The International Cessna^® 170 Association

Follow on to some previous oil temp discussions.

Since owning my plane I noticed that it tended to run hot on x-country trips and pretty much right about 240 in extended climbs.

Had my oil temp gauge checked - it is actually reading correctly and we identified several exhaust leaks. Just had the exhaust completed refurbished and re-installed and since that work I did some x-country climb and performance testing last week. Everything is currently within parameters, but it is still fairy cool outside and I may be just a little paranoid since I'll be looking to embark on the epic coast-coast trip in mid-late June when things will be alot warmer.

So, here is what I experienced since the exhaust rebuild:

Took off from San Diego and climbed straight up to 11k. Pretty much held it at 85-90 MPH IAS. Temp got up to 225 (old redline) around 7-8k and ultimately got up to around 230 and held there until I levelled off at 11k and set cruise power. Cruising at 11,000' and 2450 RPM, the temp came down to around 210-215 and held there until I started to descend. (OAT at 11k was around 40F)

Refueled at Yuma and then flew back. Alot warmer in Yuma than San Diego (mid-80s on the surface) and initially climbed up to 6,500. Oil temp went up 225-230 alot quicker this time because of the OAT, but steadied out and never got above 230 in the climb.

So....since I am still learning this plane/engine and this is my first plane with no oil cooler, I ask - does this sound normal? Everything is technically within operating specs/parameters, but I am obviously not used to seeing my oil temp that high. I am also wondering how it will be in June, and in particular getting between Phoenix and the continetal divide. I plan to overnight in Phoenix and depart at 0500-0600 in the morning to minimize the temps and will overnight at SAF and depart early morning to minimize temps/DA. Once I get past the mountains around SAF, I don't expect to need to climb very high for the rest of the trip.

Thoughts?

The next time you have the cowling off, check all the inter cylinder baffling for correct installation. I have seen times where they were mis installed, and they are desigined to direct the cooling air on the push rod tubes to provide oil cooling.

blueldr wrote:The next time you have the cowling off, check all the inter cylinder baffling for correct installation. I have seen times where they were mis installed, and they are desigined to direct the cooling air on the push rod tubes to provide oil cooling.

Yep. And otherwise yours sounds fairly normal/common.

Andrew, remind us how big your lip is under the cowl. As a '48 it should be somewhere in the neighborhood of 2.5". If not then it's been modified ad the '48 and A models only had one lip. B models had a smaller lip of about 3/4" and higher temperatures and there was a seaplane lip that I believe to be closer in width to the '48 and A model.

There are lots of variables that effect engine temperature and the lip is one. While I would not be concerned with your temperatures, they are warmer than I'm starting to hear from owners with the larger lip.

There are anomalies of course. Richards NV based A model is running cooler than expected and he has the later small B model lip. Somethings we just can't explain.

Bruce Fenstermacher wrote:Andrew, remind us how big your lip is under the cowl. As a '48 it should be somewhere in the neighborhood of 2.5". If not then it's been modified ad the '48 and A models only had one lip. B models had a smaller lip of about 3/4" and higher temperatures and there was a seaplane lip that I believe to be closer in width to the '48 and A model.

Bruce, my lip is about 3" measured from the seam/bend to the outer edge.

Thanks for the info all....I'll have them check the baffles when I do the next oil change.

It is always interesting to hear other peoples problems when you think yours are bad. Not that your oil temps are bad, but interesting how we have such opposite problems with temperature.... There is another 170 owner out here who has installed an oil cooler. Something you might be interested in if the summer temps prove to be too much for your airplane.