1.6 hyd to mech head swap

[tomm2381]

I have a '90 Jetta with a hydraulic lifter 1.6 NA.  It has a stuck valve, and who knows what other possible damage.  I also have a good 1.6 NA mechanical lifter head.  Can I swap the mechanical head onto the engine?  what changes are necessary? head gasket? head bolts?

[theman53]

head gasket and plugging the oil return holes. Maybe the antifreeze passage...I have only done it the other way mech to hydro

[Dakotakid]

You have to determine how you will plug the secondary oil return hole in the block. I used a flat wafer-type soft plug (Dorman?) (which is hard to get inserted just right, about 1/2 to 3/4 of an inch deep....then, covered with black oil-resistant silicone rtv simply flatted to match the block top. This part of it is minor in concern as there is not really any pressure from the block.

You have to drill, tap, and plug the corresponding water passage in the head......I believe I used a 3/8 aluminum plug.....and use BLUE locktite when installing it (my only regret that I did not use....instead used John Deere/Indian shellac sealant).

You use the head gasket which corresponds to the head being used. In your case: mechanical head gasket.

The most expensive part of the whole deal is the uncommon-sized drill bit to drill the water passage for installation of the plug. I would have to dig the bit up....it was something like 27/63 or something.

If you have any minor problems with anti-freeze weeping......use some solder seal in the coolant.

It ain't brain surgery and you will NEVER regret ditching the hyd. head. Send me a private message with your normal email if you need to see photos. Lucas was VERY helpful for advice when I did this. It turned out eff'ing great.

You might be able to make-do simply with rtv in the block hole.

[ORCoaster]

Might that drill bit size be 27/64ths?   I think that is the correct denominator.  Never heard of a 63.