New Base Gasket application--tips?

I now have all the parts I need to start reassembling my engine.

When I had removed the jugs, the old base gasket was glued solid to the case side. It took a lot of careful work to scrape the darn thing off. I tried to be very careful not to damage the mating surface, but I had to get "aggressive" in some places. I'm scared to death that I'm going to get this thing back together and find oil leaking from the base area.

So what can I do to try to minimize the risk of leaks? I'm assuming I should use some kind of liquid gasket sealer, right? What is the best kind to use? I have some ThreeBond 1104, and I've also got some Napa Copper sealer. I've never done this before, so any advice would be greatly appreciated.

I would place a very thin layer of the three bond on the crank cases...I have had prett good luck with the stuff myself.

Thanks.

So, I should just use the ThreeBond on the case side, then place the gasket, then the cyl block on top of that (with nothing applied to the top end of the gasket), right? Or should I also apply Threebond to the top of the gasket?

I usually put my engines back together dry without any sealant. As you experienced it makes it a PITA to clean when someone else glued it down. However if you think you boogered up the mating surfaces then yes I would put done some three bond on both sides of the gasket.
I have even used JB weld on a really bad block to case surface. I was broke and didn't have the money to replace the case as I should have but it did work. I feel sorry for the guy who has to takle that one apart.
In the future try using a flat razor and clean off as much as you can. After the razor use a fine emery cloth and finish up. That way you don't run the risk of gouging the aluminum.

Post edited by: baldy110, at: 2007/01/22 18:33

The base gasket is one of the few gaskets I use a very thin smear of goo in - not to stop it leaking, but to stick it to the underside of the cylinder block. This way it's out of the way when trying to get the pistons / rings into the bore, and avoids catching the base gasket on the sleeves then the block is lowered.

The base gasket is one of the few gaskets I use a very thin smear of goo in - not to stop it leaking, but to stick it to the underside of the cylinder block. This way it's out of the way when trying to get the pistons / rings into the bore, and avoids catching the base gasket on the sleeves then the block is lowered.

Yamabond 4 by who other than Yamaha is a great product and it doesn't dry rock hard. Not sure if this is the best application for it but works great elsewhere.

Yamabond 4 by who other than Yamaha is a great product and it doesn't dry rock hard. Not sure if this is the best application for it but works great elsewhere.

Okay, thanks everyone. I think what I will do is to smear a thin layer to the case mating surface. Then I'll smear another thin layer to the block mating surface and mount the gasket onto the block.

This way I'll get the seal I need on the buggered up case (actually, it's not too bad--I just don't want to get it all back together and only then find out there's a problem :pinch: ), and as Jeff suggested, I'll also have the gasket out of the way so I can work on getting the pistons inserted.

Sounds like a good plan. If anyone thinks differently, now's the time to chime in.

Yamabond 4 by who other than Yamaha is a great product and it doesn't dry rock hard. Not sure if this is the best application for it but works great elsewhere.

I use the orange silicone on the bottom and it hasn't leaked. I used it by itself around the chain galley and it didn't leak even after the head nuts all came loose to the fingers. I'll have to poke a hole with a screw driver to get it to leak. I use it everywhere and a word of advice that took me a long time to get through my head. Some gasket surfaces are so slick, the silicone squishes out completely when you tighten the bolts. Let it set up for awhile first and give it more time if the surface is slippery. I've used thicker gaskets, more silicone, and so on it won't seal without setting up good and firm first. On head and base gaskets you don't want to wait too long because the film is not perfect height and will cause problems when torqued. On the base gasket I smear it first then push the gasket down all around, that way I can let it set until it's fully cured without worry of high and low spots. With slippery surfaces smear it on with a finger first, then run a bead over that, let it cure some and bolt. Then look over your shoulder to see if it's chasing you. If it is see your doctor.

Post edited by: nads.com, at: 2007/01/23 00:24

id spray it down with copper kote and let it tack up really good before installing;)