vernatherm installation

[Bavafa]

Just curious if there are any special gotcha or trick in installing a vernatherm.

I will be removing it from the existing oil adaptor and moving it to the new up right adaptor in an IO390. Also any feed back if anyone has done it in this engine and if there was any interference that I need to look for?

Thanks in advance

[az_gila]

It would be a good time to replace the 76510 gasket.

http://www.aircraftspruce.com/catalo...et08-76510.php

[lr172]

The vernatherm uses a crush washer as a gasket. Reusing a crush washer introduces a good risk for leakage. However, in that application there are no surface irregularities, so risk is reduced. With aluminum crush washers, like this application, I sometimes flatten both surface with sandpaper on a flat block and anneal it with a propane torch. You coat one side with a sharpie marker. The marker completely burns off near the annealing temp. If you go more than a few seconds beyond this point it will reach a plastic state and deform.

Larry

[az_gila]

Originally Posted by lr172

The vernatherm uses a crush washer as a gasket. Reusing a crush washer introduces a good risk for leakage. However, in that application there are no surface irregularities, so risk is reduced. With aluminum crush washers, like this application, I sometimes flatten both surface with sandpaper on a flat block and anneal it with a propane torch. You coat one side with a sharpie marker. The marker completely burns off near the annealing temp. If you go more than a few seconds beyond this point it will reach a plastic state and deform.

Larry

Is all of that work (and risk) worth it for $2.19?

[Bavafa]

I will certainly not risk that and will be replacing the washer. Any other consideration? I recall some discussion about the sitting of the valve that had some trick to it but can't find that thread.
Are the torque value for the bolts are any different than the standard sized torque?

[lr172]

Originally Posted by az_gila

Is all of that work (and risk) worth it for $2.19?

I don't do this to save $2 and if I have one available always use a new one. However, crush washers are often difficult to source locally and when I don't want to wait three days for delivery, I improvise. Actually, It's not a lot of work; Takes about 3-5 minutes. I also often make crush washers from .063 stock, but in this application washer height is a critical dimension, so I didn't suggest it.

I don't see the risk of re-annealing a crush washer for re-use after insuring dimensional accuracy and annealing, other than the small loss of washer height. Maybe you can enlighten me on the risk of this method. I have done about 20 of these (mix between home-made and re-worked) on our family cars and not one has leaked or come lose.

I know many consider me a heretic for proposing such a path and I understand many think it's a bad idea. However, I posted it for all to read and I am sure some would find it worthwhile tip, especially when making repairs far from home.

Larry