192 | Assembly Lubricant vs Engine Oil
When it comes to assembling your freshly built engine, properly lubricating the new components is essential if you want a long and reliable life from them. The problem is that there are several options when it comes to lubricating products from normal engine oil through to specially formulated engine assembly lubricants. In this webinar we’ll discuss your options and the pros and cons of each.
- It's Andre from High Performance Academy, welcome along to another one of our webinars. Now this time we're going to be delving into the world of engine assembly lubricants. These are one of the vital products that you're going to need if you want to be successfully assembling performance engines and making sure that they offer a long and reliable service life. When it comes to engine assembly lubricants, there are a few options on the market, there are a few options you need to consider. They aren't all created equal and they aren't all suitable for every position inside of the engine so the correct lubricant or the correct product is going to depend on exactly what part of the engine you are assembling.
There's also some personal preferences that come into this. And I think it's fair to say that when it comes to building performance engines, most engine builders have sort of developed their own preferences, they've developed preferences based on products or techniques that they've developed or used over the years that have proven to be successful. And I think most performance engine builders do tend to be a little bit on the superstitious side. So essentially what I'm saying is once you've got a technique or a product that you've proven and know that it works, it's often something that's a little bit hard to tear yourself away from and change a habit of a lifetime. And of course if you've got something that works, that does make a lot of sense, probably not a lot of point trying something brand new unless it's got the potential for some big upsides.
As usual at the end of our webinar here, we are gonna be having some questions and answers so if there's anything that I talk about today, or anything just generally related to this topic, please feel free to type those questions into the comments and the guys will transfer those through to me. Alright so what we want to do is first of all understand why we need to use an engine assembly lubricant. This probably should be pretty straightforward, but after we've assembled our engine, during the first start up process, there is going to be limited or a lack of oil flow through the engine until the oil pump has been primed and it's had a chance to get that oil flow right through the whole engine. So essentially the lubricant is critical to make sure that we don't have any metal to metal contact or damage on our components during our initial startup. Now the other thing we need to understand here is that some components will get a fresh supply of high pressure engine oil relatively quickly.
Obviously this would be the main bearings for example and then connecting rod bearings. While other components are going to take a lot longer to get a good supply of oil. These might be, for example the valve train, another good example would be the interaction between the connecting rod, the small end of the connecting rod, the wrist pin through the piston and also where the piston is located in the pin boss inside the piston. So we want to make sure that all of these components are adequately protected until the normal supply of engine oil is established after the engine is run for the first time. Now I'm going to go over the products that are typically available and sort of where they would normally be used, and then we're going to go over some of the pros and cons of those products as well.
Essentially there are a lot of theories out there from engine builders, and again comes back down to that superstition thing, everyone's got their own theories based on what they've been doing, so particularly if you're a novice in the market, there's a lot of noise out there if you're doing any research on the internet and a lot of really conflicting opinions that does make it really tricky to form your own opinion or make your decision on what you're going to be using. So the first product that we're going to be talking about here is probably the simplest and probably also the cheapest, which is simply using clean engine oil. And any time I'm working on an engine project I've always got an oiling can sitting in my workshop. And this is always filled with a clean high quality grade 30 weight mineral based engine oil. So this is one of the products that I actually personally use for most of my engine assembly.
Now it's important there, I've just mentioned that I use a mineral based oil. And this sort of crosses over between the topic of engine lubricants and also running in processes with engines. But I will touch on this because obviously we need to make a decision on what oil we are using. When it comes to the break in process, it's always advisable that we run the engine initially in a mineral based oil. The market these days is flooded with some really high quality full synthetic oils, and they are great oils, often there's some really good quality products that I personally use, that I've shown through subsequent tear downs do a much better job of protecting the engine components than even a really high quality mineral based oil.
The problem is that with some of these really high quality synthetic oils, they can actually effectively be too slippery to allow our rings to bed in properly. Now there's arguments both ways, these days the quality of our rings, the manufacturing process for our rings and the materials used coupled with the honing techniques that our machinists use, it does make it very difficult to do a bad job of bedding in the rings against that fresh hone pattern. But it is possible with a full synthetic oil, that that can prevent the rings bedding in properly. Personally when I'm dealing with any engine build, I don't wanna take any chances, so I will be using a mineral based oil. And that's what I've got in my oiling can.
Obviously I'm using it for assembly lubricant as I've just mentioned, but there's a variety of other reasons I'll use that oiling can, one of them would be for example when I've cleaned down the hone pattern in my bore, we want to immediately apply some lubricant onto that bore to stop rust forming. So that's exactly what I'll do there, I will simply use the oiling can on a clean rag and apply a nice thick coat of my mineral based oil onto the bore walls, because I know it's a mineral based oil, I've got no problems later on with any chance of the rings not bedding in properly. Now I've mentioned there that personally I'm using a 30 weight oil, now that's not set in stone. But when we are using clean engine oil, as a lubricant for the bearings in particular, it is a good idea to use a relatively high viscosity engine oil. It's just going to provide a little bit more film strength just during that initial start up so that's why I've said I'm using a 30 weight oil there.
Obviously the upside of all of this is it is incredibly cheap as a lubricant. We might be able to purchase a four litre pack of good quality mineral based oil for maybe somewhere in the region of USD$30 or $40, maybe much cheaper that that even depending on exactly what you're buying. When we start looking at some of the more specific lubricants which we'll talk about this particular one in a second, you're buying a very small punnet for maybe as much as $10 or $15. So just something to keep in mind. Alright so moving on from the engine oil, this gets into the grey area where I think there is probably a lot more debate where we're talking about using a dedicated assembly lubricant.
And there are literally dozens if not 100s of these on the market. And it can be a little bit difficult to decide, particularly which one you're going to go for. You've sort of gotta try and sort out what exactly is in these lubricants and try and find out that information over and above the marketing hype that of course surrounds this particular industry. So I've got a couple of options here that I wanted to show you. This is a product that I use quite extensively.
This is Star Lube. Obviously depending on your location in the world, you may not be able to get this exact brand, this comes from CRC. And it's an extreme pressure anti seize engine assembly lubricant, and it uses a moly graphite base. So the extreme pressure aspect of this is quite important. Not something that's so critical on our engine bearings because we shouldn't be seeing extreme pressure in that location.
But particularly some of the valve train components which we'll just into in a bit more detail shortly, there can be a lot of pressure applied so this is where the extreme pressure assembly lubricants are potentially beneficial. On top of that, the other product that I just picked up before, this is a Red Line product and if we can just open this and get it under our overhead camera, so what we've actually got here is quite a thick viscous paste. So this has a lot of additives, again for that extreme pressure aspect there. So it is going to be able to provide a lot more protection than our clean engine oil. A couple of things that we do need to consider there, and most of these specifically blended engine assembly lubricants clearly will fit the bill here, but I'll mention it anyway.
We do want a product that is going to be oil soluble. Now as I've said, that's gonna fit the bill for these engine assembly lubricants, they are designed with that task in mind. The reason I raise this is that a lot of old school engine builders would use a grease for lubricating some of the valve train components for example. And some of these greases aren't oil soluble so that can actually cause some problems 'cause it's not gonna degrade into, or be absorbed I should say, into the engine oil during normal running. One of the advantages with these engine assembly lubricants is that they are a very high viscosity product, as you saw hopefully when I got a little bit of the Red Line assembly lubricant on my fingertip, it is quite a thick paste almost.
So the advantage there is that this does provide the ability for more protection from the product. But it also gives one of the disadvantages which is why I'm a little bit cautious with where I use it. What we'll find is that if we are using these engine assembly lubricants to provide protection on our bearings when we're assembling the crankshaft and the connecting rods, what we're going to find is that yes it will provide that protection, so that's obviously the key attribute there. We know that the components are going to be protected from metal on metal contact. The downside however is that as engine builders, what we tend to do is build up a knowledge base of what feels normal for our engines when we're assembling them.
So every single engine builder, once they've got the crankshaft final fitted in the engine block with all of the bearings lubricated and all of the main bearing caps torqued down correctly, the very next thing that you will do, is you're going to get that crankshaft and you're going to turn it. Now if you are using a clean 30 weight engine oil, then that's going to allow the crankshaft to turn relatively easily in the main bearing journal. On the other hand of you are using an assembly lubricant that is much thicker or much more viscous than our engine oil, it's going to be a lot more difficult to turn the crankshaft. And as I've found myself, this situation is made worse if you are working in an extremely cold temperature. Obviously the effective viscosity of the assembly lubricant is affected by the temperature that you're working in.
So this doesn't necessarily mean there's anything wrong with your engine, but what it does mean is that when you go to do that test rotation of the crankshaft, it's going to be a lot more difficult to rotate the crankshaft so you need to build this into your knowledge base of what feels normal and what doesn't. And if you aren't aware of that and you're not used to working with a engine assembly lubricant like that, it can set off some alarm bells and end up having you stripping down that engine to find out why the crankshaft is so tight to rotate. So just a consideration there that you do need to keep in the back of your mind if you do want to be using on of these special engine assembly lubricants. Then we'll move onto vaseline or petroleum jelly. This actually ins't a product that I use at all during the engine assembly process but I know that a lot of engine builders do so I'll just talk about this.
So our petroleum jelly, this isn't a product that we're going to be using for lubricating the actual bearing surfaces. But what lot of engine builders will do, is take the petroleum jelly and use this to pack the oil pump. This is an essential aspect, priming the oil pump like this with a product, is an essential aspect of engine building. What it does is it ensures that the pump is going to be able to suck oil back out of the sump when we go to crank the engine over for the first time. In other words it's not going to end up sucking air, we're going to be able to gain oil pressure relatively quickly.
On top of that, the vaseline will break down and be absorbed into our engine oil so there's no downsides in doing that, no downsides in using vaseline, if you're comfortable with that then absolutely fine, personally for exactly the same task, I use the Star Lube engine assembly lubricant so I'll simply disassemble the oil pump, pack the pump gears with Star Lube and again I know that when I go and crank the engine for the first time, the oil pump is going to be able to draw oil out of the sump and it's going to be able to prime really quickly. Another aspect that some engine builders will use vaseline or petroleum jelly for is to lubricate the oil seal, so front and rear crank seals, or use the vaseline for holing in o rings for example. Again absolutely nothing wrong with that, that's not going to be detrimental to the seals. Personally for exactly the same task, I'll actually use a specifically blended rubber grease, this one here is from Penrite. And it is a little bit important to understand when you are lubricating a rubber product, this isn't always the case for our engine based o rings and seals because obviously they're designed to work with oil.
But some rubber products will actually be broken down and damaged by some of the lubricants we use so you do need to be a little bit careful there. So with that rubber grease, obviously as its name implies, it is safe on rubber, we'll just open that up and go to our overhead shot so you can sort of see the consistency of that product. So it's quite thick and you can apply that to your o rings or apply that to all of your seals and that's going to protect them. Now we've also got a crankshaft seal here and another thing that's worth mentioning, this is an OE seal and I don't know if we'll be able to get this with our overhead shot, but this is quite common with a lot of factory seals. They actually are pre lubricated so hopefully inside that seal you can see the sort of a yellowy white bead of a greasy sort of product and that is actually factory pre lubricated so there's no need to do anything with those.
With a lot of the universal or generic aftermarket crank seals that people will use, that won't be the case. So I always like to give those seals just a very light smear of the rubber grease just to protect them and lubricate them during that startup so they're not going to be damaged. Alright so we've talked about those products, I'm going to just talk about my own personal use of those products, where abouts they fit into my engine building regime. And we'll start with the bearings. So with the bearings, lubricating the bearings prior to dropping your crankshaft into location and prior to fitting your connecting rods onto the crankshaft, this is obviously essential.
And we're also talking here about relatively small clearances. We might be in the region of one to two thousandths of an inch. So there really is a very limited amount of room for error here, and it you don't get this right you are going to get metal to metal contact. So we wanna be aware of that. So we've got a bearing shell here, I'll just show you exactly how we go about this.
My own personal preference as I've already given you the reasoning behind is that I do use clean engine oil. I believe that it gives me sufficient protection given the clearances that I'm running and the accuracy that I like to build the engines in terms of the alignment of the main bearing tunnel as well as the straightness of the crankshaft. So in that respect it is relatively straightforward, if we go to our overhead shot here, all we need to do, obviously this bearing will be installed in the engine block when we're doing this, and a relatively generous squirt of our engine oil out of our can, and then all I do is use a clean fingertip to generously smear that engine oil all over the bearing surface. And once that's done our bearing is protected and we can move on once I've got that all done, we can obviously drop our crankshaft into location. So if you choose to use the engine assembly lubricant, the process is exactly the same.
Again of course we want to make sure that we have adequately covered the entire bearing surface, we don't want to leave any of that bearing surface unlubricated and we can move on, of course we need to consider the viscosity and the effect that's going to have on the way our engine feels. We're going to go through a couple more aspects here and then we will move into some questions and answers, I see we've got a couple of questions there already but if you do have any more, this will be a pretty good time to ask those. So from my personal preference, on the bearings, I am using engine oil over assembly lubricant, however when we get to the wrist pin or the interaction between the small end of the connecting rod, the wrist pin, and the pin boss inside the piston, this is where I don't like to use engine oil. In my personal opinion, because of the delay in getting good oil flow or oil splash up into those locations, it's going to take longer for that to be established, so we need a little bit more protection and particularly understandably there is a reasonable amount of force being applied to the crown of the piston during the power stroke so we want to protect all of those components from any potential metal to metal contact. So this is what I'm going to be using, again my Star Lube engine assembly lubricant, and what we're going to do here, there's a couple of processes, so we've got one of our connecting rods here, what I'm going to do is basically take our Star Lube and all I'm going to do is apply the Star Lube onto my fingertip, we don't actually need that much.
And then we're going to just smear that through the pin boss, the small end of our connecting rod, and that's going to adequately lubricate that, again we can be quite generous with this product. There's no real harm in applying too much. As we'll see in a minute, we're going to deal with that anyway. With the piston, we're also going to generously lubricate the pin bosses inside the piston, so that can be done just by applying a small squirt of our assembly lubricant. And again, we just want to get in there and just make sure that it is contacting all of the pin boss surfaces so it is well lubricated.
Again, best way of doing that is just simply with a fingertip. Now the tip I'll have here though is that once we've actually assembled all these components, we've taken our wrist pin and we've slid that through our pin boss, what we're going to end up with if we can see this hopefully on our overhead shot, is, understandably it's going to end up collecting a lot of that excess assembly lubricant and it's going to tend to push it out the outside of our pin boss. And I do like to get a clean rag and just remove that excess lubricant there, and again this just helps ensure that we're not gonna end up with all of that lubricant making its way onto the wall of our cylinder and potentially affecting or having any chance of affecting our ring seal. Alright so those are probably the major components that we've got in the bottom end of our engine to consider. However there is the valve train to consider which is another important aspect there.
And this is where the design of your engine is going to affect its requirements. If we're talking about a modern multi valve engine, maybe a modern double overhead cam or even single overhead cam engine, then the forces involved, the design of the valve train in these is a little bit more advanced now than the old push rod style flat tappet style valve actuation which was very very sensitive around the lubrication and the startup process, so that's something you do need to consider. In either instance though lubricating the actual camshaft and the camshaft lobes, again I will be tending to use a high pressure engine assembly, or extreme pressure engine assembly lubricant. And particularly if you are running a flat tappet style lifter, these also need to be thoroughly lubricated. When it comes to getting good reliability with a flat tappet style lifter, it's a good idea to use a running in oil that is high in zinc or there is an additive called ZDP that will improve, basically it aids or reduces any chance of wear with metal to metal contact, so that's really important with some of those flat tappet style lifters during the initial engine startup.
So likewise I'm gonna be using this assembly lubricant for lubricating rockers, lubricating the interaction between the rockers and the valves, buckets, and the bores that the buckets run in, and basically any of those components where we're going to have a scraping effect. So the cam lobe moving across a lifter for example. We've talked about the oil pump there as well, that's obviously important and I've touched on the fact that personally I'm going to be using the assembly lubricant there as opposed to vaseline but a lot of this comes down to personal preference. So there's not a lot of magic there, there's not a lot of really critical thinking. What you do wanna do if you are going to be using an engine assembly lubricant, is find one that you're comfortable using, find one that has a good reputation and if you use that on an engine and you've had good results from it, I'd recommend that you stick to it, that's a good way of building up some knowledge with the product that you know you can trust.
But yeah just important, if you are going to be using engine oil as I do, just understand that it's probably not the ideal lubricant for every component in the engine and you need to just keep in mind or take into account some consideration around the components that are going to take longer to get a good amount of oil flow through to them. And again while this is something that probably borders more on the break in process of the engine as opposed to the assembly lubricant side of things, when it comes to gaining oil pressure for the first time, I always recommend removing all of the spark plugs from the engine. Obviously we also want to make sure there's no chance of the engine starting up by accident and removing the plugs is gonna be a great way of doing this. But by removing the spark plugs, what it does is it removes the loading that's going to be placed on the top of the piston and being transferred into the wrist pin, the pin boss in the conrod and then into the big end bearings by that compression load as the engine moves through the compression stroke, so that's a good trick. I like to do that, gain oil pressure and then continue to crank the engine for 30 to 45 seconds after we've seen oil pressure register on a gauge, before we then reinstall the spark plugs and we're finally ready to actually start the engine up.
Right so we'll move in and have a quick look at our questions here. Darian has asked, I've been asking for a while now, do you balance the entire rotating assembly when you're assembling an engine? Did you balance the rotating assembly for the SR20 VE build? Yeah absolutely. So what we need to understand is that all of the components we're dealing with will be factory balanced to some level. Particularly with some of our late model engines, the factory balance on aspects such as the crankshaft are actually often pretty good straight out of the box. But we can always go a little bit further than this and one of my policies is to always expect that the manufacturers have done a good job but we also want to verify and make sure that what they've done is actually suited to our expectations.
So yeah we balance the rotating assembly or rotating components of all of our engines. With an inline four cylinder like our SR20 VE, the way the pistons and conrods operate in the engine, we've got cylinder one and four will be at TDC, while two and three will be at BDC, essentially the mass of the pistons and rods cancel each other out. And what this means is that it's quite convenient because we can balance the connecting rods and the pistons in isolation from the crankshaft. This means they're not actually balanced as a complete unit. That's a little different to the likes of maybe a V8 or a V6 engine, where what we need to do is balance the connecting rods and the pistons first.
So they're all balanced exactly the same way we'd balance any engine, find the lightest component and balance all of the heavier ones, removing material until they all weigh within whatever our specification is. Once we've done that though, when the crankshaft is balanced in the balancing machine, the weight of the pistons, the rods, the ring pack, even an allowance for the... Guys we've just had our camera drop out but Ryan's managed to get that back up and running. So I was just finishing off the question about the balancing. With the V configuration engine, I'm not quite sure where that got cut off, but with a V configuration engine, we need to take into account the piston and rod weight and that's applied as a physical mass to the crankshaft while it's balanced.
Now another thing I'll just mention here when we are balancing the rotating assembly, so this isn't something we can do in our home workshop, I'm talking here about the crankshaft itself, this does require quite an expensive balancing machine to do this. Hey guys thanks for your patience, look we obviously are having a few problems, so to preempt another one, we really are right at the end here, I didn't have any more questions that I needed to deal with, so I think we're just going to finish off this webinar. Thanks for watching, hopefully you've learned a little bit more about the topic of engine assembly lubricants. Of course as usual, if you do have any further questions, please ask those in the forum and I'll be happy to answer them there. Thanks for joining us, we'll see you all next week.
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