seabee
Well-Known Member
Did a leak down test on the 273 today and took some pics on how I did it for the next guy that searches it. Please add any , corrections, advice, or tips.
1. Find Top Dead Center on Piston #1. I used a piston stop to make sure the balancer hadn't shifted.
Using a small level I made horizontal and vertical marks:
Each 1/4 turn of the crank will put the next cylinder in the firing order at top dead center. Firing Order: 1 8 4 3 6 5 7 2
Next I checked the gap (solid, non hydraulic lifters) to make sure the valves were fully closed. I could also just remove the rocker arms completely.
Then I used the piston stop on the cylinder opposite the firing order to prevent the crank from turning under the air pressure. Opposite pistons: 1:6, 2:3, 4:7, 5:8
Then Applied 100PSI to get the first reading. Number 8 cylinder is losing 20%.
Then I put the spark plugs into the neighboring cylinders to help rule out a head gasket breach between cylinders.
Next I use a piece of hose to my ear and listen to locate where the 20% of air is going to.
Carb: Intake Valve
Exhaust:Exhaust Valve
Dip Stick (Crankcase): Past the piston rings (Normal)
Radiator: Cracked head or cylinder wall.
I wrote down all the results:
Might be time for a rebuild, what do you think?
1. Find Top Dead Center on Piston #1. I used a piston stop to make sure the balancer hadn't shifted.
![IMG_0478_zpsfe5a5f95.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0478_zpsfe5a5f95.jpg)
![IMG_0486_zps9188d296.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0486_zps9188d296.jpg)
Using a small level I made horizontal and vertical marks:
![IMG_0474_zps218ebac1.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0474_zps218ebac1.jpg)
![IMG_0472_zps77e802e8.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0472_zps77e802e8.jpg)
Each 1/4 turn of the crank will put the next cylinder in the firing order at top dead center. Firing Order: 1 8 4 3 6 5 7 2
![IMG_0512_zps49df8ba6.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0512_zps49df8ba6.jpg)
![IMG_0477_zps2ed8651b.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0477_zps2ed8651b.jpg)
Next I checked the gap (solid, non hydraulic lifters) to make sure the valves were fully closed. I could also just remove the rocker arms completely.
![IMG_0481_zpsc079089a.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0481_zpsc079089a.jpg)
Then I used the piston stop on the cylinder opposite the firing order to prevent the crank from turning under the air pressure. Opposite pistons: 1:6, 2:3, 4:7, 5:8
![IMG_0494_zps35b665e2.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0494_zps35b665e2.jpg)
Then Applied 100PSI to get the first reading. Number 8 cylinder is losing 20%.
![IMG_0498_zps29bc8b1b.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0498_zps29bc8b1b.jpg)
Then I put the spark plugs into the neighboring cylinders to help rule out a head gasket breach between cylinders.
![IMG_0496_zpse0c42cbf.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0496_zpse0c42cbf.jpg)
Next I use a piece of hose to my ear and listen to locate where the 20% of air is going to.
Carb: Intake Valve
Exhaust:Exhaust Valve
Dip Stick (Crankcase): Past the piston rings (Normal)
Radiator: Cracked head or cylinder wall.
I wrote down all the results:
![IMG_0513_zpsf9d0b7a7.jpg](http://i186.photobucket.com/albums/x287/illkron/IMG_0513_zpsf9d0b7a7.jpg)
Might be time for a rebuild, what do you think?