1963 f100
#2
05-26-2016, 12:21 PM
IF----
It were a piston ring problem , it should burn oil just about all the time and produce the typical blue smoke.
Valve guides when worn or have no shields/seals to prevent oil from running down the inside of the guides can produce a problem like you are seeing. Once the engine is started it doesn't usually smoke anymore.
It were a piston ring problem , it should burn oil just about all the time and produce the typical blue smoke.
Valve guides when worn or have no shields/seals to prevent oil from running down the inside of the guides can produce a problem like you are seeing. Once the engine is started it doesn't usually smoke anymore.
#4
05-26-2016, 09:52 PM
One of the things you can do is,,
Remove the spark plugs, roll the engine over so you can see each of the piston tops with a good beamed light. Generally when rings are worn or possibly a seating issue, you'll see 'washed or shinny' edges or areas around the pistons circumference. Won't be able to see the whole top, but gives an idea of cause.
On lower mileage rebuilds, you normally would be able to see cylinder hone marks (cross hatching) if it has 56k actual on a complete build unless rode hard, with poor service/ long intervals. Could be somthing wasn't right, corners cut, or something went wrong after the build. Meaning, could be one cylinder, or more.
Carbon won't stick or collect on the Pistons edges if the cylinder/s is using a significant amount of oil. Most times if the oil smoke is visible, if rings, you'll see evidence of it coming up and around the piston tops.
Other than the smoke, does it run fine? No noises?
Compression check done? If so, what were the numbers?
Excessive blow by at the PCV valve? (Also a worn ring indicator)
If it were an option, a cylinder leak down test would help to prove out the bottom end as well.
Remove the spark plugs, roll the engine over so you can see each of the piston tops with a good beamed light. Generally when rings are worn or possibly a seating issue, you'll see 'washed or shinny' edges or areas around the pistons circumference. Won't be able to see the whole top, but gives an idea of cause.
On lower mileage rebuilds, you normally would be able to see cylinder hone marks (cross hatching) if it has 56k actual on a complete build unless rode hard, with poor service/ long intervals. Could be somthing wasn't right, corners cut, or something went wrong after the build. Meaning, could be one cylinder, or more.
Carbon won't stick or collect on the Pistons edges if the cylinder/s is using a significant amount of oil. Most times if the oil smoke is visible, if rings, you'll see evidence of it coming up and around the piston tops.
Other than the smoke, does it run fine? No noises?
Compression check done? If so, what were the numbers?
Excessive blow by at the PCV valve? (Also a worn ring indicator)
If it were an option, a cylinder leak down test would help to prove out the bottom end as well.
#5
05-27-2016, 05:28 AM
I agree with Hayapower !
It seems quite unlikely that rings could be worn to the point of requiring replacement.
Some of those engines did have a problem with soft cyl walls and did have considerable blowby. That engine did if I remember correctly, have a road draft tube and if compression was getting by it would put out a lot of smoke out the road draft tube.
If that engine sat for a long period of time, there is the possibility of stuck piston rings. As Hayapower stated, a compression test would reveal quite a bit of onfo.
It seems quite unlikely that rings could be worn to the point of requiring replacement.
Some of those engines did have a problem with soft cyl walls and did have considerable blowby. That engine did if I remember correctly, have a road draft tube and if compression was getting by it would put out a lot of smoke out the road draft tube.
If that engine sat for a long period of time, there is the possibility of stuck piston rings. As Hayapower stated, a compression test would reveal quite a bit of onfo.
#6
05-27-2016, 11:43 AM
I agree with Hayapower !
It seems quite unlikely that rings could be worn to the point of requiring replacement.
Some of those engines did have a problem with soft cyl walls and did have considerable blowby. That engine did if I remember correctly, have a road draft tube and if compression was getting by it would put out a lot of smoke out the road draft tube.
If that engine sat for a long period of time, there is the possibility of stuck piston rings. As Hayapower stated, a compression test would reveal quite a bit of onfo.
It seems quite unlikely that rings could be worn to the point of requiring replacement.
Some of those engines did have a problem with soft cyl walls and did have considerable blowby. That engine did if I remember correctly, have a road draft tube and if compression was getting by it would put out a lot of smoke out the road draft tube.
If that engine sat for a long period of time, there is the possibility of stuck piston rings. As Hayapower stated, a compression test would reveal quite a bit of onfo.
#8
05-27-2016, 02:18 PM
Dry compression test, meaning all plugs removed, cranking with throttle 'wide open' (ignition disabled) and cranking about 4 or so complete revolutions S/B about 150/155 pounds. You'll see the gauge needle 'stack up' the pressure until it measures it max. Wet compression tests can help prove out worn piston rings as well and may bump those numbers up 10/15 pounds.
A wet compression test is done as above, only adding/shooting a couple shots of automatic transmission fluid in each cylinder one at a time and recording the results. Normally, transmission fluid will raise compression over the dry test. If compression numbers on a wet test don't increase it may indicate a valve or valve seat problem.
Generally if the numbers are down a bit, not a huge concern, unless the comps are uneven. A good number is no more variation than 10lbs. You may see a bit more. But, cylinder comps or balance numbers should be relatively close in a healthy mill..
A wet compression test is done as above, only adding/shooting a couple shots of automatic transmission fluid in each cylinder one at a time and recording the results. Normally, transmission fluid will raise compression over the dry test. If compression numbers on a wet test don't increase it may indicate a valve or valve seat problem.
Generally if the numbers are down a bit, not a huge concern, unless the comps are uneven. A good number is no more variation than 10lbs. You may see a bit more. But, cylinder comps or balance numbers should be relatively close in a healthy mill..
#9
05-28-2016, 08:09 AM
Sounds like my 1966 Barracuda Formula when the valve seals were shot. Didn't smoke while running down the road, but did idling (highest vacuum causing oil to be sucked into the cylinders). Another sign was to run the engine up to around 2500 RPMs and look at the exhaust (no smoke), then let off the throttle and get a burst of blue smoke as the oil got sucked into the cylinders past the intake valve seals.
