[McFly]

I now have 5 hours on my O-360 powered RV-7. On the last flight the CHTs were 25 degrees cooler even though the outside temps were the warmest I have flown it in. I am assuming that I am now over the hump break-in wise.

My CHTs are low on all phases of flight and stabilize at 275, 300, 300 and 300. I am guessing that my homemade plenum is doing its job.

A friend and fellow RV builder thinks I need a dam to bring #1 up to the same temps as the others and that my temps are all too low.

Can CHT?s be to low? A 25 degree separation seems pretty good right out of the box to me. Why is it so critical to get the CHT temps exactly the same? Thanks

 

[Mel]

Your CHTs are not too low. Mine typically run around 340-350. A 25 degree spread is not bad, but I would try a putting a piece 3/4" angle in front of #1. This will bring #1 up a bit and #3 down a bit.

 

[AlexPeterson]

Mixture and mixture distribution will change CHT's by 50 degrees easily in these planes, everything else equal. Be careful making any inferences about which cylinder is "colder" or "warmer" without a thorough study of the relationship between total fuel flow and individual cht's.