This is the tenth part (check out part nine here) in our extremely popular video series in which Todd Muller, Head Motorcycle Tech here at Lowbrow Customs, disassembles a unit 650 c.c. Triumph motorcycle engine and rebuilds it. In this installment Todd gives you a step by step guide on how to rebuild your Triumph 650 top end. From installing your tappet blocks into your cylinder correctly, to installing your rings on your pistons and a neat trick on how to get your cylinder over your piston rings. From proper ring gap, to proper pushrod tube seals. Todd make sure you have all the right information to get the job done. He even goes over important info regarding to your rocker box rebuild.
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You can read a full transcription of this video below:
Hey, gang. Ready to put some more stuff together on the motor here today? Now you've been anticipating get some more work done and so am I. What we're going to do today, we're going to go ahead and put our cylinder and cylinder head and maybe we'll even get to the rocker boxes in this segment. Let's get started. Talk about the cylinder just for a sec here, this is obviously already been painted and done.
I send this stuff out to the machine shop, get it bored out for oversized pistons, what we have going in this motor, we got 20 Over. Basically this is 20,000s larger than stock. Anytime the bore's worn, you do have to go oversize. Back in the day used to be able to get 10 over pistons, they're just not available these days. This was a stock bore cylinder that got bored out for 20 Over pistons.
When you take this stuff to your machine shop, make sure they have experience working on vintage motors engines because of the fact that if they look in the books, they might not get the right specs. You need to tell them what kind of piston to cylinder wall clearance you need in order for it to run so the piston doesn't get stuck to the bore. What happens as as the motor heats up, aluminum grows and if you set it up too tight, you'll start your freshly rebuilt motor and the next thing you know, it'll be seized.
Pistons will be stuck in the bore. That's bad. I like to see about four and a half. Four and a half, 5,000s clearance is a good number for these motors. Now you got to realize the rings are doing most of the work, the pistons are just going along for the ride. Once you've got your cylinder back from the machine shop, you want to wash it. Then you want to wash it again. Then you probably might want to wash it again. Several times, hot soapy water, don't be scared to get it wet, won't hurt a darn thing.
When you get done washing it, you want to make sure you dry it quickly and if you're not going to put your motor together right away, put some oil on the cylinder wall to keep it from rusting because if this is sitting around your garage for any length of time before you get to this part of the job, it could get rusty in the bore. Now the other very important thing on cylinders is there's a crosshatch pattern in here and that's done with a hone.
There's a couple different ways that can be accomplished. I actually have a ball hone. Now the machine shop did this for me but this is called a ball hone, a flex hone and what you do is you put this on your drill motor and you use some lubrication like solvent or something of that nature. You're basically sticking this in the bore and you're going like this with it. By going like this at a certain rate and speed gives you a crosshatch pattern in there.
What you want to see is a crosshatch that's about like this. You don't want it like this and you don't want it like an X. It has to be a specific crosshatch in there. Another important thing to tell your machine shop if they're doing that portion of the job for you is to use 180 grit. 180 to 220 is acceptable on these cylinders. Basically essentially what that crosshatch does is when you start the motor up for the first time with your new rings and your new bore job, the rings need to bite into that cylinder wall in order to form a seal.
On a fresh motor, they're not seated. Very frequently, I will have customers call and say my freshly rebuilt motor is smoking. Well, a couple different reasons that could be and one is the grit used on the crosshatch and the other is dryer lubing your cylinder on it on assembly. We'll talk about that a little bit later as we move along here. Once you've washed the crap out of this thing because you want to get all the grit and all the stuff from the machine shop, from the machining process out of this bore, you want this to be as clean as you can possibly get it.
Once it's all clean, you can take a lint free rag and some brake clean and wipe it in the bore and pull it out and look at it. We'll do that real quick. Why not? This cylinder's been sitting there for a little while. What you want to see is a clean towel. You don't want to see any dirt on your towel. You're going to give it a wipe. See how that's pretty darn clean there. There's a little discoloration. That's okay, we'll be all right here. That's basically pretty darn clean.
We're going to need to do this anyway in preparation for putting the cylinder on because it has been sitting over there on the other workbench for a while. I know, you guys have been patiently waiting but we're going to get some work done today, I promise you. That's not bad. If it comes out looking real dirty, clean it again, wash it some more. Cleanliness, cleanliness, cleanliness when assembling this. It looks like I missed a spot, I can see down in there.
Okay. That looks pretty good. The other thing I did was I put some high heat paint on here. Pretty simple job. You can do that yourself. You don't need to pay somebody to do that. What I do is I just take some masking tape and I lay it all across here in strips then I take a razor blade and I cut out around the head gasket surface. I have a couple of washers around here with some tape on them that I throw over the top of block holes and I flip it over and I tape the bottom.
I'd usually tape it around here, then I tape all this flat service and use a pair of scissors to cut it around, you don't want it to overlap. Then I get this stuff at the auto parts store, Dupli-Color engine enamel, ceramic, high heat. It says 500 degrees on the label. This motor's never going to get run five-- If your motor's running 500 degrees, you've got a problem. You're in a parade. Here in Daytona, you're in the parade, the things going to blow up, you don't want to get that hot so this stuff works real good.
Want long lasting, puts a nice finish on there. When you're painting it, I usually flip it over a couple of times and I look down in between the fins and you want to give it that last coat, go to a nice heavy coat and make sure you get all in between the fins. Also I don't think it's necessary to-- Some people ask, "Me do you sandblast your cylinder?" I don't think it's necessary because that old finish on there is perfectly fine. The new paint will stick to the old finish after you've washed the crap out of it.
If you got some real bad dirt in between the cylinders, use a green Scotch-Brite in there. Well, the first thing we're going to do is we're going to put our tappet blocks back in. I know we have a separate video for this but we'll go ahead and do it again because it is part of the job here today. Obviously this-- One thing I forgot to mention, you want to check your threaded holes too.
Make sure all the threads and all your holes are clean and in good shape because you don't want to get this on the motor and then go to put your head on and go to torque your head bolt to find out you got a stripped pole or a boogered hole. I've already pre-done that on this cylinder I know all these are good. Check your threaded holes. We'll go ahead and get the tappet blocks installed. Obviously, this denotes the front.
Well, we can just take a Sharpie and mark it so we don't get confused because you know us old guys, we get confused easy. A little arrow there. Front, that's the front of the motor. I know from experience that these tappets with the holes in them are going to go on the exhaust side. They switch to this system. Early bikes won't have this later ones do and what you'll see is a cross drill right here. Basically that's pressurized feed that's coming up through this little port here on the engine.
What it does is it sends some oil up through here, it goes into that hole and then it goes across here and meets up with a groove, this groove. It forces some oil through that little tiny hole. Then if you look at your tappet, there's another little tiny hole. You got to have that oil hole facing out. If you face it in like so, you can put it in either way around, well guess what? That hole's not lining up with anything now, is it? There's nothing there. Holes need to line up to get oil to your exhaust tappets. If you have this style early, motors you'll see won't have the dowel on the crankcase, it won't have the cross drill on the cylinder.
Incidentally you don't want to mix and match in early and late cylinder, early late motor. I have read where if you're putting an early cylinder on a late motor and you want to defeat this, you need to plug this hole because it's still sending oil there and if there's nowhere for it to go, it can leak out the base gasket. There's also a groove on the tappet block, takes an o-ring. I'm going to make sure you got new o-rings on there. If you have the old ones on there, you'll find they're probably hard as a rock. Been on there since 1968. Okay. New o-ring. Maybe a little bit of luber won't hurt anything. A little bit of lube on there. Okay. Now the tappet block is going to go in with this little nubby lined up with this hole. Then you have this keeper or bolt with a sealing washer, gets threaded in there, that meets up with this, that keeps your tappet block from moving. I don't think they can move but that's just the way they designed it. When you're getting ready to drive this in there you, want to verify that you've got that nub on there centered up with this hole, because if it's not lined up correctly, you'll find when you go to put this odd little bolt in there that this won't go in.
If you drive this in and then you go to put this in and it bottoms on that because it's not lined up with that little nubby, drive it back out, line it up again. Okay. We have this official Lowbrow Customs tappet block installation tool. Let me take another quick look at my thing to make sure it's lined up. I generally look at these about four or five times, six different ways to make sure so I don't have to drive it back out again.
It's not the easiest thing to do but the last one I just did turned out perfect. That looks pretty lined up right there. Okay. It looks like we got it lined up, let's give it a shot. Looks like it's seated, we'll give it one more whack. Looks good. Okay. Sight down our hole. Look at that, looks like I got it just right. Put our odd little screw in there. You can tell right away if it's not lined up because when it gets down as far as it is right now, it won't go the rest of the way.
That means you got to take it off, bang it back out, go again. Don't over tighten this little screw because you don't want it snapping off in that hole then you're pretty much screwed. There's that one installed, go ahead and get the intake installed. Again, got my o-ring on there, a little bit of lube. I said a little bit, not that much. Make sure that's facing out, get her lined up. Take your time getting it lined up, don't be in a rush, don't be in a hurry.
It's much easier to spend a few more minutes looking at it than it is to have to drive it back out but it's not the end of the world. If you don't have it perfect, try again. How do we do? Looks pretty good, looks like we hit her. All right beautiful, that went great. You notice how I wasn't like wailing on it because sometimes you can break this tappet block so I was just gingerly tap, tap, tapping it, not bam, bam, bam. No bueno.
Now since we're done with those, we can go ahead and put our tappets in the holes. We want a little bit of assembly lube on there. We'll put some on the tappets. Also if you're using the tappets that came out of here, you want to put them back the same way they were in there. If you look on the face of these, you can see wear marks on them from the ears. We will flip this over, exhaust intake, you can see a wear mark on there from where obviously this one has to go with that out so you can plainly see that this tappet, this has to face out, you can plainly see that this tappet was in this hole by the wear mark right there.
You can kind of see the shape of this. We'll put a little bit of assembly lube on here. Don't overdo it because we are going to be putting a gasket on here so we'll wipe this off as we go along here. This one's going to go on the other side with the hole facing out again, maybe a little less assembly lube, we're kind of making a mess there. All out to verify that. Bam. That did a better job. You don't want it to be dry on startup so assembly lube's our friend. We love assembly lube.
Okay. We'll go ahead and put the other ones in. Let's take a look. That one looks like it was on this side. That one's not so defined. That looks like it right there. There we go. Now let me grab a couple of zip ties and what I'm going to do is I'm going to put a zip tie around these so that they don't slide back down the thing when I flip it over. All right. A couple of small zip ties, put them in the little groove on here. Like so.
Some guys-- You can also just stick a piece of hose down in between the two, that'll do the same thing. This to me is much faster and easier when I'm done putting it on, I can just cut these off. As we're going along, we're going to be flipping this over the pistons, we don't want those falling out. We're done with that job. Again, I can't stress enough how important it is to keep everything as clean as you can as we go along here with these jobs putting this cylinder on there.
Next thing we're going to do is we're gonna check our ring end gap. Even though these are clearly marked 20 Over, you still need to check it. What we're going to do for that, we need one of these new pistons here. We sell these pistons on the website. I know what you're thinking, they're made overseas, they work just fine. I use them all the time, not a problem. Next thing I want to do is I like to open my rings and lay them all out.
They'll be in little pockets that say top, middle, bottom but I like to keep track of what's going on here. Look at this mark-- These are marked one, two, three. One being the top, two being the middle, three being the bottom. Bottom one's going to be your oil control ring, the two top rings are what do most of the ceiling- all the ceilings. The oil control ring basically scrapes oil off the cylinder. As it goes down, it sends the oil back into the crankcase.
What we're going to do is we're going to take these all out of these little pouches and we're going to leave them. That's the ones for the top groove, that's the ones for the middle groove and these are the ones for the bottom groove. Just like so. Now I see some notes here we could take a quick look at this and see if there's any notations. Some rings will have a dot, some will be marked top, some will tell you "Dot faces up." Others will say, "dot faces down." Some will be square cut on the ends.
If you viewed the very end of the ring here-- That's not a good example. We'll look at this one. This one has a taper some rings will be completely square at the end, some will have a taper. I don't see any identification marks. Wait, I lied. Here it is, right there. Right there in little letters. It says, "Top." That means this face is up. I don't have to look at the silly chart and look at the ring and look at the end and go, "Gee, which way do I put this darn thing in there?" It's marked, "Top." Awesome. The other one, same. Oil control ring, not marked. She's got the same shape top and bottom. That won't matter if it goes in either way around.
Since we're going to put the bottom rings on first, we'll start with those. You're just going to stick it in the bore. There's no freaking end gap on that ring, it's zero. At any rate, we're going to use the piston to square up the ring in the bore and we're going to look-- There's no end gap on that. Well, that would be a bad situation if we put it together without making an end gap. The next thing we're going to do is we're going to grind the end of that ring and make an end gap.
I like to see-- On these engines, I like to see about 15,000 end gap. Let's go ahead and get a feeler gauge out here, corresponding size to what I would like to see it end up as. Oh goodness, my 15's been chopped off, must have been using that for something special. That's okay. We can deal with that. I have a handy little tool. Some people do this with a file, that's too much work. I got a ring end gap grinding tool. I got this at Summit Racing but it makes accurate and short work of this particular job.
I like to clamp it in my vise because that makes my life easier, I don't have to hold the tool. Okay. What we have here is a little crank handle and an abrasive wheel. Got these two guides, you're going to set your ring on there, you're going to squeeze it together, pushing it up against the guides and you're going to give her a spin. Essentially, what's that doing is taking material off the ends. You want to be conservative about this, you don't want to just go damn wild and then stick it back on the bore and go. Wow, now I have 20,000s end gap when I really only wanted 15,000.
Do a little bit and then check it again. That wasn't very much but we'll see what happened. See now, I'm starting to see some end gap there. Once again, you want to square this up with the piston so that it's square in the bore. You can see there's still not much of an end gap once it's been squared in the bore. We'll go ahead and grind it again. Now I can see I've got some gap going on now but it's not 15 yet.
If you want to look, you can see the gap now starting to open up from me grinding it. See it now, right there where before the first time I put it in? That ring was butted right up against each other. Now we can see we have a nice square, the tool makes short work of making that, you want the ends to be square, you don't want it to be angled. Here's our 15,000s feeler gauge. Look at that, just right. Perfect. That's exactly what I wanted to see. Pretty happy with that one.
All right. Since I was checking this ring that I just set the gap on on this hole, this is the left, I marked the pistons left and right and I'm just going to go ahead and install this bottom ring on here then I'll do this ring and this hole, put it on that one and as we keep moving along and then when I get done, we'll have all the rings on there ready to put the Pistons on. I think before we do that, we can go ahead and put the clips in one side of the piston because as we go to install these on here, it's much easier to put the inside clips on each side in the piston first then you can slide the pin from this side and put the outside clip in.
Here's our piston pin clips. That's kind of the other reason I like to mark the piston too. I generally face the size out but since I've marked those, I know that when I go to put it on the bike, that the clip will be on this side because of the way I've marked it. There's a groove in there coincides with this, you can stick it in like so at this angle. Then kind of roll it. You can also use the pin. Now it's just stuck in the hole.
Generally, if you stick this in-- There it goes, popped it right in. Then you always, always, always want to take a look at it and verify that the clip is in fact all the way around in that groove, it's not sticking out. That's good, we'll go ahead and do this one before we forget. This is facing in. Go ahead and stick your clip in there at an angle, rock it down in the hole. Sometimes it'll go right in. If it doesn't, use your pin and stick it in far enough.
Hear that clicking sound? That was the pin going in the hole- I mean, the groove. There she is. It's bad news if one of those comes out with the motor running, that's no bueno. Okay, here's the ring we just did. Then we have this handy dandy little tool here. This is for putting your rings on. Now some guys will just shove it on there and push it down over and pull on it and open it up by hand. These are kind of fragile, you got to be careful with them.
You don't want to break a ring at this stage of the game because then you'll be calling me saying, "I broke one ring. I just need one ring, they come in sets." You just take this tool and you'll see how it has these v-shaped grooves, you'll put the ring into the grooves like so and you can open it up. Carefully slide it over the piston, put it in the corresponding groove that it goes in, boom, done. Okay. Let's move on to the next one. I don't have to square it with the piston, I can plainly see there's no gap on that one either. It's grinding time again.
I'm on my last ring. Let's see how we did. Pushed it down with my feeler gauge. Perfection. We like to see, once again pay attention to dots, markings on the rings. Don't want the ring upside down. Look at that, all the rings are in the ring lens. All my ring end gaps have been verified. All my rings are installed with the part that says top facing up. We can go ahead and put the pistons on the rods and get this cylinder on there. Once again, assembly lube. You want to have some rags stuffed in the crankcase, I know these have been in here for a while.
Just in case the clip wants to jump out of there and fall in the crankcase, because then you got to fish around with a magnet and get that silly clip back out of there and that's not fun. We're going to fill up all these little holes here, clips on the inside. You can go ahead and get your pin started. In this side, you can run it in until it just gets to that spot there. This is kind of a feel thing. There she goes. Look at her. Bam, it's all the way in there. We got some assembly lube oozing out the other side. I'm going to wipe that of. We're going to put our clip in there. Now this time, since we can't use the pin, I think we'll just grab a pair of pliers and carefully use that little tang that's on there. The cokes are in there. Like so.
Once again verifying that the clip is in fact all the way around the groove on the piston. Looks pretty good to me. Hear that little click? That little click tells me she's in the groove, baby. Get that visual inspection. What do you think? Looks pretty good. Now that we got all four clips in there, we need some luber doober on her, what we're going to do now is we're going to get this baby on there. Need a base gasket. Please use one of the high quality base gaskets we have on our website.
You get one that's thin like a piece of paper, reject it. Then go to Lowbrow Customs and get this one because this is the one that works and doesn't leak. What's nice about it is it's got some wire in it. There's our hole that coincides with that dowel on there. We're going to need to get rid of all this junk we shoved in the hole along with the rags. Ease her on down making sure it's over the dowel correctly. There you go, base gaskets on.
Now before we go any further, we want to have a little bit of assembly loop on the cam lobes. Boom. Got it. Now I'm going to show you the easy way to support those pistons because obviously we're trying to shove this over two pistons at the same time. This isn't Harley. Harley, you can do one at a time. It's a little bit simpler. I got these couple pieces of wooden dowel, looks like I put a couple of cylinders together with these. Look at that.
What we're going to do, we're going to jack these babies up and we're going to put this across the crankcase like so, then we're going to run this down. Look at that. Don't be worried how it's going that way, that's not a problem. I'll see when I'm pushing on those pistons, cranks not moving now, these are supporting so when I go to slide this home, they won't go down in the hole because that would never work. Then I have these official Triumph corporation ring compressors. Look at them.
Next thing we want to do is we want to stagger our ring in gap. You want them to be a third of the way apart from each other, you don't want all your ring gaps, if you look here, you can see right now they're pretty much all in the same darn place. See them? You don't want those ring gaps all lined up, you want them staggered. We'll put the bottom one over here and then we'll put the middle one-- Where's the middle one? There she is.
There's a third of the way from that one and then we'll put the top one facing that direction so that the ring end gaps are staggered. We'll get our fancy schmancy ring compressors here. What we're doing now is we're compressing the rings into the grooves on the piston because as you can see, that would never let the cylinder slide over those. You want to make sure it's on all three rings. You want to tighten it up until it's tight where it won't hardly move and then you want to back it off just a little bit so it'll slide as we introduce the cylinder on there.
That one's good. Let's do the other one. Stagger our ring in gaps on there. Bottom one is facing that way. Next one is there and this one is over here. It's very interesting, this applies to just about any motor with rings to do that. I got to say when I was doing big bore kits at the Steelership, I'd take bikes aparts, see them darn rings almost lined up, I go, "Whoa, these things spinning around in there? Likely."
I'm just adhering to correct assembly practices. Pretty happy with that. Now with any luck, she'll slide right over both those pistons and all those rings all at the same time and we'll be done with this. If it screws up here in a sec, you'll see we'll have to start over, take it back off and redo these. If it works, we're done. If it doesn't, take it back off and go again. You don't try to force the cylinder over the ring. If it's sticking out, it'll break it.
I personally like to do mine dry. I think the ring seat better if it's dry. I don't want to put a whole bunch of oil on there. Maybe a tad bit of something right here on the leading edge so it slides easy but don't slather these with oil. I've found over the years that dry works better for receding rings. I'm going to put just a little bit of this on there. See that? Not very much. Let's give her a shot, see what happens here.
Look at that piece of cake. Right on their, first try. Now since we know we're over all the rings, we're going to take these clamps off of here and send it home. Well look at her, she's trying to go home without me. Look at that. We even got it going the right way, arrow facing forward. All right. Won't run so good with these pieces of wood in there so we'll take those out now. Come on Betsy. There we go. Look at that, she really wanted to go together without me, didn't she? There you have it. No fuss, no muss. Got these nice new cylinder based nuts. Also forgot to mention-- Maybe I did mention it but I'm going to tell you again.
You did check all those studs that these nuts are going on right now because if one of them was buggered, now would not be a good time to find out the nut doesn't want to thread on it. Anything like that needs to get addressed long before we're at this stage of the game. Check all your threaded holes, all your threaded studs, anything that has a thread gets checked way in advance. Then when you get to this point, look how every one of those is just threading on beautifully like melted butter. Would you look at that?
I believe the torque spec on these is about 25, I think. Well, guess what? You can't get a torque wrench on there so we're going to tighten them by hand. We know what that feels like. Things are moving along real well here today, gang. Now that we've got the cylinder on, we can go ahead and cut those zippy ties off for the tappets. We got all that nice juicy lube in there so every moving metal part will be happy with each other at the end of this. I like to go around here, just first snug them down. Just snug them down the first go around. Go around again. Give her our final tighten and we can move on to our cylinder head.
The next thing we're going to do is we're going to go ahead and get our cylinder head installed but before we do that, I want to talk about tappet blocks, push rod tubes, cylinder heads and cylinder head gaskets. I'm sure you may have read in your workshop manual how it tells you that you can reuse your head gasket by annealing it, where basically you heat it up cherry red hot and you dip it in some oil and that quenches it and then it makes it soft and malleable again, you can reuse it. I just always use a new one, I'm not going to go through that trouble for the cost of a new gasket.
One other thing worth mentioning on these head gaskets is if you purchase the complete top end gasket kit that we have on the website made by MgO, those head gaskets are not preannealed. In other words, some companies will preanneal the gasket like the other gasket we sell on the website. This is a preannealed gasket, no need to anneal it. If you use the MgO gasket, you should be annealing that head gasket. One less thing I got to do. Also I get this stuff right here, Permatex, copper spray gasket at the local Autozone or any auto parts store should have this stuff. Basically it's sprayed copper in a can, like a rattle can.
What I'm going to do is I'm just going to hang this gasket from this piece of coat hanger that I conveniently have here. I'm just going to spray a nice even coat on both sides of it and then I'm just going to hang it up and when we're ready to use it, it'll still probably be tacky, not a big deal. I really don't want to spray this in front of the camera, my cameraman and you so we're just going to go over here by the door.
There you go. We'll hang that up until we're ready to use it. You may also notice on these gaskets, there's going to be a very flat side and the kind of a rounded side, you want to put the flat side facing down on to the cylinder when we get there. We'll just hang that up there for when we need it. Now you're going to see several different styles of push rod tubes and push rod tube seals and I think this is worth mentioning.
I don't want to just show you the one we're doing and then you look at your engine and you go, "Wow, this doesn't look anything like what he's doing. Why is that?" Well, this is a 1968 motor and it must have been built early in the year because it has this style push rod tube. You'll see it as flat on the bottom, has a little lip on the top. With this type of push rod tube, this engine actually has a little- this little kind of cup thing and that's going to go on to the tappet block first like so.
We're going to pick the push rod tube seal which there are three different thicknesses on these flat round seals. Basically what we're trying to accomplish here is we're trying to find the right combination of seals so that the push rod tubes don't leak. Very common problem with these engines, leaky push rod tubes and I think it may be due to the fact that people don't spend the extra time to look at it and check things while they're assembling to make sure they're using the right thickness seal.
Now once we go to the next push rod tube after this one, Triumph knew there was an issue so what they did was they added an o-ring inside the bottom of the push rod tube in conjunction with the flat seal on the bottom. It would still have the variable thickness, see here's a thicker one. Then they also added this ring which got nicknamed the wedding band. You can see, it looks like a wedding ring. Basically, I have another tappet block here and you can see the difference.
Let's go this way around, sorry. You can see the difference in the tap it block. See how this has a step and it's larger. Let's just say we try the later style push rod, it fits over it but it's not very tight. If we take the later tappet block and you push it over it-- Look, that thing's tight on that o ring. What they did was they added the o ring and then you'd have the variable thickness flat washer which would go on first like so and then you'd put this on so now we have two seals and then the wedding band would sit on the outside of it.
See, I can't hardly get that thing on there now because of that seal being pushed out. Basically-- There it goes. What that band did was when you assembled everything and tighten the head down, it prevented that bottom flat seal from being pushed out. That was one of the ways that Triumph was trying to combat their push rod tube seal leaks. Now there is one other part to the equation here that is very important especially if you're building a motor from a box of parts that you bought at a swap meet and you don't know if the things are designed to work together correctly or if you have the right year tappet block, the right your push rod tube and the correct cylinder head for that application. As we discussed earlier, cylinder heads are date coded, majority of the time has a two-digit date code in a little oval here, this one says '68. Well, what I'm going to show you next is very interesting because '68 was a transitional year, they actually started to do some standard fasteners in '68, where previous to '68 it would have been all Whitworth or a British Standard fine, different threads. Here's the key to being able to identify what set of tappet block, push rod tube, cylinder head combination you have to make it work correctly and seal right.
If you notice the groove where the push rod tube is going to sit in the head like so, you can plainly see that this groove is pretty shallow. If you compare the length on those push rod tubes, you can see that the later year one, the little lip on the top is down further. The reason for that is because what they did- another thing they did to try to alleviate the leaks was they made the groove in the cylinder head deeper.
Incidentally, I'll put them both together so you can compare them side-by-side, but then the other thing they did on this style push rod tube, not the one we're using on this engine here, they put a black round o ring. There's one in the bottom of this one. They had different colored o rings, see how this one has kind of a orange looking one. They used o ring inside on the bottom, flat seal on the bottom, wedding band and o ring on the top. Where the earlier motor used flat seal top and bottom.
Then you can see with this cylinder head how this push rod tube will sit down in that groove further. Basically, the thing I'm trying to really get across to you right here is if you're using this tappet block and this push rod tube, guess what? It won't even fit over it. Look, not going to go. You have to have the right combination of parts. If any of you guys out there would like additional information about this, I do have a list of the year changes and the different parts and how you can combine the right things to make yourself a leak free top end when it comes to your push rod tubes.
Or if you're piecing something together from swap meet parts or you say your head's junk in your replacement cylinder head, then you can make an intelligent purchasing decision and not buy something and realize, "Wow, this won't work with what I have. Now I need to replace this and I need to replace these." Let's say your cylinder is still on the motor, well now, guess what? You got to pull it off to change the tappet blocks.
Just some Triumph Motorcycle trivia stuff there that's kind of important if you're building one of these engines, especially if it wasn't a complete engine when you started. Now let's go ahead and get a look at these two heads side by side so you can see the difference. We've showed you the push rod tubes. I have my little metal cup washer on the bottom, I've chosen the middle thickness because I'm pretty confident that's what's going to be on this engine.
Then I'm going to try these thinner ones on the top and what we're going to do next is we're going to go ahead and put the push rod tubes on, put the new head gasket on, now we're going to put the cylinder head on and we're going to check how much gap is there, because basically what you're doing is when you tighten the head bolts, you're kind of squishing these gaskets down so that they'll seal.
We don't want it so thick that there's a giant gap right here in between. You'll see in a second, I've set this on there with the gasket. There's actually a Triumph service bulletin on this. Once again, they were having problems getting their push rod tubes to seal in the field. Probably the new engines weren't so bad because the guy at the factory, he knew what he was doing but there was a service bulletin in it, it says that they basically want you to take a feeler gauge after you've put it together and just set the head on the gasket and they want to see to 30,000 to 40,000s and you'll be measuring in between here and the cylinder head with a feeler gauge.
I don't personally do it that way because I've done enough of these that I can tell by looking at it that it's going to work right but if this is the first time you've ever done this job, might not be a bad idea to get your feeler gauges out and give it a measure. Basically, you don't want too thick of a seal that it crushes them, that will cause a leak and you don't want to thin of a seal where it's not going to seal when it's compressed.
That's probably one of the most common ones is the thickness is not correct so that you get your rebuilt motor running and now you got oil running down your push rod tube. Crap. Take the top cylinder head back off to change these simple seals that take the time to do it as you're assembling. We got our sticky head gasket here. She's sticky all right. Once again, that's my flat side. Down, get it lined up over your holes.
We can go ahead and introduce our cylinder head. As you're lowering this down, you want to make sure that the push rod tubes are being located in those and they are. Then we'll go ahead and put the four outer head bolts in just to keep things in place while we're looking at the gap we have in the middle. Those should go in very easily like they are, if they're not, maybe your gaskets' caddywhompus. All the holes have to line up.
Probably actually even put the center one in there too. Double check your push rod tubes are located in the cylinder head in that hole that we were just discussing. Now we can take a look. Look at that gap, that looks really good. I think I like that. I don't really think I need to measure it but if you were going to measure it, I do really don't want to stick my feeler gauge in on that copper sealer that I sprayed on there.
You're just going to go in between the head gasket and the bottom of the cylinder head 30,000 to 40,000s. That's how much this is going to push down when you tighten all the head bolts. I'm pretty confident just looking at it that it's correct. It looks like about 30,000s to me. All right. At this time I'm going to go ahead and snug up the head bolts and I'm not going to be torquing the head right now because you have to have the rocker boxes off for going into the frame.
I actually won't torque this cylinder head until the engine is in the frame with the rocker boxes on. Won't hurt a darn thing now, this thing's sitting around here like this. With it not torqued, it's not going to hurt anything. It'll be fine. Now you can see that it's going to be sealed. You can also-- If the thickness isn't enough, you might be able to just turn that push rod tube ever so slightly when it's tightened down.
Once again, I'm just snugging these down, I'm not torquing anything right now. Anytime you've got open spark plug holes, you don't want anything to get in there by accident. A nut, a bolt, something falling off this crazy wall, dust, dirt, whatever, never a good idea to store any motor without having spark plugs in it. Since this is all clean and dry, maybe a dab of NICs on the threads of the plug. Not on the electrodes, just on the thread.
Little lubrication there like so. A little dab will do you. I know what you guys are thinking, you're like, "Wow, that cylinder head magically has new parts and it's all done and he never talked about it once." Well, to be honest with you, I send my cylinders and cylinder heads out to have them rebuilt. It's not because I don't know how to rebuild a cylinder head, there are some special tools required to do the job. Probably not something most guys are going to be doing in their home garages. If you need advice on a good place to send your cylinder head to have redone, I can help you out with that. To be honest with you, for the labor, my guy charges me to do this head, it's not worth something worth me doing it. If it needs guides, he checks the guides, the guide fitment, he does the installed heights for the springs, he tests the springs.
He just does a really nice job and when I it back from him, I can just bolt it on like I did today. I don't have to check anything. Once again, if you're needing a place to do cylinder head work, I can provide you with some information for that. If you are having someone local do it, just make sure they have experience with these older engines. I mean, it's not that difficult to cut bow seats but it's also not that difficult to screw them up.
She's actually starting to look like a motor again. Next thing up on the list is going to be putting the rocker shafts back in the rocker boxes and getting those ready to go back on here. Usually, what I'll do is I'll just set them on here and then when the motor is done and basically up until from 63 to 69, the rocker boxes must be removed from the engine in order to remove the engine from the frame.
Well then in 1970, they decided to change the front motor mount to a triangle plate with three holes where you could take that off and pull the engine without taking the rocker boxes. Well then in 1971, they decided to make it oil and frame and went right back the way it was before, until the 750 motor which has a short rod was a little bit shorter motor and then you could get the motor out.
Once again, no reason put your rocker boxes and tighten all your head bolts because then when it comes time to put it in your frame unless you're a 1970 model, it's not going back in there without taking those back off. I'll just leave it alone until you're ready for final assembly into the chassis. What I was just referring to on the- it's the front motor mount that we're talking about, here's a 1968 model, see how the front motor mount is part of the frame? Well it's just not possible to lift up, tilt that back and pull the motor out without removing the rocker boxes.
Now right here, we have a 1970 model. You can see they finally got smart by removing that plate. There's two holes through the front of the frame, this frame tube and one here in the engine. By removing both of those you could get the motor out without taking the rocker boxers off. We need to get the rocker shafts back into the rocker boxes. Those can be quite perplexing job at times. We'll give it a shot here.
One of the one of the important things I want to talk about before we get started is there's actually a service bulletins from Triumph Corporation in April 8th of 1969 concerning the position of this. It's called a Thackeray washer and you can see it's kind of a little spring dealio and a flat washer. If we look in the service manual, we can see the order that it's supposed to be assembled. All right.
This particular service manual is actually dated 1972. You can see, here's the picture of the components and how it's supposed to be assembled. They're showing a flat washer in the middle, Thackeray washer and then the flat washer on each end. They're saying the flat washer would be up against here so obviously flat washer, flat washer on each end, Thackeray washer in the middle. Guess what, this service bulletins change never made it into the books.
It's kind of important depending on what year your motor is that you pay attention to the correct assembly of this and I'll just read this real quickly and we'll try to make some sense of it for you. Service bulletin number 25, once again dated 1969 because of change. Change was made in the lubrication of the rocker arms and push rods during the later part of 1968. Beginning with 650 engine DU79965, the drilled hole in the rocker arm to supply oil to the ball and was deleted in favor of a notch at each end of the rocker arm bearing.
We can see the notch on these rocker arms right here. There's the notch. I grabbed earlier rocker arm, this is from a pre unit and you can plainly see there's no notch there. Back to the service bulletin. Assembly order of spring washer. Once again, this is your spring washer also known as a Thackeray washer. The picture in the parts book shows the wrong order of assembly. Any Triumph Engine which uses this new method of lubrication to rocker ball ends must have the plain flat washers assembled next to the rocker arm.
Once again, picture, incorrect. Washer should be up against here and the Thackeray washer. When correctly assembled, the spring washer will be separated from the rocker arms by the flat steel washer. Rocker ball lens could have insufficient lubrication if the spring washer is assembled next to the rocker arm. Kind of important to take a look at your parts, determine what year parts you're using because it is possible to mix and match an early rocker box on a late motor.
If all the parts that came on the motor you're rebuilding aren't original to that engine, there's year changes in middle of the road, there's a VIN number for an engine on there. If your engines before that, it might not have this. If your engines after that, more than likely it has this. Unless of course, someone's changed the rocker boxes over the years, or you're building a motor from various parts that you've gathered from swap meets and wherever else you may find you bought a motor didn't have a top end on it.
You didn't have a cylinder head and rocker boxes so you found a set of rocker boxes. I just wanted to make note of that stuff before we started because all books are showing the picture's wrong. There's also an o ring on the end of the rocker shaft. When this is assembled in the rocker box, it will seal this end of it so oil doesn't drip down out of there. You want to make sure that you use a new o ring on there. The majority of the o rings I've seen out there will shave a little bit of material off the o ring when going together.
Generally if it shaves, don't be overly concerned about it, take a look at the o ring. After you've sent it home, you can always push it back out a little and make sure it's going to seal there. Let's give it a whirl here. All right. I like to take just a little dab of grease and put it on there. That will hold the two center washers in place, like so. Otherwise, as soon as you pick it up they, fall out. What's going to? Get them lined up where you need them.
Then obviously the these are going to go like so when they're installed in there. We've got that one in, now what we're going to do is we're going to go ahead and this little springy thingy is going to go up against the aluminum like we just discussed. What I'll do is I'll slip this in here like so and then I'm going to use this pair of pliers-- Actually I think we'll get a bigger set here. I'm going to use this pair of pliers to compress that while I slip it down in there like so. This is a fiddly job. There we go. Getting it started. Now you'll notice how everything's kind of out of whack and so we need to get everything lined up in there. Once again, this is not one of the easiest jobs on this engine but a little perseverance. You can see that our spring washer's out of whack so we got to get that positioned so that we can get the rocker shaft to go through there. Sometimes it can use this to line it up. All right. Once you've got everything all lined up there, that looks like it's pretty good it should go in. I'm going to use the rocker shaft to make sure it goes through the first one. There goes our washer, we really couldn't put that on after with the grease. It's not a big deal.
See that, the first one's lined up, we we know it's going to go through. Now we're going to take the shaft back out and we're going to go ahead and put the second rocker arm in there. Now we can go ahead and put the spring in. Once again, I found this is an easy way to do it where you compress it like so to get it started. See the end of the springs hanging up on the pole there? There she goes, look at that.
Now we'll go ahead and see if we're going to hit her home here. I can tell my center washer is kind of out of whack there just by a little bit. You can see that it's not lined up. I'm just going to give it a little help. There we go. That looks like it might be better. Now we've made it through those. This one and this one, I can see how far it is and it's going to the end. Look at that, we got it. Not a big deal.
Got the second rocker box together. One of the things I noticed when assembling the first one was that the rocker shaft didn't want to seat correctly so what the service bulletin failed to say that I discovered was the best plan of action was to use the same size on all of them and then it went together a lot easier and now the shaft is seated where it should be and everything's good. When the rocker shafts are done, they should move freely like this. That's your spring- the Thackeray putting tension on the rocker arm on both sides.
See that? Free movement, spring tension, all good. Now what we're going to do is we're going to go ahead and just slap these on the engine. We're not going to bolt them down with the head bolts at this time because as discussed previously, you can't get the engine into the frame with the rocker boxes on the engine. We're just going to loosely install those. We've got some new rocker caps, you want to replace these seals- these gaskets on your rocker caps when you're doing this job.
Also you may notice I'm holding up on this little chinga here. What these do-- We'll take one off and I'll show you real quick. What these do is they have a little teat on it and that teat coincides with this. What these do if you don't have these on your engine, you just throw some screws on there, you stand a chance of losing a rocker cap when you're riding down the shady lane and the next thing you know, you've got oil all over the place and you're rocker caps' off into the weeds.
Basically those will go on then these and there should be a serrated washer under there. I don't have them right now but we'll get some on there before the end of this. Then when you tighten this down, this almost has a spring action to it. You can see-- Hear that? It's catching on that. When you tighten these, it will keep it tight and your rocker caps won't fall off. That's important. All right. Now that we got the top end all buttoned up.
As far as we can go for now until we get the engine back in the frame then we'll do the final torque on the head bolt and put some gaskets underneath our rocker boxes there and all that other kind of good stuff. I hope you enjoyed this portion of the video. Next time we get together, we're going to fill up that hole right there. Transmission assembly. I know you guys been waiting to see that one. See you next time, guys.