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Practical Engine Building: Step 4: Block Preparation

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Step 4: Block Preparation


00:00 - At this point we've got our components back from our engine machinist and it's time to actually start with the assembly process.
00:07 We're going to begin here with our block preparation.
00:10 So we've got our block unwrapped, we've got it set up on our engine stand and the first thing we want to do is just visually inspect the block and make sure there's no obvious signs of any damage.
00:21 This can easily happen in transit.
00:23 And you're going to waste a lot of time if you go about assembling your short block, only to find out when it comes time to assemble the cylinder heads and bolt those on that there's a mark on the deck surface of the engine block as a result of something being dropped on it during transport.
00:39 So during this inspection process, one of the things that became apparent to us is that we do have some marking in one of the bores.
00:46 And this is a result remember of our engine being a high mileage engine that we sourced from a wrecking yard, hadn't been well cared for and we had some water sitting in one of the bores and this was something that we noted when we disassembled the engine.
01:02 And we were hopeful that this would clean up during the honing process.
01:06 However given that we are only honing this block, it wasn't bored because of the thin liner situation, there's only a very small amount of material that can be removed.
01:16 And what we can see here is that we do have some water staining still apparent in the bore.
01:21 So if I was building this engine for a customer, or basically any application where I wanted to be 100% certain of my finished result, at this point I would discard this block and we'd source a replacement and start again.
01:33 Given that this is for our own internal use, I'm not actually that worried and we will continue with the build using this block.
01:41 One of the reasons that I'm not particularly concerned is that the discolouration, the marking in that bore is more visual than anything, we can't actually feel any marking of that bore when you run your fingernail across it.
01:53 So I'm reasonably confident that with the fresh hone pattern on the bores, we're still going to end up with our rings sealing well in that particular bore.
02:00 Worst case scenario we may end up seeing a small increase in oil consumption because of this but again for our own internal use, not something that I'm going to be too concerned with.
02:12 With the process of preparing our engine block, we'll typically start by running a fresh tap through all of the critical fastener holes in the block, this includes the holes for our head bolts or head studs in our case as well as the main studs that we're going to be using to secure the bearing caps.
02:29 Now this is one of the areas where the LS is a little peculiar.
02:32 Regardless of the fact that the engine is an American engine and the imperial system rules supreme in the U.S., a lot of the fasteners, or the majority of the fasteners on the LS are actually metric.
02:44 And to throw a little bit of a curveball here our two most critical fasteners, our head studs and our main studs, both use a very unusual tap size.
02:53 In this case the head studs require an M10 x 2.0 tap and the main studs are an M10 x 2.0.
03:02 Now that 2.0 pitch is actually very very unusual and this means you're going to really struggle to find those two taps from your local hardware supplier.
03:11 And in our case here in New Zealand, we actually would have required having those two taps made to suit.
03:17 Now that's also going to be incredibly expensive, particularly if you are just looking at a one off.
03:23 And this is where you can use your relationship with your engine builder to save a little bit of the cost.
03:29 Our engine machinist here has access to these particular taps so we've asked them to simply do that part of the job for us.
03:36 So by thinking ahead here you can save yourself time and save yourself money.
03:41 So in this case obviously we don't have to pursue that process.
03:45 Our head stud and main stud threads have already been chased clean so they are ready to accept our ARP fasteners.
03:52 Of course we can continue and do that on all of the other external fasteners on the engine block as well, just making sure that when it comes time to bolt on the likes of our engine mounts, we're not going to end up wasting a lot of time by potentially snapping a fastener off in the block.
04:08 Once we've got all of our threaded holes tapped, we can move on and the next step of the process is deburring our engine block.
04:16 In order to show you what we're trying to achieve here, let's start by flipping our LS block over on our engine stand.
04:22 Before we can go about deburring the engine block, we need to understand what we're actually looking for and what we're trying to remove.
04:28 Now depending on the particular type of engine block you're working with, some are better than others.
04:33 Some have a lot of casting flash that we want to remove but we're basically looking for any areas where there is casting flash that could potentially break off and end up moving through our engine when it's in operation.
04:45 Obviously that's the last thing we want.
04:47 So with our LS there are a few areas that we're going to focus on.
04:50 In particular we can see there are some parting lines here in the casting that we're going to want to clean up.
04:57 Those aren't too much of a concern there but in particular at the base of the bore here we can see a small area of casting flash that is quite thin.
05:06 Now this is a concern because if we actually press on that casting flash, it is possible to break off a small section of that.
05:13 Of course it's possible that that may last a long and healthy life and never go anywhere but under the stress and vibration associated with high performance use, we don't want to take any risks.
05:25 So the tools we're going to use here in order to remove that casting flash include our air die grinder, we've also got a battery powered Dremel as well.
05:34 We're just going to swap backwards and forwards between those tools depending on where we actually need to reach in the engine block.
05:41 Alternatively we can also use a needle file for these purposes and I've also got a deburring tool which works really well on round holes.
05:51 So now that we know what we're trying to achieve, let's go ahead and actually deburr the block.
06:22 So at this point we've removed the majority of that casting flash from inside of the block.
06:27 Now when we're doing this, we aren't trying to polish the surface, that's not important, all we're trying to do is remove any of that loose material that could potentially break off and go through the engine.
06:36 The next step here, while we've still got the engine turned over, is we're going to use our Dremel and just debur the edges of our sump rails.
06:44 Now this is less of a performance aspect than just more removing those sharp edges that could end up cutting us as we're actually working on the engine.
06:52 So let's go ahead and do that.
07:14 We've now got the underside of the engine block completely deburred, I'm quite confident there's nothing there that's going to cause a problem.
07:20 So we can flip the engine over and we're going to repeat the process on the deck surface of the engine, so let's go ahead and do that now.
07:28 With the engine flipped over, we're going to be repeating exactly the same process, we're going to start with our Dremel electric die grinder and we're going to be deburring the outside of the deck surface of the block as well as going through and deburring any of the water jacket holes.
07:42 Now of course it should go without saying here that when we go through this process, it is incredibly important that you are careful with the die grinder, making sure that it doesn't slip and run across the deck surface of the engine block, as that could end up giving us problems with head gasket sealing at a later point.
07:57 So let's get started with the deck surface now.
08:28 With our first deck surface now deburred, we're simply going to move the engine on our engine stand and we'll repeat the process on the other bank of cylinders, so let's go ahead and do that now.
09:04 With both deck surfaces now deburred, we've got one last deburring task, we're going to rotate the engine and we're going to focus on any areas within the valley of the engine where we may have some casting flash that also needs to be removed so let's go ahead and do that now.
09:39 With our deburring process complete, we can now have the confidence that there's no casting flash that could break off and go through our freshly built engine and while this is a process that I know a lot of engine builders will simply ignore, it can be one of those small steps that can really make a difference to the long term reliability of your engine.
09:58 We've got one last task that we're going to complete here within this module which is to remove our oil gallery plugs.
10:04 This is simply going to require us to rotate the engine on our engine stand, we're going to remove each plug in turn and that's going to allow us easy access to all of those oil galleries when we get to the process of cleaning down our block.
10:17 So let's go ahead and do that now.
10:38 So at this point we've got our block preparation complete.
10:40 Of course because this is an alloy block, there is no need to paint the block, so we're ready to move on with the next step of our process.

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