73 Honda CB750 Custom Build Episode 10 - Forged Aluminum Connecting Rod Installation

the rods came in welcome to hack a week yep forged connecting rods from Japan actually from Durham North Carolina a day that combustion cycles sold me these this week same guy that sold me the old VF 700 s there's a bit of modification you need to do the bearings on these you also need to modify the cylinder skirts a little bit for clearance and we're going to get into all that stuff but they're a bit lighter weight and I think we should weigh them up see how much difference there is right now okay let's weigh these guys the forged aluminum ones the lightest ones of the stock ones weighed 361 grams Oh 270 grams so that's pretty good that's you know roughly 90 grams lighter that's nice so 270 on that one to 71 to 72 69 so they're all pretty close to each other and I could probably shave a little bit off from the other ones right here on the the casting flashing there's a little bit there that could be taken away each one of those has a little bit so I can go ahead and do that with a dremel tool and get them all to where they weigh the same as the latest one which is 269 grams so before I do anything I think that's the first thing on the list let's go ahead and get them all balanced out weighing the same I've got a drum sander wheel on the Dremel let's crank this up go back to the scale for a second here we're zeroed out so there's my lightest one 269 grams 270 so I only need to take one gram off this that's not much so let's just give this a little pass here and here get rid of a little bit of that mold flashing and see where we are okay finally got that one there was 271 down to 270 so I'm within a gram maybe even less than a gram on that one's the lightest just for the hell of it let's try it in ounces I don't know if it'll be any more accurate nine point five ounces on that one nine point five nine point five nine point five of course the grams measurement is going to be a lot more accurate because it's down to three decimal places so well sort of 270 270 this one might be my 271 270 to 69 close enough let's move on all right crankshaft bearings that's going to go next we'll go ahead and get all of the crankshaft bearings put in the bottom half of the case and in the top half of the case I've got the timing chain pulled off from the crankshaft temporarily that way I can put the rods on put the Pistons on the rods with no rings and then slide the whole cylinder assembly on and make sure I have clearances on the cylinder skirts I'm probably going to have to grind away a little bit of those to get the clearance I need as these move around like this we don't want that banging into the whisker so let's get the bearings put in here and then go back to the chart I did way back when and that will tell me which bearing goes where and here I've got them all laid out here so go ahead and get those installed now so let's see according to my chart I've got a green bearing here Green bearing here yellow bearing here green and green so this one is yellow you can see the yellow mark on the side get that one put in and I'll take the other half the other shell and that will go in the top half of the case which I have off to the side over here now the rest are pretty easy they're all bringing and on the side there's the green little paint mark get those put in remember there's a little notch that aligns it and you want them to be nice and flush when you put them in they only go one way so I mean it's pretty much a no-brainer it's pretty obvious all right that takes care of the bottom half of the case let's get the top half over here okay all of the crankshaft bearings are in place I've got a little bit of motor oil here and a brush I'm going to put just a little bit of oil in each one of the bearing shells so that I don't damage them as I move things around here before final assembly I'll actually use some assembly Lube which is designed to help lubricate the bearings on initial startup before you actually get full oil pressure you don't do any damage to the bearings really important that you put stuff together with assembly Lube or at least some oil on all of the bearings so on these forged guys this diameter is going to be the same on all of them on the the ones from the original setup as you recall from the earlier video where I expect it all out they vary a little bit Honda decided they needed to make sure that the oil clearance was just right so you have different color bearings because they're different thicknesses to match up to this diameter and to the diameter on the crankshaft and on my crankshaft the diameter of these is all the same so I just need to end up picking a bearing that gives me the right oil clearance I've got three sets of green bearings and I've got three sets of yellow bearings so I've got to drill a hole in a set of the green ones and in a set of the yellow ones put them into a plastic age check and find out which set of bearings I need to go with but I need to measure that little pin right there and then drill a hole in the bearing shell on one side of the bearing shell so that it will insert into there properly that's going to be a little tricky so I got to figure out what size that is I just get out my callipers here and check it that way let's see I've got it set to inches and it comes out to one hundred and seventy-five thousandths whatever that is that's you know roughly a 3/16 they think but we'll get a little more precise with that and I think I can probably dig something up on my drill press to do that I don't think it's going to be super super critical it's just there to keep the bearing locked in and keep it from you know spinning around in the connecting rod so here's the challenge how do I get the hole drilled in this bearing shell exactly right dead center this way and back and forth after racking my brain on this one for a while without having a machine shop here in the shop I realized well you know just get a little creative with a post-it note use the sticky side and line it right up on the edge of that bearing right on the edge and let's stick it down and we're just going to go like this take it over to the other edge stick it down and then I'm going to mark where that edge is over here I can just take in any piece of metal and kind of score it like this and it'll just cut the paper for me right there so that is the the distance from edge to edge that piece of paper right there so if I take that piece of paper off now let's see we'll get it a little more manageable by tearing it down here a little bit now all i gotta do is fold it in half pull it in half right on the mark we're going to crease that just open this back up let's fold it again so we get a good solid mark there now I can take that and put it back on the bearing just stick it on there is on that edge make sure it goes all the way to the other edge there we go right there on that mark is the center of that bearing so and then I can just measure across here with my vernier calipers find the center that way and then I'll Center punch it put it over on the drill press line it all up and drill it and it should be reasonably close hey look at that first one not bad huh nice and flush on the bearing surface they're lined up pretty good pretty good for a post-it note alignment method alright so that's a green bearing now I'll do the yellow bearing and then I can put those on the crank do a little plastic edge action and pick up bearing and then I'm going to have to order at least one more if it's the green bearings I need then I or need to order one more set of greens and if it's the yellow ones I need to order three sets so okay let's do the yellow one and then we'll do some plastic edge action alright the next one is drilled and one more thing before I put this all together I need to deburr this a little bit so I don't scratch the crank it needs to have a little shampoo on it I can just use a countersink bit or a deburring tool I don't really have a deburring tool here but this is all it takes just a little bit by hand good enough just puts a little bit of a sham fur on that hole so there's not a rough edge that could potentially harm the crankshaft we'll do that on both sides now we'll put them all together and do the plastic age thing okay I've got a green piece of plastic edge here let's peel that away from the paper and we're going to put that in the bearing shell here make sure it stays in place yep it's going to stay in place now what we'll do is get over here on the other side of the crank and carefully place that on there I'm just going to hold it in place go ahead and get the lower half on make sure I line up my little marks that tell me which side is which make sure that they go on the right way because they're machined clamped together and it's very critical that you keep them that way when you reassemble them there's no oil on here anything it's nothing but the plastic gage I'll get the nuts on there and I've got a torque wrench preset to 18 foot pounds that should be about right I don't okay let's tighten it up do we hear the click there's one that's two let's take it back off and we'll take a look at the plastic age and see just what oil clearance we have this one is with the yellow bearing there's the piece of plastic age it stayed stuck to the crankshaft now this is with the yellow bearing let's get the the paper gauge up there with the printing on it that tells us what's what it looks like it's a little bit less than two thousandths of an inch oil clearance which is just fine so the yellow bearings would probably be okay well after all that measuring and checking things I think what I'm going to do is go with the yellow bearings I've got three sets of the yellows already and I just need to get one more and I can put the whole thing together so now that I've decided which bearings I'm going to buy and I've already ordered them up go ahead and put the rods on to the crankshaft we'll put the top half of the crank case on and then we will start checking for clearances on everything get some Pistons on these on these rods without the piston rings slide the whole cylinder assembly on and check out where things are going to bump into other things and and do some clearancing all the rods are in place it's time to set that crankshaft back in - the timing chain so that we can rotate everything around don't pinch a finger here go I've put the crankshaft in a position so that all of the rods are pointing straight up and they're just balanced therefore now the only thing keeping them in place really is the oil on the bearings a little bit of assembly Lube might help a little bit with this it would keep them from falling down all right let's see if we can get this top case half on without any of the rods moving or getting bumped this is kind of like that game operation there we go over there okay now we just need to drop the case down all the way there are some rings on the main shaft of the transmission some little alignment rings for the bearings very very important that they are in there because they keep everything locked in solid and as you drop this down you may notice a little resistance for the case to go into place right here it's dropped in on the front okay but back here it's hanging up so what you can do is move that shaft back and forth a little bit until it hits the sweet spot where those rings line up with the slots that are in the case and there goes okay we're there so let's give this a little rotation here and see what we got looks like everything is clearing down below okay so now we need to put pistons on each one of the rods with the wrist pin holding it in place then we'll slide the cylinders on and we'll check for clearances on the bottom of the cylinder sleeves I just pulled all the old piston rings off from the Pistons for those of you who have never done this type of stuff before and dealt with piston rings they're very fragile let me show you just how fragile these are this one is a broken one but watch this that's it they break that easy they're really really easy to break so when you put these on a piston they're brand new be really careful use a piston ring spreader tool we'll get to that in another video but just want you to know ahead of time piston rings are very fragile so cylinders is one in four are at top dead center high up as the rod will go I'm going to put a little bit of oil inside here where the wrist pin goes this is a wrist pin that's what holds the piston to the connecting rod so it'll slide into the piston and then go through the connecting rod and the other side of the piston hmm so let's see how easily this is going to go together I'm not sure how these things slide in here if it's just a free fit or yeah they float around so shouldn't be too bad so we're going to just ahead and one thing I just noticed there is an arrow on the piston and that indeed must go a certain way I need to check my manual and find out about that I'm guessing that arrow is going to be pointing forward in the engine yes indeed after a quick consult the arrow points forwards towards the exhaust side so let's go ahead and put this piston on to this first connecting rod there's still a little clip inside this side that holds the wrist pin in place the clip is missing from this side so I'll load it in from this side just kind of peek through there and line up the hole and then just wiggle it through and there we go that's one Hey how's it going okay let's go ahead and get this next one line up the whole little push make sure it's in all the way okay let's rotate it around now and we'll get two and three at top dead center be very careful that the Pistons don't catch on the top half of the case okay those are at top dead center let's go ahead and put those in so we're ready to figure out where the rods are going to bump into okay how do we figure out where the rods are going to bump into these piston skirts well I can take a white pink pen I could use some machinists blue dye it's also called a comb and I'll just use a white paint pen and I'm going to put some paint right on the skirt right here right in the area where the connecting rod will be bumping into it and then what I'll do is I'll put it in place and then move the engine around until the rods bump into this and then pull it back off and hopefully I can see just where they're bumping into the skirts and then we can machine away a little bit of the skirt to give it the proper clearance okay so let's get two of the Pistons a little bit higher than the other ones so we'll go for the center ones first we'll go ahead and lower the cylinders on and the part with this extra metal right here that pokes out that goes forwards it's towards the exhaust side line up all the studs and grab it right here in the middle and get the center Pistons going into the cylinders first it's a little bit tricky kind of need to it a little bit sideways so that you can get one piston and then the other there's that one almost a bit of work when I put this together with the Rings in place that's what's going to be a big challenge okay there we go they're all in push this all the way down until it's right on the deck right down on the crank case they need to rotate the engine a bit so nothing is bumping into the piston skirts and right now all of the pistons are the same height so what we'll do now is we'll just turn the engine by hand back and forth a little bit and you'll you'll see the whole cylinder assembly bump up a little bit as it bumps into those skirts that would be the rod it's bumping into the skirts and it's doing it here on the backside of the skirt right now rotate it the other way and it's in the front side probably on these two right here so let's just pull it off flip it over and see what we got well uh it's a bit hard to tell there's a little mark right there I don't see anything on that one maybe a little mark right there there's a little piece missing so that method didn't really help me too much but you know what I can do here is just pretty much figure that the rod is coming up right through the center line of the cylinder so if I measure the width of the rod and I just take out a little bit of metal right here and right here the width of the rod and then just take it down maybe four millimeters and put it all back together and see what kind of clearance we have and if everything clears okay we'll just take it from there I really wish I could see just how much clearance there is going on because ideally you should have at least 40 to 60 thousandths of clearance between anything that's swinging around on the crankshaft in relation to anything that's solid like the crankcase or the piston skirts I've done some of this on VW engines when you put a stroker crank in and it's a little bit different because so many people have done it that everybody knows right where to take off some of the metal let's see if I can get a little light on this and you'll see what's going on you can see that part of the rod right there coming up and that's the part that's bumping into the piston skirt right there so what I could do is measure that take a measurement from the deck of the top of the crank case to that portion of the rod and then come over here and measure from the deck of the cylinder assembly to the bottom of the skirt do a little bit of math and figure out just how much I need to grind away to get proper clearance well another good week of progress on the engine this time which is a good thing because I've been waiting forever to try to figure out what to do about these connecting rods so it's good to have the aluminum ones on they're all balanced got the oil clearances figured out I ordered the other set of bearings they need and we figured out what we need to do to clearance the cylinders I think I'll just take these to work I have access to a Bridgeport milling machine I'll do it down there I don't want to take too much off from the cylinders just enough so that they clear the rods and what I mean by that is right here you can see I could just shave off everything but I don't want to do that I just want to take a little bit out right here it'll be like it'll end up being like a knotch just like that so I'll do that this week next week we'll fit everything on there make sure that the clearances are okay and we'll move on from there I'm not really sure what's next but hey it's progress and that's what matters so thanks for watching thanks for the donations and until next time therefore now I can put it together with three yellow bearings one green bearing that is just fine phones ringing

Channel: HackaweekTV

Views: 269,526

Rating: 4.7837014 out of 5

Keywords: electronics, diy, hardware hacking, hackaweek, motorcycles, circuit, automobile, mechanical, Honda CB750, cafe racer, scrambler, adventure bike, custom motorcycle, connecting rod, aluminum connecting rod, rod bearing, Motorcycle, machine work, cylinder, piston, piston ring, Engine

Id: yONjImhq2iI

Length: 27min 13sec (1633 seconds)

Published: Sun Sep 28 2014