| Author | Message | ||
     Robert G. Tompkins New member Username: Drbob Post Number: 1 Registered: 09-2009 |
Dear All, My problem is that I have an Express 2000 Auriga and the oil temperature gauge is reading extremely hot. This means that I must step climb to reach altitude and cannot lean the mixture. The fuel burn is terrible and I cannot climb very high. I was supposed to ferry the aircraft over to Europe last week but my Ferry Pilot (and myself) was extremely concerned about the high oil temperature. My mechanic will see if the gauge is faulty. Otherwise, we were wondering if anyone else was having similar problems with the Express and how they fixed it. | ||
| Eric Holmberg New member Username: Erich Post Number: 123 Registered: 05-2002 |
Cooling seems to be a problem with most experimental aircraft initially and most aircraft have custom baffles that make the cooling system design unique, so I'm sure you will get a variety of helpful posts to this question. To diagnose the problem, it may be helpful to know if you have temperature sensors on each cylinder and if so, if individual cylinders are running hot or all of them? If they aren't running excessively hot and your oil temp is still high, then either the oil cooler isn't getting enough airflow or the oil thermostat in the engine is defective / not installed correctly. Most cooling problems seem to be caused by too small of an air outlet versus too small of an air inlet, so try not to fall into the trap of enlarging the air inlets if you determine that the cause is too little airflow. Keep us posted and photos of your cooling system are always appreciated for others to learn from. -Eric | ||
| Robert G. Tompkins New member Username: Drbob Post Number: 2 Registered: 09-2009 |
Thanks Eric, I will have my mechanic put together a dossier regarding this problem and will keep everyone informed. So far, the cylinder temperatures do not seem to be correlated to the high oil temperature. We are leaning to increasing the exiting air through a larger cowl flap. | ||
| Al Kittleson New member Username: Al38kit Post Number: 37 Registered: 07-2007 |
Have you given much consideration to putting it in a box and shipping it? If you are still in the stage of getting temperatures under control, it doesn't seem that an overwater ferry should be even close to what should be on the near agenda, not to mention what the weather can be like this time of year...(I just flew back from Africa this morning, and the North Atlantic is far worse.) How much time is there on the airplane/engine combo? I bought a flying CT from someone in CA a couple of years ago and was not happy with the overall workmanship and flying qualities...I flew it twice in CA and then showed several weeks later with a trailer and hauled it home...that decision probably saved my life. Just something to think about. | ||
| Robert G. Tompkins New member Username: Drbob Post Number: 3 Registered: 09-2009 |
The airplane was built with the highest quality of workmanship. It won the 1995 Oshkosh award as best built experimental. I have personally taken it apart and it is incredibly well built. It has 140 hours on a new motor, propeller and airframe. Sending it by ship is an option but I want to first give it a couple of long x-country trips in the US before I go across the pond. This will only happen in the late spring as we have missed the window of opportunity. | ||
| Eric Holmberg New member Username: Erich Post Number: 124 Registered: 05-2002 |
Since your cylinder temps are not high, it sounds like there is adequate airflow for cooling and the issue is more with the oil cooler. The oil cooler has a higher resistance to airflow, so if there is a chance for air to get around it, it will. Double check that the seal between the top of engine engine baffling and the cowling is tight. An easy check to see if your oil cooler has proper oil flow (this would rule out an air bubble in the cooler or a bad oil thermostat) would be to put a temperature sensor in the cooling fins and make sure that the temperature is within a few degrees of the oil temperature. If you don't have anything else, you could probably use an electronic oven thermometer that has a remote temperature probe. There are even wireless ones that would eliminate having to run something through the firewall. -Eric | ||
| Glen Farley New member Username: Glen_farley Post Number: 8 Registered: 08-2006 |
We had the same issue with our IO-360. We installed a larger oil cooler and the ducting assembly from an RV-10, with 4 inch SCAT tube running off the right rear engine baffling. The cooler is attached to the engine mount. We also installed cooling louvers on both sides of the lower cowling and increased the outlet area. Our oil temps dropped from 225F+ to about 190F with these modifications. | ||
| Robert G. Tompkins New member Username: Drbob Post Number: 4 Registered: 09-2009 |
Thanks Glen, I will pass this along to my mechanic. Hopefully, this should fix the problem. Robert | ||
| Chaz King New member Username: Chazking Post Number: 16 Registered: 01-2005 |
I replaced a Niagara (13 row) oil cooler with a Stewart Warner (13 row) .. my oil temps dropped from 195 - 205 to 170 - 175 .. SW is more expensive, but the cooling is superior! | ||
| Robert G. Tompkins New member Username: Drbob Post Number: 5 Registered: 09-2009 |
Thanks, Chaz, we will look into it. Robert | ||
| Reinhard Metz New member Username: Reinhard_metz Post Number: 91 Registered: 03-2003 |
I have the 11 row version with the solid tanks, and also see 170ish temps max. I would highly recommend getting a solid tank version, as I had one with the welded row ends rupture a weld once and lost all my oil in a few seconds, luckily while taxiing...Local A/P recommended the solid tanks. Check out: http://www.chiefaircraft.com/airsec/Aircraft/OilSystem/OilCoolers.html Reinhard Metz | ||
| Robert G. Tompkins New member Username: Drbob Post Number: 6 Registered: 09-2009 |
Vielen Dank, Reinhard | ||
| Robert G. Tompkins New member Username: Drbob Post Number: 11 Registered: 09-2009 |
Dear All, I just returned from the US where I test flew my express. Again, I had a problem with the oil temperature when climbing (up to 245°). When I leveled off the temperature dropped back down to about 210°. We do have the Stewart Warner (13 row) oil cooler so that is not the problem. The baffling also seems to be properly installed. My mechanic feels that there is simply not enough air getting in. Has anyone successfully reduced the oil temperature problem by cutting (or increasing)air vents in the cowling? If so where should these be located. Does anyone have pictures of how these should be located and how large they should be? I would appreciate any input, many thanks Robert | ||
| Jim Ward New member Username: Jehward Post Number: 66 Registered: 02-2000 |
One thing that I have not seen mentioned in the posts is adjusting the vernatherm. This can be related to your high oil temp. The vernatherm on the engine can be adjusted, and if it does not open at the proper time, can drive your temps up. | ||
| Jim Oyler New member Username: Midniteoyl Post Number: 127 Registered: 07-2003 |
Little more info: http://www.sacskyranch.com/eng18.htm | ||
| Al Kittleson New member Username: Al38kit Post Number: 38 Registered: 07-2007 |
It may do some good to post some pics of the installation...this is a common engine and usually not that big a deal to cool...If it is indeed an airflow thing, the problem will probably be fixed by changing the differential across the cooler, rather than just modifying the cowling...pics would help... I have this engine on my Mustang II. The cooler is mounted on the FW aft of the #3 jug. I have a very short 5" Scat tube running to it, taking air from the aft baffle. Even in the TX heat, I never see temps over 210...cruise temps are like 180-90... I would consider getting an airspeed indicator and using it to check the differential across your cooler...at least then you would have a baseline for your proposed changes. If you don't have some sort of cowl flap, start there with your experimenting. Pics? | ||
| Michael Farley New member Username: Mikefarley Post Number: 21 Registered: 11-2006 |
One good source of information is reading Vans RV forums. Try this link: http://www.vansairforce.com/community/showthread.php?t=42890&highlight=high+oil+ temp There's a lot of good information in there. There's a few cowling modifications people have tried, along with a bunch of other neat ideas. Best of luck! I hope you're able to fix your issue. | ||
| Al Kittleson New member Username: Al38kit Post Number: 39 Registered: 07-2007 |
I hate to state the obvious, but if you have not removed the sensor and tested it's accuracy, you may want to do that...temps in excess of 240F on a existing installation seem rare to me...how many hours has this accumulated with this problem...? | ||
| Shawn kelley New member Username: Skelley Post Number: 30 Registered: 01-2004 |
I have a IO 540C4B5 on my S-90. I have the oil cooler attached to the left rear baffle by cylinder #6 angle at about 30 degree down. I had started out with high oil temps at around 220 on a hot CA day 100f. Then I found a little know find in the NACA data log on cooling air. First and for most is that the exit air area must be a least 1.89 sizes larger then the total amount of inlet air. well after some measuring and foam work on the lower cowl my temps drop to 175 to 180 on the hottest days. Also you just can't just have a hole in the bottom you need to make a reverse scope so that the air is also pulled out of the cowling. My lower cowling is 4" lower then the bottom of the fuselage. And away remeber the Keep it simple. This my all be just a bad senors. If you need pics there are some of My and Jim Wards in the form. Hope all is well Shawn |