Cessna 180 engine options
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We don’t have ethanol in gasoline in Ak. Never have. We used to have MTBE for a couple of winters but that was 20 years ago.
hotrod180
FRIEND
Port Townsend, WA
I've owned this 180 for about 8 years,
and have run it on mogas the whole time--
80% mogas / 20% 100LL until fuel prices got so high,
and pretty much 100% mogas since then--except on trips when mogas isn't available.
The previous owner had it for about 15 years and I believe he ran it mostly on mogas also.
No bladder issues.
Yes, the Ponk engines are (i think) 7.5:1 compression instead of the stock 7:1,
I know people who run mogas in them with no problems.
However, as far as I know, mogas isn't approved for use in this engine by the engine STC or by a separate STC.
Running unapproved fuel is like flying out of annual, or without a medical, or without a current flight review--
everything is fine until it isn't.
I don't want to have a mishap one day & have my insurance refuse to cover any damage because of unapproved fuel.
I'd like to see EAA or Petersen add the ponk engine to their mogas stc's, or have Northpoint add it to the engine stc,
but I doubt either of those things is gonna happen.
Charlie Longley
MEMBER
Anchorage, AK
I’ve moved onto a Super Cub but owned a 180 for a bit and flew another 180 with a Pponk engine.
My 180 was a 1954. I ended up putting a heavy case O470R on it with a Mac seaplane prop along with Leading Edge exhaust. I was very happy with it. I did formation take off with my friend in his 1953 with a J engine and would walk away from him on takeoff and climb.
The 180 that I flew with a Pponk might have been a 1955 I don’t recall. It also had a seaplane prop on it along with a Snider speed mod. It was very fast. Into the yellow arc around 23 squared.
For tooling around on my own time I would prefer my old 180. If I was working the airplane I would’ve preferred the Pponk 180.
My 180 was a 1954. I ended up putting a heavy case O470R on it with a Mac seaplane prop along with Leading Edge exhaust. I was very happy with it. I did formation take off with my friend in his 1953 with a J engine and would walk away from him on takeoff and climb.
The 180 that I flew with a Pponk might have been a 1955 I don’t recall. It also had a seaplane prop on it along with a Snider speed mod. It was very fast. Into the yellow arc around 23 squared.
For tooling around on my own time I would prefer my old 180. If I was working the airplane I would’ve preferred the Pponk 180.
Upping engine displacement in a 180 isn’t much different than doing it in a Cub. The biggest advantage is rate of climb and the heavier the plane the bigger the advantage. Since my primary mission was flying family and friends to and from a 1000’ strip with 100’ trees on the end, additional clearance over those trees in unfavorable winds was what I was looking for.
I’ve told this story before but the first time my wife rode in the plane after the Pponk-C401 3-blade upgrade we weren’t even at 1000’ off of Lake Hood strip yet and she said that was the best money I’d ever spent on an airplane. And to further qualify, the Pponk replaced a 100 hour factory reman and 88” seaplane prop, so not a weak or worn out engine. There’s no replacement for displacement.
I’ve told this story before but the first time my wife rode in the plane after the Pponk-C401 3-blade upgrade we weren’t even at 1000’ off of Lake Hood strip yet and she said that was the best money I’d ever spent on an airplane. And to further qualify, the Pponk replaced a 100 hour factory reman and 88” seaplane prop, so not a weak or worn out engine. There’s no replacement for displacement.
skywagon8a
MEMBER
SE Mass MA6
That's for a 2400 rpm engine. Low pitch 15.0* High pitch 29,4*
Propeller and 1. McCauley constant speed propeller (threadless) (landplane, skiplane) Propeller Limits (a) Hub C2A34C204, blade 90DCB-8 Diameter: not over 82 in., not under 80.5 in. Pitch settings at 30 in. sta.: Low 15.0°, high 29.4°
https://drs.faa.gov/browse/doctypeDetails?modalOpened=true
I’d imagine it was little if any. Like an 86” vs 88”. I remember Steve Knopp testing the C401 in both lengths and finding no thrust difference. As he said, the only thing the 2” did was make noise.
It's also, very noticeable in takeoff distance on floats. And, as you point out, even more noticeable when you're heavy. Haven't tried it but I bet it would fly hundreds of pounds over gross where I suspect with the O-470 it wouldn't get on step (which is actually a safety benefit making it impossible for someone to fly with a stupid load).
It's still noticeable when light though. Most of the aircraft based on our lake are Cub's. When the 180's light (me and about half tanks) I break water in about the same place they do. I'm pretty sure it climbs better as well. Then I get to cruise at 142 MPH. I just pay for it with fuel.
Pitch stop? Can’t they achieve RPM by adjusting the governor? My pitch stops are set properly per spec and I know I can make it spin 2900 because it did it one summer. Everyone knew my plane without looking, because of the noise. It sure did perform well. Dial yours up to 2700 and you’ll gain more than 2” of prop can provide.
mvivion
FOUNDER
Bozeman,MT
Never underestimate the raw skills of pilots doing stupid things in aircraft, you might be surprised.
MTV
Back in the 90's I flew a 206 down to Wipline for refurbishing, installation of their copilot door, 4000 amphibs and an IO-550. They told me during flight testing they were able to get their testbed 206, with 4000 straight floats, in the air with such a load they were unable to fly it out of ground effect. We latter installed Wip 4000 straight floats on our 206 and were amazed at the ability of that aircraft to climb up on step when HEAVY, something the 3430's would never do. The takeoff run was amazingly long. We joked you needed a Six Pack License to carry five passengers in that airplane (speed boat).
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mvivion
FOUNDER
Bozeman,MT
Actually, those floats will fly out of the water nicely at 3800. I flew 185s at 3350 on late PeeKay 3500s, and EDO 3430s out of the Fairbanks float pond. Then I was handed the keys to an IO 550 206 on Wip 4000 straight floats. I cursed them for a while, till I figured out to get them to fly….on the step, a hard shove on a rudder, and the thing would come unstuck. Felt awkward, but after a few more trials, that thing would come out of the water at 3800 pounds all up, within a 100 feet or a little more of where those 185s launched, at 3350. And it’d climb away.
A great working airplane, that one.
MTV
Taking the thread a little off topic but I loved the way those 4000's step turned. Felt like you were sitting in your Lazy Boy back home. My CAP's are scarry.
I have a question that I thought would be easy to find an answer for.. How can I legally put an O470-L in my 1955 C180? Been searching quite a bit and maybe it's not complicated, but I haven't seen a solution. The title of this thread is perfect for my question..
Thanks.
Thanks.
Should be (but probably not anymore) an easy field approval as your 180 is approved by the TCDS for a O-470-K. I understand there are very minor differences between a K and an L. I've been told it's the tack drive but, in all honesty, I never validated that. I believe Continental allows in the field changes to engine model designations. You may have to call them as it now appears all links to that service letter take you to a dead end. You could then convert the O-470-L to an O-470-K and bolt it in (kind of). Do you currently have an O-470-A/O-470-J in it?
skywagon8a
MEMBER
SE Mass MA6
This is from the TC E-273. It does not appear to be a direct bolt in exchange.
"O-470-K is similar to O-470-J except for ratings, crankshaft damper configuration and incorporation of shell-
molded cylinder heads and revised mounting brackets.
O-470-L is same as O-470-K except for relocated carburetor and revised intake manifold oil sump."
hotrod180
FRIEND
Port Townsend, WA
I just read all the way through this old thread, saw some mentions of converting an A or J engine to a K or R.
Still not sure how feasible that is, due to cylinder attach details, but apparently it's possible.
Seems like if that's possible, converting an L engine to a K
("O-470-L is same as O-470-K except for relocated carburetor and revised intake manifold oil sump.")
should certainly be possible, and less work to boot.
And as pointed out, the K is legal to install on a 55 per the TCDS.
I'm pretty sure though that it must be installed as per the factory K installation--
later engine mount, single exhaust, etc).
If you're gonna run your existing dual exhaust (by installing 4 bolt flanges),
and existing engine mount (by installing the crankcase legs from the J onto the L),
you might need a field approval.
Still not sure how feasible that is, due to cylinder attach details, but apparently it's possible.
Seems like if that's possible, converting an L engine to a K
("O-470-L is same as O-470-K except for relocated carburetor and revised intake manifold oil sump.")
should certainly be possible, and less work to boot.
And as pointed out, the K is legal to install on a 55 per the TCDS.
I'm pretty sure though that it must be installed as per the factory K installation--
later engine mount, single exhaust, etc).
If you're gonna run your existing dual exhaust (by installing 4 bolt flanges),
and existing engine mount (by installing the crankcase legs from the J onto the L),
you might need a field approval.
hotrod180
FRIEND
Port Townsend, WA
I'm curious about this "Scootair STC",
who can tell me about it?
I googled it but didn't come up with anything except a link to this 2011 post from this thread.
Agreed. You also need to use the J induction system for the carb to line up with the existing airbox so you can still use the original lower cowl. I do know of several 180's where these part swaps were all done with a K engine and only a logbook entry using the term "per the TCDS". I guess the argument is the parts changes are all "minor", with the only major change being the welding of the four stud exhausts flanges. Not saying this is "legal" just saying those aircraft are still flying 40 years later. Lots of differing opinions on even installing an O-470-K, using all the associated K parts, (engine mount, air box, exhaust, lower cowl) in a 53 through 55 without FAA approval due to serial number.
Another note. All the discussed A-J part swaps and the exhaust flange change are standard procedure when installing the O-470-50 STC in early 180's. Should be an easy field approval. But I doubt the FAA will play ball anymore. Best to hire a DER. Enough available data out there. Use the S engine by just swapping the oil sump and pan from the J.
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Correction: I stated above, use the S engine by swapping the oil sump and pan from the J. I meant use the L engine by swapping the oil sump and pan from the J. I didn't check the part numbers, but I think they may be the same as a K. You would then have an identical engine install to many other 53-55 180's with K engines, except for the data tag on your L engine. If you do have to change the oil pan, ensure you change to the correct dip stick.
hotrod180
FRIEND
Port Townsend, WA
The 470A in my 53 was replaced with a 470K back in 1993.
There's two field approved 337's--
one is for replacing the crankcase legs on the K with those off the A
(to facilitate using the original engine mount).
The other is for "the only deviations to the manufacturer's O-470K engine installation as to follows":
1) retaining the original engine mount p/n 0751000
2) modifying the original exhaust to 4 bolt flanges
3) replacing the original Mac C36 prop with a Mac C203. This was done under an STC but the original spinner assembly was retained.
There's a fairly extensive & detailed work order ( 4 pages worth) from the shop doing the work.,
that also included installing / modifying the baffling & installing a different oil dipstick.
Nothing was said about changing the induction system or oil pan.
There's two field approved 337's--
one is for replacing the crankcase legs on the K with those off the A
(to facilitate using the original engine mount).
The other is for "the only deviations to the manufacturer's O-470K engine installation as to follows":
1) retaining the original engine mount p/n 0751000
2) modifying the original exhaust to 4 bolt flanges
3) replacing the original Mac C36 prop with a Mac C203. This was done under an STC but the original spinner assembly was retained.
There's a fairly extensive & detailed work order ( 4 pages worth) from the shop doing the work.,
that also included installing / modifying the baffling & installing a different oil dipstick.
Nothing was said about changing the induction system or oil pan.
Sounds like your conversion was done the way I did my original O-470-J to an O-470-R. It was easy to do things the right way back in the day when you could get field approvals easily. Now a days one gets punished with delays and rejections when one tries to dot all the I's and cross all the T's.
Your engine is a K, SuperCubs is an L. According to the O-470 parts book (you made me dig it out) both the intake manifold riser and the oil pan are different on an L as opposed to a J and K., (which both use the same part numbers). The L intake manifold riser is the same riser used on the R. I know I had to swap the intake manifold riser of the R with the one on the J for the carb/airbox to line up with the lower cowl.
Good point on the engine baffling. The A's and J's cylinders are different thus have different baffling. If SuperCub has the L baffling still on his low time engine, that will fit the install perfectly.
I do agree with stewartb about the Pponk, especially if you fly floats and skis. It makes a real airplane out of it. Although I had, (and others I've read reports on), carb issues, requiring me to run excessively rich all the time just to keep a rear cylinders EGT plus 75 degrees from peak. I was able to fix that by installing an RSA fuel injection system. Again, all back in the days of reasonable FAA cooperation.
If I had a low time O-470-L I'd probably bolt it in, fly the heck out of it, while searching for a mid-time IO-520-D. The easiest stock engine to do the Pponk conversion to a 180. You would also get the heavy case and VAR crank, and an engine built for 2850 RPM that you now run at 2700 RPM. It will probably last forever if run correctly.
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