• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

Continental oil pressure

B

bob turner

Registered User
I know the little Continentals run fine when the pressure drops, but mine is now getting to the bottom end of my comfort zone. C-85-12, undersize crank, maybe 1800 SMO. Makes 50 psi on startup, 80 degree day, but when the oil hits 180 degrees it is significantly below the magic 30 psi mark at cruise rpm.

I am expecting worn out main bearings, but wondering if a worn out oil pump can do the same? I am just going to slam a new stroker on the airplane, but the question: should I rebuild the oil pump and try it again, or is it time for new bearings?
 
significantly below the magic 30 psi mark

Whats that mean? 20 psi? A really smart man told me once that in his racing engines if he had a pound of pressure for every 100 rpm the engine was in fine shape. So if you are cruising @ 2400 rpm, 24 psi is just fine. I have a C-90 and @ 180 degree oil temp I start seeing 28-29 psi and I get all puckered up, but after talking to several people who run these little Continentals I think that I am overreacting

Pat
 
Yeah, I think 28-29 psi when the oil is hot is ok. I have flown coast to coast like that.

I am almost sure it is the bearings, although they should last longer than 1800 hours. Maybe the crank was turned by an incompetent shop.

Anyway, I will check with Plastigage and report back. Normal clearances are around six thou.
 
bob turner said:
Yeah, I think 28-29 psi when the oil is hot is ok. I have flown coast to coast like that.

I am almost sure it is the bearings, although they should last longer than 1800 hours. Maybe the crank was turned by an incompetent shop.

Anyway, I will check with Plastigage and report back. Normal clearances are around six thou.
Click to expand...

Wow, .006 is a LOT. If that's spec. then so be it, but that number surprises me.
 
Bob it's probably your bearings but Divco did some magic on my Acc case 700 hrs ago. Gauge was overhauled by Keystone before switch. I had low idle pressure before.

That 46+ psi at 200



Glenn
 
Last edited:
Could be bearings, could be something more sinister. I had similar symptoms and ended up with a complete overhaul and new case. Hope it's an easier fix for you!

IMG_2537 (2).jpg
 

Attachments

  • IMG_2537 (2).jpg
    IMG_2537 (2).jpg
    154.7 KB · Views: 808
Another place to look for a few pounds is the oil pump cover plate. If it doesn't fit perfectly, there is oil loss right from the pump.I have been told that removing the plate and lapping it flat can help. There would be a telltale stain between the mating surfaces where the oil was leaking through when you remove the plate. I hope you might be that lucky for an easy fix but the O200 crank will make an imrovement on the fun meter.. jrh
 
I did that with the stroker. (Lap the plate). My idle pressure is more or less ok - the cruise pressure is not much better when hot. I am running 50-weight, which is heavier than really necessary.

This isn't going to be difficult, since the bottom end of the stroker is essentially done. All I need to do is clean and hone the cylinders, and install the thing. I am just wondering if I should have both oil pumps redone.
 
continental oil pressure

Clearance from manual for both Main and Rod is Min: .0005 to Max .0035. Service Maximum is .006. As mentioned before...."that's a lot".
 
3Point said:
Clearance from manual for both Main and Rod is Min: .0005 to Max .0035. Service Maximum is .006. As mentioned before...."that's a lot".
Click to expand...

That is what the 80 plus year old tractor mechanic says, but it works. Gotta remember it is air cooled.
 
This is the end result from Famcypants picture, 10 minute flight, wiped out crank, cam, and case.
 

Attachments

  • IMG_0054.JPG
    IMG_0054.JPG
    93.7 KB · Views: 536
bob turner said:
....This isn't going to be difficult, since the bottom end of the stroker is essentially done. All I need to do is clean and hone the cylinders, and install the thing. I am just wondering if I should have both oil pumps redone.
Click to expand...

When in doubt......
Easier and cheaper to do that now, eh?
Rather than deciding you need to do it later (after engine is hung and running).
 
Hung and running on a J-3 is not a big deal. We just have to be careful - airport authorities are really uptight about taking fuel lines apart, and to yank the engine we need to uncouple the carb.
 
bob turner said:
Hung and running on a J-3 is not a big deal. We just have to be careful - airport authorities are really uptight about taking fuel lines apart, and to yank the engine we need to uncouple the carb.
Click to expand...

I'd wait till they were around close and bust a fuel line loose and dump water al over the ground. That oughta stroke them out.
 
Well, the weather cannot be beat. But we now have rush hour traffic beginning around 2 PM. All my movements avoid most of our regulatory and population problems, and I am old enough to realize that I will check out before it becomes intolerable to deal with.

if the doubling time remains the same, we will hit fourteen billion in maybe 40 years. How many outhouses . . .
 
Steve - the ornery in me wants to do that. But no - better to close the doors first. Go along to get along, and keep the pressure on the city council.
 
I have seen Lucas oil treatment raise pressure nearly 10 psi and lower temp about 10 degrees. Not certified but..
it works 100 hrs plus


Sent from my iPhone using SuperCub.Org
 
Yeah. I heard oatmeal works. I have decided something serious is going on - that center web has been known to break.
 
What are we worried about. i passed a car in my Chevy truck today and looked at 5,000 + rpm and 40psi on the gauge. Why are we worried about 25 to 30psi at 2300rpm

Glenn
 
Well, maybe you are right. I figure that when the oil goes to 15 psi at cruise rpm something is seriously wrong, but by golly it makes the same noise as the 40-psi bird and develops full power. Even the lifters seem happy.

But the stroker is almost ready to hang. I should have more info shortly. Good thing I have two Cubs, huh? Three landings a day unless I am paralyzed or daid.
 
By the way, the offending engine is sort of strange. I will post a photo soon - maybe somebody can tell me what it really is, and whether it has any antique value.
 
Does it have a protrusion on the top of the case between cylinders 2 and 4?

IMG_2080.jpg
 

Attachments

  • IMG_2080.jpg
    IMG_2080.jpg
    119.5 KB · Views: 1,052
PerryB said:
Them Ford Pintos are hard to catch huh ?
Click to expand...

2.0 (TL20)[edit]The 2.0 L (1,993 cc) was used in many Ford vehicles from the early 1970s. Due to its robustness and high tuning potential, it was often used as an aftermarket engine upgrade or base for building race and rally engines — not exclusively in Ford cars. The engine has bore of 90.82 mm (3.58 in) and 76.95 mm (3.03 in) stroke giving the displacement of 1993 cc. It was manufactured in several variants. 400+ HP out of some in mini sprints and sand rails

Glenn
 
You must log in or register to reply here.

Similar threads

S
0-200 Cont. in PA-11 oil temp/pressure data
Replies
17
Views
1K
salex
S
F
high oil pressure 0-360 C4P
Replies
9
Views
4K
behindpropellers
behindpropellers
N
Oil Pressure on 0 200
Replies
7
Views
949
cubdriver2
cubdriver2
flynlow
Oil pressure????
Replies
26
Views
10K
n40ff
n40ff
T
10pt Oil Pressure Change
Replies
7
Views
989
DENNY
D
Back
Top