balanced cylinder temps?

hydroguy2 · Post by **hydroguy2** » Sun Dec 12, 2010 6:56 pm

Who's on first? what? I don't know...

that's how I'm feeling these days. Kind of confused now that I'm flying. Busy trying to stay ahead of the airplane and can't really think about other stuff while flying. Hard to even write stuff down.

anyway, my CHT's have about a 35*spread. #1 is the coolest , 2 is the warmest. With only 4hrs on the engine should I even worry about trying to balance anything yet?

and if/when I work on it, Do I add a blocking plate on #1 first or ???.

finally is 178* oil temp high enough or should I blank some of the cooler?

cjensen · Post by **cjensen** » Sun Dec 12, 2010 7:59 pm

I wouldn't do anything yet about the CHT's. They will all drop a bit when the rings seat, and 35 degrees is really pretty good. I know you are FI, and I am carb'd, but I have 50-60 degree splits, and from the Lycoming Key Reprint article, that is normal.

Oil temp is good...much lower and you'll want to place a restrictor of sorts on the cooler. I will definitely be doing this as a result of my flight last Friday...

hydroguy2 · Post by **hydroguy2** » Sun Dec 12, 2010 8:09 pm

thanks Chad, I have some downtime this week, so thought it would be a good time to attend to some squawks.

I hope I'm cool enough next summer.

Lot's of little stuff to do now. But at least the engine seems to be purring nicely.

cjensen · Post by **cjensen** » Sun Dec 12, 2010 8:15 pm

Deal with the summer temps...in the summer. No worries now my friend!

lancef53 · Post by **lancef53** » Sun Dec 12, 2010 9:07 pm

My CHT's are like that, #1 is about 25-30 degrees lower than the rest. What would be the best way to fix that?

cjensen · Post by **cjensen** » Sun Dec 12, 2010 9:15 pm

I don't see it as a problem that needs to be fixed, especially since you would be making it hotter to get it closer than the others. If it's something that bothers you, you can put an air dam at the front of #1 to block some cooling air. It'll increase cooling drag slightly tho...

lancef53 · Post by **lancef53** » Sun Dec 12, 2010 9:31 pm

I didn't worry about it at all, but was curious. It seems like anything you do to #1 is also gonna affect the one behind it, and the tail chasing begins

cjensen · Post by **cjensen** » Sun Dec 12, 2010 9:46 pm

You got that right!!

Post by **bullojm1** » Mon Dec 13, 2010 8:49 am

Brian,

With only a few hours on your RV, I wouldn't worry too much about your CHT spread, especially if it is only 35 degrees, and you CHT's in cruise are under 380 degrees (and not exceeding 400 degrees in takeoff). I was able to get my CHT's within a few degrees of each other by total luck. Something easy for you to fix your #1 being the coolest is to add some metal tape to the front of it to block some of the air hitting it. Start small. I only needed 1/2" across 1/2 of the cylinder to make a significant difference.

As far as Oil temps go, I believe I read in a Lycoming SB that the temps should be 180 degrees or higher, in order to make sure any water in the system evaporates. You are pretty much right there, so I wouldn't worry about it.