The International Cessna 170 Association

Ty. The angle starter has more working parts and electrical parts to go bad. However with the pull starter, if the original clutch explodes, and occasionally they do, it is catastrophic to engine health as the metal goes right through the gear train and into the sump. In other words, your tearing your engine down right now right there to remove metal and inspect the internals. There is an original clutch and an improved type. The improved type PMA holder claims the clutch to be less likely to explode. The vast majority of 170s flying have a pull type starter so you wouldn't be an odd ball having one. You'd be like most of us.

George brought up the spinner. You have an A model. It never had a bullet spinner. The smaller readily available relatively cheap skull cap is what you want. However I will disclose that today, the way our STC is written, there has been more than one mechanic that thinks the STC requires a bullet spinner. This is not the case and the FAA has told mechanics this, but the question comes up and your mechanic has to agree the skull cap is fine. BTW the Association has two engine STCs. Long story why. If you needed the one STC the spinner issue wording has been clarified to insure everyone understands a skull cap spinner (or no spinner) is approved. On our other STC this wording has yet to be clarified.

Bruce Fenstermacher wrote:...George brought up the spinner. You have an A model. It never had a bullet spinner....

Hey George-
I prefer this picture! The bullet spinner was on the plane when I got it and even though it is only original to the C172, I still like it. If it had had a skull cap, I would have liked that too.
As far as a rebuild is concerned, my O300-D had been installed in 1972 on a field approval and had 1750 hours SMOH when I bought it the second time in 2006. The decision was made to overhaul it and all cylinders were all replaced with new, the oil pan was corroded to the point weld repair was impossible so a new pan was found and sent to Kelowna for epoxy coating/repair (not possible if ANY weld repair has been attempted or if the pan is perforated with corrosion), the crankshaft was cracked 1/3 the way around so a new one was bought from Continental (for an IO-360 = $4000), and all other components were rebuilt. Cost was $25,000 in 2006.

The O300-D has performed flawlessly the entire time I have flown it, around 1500 hours, and I am fully comfortable flying it IFR with the conditions of never flying in ice, thunderstorms, fog, or into deteriorating conditions.

I like the push button starter and have never had any problem with it.

I have never had a vacuum pump failure but have pseudo-attitude backup just in case with with my Garmin handheld GPS that I practice with regularly. A new electronic attitude indicator (Garmin G5, etc) would remove the need for a vacuum pump and is probably better in the long run.

I’m not an originality nut and prefer newer technology avionics and electronics but still respect the classic lines of the 170. I find it facinating such an old airplane can be equipped to fly and blend in with the modern air traffic system.

gahorn wrote:Wrong knob-color to be "original", Gary.

Here’s the solution to that George:

gwillford wrote:I also had this problem. I had two bad cables that I wanted to replace but I wanted my knobs to match. I came up with a solution that I thought I would share. I came across a cable print. I noticed a note that states "heat knob and press on". I had an old cable with a good knob and a new one with a non matching knob. I tried an experiment. I removed the inner wire of the old cable and placed it in a vice. I wrapped tape around the knob as well as a pair of pliers so I would not scratch the painted knob. I heated up the wire with a propane torch. Heat a few inches away from the knob! Bring the heat up slowly and begin pulling on the knob. When soft, the knob will come off. Mount the new wire in the vice and then heat it up. Press the knob against the wire. When soft enough, the knob will slip on. Hold in place until cool. Final cool under cold water. Print says pull test to 100 lbs. I gave it a 163 lb pull test (big lunch). If you are patient and careful, you won't even have to repaint the knob! Mine turned out great. Good luck!

George

I’m guessing the knob on this switch has female threads which could be duplicated on the original (replacement) knob. P.S. Sorry about the thread hijack.

gahorn wrote:

Bruce Fenstermacher wrote:...George brought up the spinner. You have an A model. It never had a bullet spinner....

N1715D.jpg

I didn't mean to say no A model ever had a bullet spinner installed, many have. What I should have said is the early cowl '48 to '52 was not designed to have a bullet spinner in front of it and a bullet spinner was not an option from Cessna till '53 with the change of cowl design.

Why this might be important to someone who has only known their 170 with a skull cap spinner is; 1. They like the skull cap look; 2. Depending on the bullet spinner used and your cowling fit, it can be very difficult to get to the cowl screws now behind the spinner, which are required to be removed or installed to use the early cowl.

It might ruin an owners day to find after spending money to change to a 0-300-C or D, that their mechanic insists they must now buy and install a $600 spinner.

Bruce Fenstermacher wrote:...............Depending on the bullet spinner used and your cowling fit, it can be very difficult to get to the cowl screws now behind the spinner, which are required to be removed or installed to use the early cowl..............

Hex head bolts can be used instead of screws and are easily removed with an open end wrench or ratchet box end wrench.

hilltop170 wrote:

Bruce Fenstermacher wrote:...............Depending on the bullet spinner used and your cowling fit, it can be very difficult to get to the cowl screws now behind the spinner, which are required to be removed or installed to use the early cowl..............

Hex head bolts can be used instead of screws and are easily removed with an open end wrench or ratchet box end wrench.

Yes there are ways to overcome.
It is still a PAIN.

I think it may depend on your bullet spinner. None of those angle/ratchet screwdrivers work on my '52 plane. Not enough clearance even for them. Hex sheet metal screws for the two behind the spinner is the only option that works for me if I want to be able to take the upper cowl off on the road. It's one of the reasons I'm switching to a skull cap. (I also like the original look.)

I have always thought that the spinner looked different than other 170s, I guess that I just hadn't researched it. If I understand all of this correctly, no matter which spinner I have, they will not interchange between a 6 hole/8 hole prop?

Mr. Richard, that is a beautiful restoration! A great picture also!

Thank you all for the replies! Your experiences and research are most helpful in compiling a pro/con list for whether to overhaul mine, or buy and overhaul the O-300D.
Ty

prairiechicken wrote:I have always thought that the spinner looked different than other 170s, I guess that I just hadn't researched it. If I understand all of this correctly, no matter which spinner I have, they will not interchange between a 6 hole/8 hole prop?
...Ty

It depends on which dome is used. The early 170 dome can be fitted with a six-bolt backing plate that is custom made for the 6-hole prop flange. The one on my B-model (with O-300-C, same crank as a D) was custom spun by a company in FtWorth and then fitted with the original-style dome.
Most 6-bolt spinners have been sourced from early 172s as Richard described. That dome is bit more "pointy" than the 170 "bullet" dome.

prairiechicken wrote:

n2582d wrote:Ty, If I'm not mistaken, I think you're also going from an 8-bolt prop to a 6-bolt one. Does the prop come with the engine?

Yes, a prop change would be required, and sadly, the prop has been reconditioned and sold already.

I have a six bolt 7653 that’s just collecting dust in the garage.

Trebork2 wrote:

prairiechicken wrote:

n2582d wrote:Ty, If I'm not mistaken, I think you're also going from an 8-bolt prop to a 6-bolt one. Does the prop come with the engine?

Yes, a prop change would be required, and sadly, the prop has been reconditioned and sold already.

I have a six bolt 7653 that’s just collecting dust in the garage.

Thanks! If I decide to go this route, perhaps we can work something out, if you're willing to part with it.
Ty

For close quarters, you modify.

John-
I did the same thing, cut the tip off a #2 Phillips and silver soldered it at 90 degrees. Then I discovered hex head bolts are much easier to get in and out with a box end ratchet or open end wrench.

For those of you with earlier airplanes using later spinners who fight those screws and spinner, check out what Cessna suggests.... see SNL dated 7-24-53: