned off when ur driving on the open road and turned on around town Quote
ke20rolla Posted March 1, 2009 Report Posted March 1, 2009 (edited) I run a worked 5k motor in my ke20 and that sits about half way on the temp guage. I am also running a davies craig thermo fan, but mounted on the inside of the radiator, and I have the original fan shroud attached and lower stone tray aswell, which helps direct the airflow to the motor. :dance: I run my thermo through a toggle switch, and I only turn it on when driving slowly or stopped at traffic lights. :dance: On the open road you don't need it. When it's on, the temp drops quite a bit under the halfway line. Check your thermostat and waterpump and are you running any coolant? Also is it using any water, as you may have a headgasket gone. Cheers, Mark. :hmm: Edited March 1, 2009 by ke20rolla Quote
KEI069 Posted March 1, 2009 Report Posted March 1, 2009 Id be checking the thermostat to make sure its opening all the way and check the opening temp, mid to high 80C should work fine. When the engine is hot leave the car running and see if both the top and bottom radiator hoses are both really hot to touch. If not you may have a water flow problem. Hope this helps Quote
Jason KE30 Posted March 1, 2009 Report Posted March 1, 2009 You could try a bonnet scoop :dance: Quote
kangaroosa Posted March 1, 2009 Report Posted March 1, 2009 I used to run a 3 row radiator and front mounted 10" davies craig fan on my 5K. I had it running through a thermatic switch. Temp never got over half even when giving it a hard time. The best setup is to use the standard fan and shroud. It will work much better than an unshrouded and front mounted thermo fan. Quote
SLO-030 Posted March 1, 2009 Report Posted March 1, 2009 In Toms ke16 theres no room to mount a thermo behind the radiator as it would be hitting the water pump etc. Quote
Felix Posted March 2, 2009 Report Posted March 2, 2009 My ke16 had a front mounted thermo fan when I got it. It tended to run on the hot side. I removed it and fitted a plastic engine driven fan, the car ran cooler afterwards. Fitting a cooler thermostat, and higher psi radiator cap also helps. How's the mixtures and timing? If it is running lean or has excessive timing it will run hotter than it should. Quote
philbey Posted March 2, 2009 Author Report Posted March 2, 2009 Try venting the engine bay space better, has it got an undertray or a front splitter? You can have all the frontal pressure in the world but if it carnt get any were you know... Not sure that's necessary quite yet, when I noticed the "blowback" the bonnet was open. Cheers for the suggestion though, maybe a drift style bonnet would look good on the wags! iv never been a fan of front mounted fans they seem to block too much airflow. I would personally mount the fan on the other side and make sure its turned off when ur driving on the open road and turned on around town I don't agree with the theory of the fan itself blocking flow, It's an urban myth because the fan assembly blocks the flow regardless of which side its on, just like Jasons suggestion. But, the idea of shrouding a front fan doesn't sit nice with me as that really stops flow. I used to run a 3 row radiator and front mounted 10" davies craig fan on my 5K. I had it running through a thermatic switch. Temp never got over half even when giving it a hard time. The best setup is to use the standard fan and shroud. It will work much better than an unshrouded and front mounted thermo fan. KE30 radiators are quite a bit bigger as well last I looked, about 70mm wider? I have had a complete bullshit time finding a good fan to fit my water pump, it's a pump for a real early KE10 fan and none of the later plastic units come close to fitting. I might just bite the bullet and buy a later model waterpump if this continues. My ke16 had a front mounted thermo fan when I got it. It tended to run on the hot side. I removed it and fitted a plastic engine driven fan, the car ran cooler afterwards. Fitting a cooler thermostat, and higher psi radiator cap also helps. How's the mixtures and timing? If it is running lean or has excessive timing it will run hotter than it should. After a bit more thought and another test drive I reckon you're probably on the money Felix. Timing is likely to be too advanced, set at 12 degrees on idle with a stock dizzy. I did run 98 octane to try offset this, but I did forget that a lean mixture will cause it to run hot. I'll pull the plugs out for a look see. Jetting on these dells was set for a worked 3K, although it runs nice the whole reason it was going to the Dyno was to ascertain how good the setup was! Apologies to all you early posters, I should have made it clear that it's a fresh built motor. Brand new waterpump, brand new thermo, acid dipped block. I'm 100% there's no engine internal concerns like blown headgaskets (especially with 200PSI cylinder pressures!) as I've spent some time building the motor from scratch. I got a price on a 3 row core, 370 bucks, so I'm not keen on that option just yet. First step, back off the timing and up the mix. Second, I'll modify my rad support to let me pull it forward about 12mm. This may let me fit the Thermo behind with a shroud on it. It'll be damn tight though..... Failing that I'll get the recore. It was running warm when I drove it medium throttle. Once I really started flexing, thats when I pushed it to boil, which makes me suspect mix/timing even more.... Quote
Felix Posted March 2, 2009 Report Posted March 2, 2009 You need a simple o2 meter setup. A heated 4 wire narrowband o2 sensor with a silicon chip fuel mixture display unit is an awesome tool for tuning carbed motors. The setup in the pics below cost me about $100 4-5 years ago. That included second hand o2 sensor, big nut (o2 sensor screws into) I ground to fit the pipe nicely, the FMD kit, and for some guy to drill the exhaust and weld the nut on. Quote
philbey Posted March 3, 2009 Author Report Posted March 3, 2009 I was going to buy myself a wideband setup from Innovate before I started the build but never got round to it. I mentioned a basic narrowband setup to my mate a while ago, just for a crude indicator, but he shut down that "nah narrowband is shit, wont tell you anything". In hindsight I should have got a fitting welded to the headers while they were sitting collecting dust! Quote
coln72 Posted March 3, 2009 Report Posted March 3, 2009 When I had a front mounted fan on my ke35, I made up a piece of alloy to fit between the radiator and the grill to help keep the airflow going through the radiator. Quote
Felix Posted March 4, 2009 Report Posted March 4, 2009 I've been thinking about this. I think your biggest problem would be the advance curve if you are running 11:1 comp with 200psi cranking pressures. Unfortunately compression is another one of those things you can get too carried away with and lose power and performance (just like with big cams and carbs). Check out the scans below. Quote
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