sealant needed on water pump gasket or other gaskets?

[VetteMed]

I've got everything all torn apart right now, waiting to be reassembled, and it occurred to me, I'm not sure if I need to use any sealant on the water pump gaskets or the oil filter housing gaskets, or even on the oil breather box gasket. Can these all be installed dry?

[A26B]

I am frequently asked about the use of gasket sealant(s) with my gaskets for the LT5 engine. Here are my thoughts on the subject.

Clean gasket surfaces well. Wipe down the surface with brake cleaner on a towel to remove any residual oil. Install gasket, engine component & torque bolts as specified, and if required, thread locker as specified in the GM Service Manual.

I am old school and was originally taught to use gasket sealants on all gaskets. Conditions are different now. Today, we have;
(1) machined surfaces with better accuracy & finish,
(2) improved gasket materials and
(3) engines are made from aluminum.

Regarding #3, the reasons I do not recommend sealant (besides reasons #1 & #2) is because cleanup requires scraping and lots of elbow grease. The scraping of residue can also scratch & damage gasket surfaces. The LT5 is a jewel of an engine, manufactured to very close tolerances. Close tolerances = better sealing.

The only time I consider gasket sealant for any LT5 component gasket, is on the Fuel Injector housing gasket, and only around the coolant port, IF the cylinder head & fuel injector housings have been ported.

On ported engines, the "material" left in between the coolant port & the runner gets pretty narrow. Apply a very light coat of a sealant with adhesive properties to both sides of the gasket, just around the coolant port, and bolt down the Fuel Injector Housing while the sealant is still wet to avoid any thickness stacking.

The gasket material I use has one of the highest tensil strengths available and is impregnated with nitrile rubber and has 12~15% compressibility. Good stuff! It will seal very well and resists squeezing out or moving due to differential pressure, as is the case aroung the Fuel Injector Housing coolant port.

The only other time I would consider sealant is if the Plenum to Fuel Injector Housing surfaces or Fuel Injector Housing to Cylinder Head surfaces have been damaged from errant porting tools or distorted by welding and no longer perfectly straight. In that case, I also recommend the thicker (3/64") plenum gaskets.