7ECA, Engine oil temperature too low

C

Cita67

New member
Owner of a Citabria 7ECA 1967, without oil cooler, the oil temperature of the 0-235C1 remains low, 150 degrees F, when the outside temperature
Is around 32 deg F. I wonder if somebody has some tips to increase that temperature. I have a restriction plate for the exit air flow which control cylinder head temp to Around 350 deg F, but i have no way to control the oil temperature!! Is there a kit or some way to keep the oil tank warm during operation?
Take-off RPM is 2600rpm. I normally cruise at 2300rpm, should i cruise at 2450rpm?
I’d like to fly during winter, but I don’t want to damage the engine.

J-P
 
My '70 GCBC is pretty cold blooded too, even with the vernatherm not closing all the way. I have an oil cooler too, but I don't think it is really getting much pressure. I'm at about 150-160 with OAT's in the 50's. As long as your oil pressure isn't too high, what is the problem?
 
I heard That if the oil is not higher than 165 deg F, the condensation in the oil can not evaporate. This in not good for the engine. That why i try to find a solution to protect the engine.
 
I have put duct tape on my oil cooler in the winter for years to keep the oil temp near 180, works fine but I had to remove the top cowl to add or remove tape for different temps.
This year I replaced the Vernatherm (oil temp regulator valve).
So far, down to about 35 or so it's working with no tape.
I did check the oil temp gauge, that is the first thing to do. I put the probe in a pan of boiling water, to find about where 212 deg. was.
Bill B
 
My 7ECA has no oil cooler!!, so the only thing a can block is the air flow. Last winter, i had tried to block the front of the cowling with tape.
Cylinder head were at max almost 400 deg F. and the oil temp remains cool, about 140 deg F. This winter i had tried with the exit plate
which control the flow by the exit (back of lower cowling), samething, Cylinder head were at max almost 400 deg F. and the oil temp at about 140 deg F.
I was told i should fly longer and with higher rpm like 2400 rpm and more. Also I have to make sure the oil temp gauge read correctly. in the summer the oil temp was at 180 deg F. What can i do? I'd like to fly a bit during winter...
 
Bill,
Do you have a oil cooler?
What oil temperature do you read?
What power do you cruise?(rpm) Is it a 0235-C1?

Thanks

J-P
 
High CHT and low oil temp does not compute.

It sounds like you need to pull the oil temp probe and put it in a pan of boiling water to see if it will register 212*F.

Oil temp at 180*F in the summer is barely high enough. 180* is barely high enough to burn out the acids from the oil. Lycoming says minimum 160*(their upper limit is the redline), but ideally it should be in the 200-210* range to insure all acids burn off.

On the O235-C1 2300rpm at 2500'msl is less than 50% power. You are not doing your engine any good running at that rpm. 2550rpm at 2500' is 65% power assuming a standard prop. (this is from memory, so check your performance manual).

See Lycoming Service Letter SL185b for information about proper leaning proceedures for our engine. Here is the link; http://www.lycoming.com/support/publications/service-letters/pdfs/SL185B.pdf .

Hope this helps

Ron
http://www.advancedtailwheeltraining.com
 
Thanks Ron for the reply,

How can 2550rpm at 2500' be 65% power, when take-off is 2600rpm?

Propeller is 72-46

The Lycoming operator's manual stipulate:

Take-off HP @ 2800rpm 115hp (impossible to obtain on my engine)
Rated Horsepower 108hp
Rated RPM 2600rpm
Cruise rpm Economy 2250rpm
Performance 2350rpm

J-P
 
My engine is 115hp. I will be at the airport sometime this week and will copy the performance pages from my manual.
 
J-P

I don't know how this will turn out, but I scanned the Performance page from my "Bellanca Citabria Pilot's Operating Manual". This is for 1975-1977 Series Citabrias. Mine is a '74 but figure it is close enough.

7ECAPerformance.jpg


Well, it doesn't look like that will work. Maybe you can copy and paste. Anyway, what my manual says is this;

7ECA Cruise Performance-Zero Wind-1650lbs-M72-46 prop.

2500'msl--
2600rpm-66%power-113mph tas-5.9gph-5.9hrs indurance-670sm range
2500rpm-59%power-108mph tas-5.2gph-6.7hrs indurance-725sm range
2400rpm-53%power-104mph tas-4.7gph-7.4hrs indurance-770
2300rpm-49%power-100mph tas-4.3gph-8.1hrs indurance-810


The chart goes from 2800rpm-90%power to 2000rpm-40%power.

I cruise at 2500rpm and find that the book figures are right on for my '74 7ECA.

Ron
 
Ron,
Are you able to reach to 2800 rpm on take-off?

If so, it sound like 7ECA from 1967 is very different than
the 1974!

Is it possible that Lycoming produced 2 types of 0-235C1
One at 108 HP/2600 rpm for the older 7ECA and one at 115HP/2800 rpm for the newer.

In the Lycoming operator's manual, the compression ratio
is 6.5 to 1. Can it be different for a newer engine?

J-P
 
J-P

My static rpm is 2350 which is right in the middle of the range stated in the TCDS(2425-2225). It will increase to about 2400 during the TO roll.

In cruise the max rpm that I can get in level flight is about 2550.

The only way I can get 2800 is in a steep dive. I can't tell you at what airspeed I get 2800 because I retard the throttle as the airspeed builds so as not to get near the redline rpm.

I don't know right offhand what the compression ratio is on my engine but I expect it is the same as yours. I believe that the only difference in the horsepower is the rpm. Looking at the different variations of the O235, the only significant difference listed between the 108 and 115hp models is 108hp at 2600rpm and 115hp at 2800rpm.
 
Thanks Ron,

Temperature is bad here in Québec (-25 deg C).... but when temperature increase between -5 and 0 deg C(probably in March...) I will try
a long flight with 2450rpm to see what's happen. Hoping it is going OK .
Then I will check the temp gauge.
Also I will check the fuel consumption.

J-P
 
My oil temperature was running too high, 240-250 deg. Turns out my tach is running 300 rpm too slow, so I've been running over red line. Hope it didn't ruin anything, new engine.
 
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