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Practical Engine Building: Step 4: Block Preparation

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Step 4: Block Preparation


00:00 - In this step we're going to go through some of the steps of preparing the block before we can go ahead and assemble the short block.
00:05 Now I'm actually going to be doing this in two parts.
00:08 Typically I would do this once I receive the engine block back from the engine machinist, however with the 4G63, we do have an area which can be a little bit trickier to clean out.
00:20 Specifically it's the area down where the upper balance shaft sits.
00:24 That forms a nice little recess in the block which is very very good at trapping dirt, debris and grit and that's exactly what we're going to be creating when we're going through this process of removing some of the casting flash on the engine block.
00:39 So while it is absolutely achievable to do this after you've got the block back from the machinist, doing some of this work prior to sending the block away for machining, means that once the machining work is completed, the machinist is going to finish up their work by giving the block a hot wash and that does a really good job of removing all of that grit, dirt and debris.
00:59 Now granted we still do need to clean down the block once we receive it back and we will still have some additional work required but this just does a good job of removing the majority of that debris before we even get the block back.
01:14 Now specifically what we're going to be doing here involves a few different tasks.
01:18 One of the first operations we're going to perform is to remove the sharp edges from the sump rails of the block.
01:25 Now normally we'd actually also do this to the deck surface of the block but of course one of the machining operations will be to have the surface of the block decked or machined, giving us a nice finish for our head gasket to seal against and if we remove those sharp edges now, we're just simply going to have to go ahead and repeat that process once we get the block back from machining.
01:45 Sump rails on the other hand, our machinist is typically not going to need to touch those.
01:49 So that's a good opportunity to go ahead and clean up those sharp edges.
01:53 We're also going to be looking inside the block for any areas of casting flash.
01:57 Now every engine is a little bit different here, even between all of the 4G63 engines, you may find some blocks where there's next to no casting flash, some where there's quite a lot of casting flash that may possibly come loose in an engine that is producing more power and running to higher RPM.
02:15 Basically what happens in a performance engine is there is a lot more stress placed in the block, the block tends to flex a little bit more and casting flash, which may stay put or stay in the same place with a factory engine may now actually break free and that can be catastrophic so we can see a few key areas in the block here where we do have some casting flash that we're going to take care of.
02:39 We're also going to be removing the parting lines on the block there, again this is an area where in some instances we can see some pretty significant areas of casting flash that could break free.
02:50 In our block here, it's actually in pretty good condition but still good practice to go ahead and remove that.
02:56 To do these tasks, we're going to use two tools, we've got a power file which is a really good way of removing the casting flash on those parting lines.
03:06 Gives a nice smooth finish there, although we're not trying to give a polished finish to the inside of the block, that's simply not necessary, we just want to remove any casting flash that could break free.
03:17 The other tool I'm going to use is a air powered die grinder.
03:21 I've got a couple of grinding burrs for that die grinder, a nice fine one that I'm going to be using in places that are a bit trickier to get to and a slightly larger one where I've got better access.
03:33 The other task we will be doing as part of this as well is just a small modification I like to make on the 4G63 blocks which is on the front of the block where the main oil gallery goes into the front cover.
03:47 Now the front cover that bolts on and includes the oil pump has got a couple of galleries that run up the front of the block and where the oil runs back from the filter, through the front cover and then into the main oil gallery, it has to go through a very sharp 90° corner which we can see inside the oil gallery there.
04:07 Oil is relatively lazy, it doesn't like turning sharp corners so it's good practice there just to spend a couple of minutes there with a small die grinding burr and just chamfer that edge or remove the very sharp edge from that, it's just going to make the path of the oil a little bit easier.
04:24 Alright now that we know what we're going to be doing, we'll move on with the first part of that process which was cleaning up those sharp edges on our sump rails.
05:08 With our first operation out of the way, we can now use our power file and we'll remove the casting flash from the parting lines in the block.
05:15 Let's go ahead and do that now.
05:35 Alright we've removed the majority of the casting flash there, which is a relatively quick and easy job with the power file.
05:42 While we've got the engine block up this way, I'm also going to use my die grinder and just remove the remaining casting flash that's obvious, down further into the engine block so let's go ahead and get that done.
06:15 Alright at this stage, I've removed the majority of the casting flash and again, it's not particularly bad on this engine block but some will be worse than others.
06:24 It is worth mentioning here, any time you're doing any of these operations, it should go without saying that you want to be very mindful of not slipping with the die grinder and ending up on surfaces that you can't score.
06:35 Particularly this becomes a problem when we repeat this process for the deck surface of the block, we obviously don't want to end up marking or scratching the deck surface where we could end up affecting the cylinder head seal.
06:48 So we've got everything done on the underside of the block here.
06:50 What I'm now going to do is turn the block over and we'll just spend a little bit of time chamfering that sharp edge, which I've mentioned where the oil gallery transitions into the block.
07:11 Alright so we've completed the key operations there that I like to get done before we send the block off for machining.
07:18 We'll now do exactly that and we'll revisit the rest of this step once we get the block back.
07:24 We've now got our engine block back from our machinist and we've still got a few tasks left to complete with our block preparation.
07:30 Now one of the aspects that we haven't touched on this far through our block preparation step is the cleaning of our more mission critical threads in the block.
07:40 Particularly here our head stud holes as well as our main stud holes.
07:44 Now normally I would do this myself, it's not that difficult to do, in the case of our 4G63 we need to understand the second generation or 7 bolt blocks using 11 by 1.25 mm head stud and 10 by 1.25 mm for the main stud.
08:01 And all we need to do here is just use a clean, sharp bottoming tap to chase out those holes.
08:08 So this is an 11 by 1.25 mm tap.
08:11 All we need to do is essentially wind that down through the stud holes or bolt holes, making sure that we do that all the way to the bottom.
08:18 Using a thread wrench or tap wrench like this one here is a nice way to make that job a little bit easier.
08:26 Now when we're doing that, we also want to make sure that we're using a cutting oil to lubricate our tap and make sure we're getting a nice clean, sharp thread.
08:33 We shouldn't be removing much material, the aim of this is just to clean out any debris that might be left in the threads, particularly if we've got an older block that's maybe not been that well cared for, you may have some corrosion, some rust, some debris down in those holes as well and we want to make sure that those are nice and clean so it makes it easier for us to install our studs during the assembly process.
08:53 In our case though, this was actually completed by our machinist so we don't have to worry about that.
08:59 We do have the aspect of our freshly decked block surface and as I mentioned earlier, this can result in some sharp edges, we didn't deal with those so this is the time to clean those up.
09:11 We've got two ways of doing that, going to use an electric die grinder here or dremil and we've just got a carbide burr on the end of that which we're going to use for cleaning up those edges.
09:21 The other way we can do this as well, particularly with some of the internal holes in the block for the oil galleries, the oil drains, the coolant jacket, we often will end up with sharp little edges where the machinist has taken a few thou off that deck surface and that can leave a little burr there that we do want to remove.
09:38 And a nice way of cleaning that up is just to use a deburring tool which are more typically used for metal work.
09:44 That does a really nice job, all we need to do is locate the deburring tool in the relevant hole and just run that around a few times and that's going to break down any sharp edges and remove any burrs.
09:55 So now we'll just quickly go over those outside edges on our deck surface using our die grinder.
10:12 Once we've got our engine block completely deburred and everything's ready to go, we need to move a little bit out of order here.
10:21 Considering we've got a cast block, we know that corrosion on the surface of the block is going to be a problem so of course we want to paint the outside of the block in order to protect it.
10:30 However, obviously we can't do that until we've thoroughly cleaned so we want to clean down the block and we cover this in the cleaning step of our 10 step process.
10:39 So we're jumping a little bit out of order there, once we've got our block cleaned down, we will just cover that painting process which is relatively straightforward.
10:47 For this I am just using a product called VHT engine enamel and this will be sold under various different brand names around the world, depending on where you are and what you can locally get hold of.
11:00 But essentially any automotive parts store will be able to provide you with a high temp paint that is designed specifically for the task of painting engine blocks and why that cleaning process is important is twofold.
11:12 First of all, in order to get a good finish on the surface of the block, we obviously want to have that outside surface of the block thoroughly cleaned so there's no hidden dirt or debris and also no oils or grease on the surface that could affect the adhesion of our paint.
11:26 Likewise as well, the internal surfaces need to be cleaned down because the process we use to do that involves brake clean and compressed air.
11:35 If we are applying brake clean to any of the internal components of the engine after we've already painted it, that's going to in turn affect the paint surface finish so that's why we need to move out of order.
11:46 Now there's a couple of considerations here.
11:49 We obviously don't want to get paint on any of our machined surfaces.
11:52 In particularly our deck surface, we don't want to get any of our paint into the bores.
11:56 It is recoverable but it's much easier if we just don't have paint there in the first place.
12:02 So what I'm going to do in order to protect those surfaces is just use some masking tape and we'll just lay this down on the deck surface of the block while we are painting it.
12:11 Inside of the cleaning step, once the block has thoroughly been cleaned down, I do recommend applying a light coat of engine oil, mineral based engine oil to the deck surface as well as the bores just to prevent corrosion beginning before the assembly process.
12:26 Obviously while we're applying our masking tape here, we're going to want to just clean that deck surface down with some brake clean and a clean rag so that our masking tape will stick to it.
12:35 We can reapply that lubricant once we've completed our painting step.
12:40 So at this point I'm just going to go ahead and apply our masking tape to the deck surface.
12:44 I also want to cover off the oil gallery holes in the block, particularly on the Evo 9 block, there is an oil gallery that runs the oil feed up to the MIVEC control on the cylinder head so we want to blank that so we don't end up with paint going into our gallery.
13:00 So let's go ahead and get everything masked up now.
13:08 Once we've got that masking tape applied, we can go to the trouble of using a razor blade or a sharp knife and just trimming that to the actual shape of the block, so I'll just do that as well.
13:27 Alright we've got our main areas of our block masked off and you've probably noticed at this stage, I haven't masked the front surface of the block nor the sump rails and I've found that that's really not necessary if we're a little bit mindful of how we apply our spray paint.
13:41 Essentially when we are painting the block, I am going to have it upright like it is now on the engine stand and by making sure that we're not spraying up into the sump or the crank case, that's going to prevent any paint getting up into those areas.
13:55 So we're always going to be spraying either horizontally or slightly down.
13:58 Now we will likely get some overspray onto this front surface of the block but as you'll see, that's really easy to remove as long as we do it pretty promptly.
14:07 So just a little bit of care really is all that's required and our key areas are now protected.
14:12 What we're going to do now is get the block outside into a well ventilated area and we can go ahead and paint the block and this is a relatively straightforward process.
14:22 Couple of key tips that I've got here with this process, it's always a good idea to make sure that we're doing this in warm temperatures.
14:29 Don't like to paint in anything below about 10°C otherwise you're going to have problems with the paint curing or even running and generally I also try to apply at least two if not three coats, leaving ample time for the paint to dry between each of those coats.
14:45 The process of painting the block really is relatively straightforward and a little care and attention should give you a great looking finish.
14:52 Once we've got our block painted and the paint's dry, obviously the next process is simply removing the masking tape so let's go ahead and get that done.
15:04 For the most part, obviously our masking tape's done the job and everything's looking perfect on our deck surface however particularly on the front face of the block we can see that the areas of the casting that we did have to paint, particularly these areas here, we have ended up with some overspray onto the front of the block and while that's not the end of the world, it is really easy to clean up if we do this just after we've painted the block before that paint has fully set.
15:28 We can do this at a later point but it makes everything much more challenging.
15:31 What I'm going to do here is use some brake clean and a rag and it'll come off really easily so let's get that done.
15:47 Once we've cleaned off any remaining overspray, our block preparation step is finished and we're ready to move on with the next step of our process.

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