Franklin 165 oil burn
- Thread starter dtreid
- Start date
Dan Cullman
New member
I would say that anything less than 1 qt./4 hours is acceptable. Continental is a lot more liberal with their engines. Make sure you are not "leaking" measurable oil.
In your part of the world, I'd be using a multi-vis oil in the winter and SAE 50 in the summer.
Dan
In your part of the world, I'd be using a multi-vis oil in the winter and SAE 50 in the summer.
Dan
Dan Cullman
New member
I think there are posts on drying up the Franklin. Most leaks are from old, hard pushrod housing packings.
Dan
Dan
blimpy
New member
I have 150.. so no idea about BURN-
but found the following leaks which were enough to decorate the whole
removeable belly plate in 1 or 2 hours of flying:
1. Tachometer drive. Actually mostly from bent "nut" that hold on the flex cable.
a new tack drive is about $90.. is only held in by two bolts.. and can be replaced
by the braille method. Stick a small digital camera in there and get the layout first.
1/4 " drive ratchet with short extension should make it easer.
2. External oil lines attached to the oil pressure relief assembly.
The screws were loose on the " hose clamps".
3. Front Engine Seal.
This is replaceable. $ 27 part. Seems to been a major source of leaked oil.
apparently this was a bit of a "bitch" for the experienced mechanic who did mine.
But when the cowl comes off next... give it a look, and if it is leaking.. do it.
4. Yes - like Dan C said - the pushrod tube seals leak. See archieves for various posts.
this can be done without removing cylinders or manifolds ! Real Gaskets again or
Larry L and Dan like double O-rings.
5. Rocker covers.. if you don't have Real Gaskets.. get 'em. Cheap and fast to do.
6. Read your engine manual - then make sure all the various engine cover and pan bolts are snug.
Do this every 25 hours like the manual calls out. Be gentle !
Never had any puddles that sounds extreme - but you can buy a metal drip pan at any auto parts store.
BTW... it is wise to wipe down the engine and inside of the cowl every time.
That accumulated oil can and will burn.
Seems almost impossible to separate Burn from Leaks.. unless you have Low Oil Pressure
which should be diagnostic of an engine well past it's prime.
Do you get much blow by out the vent tube ? That also would be diagnostic.
I have been adding a qt about every 4 hours... but think most is leaks.
Plugs are brown, and little out the crankcase vent tube.
Every time I fix another leak, I'm closer to knowing what is actually being burned.
And the belly stays a bit cleaner.
I use straight 80w ( 40 wt) per the manual. Previous owner used 100W.
1000 smoh.
but found the following leaks which were enough to decorate the whole
removeable belly plate in 1 or 2 hours of flying:
1. Tachometer drive. Actually mostly from bent "nut" that hold on the flex cable.
a new tack drive is about $90.. is only held in by two bolts.. and can be replaced
by the braille method. Stick a small digital camera in there and get the layout first.
1/4 " drive ratchet with short extension should make it easer.
2. External oil lines attached to the oil pressure relief assembly.
The screws were loose on the " hose clamps".
3. Front Engine Seal.
This is replaceable. $ 27 part. Seems to been a major source of leaked oil.
apparently this was a bit of a "bitch" for the experienced mechanic who did mine.
But when the cowl comes off next... give it a look, and if it is leaking.. do it.
4. Yes - like Dan C said - the pushrod tube seals leak. See archieves for various posts.
this can be done without removing cylinders or manifolds ! Real Gaskets again or
Larry L and Dan like double O-rings.
5. Rocker covers.. if you don't have Real Gaskets.. get 'em. Cheap and fast to do.
6. Read your engine manual - then make sure all the various engine cover and pan bolts are snug.
Do this every 25 hours like the manual calls out. Be gentle !
Never had any puddles that sounds extreme - but you can buy a metal drip pan at any auto parts store.
BTW... it is wise to wipe down the engine and inside of the cowl every time.
That accumulated oil can and will burn.
Seems almost impossible to separate Burn from Leaks.. unless you have Low Oil Pressure
which should be diagnostic of an engine well past it's prime.
Do you get much blow by out the vent tube ? That also would be diagnostic.
I have been adding a qt about every 4 hours... but think most is leaks.
Plugs are brown, and little out the crankcase vent tube.
Every time I fix another leak, I'm closer to knowing what is actually being burned.
And the belly stays a bit cleaner.
I use straight 80w ( 40 wt) per the manual. Previous owner used 100W.
1000 smoh.
Larry Lowenkron
New member
Just remember, Franklins are externally lubricated!
I use Aeroshell 15-50 in winter and Aeroshell 100 in summer. I agree with Dan on the oil burn. When I first got mine, I was burning one qt in 15 hrs - with 85 SMOH( I swore people were sneaking into my hangar and adding oil to it just to drive me crazy, I wasn't use to such a low oil burn as I always had older Continentals prior to that). Now at ~1300 hrs, I burn (leak, seep, blow out) 1 qt in 4 hrs. Also, I always had my Franklin "mark it's spot" ever since I got it. After a while, I stopped banging my head against a wall, and learned to live with it, and just wipe off my belly every few flights and try to be aware of new leaks/high consumption.
I use Aeroshell 15-50 in winter and Aeroshell 100 in summer. I agree with Dan on the oil burn. When I first got mine, I was burning one qt in 15 hrs - with 85 SMOH( I swore people were sneaking into my hangar and adding oil to it just to drive me crazy, I wasn't use to such a low oil burn as I always had older Continentals prior to that). Now at ~1300 hrs, I burn (leak, seep, blow out) 1 qt in 4 hrs. Also, I always had my Franklin "mark it's spot" ever since I got it. After a while, I stopped banging my head against a wall, and learned to live with it, and just wipe off my belly every few flights and try to be aware of new leaks/high consumption.
SoCalPlaneDoc
New member
I had a similar experience as Blimpy with the 150 that was in my Stinson and I'm also a believer in using REAL seals - the pushrod tubes are especially easy to change compared to other engines...
I also discovered that, although my engine ran beautifully, the valve guides had excessive wear and the engine was consuming oil through there... fixing that had a HUGE impact on oil consumption.
I also discovered that, although my engine ran beautifully, the valve guides had excessive wear and the engine was consuming oil through there... fixing that had a HUGE impact on oil consumption.
I wrote this last night and since then Socal commented on valve guides, so this ties in:
I think the following is interesting about Franklin oil consumption.
My 150 burned about 1 quart every 5 or 6 hours hopping around nearby southern cal airports and local flights. But suprisingly on long x-country flights, it burned almost NO oil.
I once flew from SoCal to Michigan to Louisiana using much less than a quart. It was always full throttle for 5 hours or so from take-off to top of descent. So the obvious quart every 5 hours consumption on local flights was due to the intake manifold vacuum sucking oil through the guides when the engine was mostly throttled during these flights. I was tempted to install seals on the intake valve stems to further research this but never did.
The cast iron surface of a Franklin cylinder can be a superb surface, apparently, if set up right. So, the potential for an engine that uses very little oil is there.
My engine was a Haglin overhaul with about 500 hours on it. Haglin was a highly regarded engine builder then. Also don't recall using anything but Aeroshell 80.
Ron
I think the following is interesting about Franklin oil consumption.
My 150 burned about 1 quart every 5 or 6 hours hopping around nearby southern cal airports and local flights. But suprisingly on long x-country flights, it burned almost NO oil.
I once flew from SoCal to Michigan to Louisiana using much less than a quart. It was always full throttle for 5 hours or so from take-off to top of descent. So the obvious quart every 5 hours consumption on local flights was due to the intake manifold vacuum sucking oil through the guides when the engine was mostly throttled during these flights. I was tempted to install seals on the intake valve stems to further research this but never did.
The cast iron surface of a Franklin cylinder can be a superb surface, apparently, if set up right. So, the potential for an engine that uses very little oil is there.
My engine was a Haglin overhaul with about 500 hours on it. Haglin was a highly regarded engine builder then. Also don't recall using anything but Aeroshell 80.
Ron
It appears that my Cruisair is going through a liter every 5 hours. I was rotating the spark plugs today and found the bottom plug on #6 to be full of oil. No oil ran out, it had just filled the spark plug up.
Is this anything to be terribly concerned by? The engine does fart around for a bit on cold startup and now I would assume that is from burning the oil out of that plug. Once warmed up, it runs like a champ.
Is this anything to be terribly concerned by? The engine does fart around for a bit on cold startup and now I would assume that is from burning the oil out of that plug. Once warmed up, it runs like a champ.
kitepilot
New member
dtreid said:
I found the same thing in my mid-right cylinder (from the cockpit, whatever number it is) and 2 mechanics recommended that I pulled the cylinder. It ended up being (words that I remember from the mechanic that overhauled the thing) a bad exhaust guide that was causing the valve to stick (I have the removed valve).
It was impossible to push the valve open with your fingers and he had to hammer it out.
After my experience, I'd pull that cylinder.
My guy ended up building all the tools to re-torque the cylinders and I'll be glad to publish the specs if somebody helps me with measurements and drawings.
I am a computer geek, I duno'bout real engineering...
SoCalPlaneDoc
New member
Removing a Franklin Cylinder isn't hard but there's a few things unique to the engine that, if not done correctly, can cause some real headaches later on (like the fastener tightening process). If you go that route be sure to educate yourself or find someone who knows Franks - and can prove it.
The good news is, Rings are still available
Valves stuck closed will cause pushrods to bend. If someone tells you your valve is stuck *closed* and your pushrod isn't damaged - be suspicious. Valves stuck *open* are much more common. Compression test can confirm that easily.
Back when I was a newbie mechanic and hadn't kissed a girl yet, I worked for a few different shops. Almost always when a customer brought a complaint that could be explained with a cylinder issue they went right to the "pull-and-overhaul" recommendation. Most often it wasn't needed but hey, they get a lot of money for labor that way.
Before you pull it, do a compression test and check the interior with a bore scope. If the intake valve is sticking it'll be obvious when it's running. If the exhaust valve is sticking you could see evidence on the valve.. If the rings are bad, you'll hear air leaks in the crankcase breather.
check it before you yank it.
ya know, it could be just a bad plug How's the mag check? have you tried swapping the plug to see if the new one gets oily too?
The good news is, Rings are still available
Valves stuck closed will cause pushrods to bend. If someone tells you your valve is stuck *closed* and your pushrod isn't damaged - be suspicious. Valves stuck *open* are much more common. Compression test can confirm that easily.
Back when I was a newbie mechanic and hadn't kissed a girl yet, I worked for a few different shops. Almost always when a customer brought a complaint that could be explained with a cylinder issue they went right to the "pull-and-overhaul" recommendation. Most often it wasn't needed but hey, they get a lot of money for labor that way.
Before you pull it, do a compression test and check the interior with a bore scope. If the intake valve is sticking it'll be obvious when it's running. If the exhaust valve is sticking you could see evidence on the valve.. If the rings are bad, you'll hear air leaks in the crankcase breather.
check it before you yank it.
ya know, it could be just a bad plug
How's the mag check? have you tried swapping the plug to see if the new one gets oily too?