The International Cessna^® 170 Association

The ability to lean effectively without damaging the engine - as with a 6 pt EGT system with "lean find" capability (we have the JPI EDM-700 and fuel scan 450) helps increase range/endurance. You can lean to peak EGT at higher altitudes without fear of detonation, because the power the engine makes and temps involved are low enough to prohibit it. My leaning schedule typically follows along these guidelines:

10000 and above; lean to peak
7500-9500; lean 25 degrees cool of peak
below 7500; lean 50 degrees cool of peak

As Charles Lindbergh did with the P-38s in the south pacific, you can experiment with oversquared power settings (low rpm compared to MP). As I said before - higher altitudes would be preferable - and as a general practice I don't do this. But I have played with my fuel flow and engine monitoring gagetry just to see what I can expect if I got in a pinch. I run my Franklin at 2300 rpm typically - it "feels" best there. But your fuel burns drop off even more as you decrease rpm for the same power setting. Keep in mind, any time you change your engine cruise configuration (power or prop) you'll have to relean the engine.

When I'm trying to get somewhere, higher is better (no large headwind component). I try to go at 10K and plan on burning 8 gph. My actual burn (per the FS-450) ends up being around 7.5 at full power (20" MP). This provides the same endurance and better range than the original powerplant.

Compressions at the first annual (100 hours since new) were ALL 80/80. The second annual at 160 hours were mixed 79s and 80s over 80. The plugs were clean and healthy both times. My engine (yes it IS a Franklin!) does not leak any oil. The only dribbles in the drip pan are usually a quarter-size blob of super-aireated fuel from that huge carb airbox & induction system - annoying but normal for a Franklin.

Extra fuel: I have not had the wings off Punkin. I understand from others that the Javelin aux tank is the way to go. Personally I just don't like putting fuel in the cabin. I also find myself bulking out so quickly that I need every cubic inch of space in the baggage area. I understand that Del-Air is working on the STC to install the 175 long range tanks (52g useable?). If I go with extra fuel someday, I think that might be it. For now, with all the options we have for fuel stops down here in the ConUS; I just let my bladder dictate when to stop. It usually reaches critical mass before I find myself on vapor anyway!

Things I'd do different? Hmmm... Maybe do a Garmin 430 from the start instead of the VFR-only 250XL. Maybe put in the EDM-700 with fuel flow instead of adding on the FS-450. These are pretty minor. I love our version of the installation and am happy with the Franklin so far. Ft. Collins claims to have parts and lotsa new engines on hand, but I haven't had need for parts yet (knock on wood). I sure would like to see PZL resume manufacturing someday soon. That is my only worry...

Matt

thank you punkin for the info.

I am now an member and look foward learning about this unique airplane....

The Javelin baggage aux tank is a Type Certificate approved installation if you can find all the parts. Also, some airplanes have either 175 wings or 175 tanks installed (52 gallons).

Whats all involved in installing a set of 175 tanks? Are they hard to find? Is there a difference between the 52 gallon 175 tanks and the 52 gal 172 tanks?

Almost done with my Franklin conversion. Hopfully by the end of the month. Will give a full report with pics when done.


Thanks,

Brandon Leary
Bethel,Alaska

Someone posted a "for sale" ad for a Javelin tank set-up on the Trademart forum just within the last week or so.

Eric

Long range 172 tanks are the same as 175 tanks.

icepilot wrote:Whats all involved in installing a set of 175 tanks? Are they hard to find? Is there a difference between the 52 gallon 175 tanks and the 52 gal 172 tanks?

Almost done with my Franklin conversion. Hopfully by the end of the month. Will give a full report with pics when done.


Thanks,

Brandon Leary
Bethel,Alaska

What's up with the jury and the wind sock case down there! I can't believe that they gave that guy a million bucks!

I spoke to Harry at Del-Air today, he has received STC's for two different extended range fuel tanks for the 170.

Choice 1 is 7 1/2 gallon addition to each of your original tanks for a total of 52 gallons (the option I chose) and Choice 2 is 15 gallon addition to each of your original tanks for a total of 67 gallons (way to much range for my attention span to say nothing of my bladder).

One the benifits of Del-Air's modification is the movement of the Filler neck to the top outside end of the tank permitting fueling to full capacity something not possible with stock inboard fuel fillers owing to wing dihedrel (dihedrel as found on the superior faster B models).
Johneb

johneeb wrote:I spoke to Harry at Del-Air today, he has received STC's for two different extended range fuel tanks for the 170.

Choice 1 is 7 1/2 gallon addition to each of your original tanks for a total of 52 gallons (the option I chose) and Choice 2 is 15 gallon addition to each of your original tanks for a total of 67 gallons (way to much range for my attention span to say nothing of my bladder).

One the benifits of Del-Air's modification is the movement of the Filler neck to the top outside end of the tank permitting fueling to full capacity something not possible with stock inboard fuel fillers owing to wing dihedrel (dihedrel as found on the superior faster B models).
Johneb

Did he say if he does the tank mod by itself? Or does he require the wing and do the changes needed to it also at the same time? Or will he sell a kit and the paperwork that a local A&P could assemble? Did he give any turn around times? Anything about gross weight increase? And how about prices??? Last time I talked to him he had the 172 STC but not the 170 STC so I'm asuming he actually has received the 170 STC? Have heard some grumbling about time and cost overruns. Anybody else have any firsthand experience?

The court case about the pilot suing the state of Alaska for the frozen windsock is a joke. I know the pilot personally. had a few beers one night awhile back and told him what I thought of it. Didnt go over to well with him.

The guy is a fraud. people like him shouldnt be flying. They are whats hurting G.A.

Several other planes had turned back to Bethel after trying to land at this uncontrolled village airport , a couple of 207's and a Caravan I think. There was something like a 30 kt direct cross wind. Who needs a windsock with that kind of wind? A state worker flew over the field after the accident and the wind sock was pointing in the right direction.

Sounds like the state is appealing the case. Brandon

You might ask Dave Stoots in FAI; I think he has a set of 2440s that he used to have on a 170, now on a highly modified 175TD seaplane.

If you have trouble finding a template for a fin - PeeKay floats required the fin and they have a drawing - or maybe someone who has some PKs has a copy.

Icepilot,

Another option for longer range fuel is convert to Cessna 175 tanks, which offer 50 gallons total. I don't know if there's an stc out there, though. I know of several that are field approved with those tanks.

There was an outfit in California which had stc's for increasing the size of Cessna 172 tanks (of which the small tanks are the same as the 170 tanks) by 5 gallons each, thus making them the same as the 175 tanks.

At the time I talked to them, they didn't have an stc for the 170, but they may now.

I have Flint tanks, and don't like them, I wish I'd gone with the 175 tanks at the time. The flint tanks put too much weight out at the tips, which can be spooky on floats or wheels, and there's too much "stuff" out there, as well. Also, I really don't need 60 gallons of gas, 50 would be about perfect.

As to ventral fins, if you can't find one anywhere, contact Alton Bushard of PeeKay, Inc, in Maine. I bought one from them for a really good price a while back for my 170. These are for the PeeKay installation, but they are identical to the ones I've seen on 2440 equipped planes. Alton is a good guy to work with as well.

Good luck getting the floats approved, unless you have some bullet proof prior documentation, or a VERY benevolent FAA guy. Hope it works for you.

Mike Vivion