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How to keep the Cessna 170 flying and airworthy.

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nameuser
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Joined: Sun Aug 09, 2020 2:35 pm

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Post by nameuser »

Hi, I owned a 120 for a number of years and am now the joint proud owner of a 1955 170B (D-ENRA but will be re-registered EI-something). We had to buy the aircraft sight unseen as we could not travel with Covid. The engine is toast (O300A) and we had to get it disassembled and put in a container to ship from Germany to Ireland. We are happy with the aircraft and while it flew in January of this year it does needs some attention.

We are obviously rebuilding the engine and wish to install an external oil filter, currently, there is a dynamo installed and I figure we will need to replace it at some stage with an alternator, is there a clearance issue given the larger diameter of the alternator. Do I need the "remote oil filter" on the firewall?

We need to respray the aircraft as the paint is really faded, so faded I originally taught it may have been original paint until I found the trim plate. According to the trim plate, the external paint is Chartreuse, which when you google it is a pretty mad color for 1955. We want to try to keep it in the original color scheme, where would I find the scheme for 1955 and does any one know of a 170 with Chartreuse paint.

We also hope to install the Sportsman STOL kit and install 8.50 tires four-point harness and a new transponder.
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Bruce Fenstermacher
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Post by Bruce Fenstermacher »

Congratulations Enda

You have a dynamo. That is not a common name here in the US, we refer to them as generators. Generators being DC vs alternators being AC. Alternators were popular when avionics and incandescent bulbs sucked lots of energy. Todays avionics and the advent of LED lighting, IMO has practically eliminated any need to convert to an alternator. Simply replacing the incandescent nav light bulbs with LED saves 10 amps. If you must run with your landing light on continuously you need to replace the incandescent bulb with LED as well. To answer your question, alternators approved under STC with fit fine.

Sounds like you currently have a firewall mounted oil filter. No need for that. You can install a Tempest (formerly F&M) oil filter adapter to the engine and eliminate the oil lines and remote mount. Of course you could also revert to the original oil screen and eliminate a filter all together but that is not the usual path folks take. the Tempest (F&M) option is most popular. https://www.aircraftspruce.com/catalog/ ... dapter.php

I've just connected the dots and upgraded your forum privilege for TIC170A members. You can now see much more information here. IN our MX library you can find photo documentation of the various model years. We also have some paint layout drawings. We don't have any pictures of a chartreuse '55 except the drawing in the sales brochure. viewforum.php?f=31
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
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GAHorn
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Post by GAHorn »

nameuser wrote:Hi, I owned a 120 for a number of years and am now the joint proud owner of a 1955 170B (D-ENRA but will be re-registered EI-something). We had to buy the aircraft sight unseen as we could not travel with Covid. The engine is toast (O300A) and we had to get it disassembled and put in a container to ship from Germany to Ireland. We are happy with the aircraft and while it flew in January of this year it does needs some attention.

We are obviously rebuilding the engine and wish to install an external oil filter, currently, there is a dynamo installed and I figure we will need to replace it at some stage with an alternator, is there a clearance issue given the larger diameter of the alternator. Do I need the "remote oil filter" on the firewall?

We need to respray the aircraft as the paint is really faded, so faded I originally taught it may have been original paint until I found the trim plate. According to the trim plate, the external paint is Chartreuse, which when you google it is a pretty mad color for 1955. We want to try to keep it in the original color scheme, where would I find the scheme for 1955 and does any one know of a 170 with Chartreuse paint.

We also hope to install the Sportsman STOL kit and install 8.50 tires four-point harness and a new transponder.
Hello “Nameuser” and WELCOME!
I believe Bruce may have misunderstood your question, so allow me to give a slightly different view:
The Tempest (formerly F-M Enterprises) spin-on oil filter adapter can work with most alternators, athough you MAY find it necessary to remove a small amount of metal from the oil filter adapter to avoid physical contact between the two. The installation instructions included with the Adapter should explain it in detail, but it only requires a small amount of “filing” or “grinding” on the new adapter to make the fitment.

The “Wolf” oil filter adaptor will fit upon the fire-wall but also will require hoses (which can be a future maintenance issue as well as expose the system to external leaks) and should include a “doubler” on the firewall to stiffen that mount to avoid firewall cracking from vibration.

I agree with Bruce that an alternator conversion may not be the best choice, depending upon your electrical load analysis. Generators (dynamos) have advantages that make up for the additional 11 lbs of weight they include compared to most alternators. One example of generator advantage is , if your battery is “dead”,... the engine may still be started by the old technique of hand-propping and the generator will still “excite” and produce electrical current...while an alternator will not . Another advantage the generator has is cost: A generator may be completely overhauled for a FRACTION of the cost of an alternator conversion. Generators are more sturdy devices than alternators in that they do not have diodes/rectifiers which are sensitive to reverse-current failures, over-voltage-protection, and do not produce audio “whine” in the avionics. The only problem I’ve seen with generators is that many mechanics (engineers) do not understand generators because of youth and inexperience. As a Member of the Assoc’n you can download a copy of the Electrical System Service Manual from the Members Only page. Although the author of that document is of questionable “character” :wink: ...he tried to make the generator system understandable and included a “trougleshooting” guide that should be easily followed should your generator system give any trouble.)

Also keep in mind that some alternators are VERY expensive when they fail... the example I am thinking of is the Jasco brand of alternator. Those may not be repaired except by complete (expensive) exchange for another Jasco. No parts and no service is allowed. (If I were to convert to an alternator I would only be interested in the genuine Cessna (Ford) method used in Cessna 172 aircraft in the early 1960’s.)

If you have a generator, you might wish to select the 35 Amp unit and the associated 35 Amp regulator. I doubt you will need more than that with modern avionics, and L.E.D. Lamps will reduce demand even further.

The original paint colors of these airplanes are difficult to match exactly because the paint-numbers published by Cessna are no longer available. However you might find some evidence of the color beneath fairings and behind dataplates, and other hidden areas on the airplane, and you might have the color “computer-matched” by your local paint supplier. Otherwise you will be forced to find photographs of existing airplanes and attempt a “near” match.

I hope this is helpful, and again, WELCOME! Post some pictures of your airplane!
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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cessna170bdriver
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Post by cessna170bdriver »

Jasco alternators may be expensive, but they are very reliable. I ran mine over 1000 hours from initial installation in 1990 to engine removal for overhaul in 2004, then 175 hours on another engine. I had it overhauled in 2006 when the original engine was overhauled, just because I was replacing or exchanging all the other accessories, and I’ve run it nearly 650 hours since. I have had ZERO issues with it or the regulator (solid state) in 30 years, and other than changing the coupling rubber and cup at the recommended interval (500 hours I think), it has been completely maintenance-free. After engine start it comes online at about 1000 rpm, will stay online down to idle, and recovers the battery in a matter of minutes.

I paid about $1000 for the kit in 1990, and about $1000 to have it overhauled in 2006. Today’s replacement cost is about $1750. My Dad ran one on his stock Stearman for 20+ years (3 engines to TBO) and don’t recall him ever saying he had an issue with it. Knowing what I know now, I wouldn’t hesitate a minute to do it all over again.
Miles

“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
nameuser
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Joined: Sun Aug 09, 2020 2:35 pm

Re: New Member

Post by nameuser »

Thanks for the reply's, I am just to future proof the aircraft in relation to the oil filter. A dynamo is what was installed and it will be refitted on this occasion, but I can see it been replaced down the road. As for the colour "Chartreuse" I can now see why I can not find a picture of a 170 in this scheme. Lets just say its not something I would go for. Again thanks for the reply's, I am sure I will have a lot more questions before we get this 170 back in the air
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