New plane owner here, lets talk specs on an engine upgrade.

Doherty · Post by **Doherty** » Fri Sep 24, 2004 11:58 pm

Hi all! I just bought my first plane last week, its a 1956 170B! I have been flying professionally in Western Alaska since '91 and have lost touch with non working aircraft. I plan to use my 170 for very short gravel bar work at redueced loads. I will be doing an engine upgarde & have read most of your opinions on wich ones are best. Seems the Franklin would be best, but without them being made anymore, I can't stomach the gamble it takes to buy one. What I would like to know are the facts of the upgrades, such as the weight of each engine upgrade, the cost, and any other information that will help me make my decision. My goal is to get as much power as I can, & keep the 170 as light as possible.
Please post your thoughts.
Thanks agian, proud to be one of you!
Doug

zero.one.victor · Post by **zero.one.victor** » Sat Sep 25, 2004 12:17 am

You can count on spending between $20K & $30K for an upgrade to an IO-360 Continental or an O-360 Lycoming. Probably about the same for a Franklin 350 (220 horse). depending of course on how fresh the engine is, how much of the work you hire out, etc. That's a lot of dough, in my book. I don't know what you paid for the 170, but add in the cost of the engine upgrade & you're probably gonna be getting close to the price of an early 180. Maybe that woulda been a better choice? (no offense intended, just my opinion--even thought I love 170's)
You emphasize that you want to keep it light, and will be operating off short gravel bars with reduced loads. You might consider just getting an 80" seaplane prop, and stripping the bejesus out of the airplane (interior & panel) to lighten it up. You might be surprised by what it can do. One of our members ("funseventy") has a real light 53 B model & flies it in the Idaho backcountry alot. It weighed in at an HONEST 1250 pounds before he decided to paint it. Lotsa guys claim theirs weigh 1250 or so ,but
unless it's been severely stripped I have my doubts. My ragwing is painted, & about average re: radios, etc ( but no gyro's or vacuum system, and only a single rear jumpseat) & it weighs 1310.

Eric

Doherty · Post by **Doherty** » Sun Sep 26, 2004 6:24 am

Ok, I will bite. Are you trying to tell me that a 180 will take off sooner than a C-170B with an IO-360 210hp? Any idea on the thrust to weight ratio between the two?

zero.one.victor · Post by **zero.one.victor** » Sun Sep 26, 2004 3:36 pm

Doherty wrote:Ok, I will bite. Are you trying to tell me that a 180 will take off sooner than a C-170B with an IO-360 210hp? Any idea on the thrust to weight ratio between the two?

No, I'm not trying to tell you that one will necessarily take off shorter than the other. Probably be pretty close in that department. I'm saying that considering overall performance for dollars spent, the 180 might be a little ahead. Say you have the same money into a hotrod 170 & an early 180. I believe that the 180 will carry a bigger payload, faster. Plus, you don't have the airplane down for several months doing the conversion. Of course, you will be burning somewhat more fuel per hour too.
My point was that you don't necesarily have to put a bunch of time & money into an engine upgrade, maybe you can get the performance you're looking for with a prop replacement (or even just a repitch), and some thoughtful weight reduction.
Reagrding power/weight ratio:
hotrod 170: 1400# empty + 180 + 240 gas = 1820# / 210 horse = 8.7
180: 1600# empty + 180 + 300 gas = 2080# / 225 horse = 9.2
or 2080# / 230 = 9.0
at gross weight
170: 2200 / 210 horse = 10.4
180: 2550 / 225 = 11.3, 2550# / 230 = 11.0
stock 170: 2200# / 145 = 15.1
But remember that numbers don't necesarily tell the whole story. As they say, figures don't lie, but liars can figure.

Eric

Doherty · Post by **Doherty** » Sun Sep 26, 2004 7:47 pm

Hi Eric. Thanks for responding. I hope I get more people to respond as well, I am
looking for actual cost. I figure there should be 170 owners out there that wouldn't
mind sharing this information. You are correct in observing that the 170 is not the
ultimate bush plane. But I am sure you agree, they sure are nice airplanes! I bought
mine because I got a good deal on it. To be honest, if I find I can get myself (250)
plus another 250 pounds out of a 500 foot long gravel bar with no obstacles with
the O-300, I don't think I will need the upgrade. However, if I find that I need more
like 800 feet for the above conditions (sea level, 40f) (half tanks) then the engine
upgrade may make perfect sense to me. I know its not a super cub, but if I fly it
light, I am hoping to keep from being not to far from it.
You mentioned it may take two months of downtime, this is good information, keep
providing me with solid stuff like that. I am curious, why it takes so long? I used to
fly a 185 and whenever we hit TBO, it went down in the eve, and was back up in
the air the next morning, with a new engine in it. I figure the motor mounts need to
be changed along with the rigging, some stuff if I go injected, but I just don't have
any experience with the details. That is why i am here.

doug8082a · Post by **doug8082a** » Mon Sep 27, 2004 12:44 am

Somebody stop me if I get the wrong info here (not that I wouldn't expect that from our famously quiet members

), but I seem to recall that some of the engine mods may require some of the following changes:

New engine mount
New baffling
New controls (i.e. prop control)
New gauges (i.e. MP)
Battery relocation to correct for CG changes
Cowling mods (Lyc 180)
Larger diameter fuel line
Other...

I'm not saying that all engine mods require all these changes. These are just some that I've picked up in hearing/reading accounts of Lyc 160/180, TCM IO-360, PZL Franklin 220 changes.

Then there's the paperwork and approval process which may or may not be easy depending on your choice of mod, diligence of your paperwork, and cooperation of you FSDO. All this can add up to a bunch of time.

This isn't meant to be a deterrent, just to point out why some of these take a while to do.

Punkin170 did the PZL Franklin conversion. Go to the Links section of the TIC170A website and you find his link there.

Doherty · Post by **Doherty** » Mon Sep 27, 2004 2:33 am

Thanks Doug. I do not see your post as a deterent, you are simply trying to supply me with the information I have joined the association to acquire. I think I will sit back and wait a few days to try to get some time for folks that have done the mods to respond. At this point, I am leaning very strong towards the TCM IO-360. I'll check out the Franklin thread.
Thanks again!

Doug D.

Roesbery · Post by **Roesbery** » Mon Sep 27, 2004 2:58 am

Might want to contact Dave Stoots in Fairbanks. 907-474-4039, stoots@gci.net , He should be able to give you some solid current numbers and comparisons.

mvivion · Post by **mvivion** » Mon Sep 27, 2004 3:34 am

Dave's latest ride has a Lycoming IO 360. Don't know what his approval basis was, but he's been pretty thorough. This conversion is on a 175, by the way.

Mike Vivion

blueldr · Post by **blueldr** » Mon Sep 27, 2004 4:27 am

I've done the Cont. IO-360 conversion and can give you plenty of info. Contact me via email or phone. Email me your phone number and a good time to call. I have cheap phone service.

Dick Lemmon
blueldr@earthlink.net
(916) 635-5566 Before 0900 or after 1800 pacific time.

ak2711c · Post by **ak2711c** » Mon Sep 27, 2004 7:04 am

Doherty, I think you are definitely going to need an engine upgrade to do what you are talking. My 170B is set up with a stock engine, Bore prop, 180 gear, 26" Gar Aero tires, and a Sportsman STOL kit and with that load my plane would use up around 700'. Keep in mind that is on a hard surface. If you get off airport on a beach or gravel that is a little soft you could easily add another 200'-300' to that. It takes very little adverse conditions to dramaticaly change the performance numbers with that stock engine. I do a lot of off airport landings with my 170B and it works fine you just have to make sure you know you and your planes limitations and think way ahead because it doesn't have the power to save you from poor speed or altitude managment. Good luck.
Shawn

2814C · Post by **2814C** » Tue Oct 05, 2004 8:33 am

Hi Doug,

I would agree with Shawn. I have a 170B with 180hp Lyc., 80' prop, Sportsman, and 180 gear. I don't have the VGs. Maybe some day?? My plane is heavy -- it's now near 1500 pounds. I plan to take out some heavy stuff some day. Anyway, I have flown off in far less than 500 feet at 2500' elevation, with 20 gals of fuel and roughly 400 pounds of people (counting me). The hp made a huge difference. A buddy in a very light stock 170B got off in about 550 feet at 2500' elevation, but with minimum fuel and just the pilot. The ground was nice and hard; no mud, and no obsticles to clear. A cold day with very little breeze.

It has been suggested that by the time you put the money into a conversion, you should instead buy a 180. Perhaps you could by a stock 180 for a little more (maybe), but I personally would rather have an upgraded 170B than a stock 180. Don't get me wrong, the Cessna 180 is a nice plane. My Dad had one for years and we really loved it. But, I respectfully disagree that going from a 170B to a 180 is an upgrade in performance. I believe that the upgraded 170B will haul more than most stock 180s, imho -- and I could be wrong. I believe an upgraded 170B will get off quicker than any stock 180 that I've seen. I also believe the 170B will get in shorter than the 180. I suspect, however, that there are 180s that perform quite well, perhaps better than an upgraded 170B, after adding modifications. But then you're adding more $$$ to the equation. I submit that the upgraded 170B is quite the performer! Better than most.

I have heard people say that the lycoming is bullet proof. Mine has been wonderful. As for the bigger Continental and the Franklin engines, I don't know. Many on this listserve have experiences with these engines.

Of course, these are just my opinions -- and everyone has opinions. Many may disagree. I'm a little biased and partial to my baby.

Take care and good luck.

Doherty · Post by **Doherty** » Thu Oct 07, 2004 2:17 am

Your friend who has a stock 170b, do you know what type of prop he has? It has been sugested to me, that with a floatplane prop, & a very light airplane, I may get the performance I desire. I operate at or near sea level at temps around freezing. If I could get a total of 500 pounds off in 500 feet with 1.5 hours of fuel, I would be happy. I have yet to give it a try. So far, I am still undecided about the engine upgrade, I am, however, going with the sportsmans STOL and VG's.

2814C · Post by **2814C** » Mon Oct 11, 2004 8:49 am

Hi Doug,

I don't know a whole lot about the short-field performance of the stock 170B, but this is the right group to ask. Note that I said that my buddy got off in 500 feet, but he was by himself, with no gear, and minimum fuel for a very short flight.

-Rob

Jr.CubBuilder · Post by **Jr.CubBuilder** » Mon Oct 11, 2004 6:38 pm

Doherty, I'll offer this for contemplation. I bought my 52, 170B a couple of months ago. It has no interior except the origional door panels, and a new wool headliner (Airtex) oh and the seats are there to. The plane is on early 180 gear, with 800x6 tires, a mid-time C145 and a 7648 prop that was repitched to 45. I don't know how soon it gets off the pavement exactly but I'm pretty sure that it's less than 2 football fields. With full tanks and me I'm climbing out at 1000fpm 65mph and 2600 on the tach. If I let the nose drop off a little the motor wants to over-rev to much for my taste. It also only gets 85mph for cruise at about 2350rpm. It'll do 95-100 but that's just beating the piss out of the motor and burning a lot more gas, it's not worth it for 10-15mph. There's also a noise issue, the harder I run that motor the louder it is. So I'm thinking about buying a cruise prop later on, or having this one pitched back to 48".

I would suggest flying it for a while before you do anything to it. I suspect that you will find yourself having to address other mechanical bugs right off the bat, at least that's what's been happening to me I've been busy fixing leaky valve cover gaskets, a sump drain that started leaking, my tach is about to expire, and now it looks like my gascolator is in need to some TLC.

I still have some vacation left though, the sun is shinning, so I think I'll take my tach squealing, gas dribbling, oil stained old bird for a fly this afternoon.