iceminion
11-16-2008, 11:21 AM
Lets say you have a complete longblock 4G63 with a new stock head gasket.
Now lets say you want to upgrade the springs.
Ideally you would have taken care of this before you coppercoated the headgasket and torqued it down.
I have been brainstorming this one and rather then taking it apart and being forced to buy a new $40 head gasket + cleaning of block/head.
All that is needed is to have force put on the bottom of the valve, one recommendation is to get a spark plug adapter and hook it up to an air compressor, pressurize the cylinder = force on the bottom of the valve.
unfortunately, in practice, this does not work, when you use your custom valve spring removal tool, and you push down on the spring, the retainer/keepers are stuck together and all you succeed in doing is opening the valve allowing the pressurized air to excape.
practicing on another head, it seems like you need a quick 20-30 LBS of force to break the bond between keeper/retainer.
so I have been thinking about things you can put INSIDE the cylinder (other then AIR) that can resist compression.
First thing that comes to mind is OIL/Trans fluid. You could put the piston at BDC fill the cylinder with the fluid, put the spark plug in, and have a friend crank the crank to provide the pressure needed to break the keeper/retainer. It would leak, but alot slower then air, and this would give you more time to work and possibly a better result.
My other idea, which would be less messy (but more dangerous) is fill the cylinder with Airsoft ammunition, and turn the crank so the piston is providing positive pressure on the plastic BB's so you can press down on the valves all day long.
you could remove the airsoft ammunition pretty easily, take the spark plug out, let em drain out upside down, maybe blast a little compressed air in through the spark plug hole.
And if you were to miss one round, it would just bounce around/melt as you the car warmed up.
Any thoughts/insight?
Now lets say you want to upgrade the springs.
Ideally you would have taken care of this before you coppercoated the headgasket and torqued it down.
I have been brainstorming this one and rather then taking it apart and being forced to buy a new $40 head gasket + cleaning of block/head.
All that is needed is to have force put on the bottom of the valve, one recommendation is to get a spark plug adapter and hook it up to an air compressor, pressurize the cylinder = force on the bottom of the valve.
unfortunately, in practice, this does not work, when you use your custom valve spring removal tool, and you push down on the spring, the retainer/keepers are stuck together and all you succeed in doing is opening the valve allowing the pressurized air to excape.
practicing on another head, it seems like you need a quick 20-30 LBS of force to break the bond between keeper/retainer.
so I have been thinking about things you can put INSIDE the cylinder (other then AIR) that can resist compression.
First thing that comes to mind is OIL/Trans fluid. You could put the piston at BDC fill the cylinder with the fluid, put the spark plug in, and have a friend crank the crank to provide the pressure needed to break the keeper/retainer. It would leak, but alot slower then air, and this would give you more time to work and possibly a better result.
My other idea, which would be less messy (but more dangerous) is fill the cylinder with Airsoft ammunition, and turn the crank so the piston is providing positive pressure on the plastic BB's so you can press down on the valves all day long.
you could remove the airsoft ammunition pretty easily, take the spark plug out, let em drain out upside down, maybe blast a little compressed air in through the spark plug hole.
And if you were to miss one round, it would just bounce around/melt as you the car warmed up.
Any thoughts/insight?