Gaskets and SealersI am asked often about what sealers we use and what gasket materials we prefer. We use black RTV and black weather strip adhesive AKA Gorilla Snot. Most applications we use the RTV on the less that perfect surface and the Gorilla Snot on the smoothed machined ones. We don't use RTV on both sides of a soft type gasket, that would allow the gasket to squish out. Things like water pumps and fuel pumps we use Gorilla Snot to glue the gaskets on to the pumps and RTV between the gasket and the engine so when those parts are removed for replacement the gaskets stay on the part that gets thrown away. We prefer cork, rubber/cork (made from half of each) or felt type gaskets for valve covers, valley pans and oil pans. Rubber gaskets do not compress enough for a good seal or squish out when tightened. When we install the oil pan gasket, we glue it to the block with Gorilla Snot then we put a very thin coat of RTV on the pan (be sure the pan rails are straight for a good seal) and bolt it on, tighten with a 1/4" ratchet so you do not over tighten the bolts. We use sealer on the threads of the two bolts that go into the rear main cap, we have found oil tries to leak past the threads. On the valve and valley covers we Gorilla Snot the gaskets to them (let it dry until tacky), thin coat of RTV on the engine side. Do not over tighten. On the water manifold, this is only part we only use RTV, the fat O ring gets coated inside and out, installed on the water manifold and slid down into place, the side gaskets are coated with RTV and slid in. Remember, if you see sealer squeezing out that same thing is happening on the inside! You don't want that stuff floating around in the engine so use sealers sparingly. Intake gaskets do not need any sealer, it you must then use a spray on sealer like what is used for steel head gaskets, this is only for the stock type metal gaskets. If you have the softer type composite ones then NO sealer should be used. No sealer on carburetor gaskets and NO gaskets on exhaust manifolds were they bolt to the heads! That's right, gaskets will cause the manifolds to crack, GM did not use them. No need to put sealer on Nailhead head bolts, that is a Chevy problem, we have never seen a Nailhead leak coolant out of a head bolt. One last thing F-E-L-P-R-O head gaskets, the thick ones are pron to oil leakage, avoid using them. We sell Victor and BEST head gaskets ONLY.
Holes in the block and heads but not in the head gaskets??
I get this question over and over so I guess I have to put it in here.. There is not suppose to be extra holes it the gaskets! if your old ones have them the gaskets are rusted out or modified.. The water pump pushes coolant through the block to the back of the engine, comes up in through the rear of the head and then forward to the thermostat. Holes in between will miss direct the coolant, bypassing the rear and overheating it..