Cylinder Four Baffle

[markejackson02]

Been having a really hard time keeping the cylinder 4 temperatures under 400 in normal cruise.  I was changing the oil and looked at the baffle over the #4 cylinder in front of the oil cooler.  I'm sure the baffle is original equipment but it covers most of the cylinder's cooling fins.  Is this the stock part or is it too large?

 

Mark Jackson

N201TK - KAXH

 

 

[Guest]

That is the stock baffle for cylinder 4, others have trimmed it back to improve cooling for the cylinder. You might also consider filling the hole where the ignition wires pass through the rear baffle as well. Any hole which allows air to escape without passing through the cylinder fins should be sealed.

Clarence

[FloridaMan]

I had #4 IRANed last annual. An A&P friend said that he wasn't surprised, given the way it was baffled. 

[jetdriven]

I removed that baffle and I think it cools #4 better. The J oil cooler is so large I have never seen any oil temperature past mid scale green.

[aaronk25]

I didn't pull the cowl for this pic but if you look to the back you can see I bent it up. This lowered CHts by 40-50d for the number 4. Just bend it up so it will stay in position and use some JB weld to secure it to the side of the oil cooler so it doesn't vibrate or wiggle in there. Been running 500 hours this way and it's a much better improvement.

Also behind the front of the lower cowl near the starter get some black silicone and fill every single hole or seem forcing the high pressure air to go though the cylinder find, not around.

Also if your #1 cylinder is running hot I ended up cutting this front baffle down by 7/8". Lowers CHt by 30d.

[wpbarnar]

I am not a J model owner, but the baffle seal in the corner looks suspicious. Can the seal for the rear flex up and seal against the top cowling or is being held down in the corner by the baffle seal on the side? Need to make sure you don't have a gap in that corner.

Bill

[THill182]

For what it's worth and as another root cause: After my annual Cylinder 3 would peek first going from LOP to ROP (while leaning from the Rich side), and ran so hot at altitude and LOP that I had to lean aggressively and run at less than 60% power or so, in my Ovation (310 HP conversion). Long story short, the root cause was that during the annual apparently the (non-numbered I understand) injector nozzles got swapped. When my mechanic put the #3 nozzle into the #2 (the coldest cylinder) and vice versa it all evened out wonderfully again.

 Just wanted to put that out there; I also first looked very carefully over the baffling but nothing seemed leaking...

 

 

[INA201]

I also bent mine and sealed where the ignition wires pass through. My #4 cylinder is now at least 25 degrees cooler than before.

[mooneyflyfast]

I agree with shortening the no. 1 baffle. It went from being the highest cht to the second lowest.  On the no. 4 I bent the baffle up just enough so that it was not resting on the cyl. fins. It now runs the same cht as no. 3..