My 180 needs an overhaul, should I overhaul the 470A or consider a new model of the 470? This is a Midwest based airplane that is used for my personal flying only. I don’t have any interest in more horsepower or turbos, just simple VFR flying.

I'd say it depends on how your "A" was put together----assuming it has been overhauled sometime in the past.. My 54 came with an A that Pacific Continental overhauled in 1972. It had round intake runners just like a J instead of the square originals.. The crankshaft was the same as an R except it had smaller bolts for the timing gear. The case was the same as an R except it had smaller through bolts, starter drive and oil pump were different. Had a bushing instead of a needle bearing for the starter drive in the crankcase. If your crankcase, crankshaft and accessories are still good for awhile, I wouldn't be scared of keeping the A and put 4 ring pistons in. If you could find a good J that would fit nicely too as far as baffling. A friend had a J that had the same exact bottom end as an R so he could have just bolted R cylinders on and changed the baffling. Pacific Continental put a big oil cooler on my A that would be like on later Cessna's and when I changed to my K I used it. Never had an oil temperature problem.

I had a '54 180 I bought in 1992. It had an A in it when I bought it and ran fine but was near TBO. At the time everyone was of the mindset of "if its an A then walk away." My motor served me well for about 200 hours. I decided to replace it with a J for the above mentioned reasons. I'm not sure of parts availability and overhaul capability in the future if you were to overhaul. I think I'd go for a J if I were in your shoes.

I'm sure you will get lots of opinions but ultimately make a great decision.

MW

It's pretty common for owners of early C180's to replace the A or J engine with a K or R.
Therefore it seems like there should be a fair number of J engines out there & available.
I don't necessarily subscribe to the "if it's an A, walk away" school of thought,
in fact I've heard the same thing said of J's,
but given my druthers I think I'd go for a J instead of an A.
I do know several people who've run their J engines to TBO (and beyond),
if I was in the market to buy a 180 I sure wouldn't turn my nose up at one if it had a J engine.

FWIW my own 53 model was upgraded back about 1993 from an A to a K,
and I've been very happy with it the 5 years that I've owned it.
A hundred plus hours past TBO now, and all's well.

My 180 had an A, great engine. Having said that, if I were in your position I’d be seeking a K engine for replacement. If your 180 has an A, I assume it’s a ‘53 or ‘54 model. If so, the K engine is already on the Type Certificate, no STC required. I say this mostly for resale purposes, as the K is a more desirable engine. Will need to have 4 bolt exhaust flanges added to your manifold, and I believe you will also need to use the A’s engine “legs” to attach to the original engine mount. As well as my A served me while I owned my 180, I think that overhauling an A would be throwing good money after bad. Now would be the most economical time to swap it out with a K. Best of luck on whatever you decide.

I went back and found some old logbook entries. I put a K in my '54 way back when. Not a J. Sorry for any confusion.

upnorth180 wrote:…. If your 180 has an A, I assume it’s a ‘53 or ‘54 model. If so, the K engine is already on the Type Certificate, no STC required. I say this mostly for resale purposes, as the K is a more desirable engine. Will need to have 4 bolt exhaust flanges added to your manifold, and I believe you will also need to use the A’s engine “legs” to attach to the original engine mount......

My 53 model was upgraded to a K using the original mount & engine case "legs".
IMHO the rubber mounts for that early A/J mount are much inferior to the rubber mounts for the K & later mounts,
for one thing they deform & need replacement much sooner.
There's actually a very early service bulletin which authorizes using the later mount with the A or J engine.

for one thing they deform & need replacement much sooner.

Since I put the MT two blade prop, the original style Lord Mounts don't seem to be sagging after almost 10 yrs. With the heavy Hartzell and 88 Mac I've had in the past, they'd be sagging. Another plus for MT in my opinion plus I am happy with how smooth it runs.

Yup, just goes to show you there's more than one way to skin a cat.
I like my Mac C203,
I'm planning on changing to the later mount & rubbers at engine overhaul time.
I already have the later engine case legs.

upnorth180 wrote:…. I assume it’s a ‘53 or ‘54 model. If so, the K engine is already on the Type Certificate, no STC required....

I can't find it now, it's not on the TCDS,
but I kinda recall reading something about putting a K engine on a 53-54 C180 required it to be installed as per Cessna drawing # xxx.
I'm sure this is the engine installation drawing for a model which had the K engine as standard.
Might be worth looking into if you go that route.

My own K engine was installed (like many others) on an A/J mount,
there were two separate field approval 337's done to document
1) modifying the K engine by installing the earlier legs, &
2) installing it on the airplane.

Thank you for all the objective opinions. My A engine is running well, has good compression but is sliming the belly with lots of oil. Removed a 6” breather extension, running the engine at 9 Qts but still the same issue. Engine was last overhauled decades ago but low time. My decision now is to overhaul or replace based somewhat on your replies..

180Marty wrote:….. A friend had a J that had the same exact bottom end as an R so he could have just bolted R cylinders on.....

Not sure if it's the cases, cam, or just what,
but it's my understanding that the angle valve cylinders (470K and up) are not compatible with the early 470A/J case.

PiperGoose wrote:... My A engine is running well, has good compression but is sliming the belly with lots of oil. ….Engine was last overhauled decades ago but low time. .....

With that said, it might be overkill to do a major overhaul.
Even though it's got good compressions, could it be that blow-by past the rings is causing a lot of oil to puke out the breather?
Maybe freshening up the top end (and adding 4 ring pistons if you don't already have them) might do the trick.
Or is the oily belly due to engine oil leak(s)?

As far as staying with the A or upgrading goes,
IMHO if you've been happy with your A model engine maybe you should stick with it.

but it's my understanding that the angle valve cylinders (470K and up) are not compatible with the early 470A/J case.

My friends's J had a Phase 1 crankcase and my K has a Phase 1 CC. They both use the same bearings and the cam is the same. I still have my original A crankcase and the K crank would work in it since the bearings are the same. The difference on that crankcase is---the breather is at the back and not up front left. There is an Acorn nut on the oil galley at left rear to adjust oil pressure since the oil pump is different. Starter drive goes into a bronze bushing instead of a needle bearing in the CC and my A had 7/16 through bolts instead of 1/2 ( could be machined out to 1/2 in). I remember my friend got a different cylinder for his J and it would not fit until he drilled it out for the 1/2 in through bolts. It was for a E225 or A model. Then when it comes to cylinders for the straight valves-----there is a 453 light cylinder and 727 heavy that are the last three digits in the casting number. My A from Pacific Continental had a mix of those two numbers.

It is on the TCDS. A C180 (53/54) May be equipped with an A,J or K engine.

http://rgl.faa.gov/Regulatory_and_Guida ... Rev_68.pdf

Another thing to consider with engine changes is W&B.
When they converted my 180 from a 470A & Mac 2A34C1 prop to a 470K & Mac C203 prop,
the W&B revision shows it gained 26 pounds.
Near as I can figure from the information I've got,
the C1 prop weighs 64 pounds & the C203 comes in at right around 50.
So the K engine may be as much as 40 pounds heavier than the A.

So the K engine may be as much as 40 pounds heavier than the A.

According to Wiki, the A and J are 26 lbs lighter than a K. R is 3 lbs lighter than a K which must be because of fewer counterweights.

hotrod180 wrote:

PiperGoose wrote:... My A engine is running well, has good compression but is sliming the belly with lots of oil. ….Engine was last overhauled decades ago but low time. .....

With that said, it might be overkill to do a major overhaul.
Even though it's got good compressions, could it be that blow-by past the rings is causing a lot of oil to puke out the breather?
Maybe freshening up the top end (and adding 4 ring pistons if you don't already have them) might do the trick.
Or is the oily belly due to engine oil leak(s)?

As far as staying with the A or upgrading goes,
IMHO if you've been happy with your A model engine maybe you should stick with it.

Wet vacuum pump blowing oil? Ya never know......