The International Cessna^® 170 Association

Bruce Fenstermacher wrote:Why do you want to loose the venturis, generator and starter for lighter equipment?

Are you not going to have a vacuum system? If so, without venturis, where are you going to put the pump? And why would you want to replace a venturi system that won't break for a pump that will.

In todays age of low amerage LED lighting significantly reducing load, you'll never need more than the 35 generator, why go through the expense of a alternator and wiring upgrade required of it.

Personally the weight savings of a chinese starter and the electrical changes required aren't worth it either.

But you've got time to think all that through.

Bruce, I just don't see the need for a vacuum system these days. I'll be designing a simple VFR panel using both steam and glass components. I like flying into remote areas for recreation, and weight is always an issue. The back seat will probably not go back in, unless I discover a structural issue with that. Lightweight starter and alternator will go on, again unless I find another problem with it.

What are the main differences between the O145 and O300? Are the cylinders interchangeable? Pistons?
I have much to learn about this model, STC's and such. I've got 60 years of AD's to look at too.
Dave

The C-145 is a 145 horsepower engine that is 300 cubic inches.
The O-300 is a 300 cubic inch engine that makes 145 horsepower

The C-145 has an 8 bolt prop flange while the O-300 is a six bolt but I don't think every O-300 is 6 bolt and the crank is interchangeable.
There are no functional differences between the engines. You can't tell them apart unless you look at the data plate.


But since TCM changed the name, the FAA feels an STC is needed to interchange.

Keeping the interior minimal will save a bit of weight. I think the rear seat is 20 pounds by itself.

bagarre wrote:The C-145 is a 145 horsepower engine that is 300 cubic inches.
The O-300 is a 300 cubic inch engine that makes 145 horsepower
.

That's going to make my head hurt.
Fun times ahead.
Dave

Rangeflyer wrote:

bagarre wrote:The C-145 is a 145 horsepower engine that is 300 cubic inches.
The O-300 is a 300 cubic inch engine that makes 145 horsepower
.

That's going to make my head hurt.
Fun times ahead.
Dave

I think what David is trying to say is that they are the same engine. At some point, Continental changed from designating engines by horsepower (C-145) to cubic inches (O-300). Later models of the O-300 switched to crankshafts with 6-bolt prop flanges from the C-145 and earlier O-300's 8-bolt flanges. There are other minor differences among engines with both designations that are detailed in the parts catalog.

bagarre wrote:
Keeping the interior minimal will save a bit of weight. I think the rear seat is 20 pounds by itself.

I am sure they are all slightly different, but mine weighed in at 28 lbs when I did the W&B for each configuration/seat in/seat out. I generally fly without mine.

Absolutely no difference between a C-145-2 and an 0-300-A other than minor casting changes in production. All parts specified for the first are specified for the second. Same between the C-145-2H and the 0-300-B. As stated in 1956 Continental marketing changes naming convention to be in line with their competition who used cubic inches rather than horse power to describe an engine.

Now if you ask the FAA, the C-145-2,C-145-2H, 0-300-A and the 0-300-B are 4 different engines. Without STC or another means of approval, only the C-145-2 and the 0-300-A can be installed on a '48 170. Only a C-145-2, C-145-2H and a 0-300-A can be installed on all other 170 models.

Our Association's STCs fix all but one. You still can't put a 0-300-B on a '48 though we are in the process of getting that fixed. Our STC's also allow the 0-300-C, D and E to be installed on all models of 170 and 172 up to the 172A.

Bruce Fenstermacher wrote:

Bruce Fenstermacher wrote: Our STC's also allow the 0-300-C, D and E to be installed on all models of 170 and 172 up to the 172A.

Bruce, I was curious about that. The STC says it is applicable for the C-172 under the TCDS number 3A12 which covers those built through the 172S. Or when it says "Cessna 172" does that exclude later models; the 172A, 172B, etc.? And if that's the case why can't the O-300B be installed on the '48? All three variants, the 170, 170A, and 170B, are listed on the STC.

Gary,

I said that wrong. Our 0-300-B STC allows a 0-300-B engine on a '48. But currently you can't install a C-145-2H on a '48. The Feds have been studying my application to include the C-145-2H to that STC for the last 4 months.

TCDS 3A12 allows only an 0-300-A or B on a 172, 172A. Our STC allows installation of 0-300-C, D and E engines on the 172A.

Looks like the FAA could use some editing on their approved model list.

Rangeflyer wrote:...The only thing missing is the left elevator, which I think he loaned to a fellow passing through and never got replaced. ...
Dave

Dave, I see 170A elevators for sale on a popular online auction site. Was the guy who borrowed the elevator enroute to Pennsylvania?

Here's another possible lead. Does anyone know what happened to Don Harrell's stuff? If I recall correctly, he had some tail feathers hanging on the side of his hangar.

n2582d wrote:Looks like the FAA could use some editing on their approved model list.

What do you mean? What the FAA needs to understand is what is the same engine and what is not and why. They don't. They only understand paper trail. A C-145-2 can't be the same as an 0-300-A because the first nomenclature uses no letters or numerals the same as the second name. And to further their argument both the C-145-2 and the 0-300-A are listed as approved separately so they must be different. Use to be the imperfect system was a real live person, who was suppose to understand this stuff, at the local FSDO level, would make a determination or investigate. Now there is no one at the local level and you can't get to someone directly in a timely manner at the national level.

Our application is going on 5 months to add the C-145-2H and to make clear that a skull cap spinner, or no spinner is an appropriate installation, to our existing STC is being held up. The certification branch thinks we need a ICA for the additions even though the STC that already has meet the requirement for a ICA for an 0-300-B (C,D and E) on the '48. Luckily we do have a Fed working on our side who understands that is ridiculous. Hopefully he can persuade the certification branch.

This should take no more than a few phone calls and an approval issued. Not a 3 page application which needs to be studied to insure the application was filled out properly. Only then is it sent to the certification branch to wait consideration for the actual change requested. Its an example of the worst side of government.

Can't wait for this application to be completed so we can apply for changes to our other STC (yes we actually have 2 engine STCs) to make it clear a skull cap spinner or no spinner is an appropriate installation as per the TCDS. This is clear to some of us, but not all including the Feds and has been questioned on an individual bases in the past.

Bruce Fenstermacher wrote:TCDS 3A12 allows only an 0-300-A or B on a 172, 172A. Our STC allows installation of 0-300-C, D and E engines on the 172A.

TCDS 3A12 calls for the O-300A or O-300B to be used on the Cessna 172 - i.e. through s/n 46754. Cessna 172A through 172H are already certified with the O-300 C or D. Does STC'ing the addition of the extremely rare O-300-E make sense?

P.S. I don't see a 172B in the TCDS. Was this ever produced?

I know better than to try to type anything here from memory.

Our STC only covers the 172, not the 172A.

The 172B is listed on page 2 with the 172A.

And no there is not any practical reason to include the E model. However, we did because there was no penalty to do so. Had we taken the same tack and outlined every single possible combination of spinner ie no spinner and skull cap as well as insuring the C-145-2H was included from the start we wouldn't be rehashing the approval of these "changes" now.

And you might say how many people are going to install a 2H on a '48. And the answer is we have a member right now who, last I heard, was having a hard time getting this approved. And you might ask how many people are going to question the installation of the stock skull cap spinner and I'll tell you the count is up to 3 that I know off. Today, if it is not specifically spelled out people question starting from the position it is not approved.

Should have looked closer - missed the 172B listing.

Bruce I empathize with your frustration with the FAA. What should be a no brainer somehow has to become this paperwork nightmare. It's no wonder the homebuilt industry is thriving.

Back in 1941 Taylorcraft built the BC12-65 with a Continental, the BL12-65 with a Lycoming, and a BF12-65 with a Franklin. The airframe is identical in all three versions. Years ago I restored a BF12-65 but it had long since been converted from a Franklin to a Continental by field approval. It was in every way identical to a BC12-65. So, because Stits didn't think to include the BF12-65 in their STC, I had to go to the Fresno FSDO to get a field approval for the Stits covering. For acceptable data I included Stits' STC for the BC12-65 but it was like pulling teeth to get that field approval. The inspector there had no previous practical experience in general aviation.

My A&P instructor trailered his Command Aire project from California to Florida so he could deal with a reasonable FSDO for the field approval on an alternate engine installation.

As long as you're in the STC business why not get approval for the O-300A and O-300B (and their earlier twins) in the C-172A through C-172H? Seems like the association could make some money with that.

Looks like I've successfully hijacked this thread with my rant. Sorry Dave. To get us back on track you might consider putting an "elevator wanted" ad in the Trademart and Fly Paper. Barnstormers.com also allows you to list for free. Finally, in the Maintenance Library there is a list of salvage yards that you can call.

n2582d wrote:...
As long as you're in the STC business why not get approval for the O-300A and O-300B (and their earlier twins) in the C-172A through C-172H? Seems like the association could make some money with that.....

If we were in the business of making money we wouldn't sell it as cheaply as we do. I suspect that it actually costs us money (printing/mailing documents/supplies the buyer really doesn't want or need) when we suggest buyers join the Assoc'n to get it at the cheaper Member-rate.
But we are a non-profit, after all.

Rangeflyer: WELCOME! And I suggest you absolutely make the 2017 Convention in Deming, NM next summer! (finished or not)