Proliters now have 2 overheating EG33 engines (plus 3 interstate that I have spoken to). If anyone knows any very smart subaru experts can they please let me know so I can contact them. There has to be a remedy! A free carton of grog goes to whoever solves my problem:)...and hit up Gary Simpson for one too! Maybe this crossover pipe from a WRC car might jog peoples memory of some mods that can be done.
I dont run a recovery bottle, and never run one on any of my buggies, but I am in the process of fitting one! I dont see the need anyway, as the recovery bottle only stores expanded water excess while engine is hot, and then returns coolant to the radiator as the engine cools when NOT running. My radiator is full before each heat, and as the engine warms up excess water escapes, but the radiator is still full, so I dont see the recovery bottle to be an advantage. Or is there some other reason to run one?
Dont know if this is any help,but when u were sitting on the start line on sunday morning,u were dropping some sort of liquid near the engine onto the ground ,looked like coolant.
thanks cobra, that was just the excess coolant out the overflow as said above. A radiator will always find its own level (before overflow tanks were invented anyway)
Steve, I have sent off a few emails to a few different companies, etc to see if they can help, know of a fix, etc. I will let you know what they come back with (if anything).
I then returns coolant to the radiator as the engine cools when NOT running.
Certainly that is the conventional wisdom. However with a highly efficient cooling system it can draw water in when the engine is running.Can you fit a pressure/vacuum guage to the radiator and monitor what happens when the fan switches on at idle?I had a quick look at your car @ Milbrodale, looked like it could use a better fan setup.
Thanks everyone, Sorry toyotapower, If you suggested a Nissan you might have got the grog! Trekka, I have also emailed everyone I can think of, and joined heaps of forums, the modified cooling pipe and maybe an oil cooler are probably the best responses so far. I run an operable 16psi radiator cap, and I probably could run better fans, but a good cooling system shouldnt rely on the fans. (b.t.w. Buzzard, why didnt you into yourself at milbrodale, I would still pick on your hondas there too!) Blurr, Greg Campbell is still fitting his EG33 engine, should be at Mildura...he has a mod for his system that I hav'nt tried yet, waiting to see what happens. Also, Vern Crawford from kadco has the same problem, if anyone wants to contact him, he will pass info to me!
I got one email back from a guy who does a lot of Subaru engines. I have sent him some more information but basically he said that he has not been aware of any particular problems with this engine in relation to overheating. He did mention that the most common cause of over heating with Subaru engines is poor bleeding of the system creating an air lock, but I know you have spent a lot of time trying to ensure that your problem is not caused by this. This problem was also more prevalent in engines when they were installed in a normal car with hather hoses, etc hooked up.
If possible put the car on a chassis dyno and get an infra red temp gun and check a few temperatures such as water into radiater and water out of radiater to see if the radiater is efficient enough. Where is the temp sensors located. Is the ecu seeing the same temps as the gauge and is the ecu going into protection mode or are you just seeing high temps on the gauge.
Have used an infra red guage, but not on the dyno. Radiator seems efficient (90deg in-70deg out) All temps from infra red, temp sensor, and ecu temp sensors all match. I have now turned off the ecu warning cut (set at 120 deg), but the temp guage is definitely accurate. Temp sensors located in what i beleive to be the hottest part of the engine (block outlet) which is the factory position. What do people think would be the best location for temp sensors, should we measure the inlet of the engine,(cold side of the radiator)?
Steve, this may sound crazy but have you considered that your test figures, (I assume that they were during stationary testing) are going to climb during a hard run & I guess that the temp' difference isn't going to change much & I doubt that the engine temp is going to stay low with a high radiator outlet (water pump inlet) temp, so is it worth going backwards (as nothing has worked yet) & place a restrictor at maybe the radiator bottom pipe to slow DOWN the coolant flow, it may make the radiator more efficient, don't forget that the more efficient you have made your outlets, the fluid speed throughout the system will be equal, ie; the faster it comes out the faster it must go in & the faster it must go through the radiator, there must be a time when the radiator can't keep up. Do all the others having the same problem use straight water? Coolant bottles all say 'anti-boil' as well as 'anti-freeze' after all. Maybe theres merit in running coolant. Basic suggestions I know but havn't you watched enough Scooby Doo on TV to know that there must be a logical explanation? Just in case, I still drink Coke.
I have decided to rebuild my engine (check for headgasket problems), modify crossover pipe as above, try a thermostat again, (or possibly one in the top hose), add an overflow bottle, and re-dyno with particular attention to fuel/ignition curves! I did read in a Dirtsports cooling system article that the higher the coolant flow the better, but the yanks have been wrong before! The article read-- WATER-FLOW RATE IS VERY IMPORTANT AND CONTRARY TO OLD SCHOOL THINKING, THE HIGHER THE FLOW RATE, THE BETTER THE COOLING. FLOW RATE IS REGULATED BYTHE SIZE AND SPEED OF THE PUMP, RESTRICTIONS IN THE ENGINE WATER PASSAGES, RADIATOR SIZE AND PLUMBING. HIGH FLOW RATES DO TWO THINGS: ENSURE GOOD PRESSURE IN THE COMBUSTION CHAMBER AREA OF THE CYLINDER HEADS AND RAISE THE VELOCITY OF WATER FLOWING THROUGH THE RADIATOR TUBES. THE HIGHER THE VELOCITY THROUGH THE TUBES, THE MORE TURBULANCE IN THAT TUBE, WHICH EQUATES TO INCREASED HEAT REJECTION. GOOD WATERPUMPS WILL FLOW UP TO 100GPM UNRESTRICTED. WITH RESTRICTIONS FOUND IN THE COOLING SYSTEM, YOUR PUMP SHOULD BE CAPABLE OF AT LEAST 50GPM. This article was written by C & R Racing. Thanks everyone for their help, If the above doesnt work...then you are all invited to my funeral:)
So if someone makes a suggestion that works they get a case and get drunk... and if it doesnt work, you suicide and we ALL go to the wake and we all get drunk.... just checking my facts here! haha!
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You guys may be interested in a simple fix for the EG33 to solve the cooling issue, it involves the thermostat cover which any fabricator can make and seems to have a 100% success rate in solving the issue.
http://diyracecar.com/cooling
-- Edited by diyracecar on Tuesday 23rd of October 2012 09:03:46 PM
Thanks for that, I was actually involved quite heavily with Tony in all the mods we did. the thermostat housing is definately a good fix, but mine still overheated, we believe from cavitation still as I had an auto gearbox, which meant the poor engine was revving hard constantly. The mod definately fixes road/rally cars and manual gearbox cars though! My fix was to get away from the faulty designed subaru and go Nissan!
Coolant: the faster the better as long as you aren't getting cavitation. It's the law (of physics)! Yes with slower flow you will get a lower radiator outlet temperature but it's irrelevant, its the temperature coming out of the engine that is the control point. Large radius bends, large diameter pipes. Run a thermostat that closes off the bypass as it opens, we dont run heaters so you really need to think about your bypass flow, dont just thoughtlessly cap off the heater pipes without looking at what is going on. If you dont have a bypass closing thermostat and you use lots of tight radius bling aeroquip fittings and really long small diameter pipes a greater proportion of your coolant flow is going to take the easy way through the bypass. Consider restricting your factory bypass. Make sure all your steam vents go to a low pressure part of the system. I made a venturi in the top hose to actually suck the steam out from the high points above the hot spots in the head. You may be able to do a test to see where your pump cavitates, simulate an open thermostat, apply your cap pressure with comprerssed air and a regulator and free-rev it with a couple of sensitive pressure gauges across the motor, watch the pressure differential climb then flatline or drop off with revs. there's your cavitation point, less restriction in the system will raise that point. so will additional pressure, because cavitaTION IS THE FORMATION OF A VACUUM (-14.7 PSI compared to ambient pressure) in parts of the pump. By piling more pressure on top of it with a heavier cap you move the cavitation point higher in the rev range. Make sense? low restriction pipes reduces the pressure differential across the pump.
Dont forget airflow, it's half the problem. I haven't seen your car but you dont want to let air spill over the sides of the radiator. Get onto youtube and watch the dust swirling in the low pressure area behind the radiators in some cars and you can see they have airflow issues as the dust is flowing toward the centre of the radiator. Instead of a massive angled core you are better off with a thicker vertical core, forcing the air to make a Z turn isnt doing you any favours. You can get proper angled cores, they arent cheap. If you must angle the core you need to duct it fore and aft, you dont want 50% of your air going through 10% of your radiator especially if your radiator outlets are in the other end of the radiator. Horizontal louvres in the intake duct which finish within 1/4 inch of the radiator core will help stop the air piling into the bottom 1/3rd of the core. I haven't seen anyone with an angled radiator do this. But if you visualise the airrflow going onto your wedge shaped box it's pretty obvious.
Some people need to be beaten over the head with their own intercoolers. About 1/3 of the setups I've seen are atrocious.
I'm not an expert but I've been looking into this very closely, I was making around 300% of the factory horsepower through a largely unmodified engine and I managed to keep it cool except for when it car stopped after a section it boiled, even with a massive engine driven fan. The new system is going to be working even harder so I'm doing everythign I can think of to keep it cool.
Good luck with your problem, I'd be interested to see how you go.
PS: Coopers Pale.
-- Edited by Patrol842 on Friday 26th of October 2012 10:01:26 AM
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Thanks for the reply mate, but I think you miss understand what cavitation is. It's simply the formation and subsequent collapse or implosion of vapor bubbles in a pump. It occurs when the absolute pressure on the liquid falls below the liquids vapor pressure. The definition and a subsequent formula's to determine cavitation have nothing to do with 0 PSI absolute. They take into account required suction energy and available suction energy. When the required energy is greater than the suction energy - the pump will cavitate. There are many good engineering books that go into this in detail as it's quite a complex field.
I had a good chat with Steve and he mentioned his buggy only started overheating about 300 kms into one of those amazing endurance events you guys do but was fine for short course events - this was after installing the bigger thermostat cover as per Tony's advice and proved to see major improvements. What I put my circuit car through is nothing like the stress of what you guys do so it's a little harder to compare and learn from each other.
But anyway after chatting with Steve and Tony it would seem the only thing missing from Steve's NA buggy EG33 and what the turbo EJ engine has is the header tank. The header tank is designed to get the hot turbo return water and steam pockets and condense it all back to liquid. It then has a direct line to the pump inlet (suction). The "cap" is located on this header tank. Obviously being on the low pressure side (suction side) of the pump the pressure here would be less than on the top of the radiator - therefore less water seepage over time. Tony found in the Simpson desert that after driving all day in his SVX (EG33) it would get upset after about 10 hrs of driving and overheat and this is simply because his cap is on the high pressure side and allowed seepage but didn't allow the water to easily re-enter the system. He is now moving it to the low pressure side so we expect to have this issue sorted for the long endurance type stuff. I'll post up how he goes.
Also this is my radiator for interest sake - it's fking massive haha - found in the big Ford F350's:
