Mercury 305 rebuild | part 1

[Music] welcome to dark blood's garage this is a mercury 5 liter a 305 this is out of a 1990s bayliner the engine does run it doesn't have that many hours it is pretty clean and all that however this was brought to me because at one point it wasn't winterized correctly and if anything if anybody knows anything about boat motors you know that you're supposed to winterize these things by draining the plugs draining out the water and so forth if you don't do that this is basically what happens so the water that is inside the block that doesn't get drained it freezes and then it expands and it causes the block to actually crack so we have that kind of damage on this side of the block as well as the passenger side over here so best case scenario is just the outside walls of the block worst case scenario it's the block the heads the water pump and possibly water mixed with the internals of the engine so everything is going to get inspected and tolerance checked before we assemble this so the first thing we're going to do here is we're going to pop off the valve covers and we're going to pop off the intake over here one quick note that you can do to help you in the future if you're doing something like this is you put a little mark over here with a marker and what that does is it allows you to put the distributor back into the correct location just so it helps you uh with the initial startup so as we can see here the rockers look pretty clean they're just a standard stock stamped rocker from gm you can also see with this retainer that this is obviously a roller motor which means it has a roller cam shaft so before we start pulling the whole valve train apart it's important to note to keep everything in order so keep all the lifters in the exact same order that they came out of keep the corresponding rocker with the corresponding push rod and the corresponding valve all these components have their own individual wear pattern and you don't want to mix up that wear pattern with other components of the engine [Music] [Music] [Music] so a quick tip for removing heads is usually when you install the head there's a torque sequence and it's followed with a spiral pattern and this is to ensure that the head gasket gets a nice even squish across the entire surface and it also ensures an even torque sequence for all the bolts so it's good practice to reverse the sequence when you're removing the head the other thing is if you have an aluminum head and you unbolt from the left to the right or right to the left what can happen is your head might actually bow from all the excess force from the last remaining bolts [Music] oh that was easier than i thought go ahead and pull this off now so we're going to go ahead and have a quick look at these bores and you can usually tell if the if the engine is really rough so because this is a marine engine uh when it sits it obviously will build up a little bit of surface rust that's normal nothing really to be alarmed of but things like this over here are a little bit uneasy this this motor obviously sat a little bit longer than it'd like to be sitting but the other thing to look at is to see if there's any cross hatch patterns going on here which this block does have it so it is pretty clean there is still a pattern there what you don't want to see is absolutely no cross hatching because that'll tell you that this motor's obviously got a lot of kilometers or a lot of hours in this case other than that that's what these uh this one's look like at the moment [Music] this bolt doesn't look like it has any real sealant in it also going to have some sort of sealant that would have passed through here and this is to prevent the water and the oil from mixing back and forth because these are not blind holes these are through holes and they will go into the water cavities this bolt didn't have any of that [Music] so so let's go ahead and have a quick visual over here we can see this bore obviously still has the cross hatches still has the cross hatches so this motor obviously doesn't have too many hours on it [Music] so let's go ahead and remove the dipstick as it's in our way now [Music] so we're gonna go ahead and let this motor uh drain while it's upside down here we can go ahead and remove the oil pan so we can get access to the crank and everything else under here so let's go ahead and just remove all these [Music] you

Channel: Dark blood Mechanical

Views: 515

Keywords: mercury, 305, sbc, engine, build, chevy, bayliner

Id: 11Vi8LH5CWc

Length: 8min 59sec (539 seconds)

Published: Tue Jun 29 2021