Twin Cam Harley Engines Can Be Bulletproof

what's going on Friends Harley Davidson's twin cam engine has never really been regarded as the absolute most reliable motor out there but the twin cam engine does offer more power over the Evo and also it can produce pretty close to the numbers that we could get from a Milwaukee eight albeit with better sound as well now if you want to take a twin cam engine and absolutely make it bulletproof there's a lot of steps you're going to have to go through and I suggest you do all of them but at the same time you could do just what you could afford or what you feel like you need but to make sure it's a hundred percent bulletproof you want to start from the bottom and work all the way through the top oh Harley Davis's twin cam engine these are not bad Motors I wouldn't say they're the absolute best engine they've ever built but they do make power and they're pretty good right out of the box as far as reliability there's been a lot of changes over the years to the twin cam engine and a lot of them necessarily weren't the best decisions ever maybe they were for production but for us as consumers they really kind of screwed us there with a lot of things they did with the twin cams now of course you could go buy a twin cam crate engine those are arguably cheaper than building your own engine or having your own engine built but the issue with a crate engine is is it comes with some problems of its own with numbers matching you definitely want to cover all your bases with documentation but if you build your own engine you're retaining the VIN number and it'll still match the bike and it can save you a lot of potential headaches down the road guys please don't forget if you enjoyed today's video please don't forget to hit that like button and consider subscribing to the channel if you haven't done so already now if you want to build an absolute bulletproof twin cam engine the first thing that you've got to do is you've got to strip this thing down and split the cases because the number one area where we first got to start is the crankshaft now there are differences in the crankshaft this doesn't matter if you have an 88 a 96 or a 103. now if you have a 99 to 2002 88 you're already in pretty good shape down there as those have the Timken bottom ends and those cranks were bolted together instead of pressed but either way the older models you're probably going to want to stroke that out anyhow because if you've got an 88 tour apart you might as well make it a 103 or go a little bigger with a 110 because that is your opportunity to put a stroke or crank in it same thing with a 96 or 103 but the main goal with getting down that far out of your twin cam engine is if you have a 2003 or newer you're definitely want to go ahead and convert that back over to the Timken bearing with the sleeve and this is going to be important here in a little a bit now the other idea when you have those cases split is to go out and buy you a good built crank something from like dark horse or s s where they've actually gone through it welded the crank pin it's got really good connecting rods in it that matched with the Timken bearing setup and set up properly that's going to be very important on this next step it was set up properly you're never really going to have to worry about it again if you're just touring and riding this bike this will be nothing you'll ever have a concern with now after we address the bottom end the next place I like to look at is moving over to the cam plate now obviously we're going to want to put some performance cams in there because what's the point of doing all this if you're not going to go pretty much all out or at least Build It Up over stock the next important part is definitely we know we want to put heavy duty cam bearings in it to match our heavy duty bottom end bearings but this is we're setting that crankshaft up properly with the Timken bearing comes into play The Press effects have run out and one of the most dangerous things you can do to a twin cam engine is not measure your run out if you have a stock crank because you go out and you spend the money on a high dollar race plate your cam plate for these things the high volume oil pump those stock cranks over time if they start to develop run out on the shaft This Will Destroy a race plate you put one of those race cam plates in there those things really ideally need to be at about five thousandths or less when it comes to the run out any more than that you will chew up the oil pump and you will chew up that cam plate we're good to go from there we're not going to have to worry about any kind of run out issues because that bottom end is now completely solid that Foundation right there is what's going to allow you to go out and put whatever Big Bore Kit you want on the bike and honestly when it comes to a Big Bore Kit and we start talking about compression and things you really want to be and I would say probably ten to one or less you might be able to go to ten and a half to one but I would really highly suggest either way getting some compression releases machined into the heads now you're going to want to send your heads out get your heads cleaned up get them reworked a little bit get imported and now if you have a 103 that already has the automatic compression releases you don't have to worry about this but if you have an earlier model that does not have compression releases in the heads this is going to be the time to have those machined to fit some compression releases in there this is very important because this is going to make your bike start a heck of a lot easier especially when it's hot and you're not and not only that you're going to save your starter and you're not going to tear a bunch of stuff up trying to push all that compression over with the starter now that we've got our Big Bore Kit settled our Pistons our compression we can't Overlook the little things the little things being just like a set of lifters I would highly suggest spending a little extra money and going out and getting something like like gems s some fueling lifters these actually have larger needle bearings and more of them in there because if you've got a good high performance set of cams in there you're going to be bumping that valve train a little bit harder so you definitely want to match that with a set of lifters that's going to be able to handle that and the other important part too is is how many miles do you have on this engine when you took it down you could run into some fitment issues with standard lifter sizes and the twin cams lifter blocks the lifter blocks the twin camera actually part of the case we can't actually unbolt those and change them out like we could on the EVO but the solution to that is is there are different lifter sizes out there that'll allow you to get a lifter that'll fit snugly in there when I say snugly you're able to drop it in and you don't have a lot of plate when you put that lifter down in that lifter bore now of course when you're going back with gaskets I know there's a lot of gasket options out there but don't trip yourself up by cheaping out personally I would recommend going with kemetic gaskets kemetic gaskets are good enough that a lot of times you can even reuse these gaskets like if you pulled the top end back off you could go ahead and reuse them I've heard of a lot of people doing that I personally even though you can do it I don't know if I do that myself I'll go ahead and put a new set on there but don't trip yourself up with cheap gaskets go ahead and go with the kemetic gaskets now when it comes to your push rods this is really a judgment call on your part there's really nothing wrong with adjustable push rods I personally kind of prefer solid push rods it's because there's not a jam nut in there to back off or anything to happen but on the other side of that you've got to know exactly what length you need with the cam that you put in the bike if you went with anything other than a bolt-in cam things get a little complicated there you can't just make length out of a solid push rod but also the solid push rods obviously being solid they're going to be theoretically stronger than an adjustable push rod so that's just something to think about that's a judgment call on your part there now one other weak area with the twin cam engine has always been the compensator if you like running a compensator there's nothing wrong with it they just cost a lot of money I mean to get a baker they're usually about five six hundred bucks and honestly those things break too what I'm a big fan of is the other Dark Horse product going with the compensator Eliminator the Sportster itself uses basically just a dry sprocket so you want to upgrade your twin cam up to a drive sprocket but what I like about the Dark Horse they took it a little further it's actually got a cush Drive in there so that cush Drive actually helps kind of absorb some of that shock from starting and shifting of the bike at the same time it's also rebuildable so later on down the road if you keep it that long and it does happen to wear out no problem you can pull it down you can change that out get a new cush Drive in there completely rebuilt ready to go so guys our twin Cam's bad Motors absolutely not but to build one up and to build it right you need to make sure that you take each and every step and you don't skip anything if you do that you end up with an absolute pretty much bulletproof engine that you could do anything with now even a stock twin cam with a set of cams in it maybe a little head work run on a stock crank is that necessarily A Bad Thing not really but I would caution you though also with those cranks and the run out that they have be very careful with your choice of Cam plate that you put in there personally if I'm going with a stock crank and I want to upgrade the oil pump and the cam plate yeah I do want that solid aluminum cam plate but I would want to go something with the fueling OE they just allow a little bit more slop in there more like the stock cam plate does and that way you don't really have to worry about chewing up a high dollar cam plate oil pump so guys by and large for the most part twin cam engine is generally very reliable motor they do really well are there some bad apples out there absolutely there are quite a few of those and if you do have an 88 or something same thing you're going to be changing the cam plate out you're going to go ahead and upgrade it anyhow so it's up to you how far you want to take your twin cam if you're not going all the way I would say be very selective as I mentioned with that cam plate and that oil pump and just be mindful of that crank run out and depending on how hard you ride how many miles you got on it they do tend to develop more run out over time so just be wary of that and plan ahead so you don't waste your money on a bunch of expensive Parts they get tore up due to that then it can cause you a whole heck of a lot of other problems when you lose oil pressure and shell an oil pump but anyhow guys that's all I've got for you this week you guys stay safe on the streets ride smart Dodge those cars and I'll catch you guys back here next week with a brand new video thanks for watching how did I get hit [Music]

Channel: GixxerFoo

Views: 86,740

Keywords: twin cam harley engine, harley-davidson, harley davidson, twin cam engine, harley twin cam, twin cam, twin cam 88, twin cam 96, twin cam 103, harley-davidson motorcycles, harley engine, harley motorcycles, twin cam harley, twin cam big bore kit, twin cam 110, harley upgrades, 88 twin cam, 96 twin cam, 103 twin cam, 110 twin cam, harley performance upgrades, harley-davidson twin cam engine, harley twin cam problems, harley big, harley big bore kit, gixxer foo, gixxerfoo

Id: U4egVAPeyJw

Length: 10min 41sec (641 seconds)

Published: Fri Mar 03 2023