Hot Rods Sealing 471 Blower Manifold/ SBC

Throwing out the question for alittle help. I’m in the process of pulling of my blower and changing out the manifold to a new , machined one. I was getting some oil blowing out the back of the manifold, that I just couldn’t deal w/ anymore. The manifold is an original Cragar manifold, that didn’t seat that perfectly. My question is what guys are using to seal between block/ manifold? I was told Clear Silicon works best... Do you still use a gasket? Is there a special type? Healthy bead on block, then gasket, and another bead on manifold? Any input would be appreciated in-regards to type and/or part#. ( or any other suggestions)...

 

Use ,The Right Stuff.lay a fat bead on the front and back of the block and bolt the intake on and let it sit overnight.should cure your prob.i would never use clear rtv on anything.

 

ANY...color silicone works just fine. I've seen "pro's" use the clear silicone, right out of the big industrial squeeze guns..!
I normally use black.

Have the block and manifold "clean and dry". Lay a light bead down on the block rails and a little up onto the side gaskets (DO NOT use silicone on the main side gaskets). Lay a second light bead down on top of the first, quickly (before the second layer has a chance to start to set) set the manifold in place and install the fasteners, snug the manifold. Clean up any silicone squeeze-out. A few hours later complete the torquing of the manifold fasteners. Clean any squeeze-out of the silicone up. Complete the assembly.

And NO, do NOT use the rubber or cork gasket. I think most of the instructions recommend against any gasket at the ends, just a silicone sealant.

Mike

 

make sure you have adequate crankcase ventilation, too....make it easy on the gaskets/seals

 

The rubber gasket will squeeze out like bologna between two slices of bread with mayo. The trick for blown apps is to drill some 1/8' holes where the silicone would be applied and fill those divets and then the thick bead on top of the sealing surface. When dry they act like pins to keep the silicone from moving

 

the best stuff that I have used for this is unfortunately from a Honda car dealer. I use grey Honda Bond RTV. I don't know exactly what is different about it, but it lays out in a nice bead, sticks to everything perfectly and stays pliable forever. you have to cut thru it with a razor when you go to pull the manifold off after its been put on with it. and it will not blow out at all if you have a bunch of crankcase pressure. Highly recommend it.

 

I second the Hondabond.
There is also Yamabond. Guess where you find that.(same stuff)