Found Loose Cylinder Bolt

On preflight I noticed a little oil seeping around the bolt on the
pilot's front cylinder (Superior Milleniums). This is on a '67 C150
w/ the Continental O200. I grabbed the bolt and turned it @ 2 1/2
times until it was finger tight against the cylinder.

Partner and I have grounded the plane. The gents hanging out at the
FBO say, put a wrench on her and fly the darn thing. We'd prefer to
stay safe, legal and alive.

Anyone else experience this and what am I in for? Thanks folks.

Greg

"Greg Hopp" wrote in message
om...
On preflight I noticed a little oil seeping around the bolt on the
pilot's front cylinder (Superior Milleniums). This is on a '67 C150
w/ the Continental O200. I grabbed the bolt and turned it @ 2 1/2
times until it was finger tight against the cylinder.

Partner and I have grounded the plane. The gents hanging out at the
FBO say, put a wrench on her and fly the darn thing. We'd prefer to
stay safe, legal and alive.

Anyone else experience this and what am I in for? Thanks folks.

Greg

Yeah, use a torque wrench and tighten it to its lower or middle torque limit
and go fly. Check the torque on the rest of the nuts too. You should be
tightening a nut instead of a bolt. There are two sets of torque values on
those nuts because they go on bolts (or studs) of two different diameters.
AN5 and AN6? You're probably going to have to use a special wrench for the
torque wrench to connect to, but there should be plenty of those around to
borrow. There are here.

Partner and I have grounded the plane. The gents hanging out at the
FBO say, put a wrench on her and fly the darn thing. We'd prefer to
stay safe, legal and alive.

Anyone else experience this and what am I in for? Thanks folks.

Were all the bolts lose, or just one?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

In article , Greg Hopp wrote:
Partner and I have grounded the plane. The gents hanging out at the
FBO say, put a wrench on her and fly the darn thing. We'd prefer to
stay safe, legal and alive.

Don't just crank it down with a wrench! In general, every bolt connecting
everything to your engine has a proper torque. A lot of those torque settings
are way lower then you'd think, and you can overtorque things easily.

With that said, you have two choices he

A) Put a torque wrench on it, tighten it and then fly it. Torque
settings are in the Lycoming Direct Drive Overhaul Manual (~$17 for a
reprint from Aircraft Spruce, or find the equivalent Continental
publication). Check it every few hours.

B) Take it to your A&P. He will pull out his torque wrench, his copy
of the Lycoming Direct Drive Overhaul Manual, tighen it, and tell you
to check it every few hours.

It's up to you.

Tina Marie
Tripacer N3653P
--
http://www.tripacerdriver.com "...One of the main causes
of the fall of the Roman Empire was that, lacking zero, they had no way
to indicate successful termination of their C programs." (Robert Firth)

In article ,
Greg Hopp wrote:
On preflight I noticed a little oil seeping around the bolt on the
pilot's front cylinder (Superior Milleniums).

A guy across the hanger row from me lost a cylinder in flight on a
relatively new (60-70 hour) engine. Looking at the studs it appeared
that one bolt had been lose and backed off, allowing the other 3 to
shear off. I'd be looking at what kind of damage might have happened
to the adjacent studs while the bolt was loose.

--
Ben Jackson

http://www.ben.com/

"Ben Jackson" wrote in message
news:jMcYb.46366$uV3.92300@attbi_s51...
In article ,
Greg Hopp wrote:
On preflight I noticed a little oil seeping around the bolt on the
pilot's front cylinder (Superior Milleniums).

A guy across the hanger row from me lost a cylinder in flight on a
relatively new (60-70 hour) engine. Looking at the studs it appeared
that one bolt had been lose and backed off, allowing the other 3 to
shear off. I'd be looking at what kind of damage might have happened
to the adjacent studs while the bolt was loose.

What kind of engine only has three studs/bolts holding the cylinder on?
OBTW nuts go on studs not bolts.


--
Ben Jackson

http://www.ben.com/

"Dave Stadt" wrote in message
...

"Ben Jackson" wrote in message
news:jMcYb.46366$uV3.92300@attbi_s51...
In article ,
Greg Hopp wrote:
On preflight I noticed a little oil seeping around the bolt on the
pilot's front cylinder (Superior Milleniums).

A guy across the hanger row from me lost a cylinder in flight on a
relatively new (60-70 hour) engine. Looking at the studs it appeared
that one bolt had been lose and backed off, allowing the other 3 to
shear off. I'd be looking at what kind of damage might have happened
to the adjacent studs while the bolt was loose.

What kind of engine only has three studs/bolts holding the cylinder on?
OBTW nuts go on studs not bolts.

There would be six nuts holding each of four cylinders down on an O-200
Continental, the standard engine on a Cessna 150. IIRC, 2 are AN5 and 4
are AN6, i. e., the stud diameters are 5/16" and 3/8" respectively. I
watch my nuts, you should pardon the expression. They have anti-sabotage
paint on them and palnuts are even better. Torque is often not enough to
hold them from backing off, and they certainly do not have (and are not
supposed to have) lockwashers under them.



--
Ben Jackson

http://www.ben.com/

In article ,
Tina Marie wrote:

In article , Greg Hopp wrote:
Partner and I have grounded the plane. The gents hanging out at the
FBO say, put a wrench on her and fly the darn thing. We'd prefer to
stay safe, legal and alive.

Don't just crank it down with a wrench! In general, every bolt connecting
everything to your engine has a proper torque. A lot of those torque settings
are way lower then you'd think, and you can overtorque things easily.

With that said, you have two choices he

A) Put a torque wrench on it, tighten it and then fly it. Torque
settings are in the Lycoming Direct Drive Overhaul Manual (~$17 for a
reprint from Aircraft Spruce, or find the equivalent Continental
publication). Check it every few hours.

B) Take it to your A&P. He will pull out his torque wrench, his copy
of the Lycoming Direct Drive Overhaul Manual, tighen it, and tell you
to check it every few hours.

It's up to you.

Tina Marie
Tripacer N3653P

According to my Lycomung Overhaul Manual, the cylinder torque settings
a

1/2" base nuts: 600 in-lb (50 ft-lb)

3/8" base nuts: 300 in-lb (25 ft-lb)

Tightening sequence: (1/2" first)

On the O-235, tighten as if you have 1/2" bolts, too

1/2" 3/8"

4 1 4 1

3 2 3 2

"Orval Fairbairn" wrote in message
news ...
Tightening sequence: (1/2" first)

This is something I was thinking of. What happens if one comes loose?
Should you just tighten it to thee correct torque, or should the others be
loosened then all tightened in sequence? Maybe even replacing the
gasket? (don't know about gaskets...I would only guess as to the
presence of one)

Paul

90% of engineering is common sense and only 10% is an incredibly complex
science... Luckily the first 90% is what keeps common machines running, and
that last 10% is reserved for machinery like the space shuttle, mars
explorer, etc..
denny
"
The gents hanging out at the
FBO say, put a wrench on her and fly the darn thing.