Huge cloud of bluish white smoke, what happened?

[Pinzgauer Pete]

Oh Boy...Im not trying to start a new thread here but Pinzinator made reference to the pinz not having seals and one day installing them...has anyone done this? is there a kit or a part number for the seals...sounds like something I might want to do over the winter!

[Jimm391730]

pinz not having seals and one day installing them...has anyone done this?

I did it myself at the old SoCal shop. You rotate the crank until one cylinder has both valves closed (TDC) and put the tranny into high gear to lock the crank. Remove the spark plug and put an air fitting into the hole; using compressed air you can keep the valves closed. Take the valve cover off, remove the intake rocker. The hard part (but not too difficult) is to compress the intake valve spring, pull out the keepers with a magnet, and release the spring. If all has gone well the air pressure holds the valve in place and you can remove the spring(s) and install or replace the seals. Then reverse the proceedure. The trick is to not push down on the valve shaft as doing so releases the air pressure and the valve can fall inwards, but if the piston is at the top then the valve cannot fall inward too far and you can still pull it back up. But the air pressure is also trying to push the piston down so it really needs to be truely at top dead center. Compress the valve spring, hold it in place while you get the keepers back in place. Now the hard part is done, put the rocker back on and finish the reassembly. IIRC it took less than two hours to do all of them even with my fiddling around.

So (unless you pull the head off completely and do it on the bench) you need the air fitting and a valve spring compressor to do it on the truck.

[edzz]

pinz not having seals and one day installing them...has anyone done this?

I did it myself at the old SoCal shop. You rotate the crank until one cylinder has both valves closed (TDC) and put the tranny into high gear to lock the crank. Remove the spark plug and put an air fitting into the hole; using compressed air you can keep the valves closed. Take the valve cover off, remove the intake rocker. The hard part (but not too difficult) is to compress the intake valve spring, pull out the keepers with a magnet, and release the spring. If all has gone well the air pressure holds the valve in place and you can remove the spring(s) and install or replace the seals. Then reverse the proceedure. The trick is to not push down on the valve shaft as doing so releases the air pressure and the valve can fall inwards, but if the piston is at the top then the valve cannot fall inward too far and you can still pull it back up. But the air pressure is also trying to push the piston down so it really needs to be truely at top dead center. Compress the valve spring, hold it in place while you get the keepers back in place. Now the hard part is done, put the rocker back on and finish the reassembly. IIRC it took less than two hours to do all of them even with my fiddling around.

So (unless you pull the head off completely and do it on the bench) you need the air fitting and a valve spring compressor to do it on the truck.

The less professional way to do this is to use nylon rope. Lower the piston, feed nylon rope into sparkplug hole, then move piston towards TDC compressing the rope between the top of the piston and the valves.

I’ve never used this method on horizontal engine; it’s worked for me on verticals and V’s.

The air method is defiantly preferred if you have the equipment. The spark plug fitting I use for the air method came with a compression gauge set I bought at Harbor Freight.

[pinzinator]

I thought the leak-down test was done with the piston at TDC of the compression stroke. This is also when both valves are closed. With the piston at any other position in the cylinder one of the valves may not be fully closed.
I assumed the test was done at the position I described due to the cylinder pressures normally being the highest at that instant, which is when a mechanical seal is the most critical (valves and rings).
Most of the cylinder wear is at the top of the cylinder, which further validates my reasoning for the TDC position for testing.

[cronapress]

Did you check the breather pipe ?? On the "go for the simple job first" basis ???

[Jim LaGuardia]

Leak down tests are done with the rocker arms removed and pistons at the bottom of the bore, it is very dangerous to attempt a leakdown test at TDC as crank needs to be locked in position and I have seen quality flywheel locks fail with very bad results(lock broke and fractured techs arm).
So if the rings are leaking at the bottom of the bore, they will also be leaking at the top as the bores are not tapered they are the same diameter from top to bottom.
For the plume described in the thread header it is either worn sticking rings or brake fluid in the booster, bad valve seals only cause a puff of smoke on start up or between shifting gears.
In most cases the cylinders are too worn(egg shaped) to re ring pistons.
SAV has replacement pistons(93mm) and cylinder boring/piston fittment is available.
So basically it needs to be torn down and repaired as needed

[krick3tt]

The breather pipe from #4 cylinder to the bottom of the oil filler pipe is blocked, take it off and clean it out or it will happen again.

Took the hose off and straightened it out, looked through it...no blockage. Now I'm back to rings and valves as possible issue. Lots of smoke and a little oil consumption.