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Hello all. I have a Waiex with the 2180 Aerovee. Purchased 3 years ago and personally flown about 50 hours in that time. The previous owner rebuilt the engine just prior to me buying it. It took almost a year for me to get it into the air and when I did I started noticing about 30 minutes into the flight the oil Temps would start to rise to over 200 degrees and could not come down with adjusting the power. . The previous owner installed a second oil sump, relocated the oil cooler to near the firewall and installed the aeroconversions air oil separator and external oil filter. All mounted on the firewall.

After several attempts to increase air flow to the oil cooler mounted ver far back under the cowling I decided to return the set up as close to the stock bottom mount oil cooler as I could. I even added a larger 19 row oil cooler vs the stock 12 row.

The question I have is currently the oil cooler, separator and filter are routed oil from an EMPI oil cooler delete adapter on the top of the engine where a top mount oil cooler goes. After hours of testing I am of the assumption that those ports do not have enough pressure or flow to move the oil through several feet of oil lines, the cooler and the filter. I believe replacing the aeroconversions blockoff plate with a plate that has oil line attachment points and routing them directly to the oil cooler could solve this problem. Looking for other possible solutions. I have been told in person to check my oil Pressure relief valve and oil Pressure control valve and ensure the aren't sticking.

Oil Pressure is steady at idle with 30 to 40 Psi. When at flight at 2200 rpm its around 50psi and at WOT around 60psi.

Oil temps in the traffic pattern this week were sporatic and could change from 170 to 220 degrees in a matter of seconds. CHTs and EGTs are all within limits and monitored by an MGL EFIS.

I have ordered a new temp sender as i suspect it may be faulty. The sender is mounted on the lower left side of the engine sump as you sit in the cockpit.

Hi 429TB,
I've been going through my own oil cooler issues for a top mounted setup:
viewtopic.php?f=7&t=7279

There are two factors in play, I think. Air flow through the cooler and oil flow through the cooler.

Your pressures are good. Have you popped out and polished your front plunger? If it is stuck in the bottom of the bore then oil will not go through the cooler.

The stock Sonex oil pump for a remote cooler will send 100% of flow through the cooler:
https://www.sonexaircraft.com/eshop/car ... g=Oil+pump

My sender is in the same spot. It does not change readings very rapidly.

Thanks for the quick reply Bryan.

I will check both plungers/pistons in the check and pressure valves.

Do you see any issues with swapping back to the oil pump cover with two oil lines going directly to the cooler like a revmaster set up ? A fried of mine has the revmaster and sees no issues with oil Pressure fluctuations and high Temps like me.

I would probably keep the filter and air oil separator feeding off the top location and the cooler fed off the oil pump itself.

I also have a new temp sender coming just in case.

Thanks again.

The one thing to beware of with the oil pump I listed is the cold start. Below 50F or so, maybe higher, you can get a big oil pressure spike on startup. I blew out my oil filter twice. I have since removed the filter and gone back to a conventional pump and used a Gene Berg 239 pressure relief oil pump cover. Before I did this, I needed to preheat to avoid blowouts. Your oil cooler would be subject to the same cold start pressures.

Check out the last 5 pages or so of this thread:
viewtopic.php?f=7&t=4030

Thanks for the information.

I think I'll try checking the valves first. Then resort to changing the pump and oil lines if that doesn't fix it. The interesting thing is the temp fluctuations... I flew 2 patterns a few days ago. The first pattern saw a steady climb in temp to 177. On final approach, 70mph indicated it climbed to 210. On climb out on the touch n go it went to 175 then back to 220 on the down wind. I didn't like the fluctuations so I landed, taxied about a quarter mile and it went from 220 to 230 then down to 200 by the time I got to the hangar. Very odd to me. What's your thoughts there ?

That's a good approach I think. You can pop out the plungers with only a little oil loss. I found my Harbor Freight 1/2" center punch was a snug fit in the bore of the plunger. Good for removing them, and with a piece of tape over it I was able to chuck it up in the drill press to polish with scotchbrite. Any 1/2 metal rod would do.

429TB wrote:What's your thoughts there ?

I would be checking the wiring. My sensor is an RTD, so the resistance changes with temperature. If you have a bad connection that could give fast resistance changes. The oil has a lot of inertia with respect to changing temperature, so I doubt it is actually changing that fast.

Edit: I also had to run a dedicated sensor ground from the RTD to my Alpha MFD, else my temps would change with electrical load.

Awesome info, thank you. Is your oil Pressure wire shielded in anyway gong to the temp sensor ?

429TB wrote:Awesome info, thank you. Is your oil Pressure wire shielded in anyway gong to the temp sensor ?

I think I used twisted shielded wire to the sensor because I had it. I think from the rear of the engine back it is single conductor. I'll have check, but it won't be until at least the weekend.

No worries. No rush. Thanks again for the help.