Low oil temps and high CHT temps..

[Cubrath]

I taped up my oil cooler this morning in an attempt raise my oil temps. I ended up taping off about 70% of the cooler to get the oil temp to 200. I think this is a little much because the OAT was about 65 and that might cause me to run hot when the OAT comes up this summer. I will probably back it off the 50%.

I was hoping that taping off the cooler would lower my CHT's but it actually had the opposite effect. Now that my oil is up 30 degrees that raised my CHT's about 15 degrees. The lower oil temp did more for cooling than the increased air flow over the cylinders.

When I put my plenum on I did not seal the lower portion of the plenum to the cooling fins. The manual said to seal to the mating surface. Since the plenum did not touch the fins I did not seal them. I couldn't find any pictures in the manual that showed the lower portion sealed. I wonder if I should run a bead of sealant to force the air through the cylinder fins instead of around them? Not sure how the factory does it. If anyone with a factory cub could check and let me know I would appreciate it.

[TroyBranch]

All of the different engine pics I have seen they only sealed to that lip and not on the underside. I cant see it hurting but I dought it will do much on the bottom. One thing that I always did was put a bead of silicone on top closing the gap between the cylinders. I of course was only thinking silicone after the plenum went on so I did not get it on. I plan to try and rig something up to do this. If forces the air through the fins at the top. Talking to other CC owners, 350 seams to be the norm. Might just need more break in time. Frustrating though.

[kemper28]

All of the different engine pics I have seen they only sealed to that lip and not on the underside. I cant see it hurting but I dought it will do much on the bottom. One thing that I always did was put a bead of silicone on top closing the gap between the cylinders. I of course was only thinking silicone after the plenum went on so I did not get it on. I plan to try and rig something up to do this. If forces the air through the fins at the top. Talking to other CC owners, 350 seams to be the norm. Might just need more break in time. Frustrating though.

I just flew from Utah to Johnson creek. My ex-2 is not useable when it is 80 outside. On the way here it averaged about 45 oat. My cht at 2400 rpm and around 8-9k was 420. Half of my cooler is blocked off and I see 160-165 oil temp. I spent so much time with a bright flashlight sealing my plenum I know it is sealed well. I have seen no temp decrease from 0-80 hours. While flying in Utah the other day I was seeing red line oil and cht had to land and unblock the oil cooler, once I did this I saw 150 oil and 420 cht. I also sit on the ground for 15 min to get my oil to 90 when it was is 45-50 outside. I am burning way too much fuel to keep the chts at 420. I would trade my 340 for a stock 320.

jason

[EVRoosevelt]

On my EX # 56 #3 always ran 25 to 30deg. hotter than the other 3, yesterday I removed both heat muffs and the hose from the cowl to the fwd. muff and the hose to the heater box then went flying #3 was within 7 to 14 deg. of the other 3. Don't know why
EV

[Cubrath]

That might be a factor. You put a lot more heat closer to cylinder #3 probe and #4 probe has the carb heat muff next to it.

Maybe be it needs to be like the good old days where you had no info and you just ran it. I've never replaced a cylinder on the four airplanes I have owned over the years. Ignorance could be bliss!!