exhaust

[GAHorn]

A field approval or one-time STC IS a solution, Dick. I didn't stop short. Those who installed that engine without proper approval is who "stopped short".
Ron has been fortunate to deal with an inspector who isn't as critical as most, and hopefully success will follow the inquiry he is making, but I wouldn't place any bets on it either way. The concept of the -A engine being to the -B as the "E" is to the "D" is an oversimplification, in my opinion. If it were all that simple then the type certificate of all the 172's would include all the "dash" model engines throughout the series...which clearly ain't the case. (And the part numbers of cams which are the same...may be interchangeably installed in all the engines.... but that doesn't mean all the other parts are... or that by installing the other dash-engine parts makes the engine the "same" as the D or E or whatever unless the paperwork meets the established criteria.
Before blu elder and Ron and some others get their shorts in a wad over this, keep in mind that I'm not saying the B engine isn't an airworthy installation in a 170. I'm just saying that unless it's done under some basis of approval...it ain't legal.
It's up to the owner of that illegal airplane if he wants to risk flying it over other folks with legality problems he already knows about (and whether his lawyer or insurance underwriter is also comfortable about it, or if those are issues of import or not.)

[Bruce Fenstermacher]

The concept of the -A engine being to the -B as the "E" is to the "D" is an oversimplification, in my opinion.

George, many of us think your overcomplicating this, in my opinion.

[N1277D]

My 170A came from the factory with the C145-D however it failed a lifter and the result was a case crack 30 plus years ago. It ended up with a replacement case for a -H, with the hydraulic arm safety wired closed.

[GAHorn]

The concept of the -A engine being to the -B as the "E" is to the "D" is an oversimplification, in my opinion.

George, many of us think your overcomplicating this, in my opinion.

I haven't rec'd any communications from the "many". Although privately I may not be concerned with operational safety, etc.,... Officially, I am compelled to offer advice that I believe is as close to accurate as possible.

[Bruce Fenstermacher]

OK perhaps I shouldn't have taken forgranted that the guys you mentioned with " their shorts in a wad" would join me in a group of "many". And how many that would be is of course questionable. Depends on which campfire has the best beer I suspect.

I should have just said "I" think your are over complicating this.

[ron74887]

George, The case of the 172's, in the straingt 172 it was certified with the A and B engine. In the case of the 172A it was certified with the C and D engine not mentioning the E engine, however the E engine was not approved til 63. I don't know if the E was approved in the later (after 64) 172's. My statement was to the fact that the 2H, B and E just added the hydraulic controls to there counter parts C145, A and the D which is not really an over simplification it's a fact that the only difference is the addition of the hydraulic control. The type certificate for the 172 changes when they went to the different prop flange on C-D engines. The reason for the STC that allows us to put the C,D or E in the 170, however, without the hydraulic accessory of the E using a controllable prop-I did not want to try to approve another prop. So the E is approved on the 170 but for use of a fixed pitch prop only. I have to agree it may be a paper work thing just like some of the 337's installation of the C-D engines in the 170 another discussion--some are legal and some are not . Ron

[GAHorn]

... My statement was to the fact that the 2H, B and E just added the hydraulic controls to there counter parts C145, A and the D which is not really an over simplification it's a fact that the only difference is the addition of the hydraulic control. ..

It's also a "fact" that the methods of achieving that hyd prop control was very different between the E and earlier engines. If memory serves, there are numerous differences in how those very different props were controlled. (The "E" used a Garwin hydraulic propeller governor mounted on a very different engine case in a very different location, and that is not interchangeable with other O-300 engines. And the C-20 McCauley prop was not the same as was used by the B engine.
Another example of how such simple assumptions as we are discussing are not appropriate, a Cessna known as a C-172 (the "Powermatic") was actually morphed from a totally different type certificated airplane....the Cessna 175 SkyLark. That does not mean all we have to do is install a geared GO-300-E engine in our 170's and go fly.

[ron74887]

point taken! the fact is that the engines are identical in operating limits and specs and now we are talking about props. If we are using the fixed pitch props or the areomatic that is automatically controlled by counterewgts, props approved for the 170 or 172 with the STC, then the engines are the same. If you are not using the hydraulic control option???? what the hay? you are not changing any specs for the plane. When the STC was issued it was because of the prop not the engine. I was told I could put the D engine in I could not fly it because the prop had never been approved for that plane, go through engineering, which is what happen! Paper work problem, you bet engine problem none. Ron

[Bruce Fenstermacher]

So Ron I seem to remember hearing you say this before. Your initial FSDO inspector had no problem installing an 0-300-D on your plane. He had a problem with the propellor you needed to run with the 0-300-D. That is very interesting.

So we need to start thinking of your (the associations) STC as a prop STC that also requires a certain engine that will bolt to it. The tail waging the dog I don't know.

In any case George this interesting engine discussion, exhausting as it is, should probably be split from the original topic to one more appropriate.

[kog]

Just finished with mechanic checking out O-300-B insatllation on 3166A with regards to the STC purchased from the Association. All is well and "legal" so I'm happy. Thanks to those who made the STC available for the 0300-B; it's appreciated.
kog