You will find the allowable limits for oil temperature when using 50wt oil in the Type Certificate Data Sheet for the O-300.  Available on www.faa.gov

I am unaware of a service bulletin discussing oil temps, but it might exist. 

My '65 172 will run near redline (gauge is 225 degrees) on a hot day.

Good Luck!

Tom McFadden

Do you remember writing the way below.  You threw me for a big loop.  One sentence you said one thing and the next seems to contradict it.   You seemed to have some good experience and I would like to learn from it. I have my personal 1956 172 with an O-300-A and it seemed to run rough when pulling it back after T.O. and I am guily of papmering engines and am now working on taking that out of my habits. Well I mean when setting RPM not from stopping myself from engines warming up and cooling down and leaning on ground and smooth increase and decrease and shock cooling and running rich for cooling on T.O. and climb.

But can you re read and think out your writing below.  i would like to learn from what you said.

I am now in the process of working on my engine which I have only had this airplane 20 hours. I am changing the engine mounts, the intake gaskets and tubes, disassembled and checked the carb and one piece venturi, the fuel lines and screens, the propeller balance, tracking, blade to blade angle, and am replacing all the valve springs with new and checkng the valve guides are not sticky and going to ream the ones that are.  I have already replaced the plug wires and plugs and checked the mags and compressions after running are good.  It just seemed to run rougher pulled back to 2250 to 2300 then at higher power settings and I thought it must be a prop problem or and that it would have been not so rough pulled back.  I am now going to run it a little harder because 2500 in alot less than what it is capable and rated at .......... right?   Is still though it should be smoother though when I pulled it back.  But I am a turbine pilot using it to get back and forth to work at night.  Maybe I am feeling more turbulence than I expected out of a O-300.  I thought it should have run as smooth as a O-470 or O-520 or O-550 that I fly once in a while.
______________________________________
Re: RE: O-300 questions
From Tom McFadden

I own a C-172G with the O-300D using 100LL all the time. Never had any issues with stuck valve or spark plugs. Based on my experience of over 700 hours of operation with an O-300D in less than 2 years, I would suggest the following:

Lean on the ground as soon as your get the engine running and as soon as you land. I typically lean to an EGT of 1000 or so. In other words, do not be scared to touch the red knob.

I also use AV-BLEND. I only use one can for this O-300D. I think two cans make the oil too thin in my personal opinion. Oil used is Phillips X/C 20W50. I do not use MMO.

Do not baby the engine. I fly at 2500 - 2550 rpm. The engine is designed to operate efficiently at this RPM. Too low of a RPM with RICH mixture settings is the worst thing you can do. Some where around 35 -50 degrees of peak (RICH) is the worst for your cylinders. 25F ROP is okay; however, be careful and stay on top of EGT, in others, words keep your eye on it. If you fly around 100 ROP, you will be fine.

I get 7GPH at 7,000 feet @ 2550 RPM = 110 knots. I have the K&N air filter.

Lean the engine. You can lean at any altitude. Realize, you cannot lean above 75% power. So do not fly around at 2000 MSL full mixture rich with a 2400 power setting. If you are going to do this as in fly low with full rich mixture, at least bring the RPM up to 2500 - 2550. If you are for whatever reasons flying low with less than 2500 RPM, which will be less than 75% power, then LEAN the engine.

If you disagree, call any big overhaul / repair shop and/or Engine manufacturer asking which engine method is worst to operate ... an engine that is pampered (baby) and never hardly leaned or one that is ran that is leaned during ground operations and ran at 2500-2550 and leaned at 75% power when and as much as applicable.

This is my 5 cents worth.
----------------------------------------------------------------
My public view calendar at http://www.calendar.yahoo.com/pilot_mike.robinson

Mike Robinson 912-547-5477

8353 TT 3174 Turb pic 7305 Multi ATP with A&P and IA


PIC Typed via United on Boeing 737 -300 & -500

and via NW Airlink on Challenger 850 : CRJ -200 & -900

Operated Baron 743 hours, also King Air 200 & 90, Aztec, Navajo, C-414, C-441 and C-310

ATP 8353TT, 6630 Jet, 3174 PIC Jet Captain, PIC 4873, 7305 Multi,704 SEL
A&P I.A. Licensed Maintenance Technician with (Inspection Authorization)
27yrs Experience on all types of maintenance, sheetmetal, piston engine & jet.
Available for day work as pilot and can commute to your aircraft on free airline passes.

Commute from:
Jacksonville International Airport ( JAX )
Brunswick - Glynco Jetport Airport ( BQK )

Have 5000 sq ft Hangar 23 miles northwest of Jacksonville on paved lighted county airport - Davis Field 3J6 where I can store cheaply, maintain and operate your aircraft to pick you up at location of your choosing.

From my hangar on Davis Field identifier 3J6 by air in either my aircraft or yours I am 15 minutes away from JAX, Craig CRG, Cecil VQQ, Fernandina Beach/Amelia Island 55J, Herlong HEG, Brunswick BQK, Saint Simons SSI, Jekyll Island 09J or Waycross AYS

o300 left mag fires bottom and right mag top  plugs. Recent annual found moderate/heavy deposits on bottom plugs,,approx 85 hrs.cause/concern  john

I am a new pilot and cessna 172e owner.  Being a newbee in both areas of flying what advice would you give me as far as taking good care of my aircraft engine?  3700TTAF and 500SMOH. There is an AP mechanic who lives on the airstrip where I keep the plane.  He is also a pilot.  Thinking of asking him to take my plane up and give me some of his insights.

Hello all, I own a 1963 cessna 172. my mechanic accidentally broke oil temperature  tube which runs to the gauge in the the instrument panel. Please advise from where I can buy the same type of oil temperature guage or if there is some technical bulletin which allows replacement of mechanical type of oil temp guage with electrical guage.

thanks,

Azhar

where is the best place to buy a nice crankshaft for a 0-300c or d and case?..and 0-300 pARTS FOR OVERHAULS..

Can you do go to skyhaven airport in Northeast PA, do a trimmed down pre-buy inspection on a 1962 C-172M, O-300. It has 2900TT, 900SMOH, 10 since new ECI cylinders.  Destination would be KTKI-Collin County Regional in Mckinney, TX.  I would need it done approx. April 15-may5, if so, how much?  This e-mail address is being protected from spambots. You need JavaScript enabled to view it

How do you lean the engine at 75% power?

mike11003 Wrote:
-------------------------------------------------------
> Does anyone make an electronic ignition system for an O300D

I am sorry this is not about the 300.  I am needing some input about someone's flying.  They fly a c 182 for skydivers and the descent goes as follows:
throttle  1500 rpm
mp     22
90 deg bank
full right rudder
full right rudder trim
spiral from 10000 to 2500 pulling 2 to 2.5g 
I told him I had concerns about this and now I no longer am flying for him. 
There is also noticeable fatigue on top of the wing on one of the spars with a couple of rivets popping out.
any input or thoughts would be appreciated.

David Wrote:
-------------------------------------------------------
> mike11003 Wrote:
> --------------------------------------------------
> -----
> > Does anyone make an electronic ignition system
> for an O300D


I've never heard of a Certified one.

Slick  has LASAR but I think it was for Lycoming 172's.