Wow,

I would have never thought about leaving the filter off during breakin time.  I would think that leaving the filter on during breakin would be even more important than leaving it on after about 500 hours on the engine.  I would think that there would be lots of benefit to leaving the filter on in the first 25 hours, especially and I would get paranoid and probably change the oil at about 10 hours and then maybe 15 hours and then resume the normal 25 hour changes.  The mortality phase of recently overhauled engines is what I would be paranoid of and then after about 100 hours it would probably be a much higher probabilty of not coming unglued.

Did an A&P suggest this procedure about leaving the filter off?

BTW, where did you get your 0-300 Overhauled?  We have an O-300-D in our 172H and in about two years we will have to start looking for an overhaul place pretty seriously.

Over to you,

Stan

Hi Jay
Look at it this way.
A spin-on oil filter is not expensive - maybe $300.00.

It will catch a lot that a screen won't, so it is Very cheap insurance AND will probably extend your engine life.

Oil changes will be every 50 hours instead of every 25 hours, so it is not a cost, it's an investment that pays for itself 100% and then goes on saving you money as long as you own the aircraft.

If you ever sell the aircraft you'll get your money back again - buyers don't like oil screens as much as filters.

What's to think about?

Tony
C-GICE  (172H with 0300D AND spin-on oil filter

El-Rino makes a nice spin on oil filter adapter for the O-300 Cont. (STC'd also).  Have used it on numerous O-300, no problems and no AD's .

OK, I'm convinced! Now what kind to get? There are some that are designed to replace the oil screen and some that attach to the firewall. Pros/Cons of both would be appreciated. I believe the remote type are a bit more expensive but probably easier to change the filter then the unit hanging on the back of the motor.

My 172G 0-300D has the F&M engine mounted adapter. I love it. Changing the filter is easy and not an issue with this adapter on the 0-300D. What is an issue with the F&M adapter is making sure it comes with the new, updated gaskets (fiber towards the engine) and is properly torqued. Old torque setting was I believe 45 ft lbs, new setting is 65 ft lbs. If you get one with the old style gaskets the adapter is prone to moving when changing the filter and then leaking at the gaskets. F&M will send you the new gaskets and installation instruction for about $10 if needed.
I'd still change the oil every 25 - 30 hrs, even with an oil filter. The filter will keep the oil clean longer than a screen but the additives in the oil will be all used up way before 50hrs.
Definately put on an oil filter before break in. It will help in determining if the engine is breaking in properly, or just breaking. My 0-300D has only 100hrs SMOH. Cutting open the filter at 30hrs showed a lot of metal that would have passed through a screen. It was due to the overhaul shop (Kline Aviation in WI, don't use them, they suck and don't stand by their work) not installing new rocker arm shafts. New shafts are called for by TCM on an overhaul. The old shafts, which they polished, were eating into the rocker arm bushings. 30hrs on the engine and I had to have extensive work done due to the overhaul shopes error. Kline aviation did replace the shafts with new and re-bush the rocker arms for free but they refused to cover my shops labor costs ($1200) which they originally agreed to cover in full. Paul Kline (owner) sent me a check for $300 to cover $1200 in labor costs. Doesn't add up to me.. I hope they did not screw up anything else in my engine... If I did not have an oil filter I might not have know there was a problem until a rocker are or shaft failed... Ouch