My Cyl. No.6 runs about 270 deg during cruise. Can go down almost to 250 at certain phases of flight. Others are Aprox 65 deg. warmer except No. 1 which I would like to have cooler.

Cyl.6 is the one up front on the left side, has anyone put an aluminum plate up to say half the cyl. head height to increse its Temp. and how did it affect temps to No.4 and 2?

Just did a 185 520 with same problem worked on both side. Did them like my 180k with 520 that has airforms pressure baffles . Cylinders are with 30 degrees. Look on there web site as to what u need to do

Yes putting an aluminium plate part way up works good. Use some qluminium tape and work it up a bit by bit until you are happy with the temps, then fabricate out of aluminium. Easy way to get it right without having to mess around with your fabbed plate.

Another factor is that the balance tube between cylinder banks on the front of the engine can cause the EGTs to fall very low on the forward two cylinders in colder weather. It is a common modification to insulate that tube. Here are two different scenarios that I have observed:





There is still a pretty good delta, but at least they are all above 300F in warmer conditions.

I put vertical baffles from a 1959 172 on my O-300 in my 1955 170B and they solved my front cold cylinder problem right away. The front 2 no longer run 75F colder than the rest.

Should have done this years ago.








Before the vertical baffles were installed:

I actually have the opposite problem on my 520. I can't get my rear 2 cylinders to warm up. The rest run at a nice temp, but the rear 2 run cool. Any ideas? Here's a pic of my temps.

Thx for the good Info. and ideas.


A-1
Very seldom do I fly 520 and 550 Skywagons but on the C-206 what I get to see is No.1 and 2 Cyl´s. to have the highest CHT´s.
Just like my 180 with O-470.

[email protected] wrote:Thx for the good Info. and ideas.


A-1
Very seldom do I fly 520 and 550 Skywagons but on the C-206 what I get to see is No.1 and 2 Cyl´s. to have the highest CHT´s.
Just like my 180 with O-470.

Ok, mine is a 206. I'll start my own thread so I don't derail yours.
Thanks v

No problem with me...

Case solved.

Cyl 2-4-6 now sometimes even just 10 Deg. Diff.

Oil cooler plate also raised temps to get 180 at cruise.

A1Skinner wrote:Yes putting an aluminium plate part way up works good. Use some qluminium tape and work it up a bit by bit until you are happy with the temps, then fabricate out of aluminium. Easy way to get it right without having to mess around with your fabbed plate.

That's a great idea. I had my right front (O-360) running cold, it has no vertical part, while the left front has a 1" vertical across both the head and barrel. I fabricated an aluminium part for the head only and that has helped, (270 up to 300 - the other three are 330/340s), but Im going to try the barrel as well now. Wish I had thought of the tape.

[email protected] wrote:Case solved.

Cyl 2-4-6 now sometimes even just 10 Deg. Diff.

Oil cooler plate also raised temps to get 180 at cruise.

Great job. Looks good, works good. Success.