| Author | Message | ||
     Venom022 |
Hello, I few months ago I posted a thread about engine knocking. Remove the engine of the bike, remove the head to verified a loose rear rod. My questions is, has any body replace one of this before? any tips? Where is the best place to find engine parts? I have 19k on my bike 2004 XB12R Firebolt and 3 track days. Thanks | ||
| Greg_e |
I haven't done it but I would suggest honing the cylinders, inspect and replace (if needed) the pistons, new rings, new rods (both of them), new bearing for everything involved. The real killer expense is the labor if you don't do it yourself so you might as well have everything done. Now the big question is.... Is there damage to the crank? Probably better check that too unless the knock is at the piston end and then you should probably replace the wrist pin (or both). Yes it sounds like a lot of money, but how often do you want to tear the engine down? If you really want to get into it, send the crank and rods/pistons out to be balanced and maybe lightened. Depends how hard core you want to be on the track. And while the heads are off send them out for port/polish/unshroud the valves. And then do some tuning on the computer. This might be getting a little out of hand but it gives you something to think about while it is torn down. | ||
| Jraice |
Screw the rebuild and put a big bore kit in there  . | ||
| Gentleman_jon |
Might be better idea to just buy a low mileage used motor out of a wreck. They show up on eBay from time to time for $1500 to $2000. Rebuilding is expensive, and as Jraice suggests above, it really only makes sense if you are going to extensively modify the motor. And it really doesn't make much sense to modify these motors a whole lot unless you plan on racing them: they are already at the limit of reasonable reliability for street use. If you need a much faster motorcycle, now is the time to get a smoking deal on a 1125. | ||
| Jraice |
I have heard you can get a good bit of power out of these with some internal mods but its probably not the smartest idea for a street bike. I am suggesting a big bore kit, which yes may include higher state of tune internal parts but most of all you get displacement.. which equals power. | ||
| Greg_e |
Lots of "more power" = lots more money. Cams are needed, shave the heads, run XB9 pistons to up the compression ratio, 3 angle valve job, port & polish, balance and lighten everything. Also convert everything to roller bearings to reduce friction. Put in oil jets to cool the underside of the pistons. The list of little things will go on and on and most of that is labor. For racing I would think large diameter and short stroke would be best (over square), keeps the speed of the pistons down. But I think we've strayed pretty far from the original question. If the bad bearing is at the piston end, you might be able to replace the wrist pin and not have to split the case. Splitting the case could be a difficult thing if you've never done it before. Never doing something like this never stopped me when I wanted to rebuild the engine in my Beetle. Bought all new bearings, valves, lifters, cam, cylinders and reworked the heads. Ran great after I was done so can't complain about my success rate. | ||
| Brumbear |
I would split the case and do it right it isn't that bad you don't have to go nuts with power stuff it isn't gonna make that big of a difference anyway. | ||
| Jstfkndi |
Greg_e, didn't know you were a VW man! I owned a 69 Beetle and a 73 Bus! I love them, unfortunately at my age and all at the time, I sunk a mint into them and sold them for a fraction of the price after I finally got them running right. Venom, sorry for hijacking your thread. Definitely have the crank balanced and lightened if you're racing! It can be rebuilt at a fair price...it just depends on what you want done. There is no substitute for displacement, but as said before, the modifications may get pretty expensive and you will keep finding out you need to change this, or you need to do that to accomidate the changes. Oh well, you just got the extent of my rebuild skills  , I'll leave the rest to the pros! | ||
| Slaughter |
Minor point - the XB motors already have the oil squirters under the pistons. Everything else is kinda like asking "speed costs money, how fast you wanna go?" The remove/replace the flywheels/rods isn't horrible if you're wrenching yourself. | ||
| Xl_cheese |
I have engine parts in the classifieds. | ||
| Venom022 |
Thanks to everyone for all of your suggestions and ideas. I would love to stroke the engine, increase RPM'S for more top speed. How ever that would cost way too much money... Will my transmission support the extra HP? Will I have to upgrade my brakes? Call my local Harley dealer and they sell the complete rod with crank and flywheel for around $500... have not split the case open but at this point I think I will replace the complete crank with rods, pistons and maybe cylinder sleeves. I would hate to have to remove the engine out again. Would love to race, but after 3 track days this happens. Having second thoughts. | ||
| Jstfkndi |
Hate to say this, but these motors don't seem to handle the range needed to race. I'm sure I will get a bunch of replies about how die hard they are and I believe they are...if you ride them more conservatively on the street. I have not heard of a racer not blowing a piston, spinning cam shaft bushings, or throwing a rod. They are great handling bikes, but to build them to compete and ride by wringing out as much power as possible, the measurements of the internals have to be meticulous and it is going to cost money. Not badmouthing the XB, it is just the way I feel. They are great street bikes and handle like nobody's business, but the motor is not meant to hit that high range but for so long. | ||
| Vagelis46 |
Wait a minute..... R6/R1 motors range 20.000-30.000 miles if ridden very fast/raced. So why a XB engine is not reliable ?? That is what I get from my old version of the XB12R engine with XB9 pistons & other mods (see my profile), before a rebuild is required. I am sure the new thunderstorm engine will last even longer.....R6-R1 engines cannot be rebuilt, while the XB12 engines can be rebuilt for $1000....So what is wrong with the XB engine ?? Fitting XB9 pistons is a cheap and great mod, just use 98 or 100 octane gas, but I know it is not available in the US, so you could use additives when you go for a fast ride/track day. You will not regret it. The Buell race kit you have is great is great, just do the pistons. | ||
| Slaughter |
DO NOT stroke it if you enjoy spirited riding and tend to keep RPMs up high. The bottom end doesn't tolerate hitting the rev limit all the time - ESPECIALLY with longer stroke!! In 2008, they beefed up the big end. There are some folks who specialize in crank systems - Hal's and Darkhorse Crankworks. IF you are thinking of a bit more power, you CAN get bolt-on big bore kits (look them up - can't remember the final displacement) - they use lighter pistons - keeping the stresses on the bottom end within reason. If you do want to stroke it, you really MUST build up the bottom end - big flywheels, bearings, the whole deal and it's WORTH having the pistons/flywheels/C-rods balanced (maybe lightened a bit too) but now we're into like $4K for the whole deal (and you're doing your own wrenching) | ||
| Greg_e |
If you stroke it couldn't you just drop the limiter down? | ||
| Slaughter |
Remember, just HITTING the rev limit - the spark interruption - actually loads up the bottom end and if you could "trust" your wrist, it would be much better than relying on the rev limiter. If you drop the rev limit, it may actually not do that much to "save" the bottom end if it means you're hitting the limit more often. Better yet would be putting in the beefier bottom end. | ||
| Jstfkndi |
I'm not saying they are not reliable, but the motors that they are racing against are built for range and ease of operation. A pushrod motor may get the torque, but the mechanics of it are reaching farther and working harder than an overhead cam and they are air cooled which in real life world riding is nice, but in racing (especially many laps and full throttle, just doesn't cut the mustard. I do believe things can be done to make them competitive, but let's face it...you slap a can on a gsxr or CBR and a few mods and you have a competitive racebike. Sink $5K into the motor of an XB and you have a similarly competitive bike. It just depends on how much you want the underdog to take precedence. I love to see air cooled, pushrod motors put inlines in their place, but it takes mucho bucks to do it. IF you are an able rider, of course that will give you the edge also. | ||
| Reepicheep |
Thanks for the hitting the rev limiter tip Steve, I didn't know that. Never hit it often (I'm blessed with a 9  ), and by the time it's kicking in I'm usually starting the shift sequence anyway, but it's easy enough to avoid completely... though a 9 at the edge of redline sure has a pretty sounding howl... | ||
| Prowler |
Let's hear it for the air cooled Beetles! Have had a few that I've run, shown and sold. Currently working on assembly of a 1973 std that's been lowered front and rear, ragtop insert, got Porsche wheels and a 2184cc engine running a pair of Weber 48 IDA's. Fun stuff and very similar to these updated Sportster motors. Fast, too..... | ||
| Greg_e |
Except you'll get more than 100 horses out of a beetle in that configuration. Assuming you have a nice free flowing exhaust you'll probably get nearly 200 horses. I assume with that kind of work the cam has been replaced, maybe a smaller pulley on the generator/fan to use less HP to blow air. One question though... with all that money in carbs why not go EFI with a MegaSquirt? Got to be about the same money if you just go with the standard TPS, MAP setup that most people run. What about a 6 speed transaxle? Yes I miss my Beetle, first car I ever bought. Also first car I ever tore the engine completely down and rebuilt. I used to be able to tell you the year the engine was made by looking at the number stamped in it. Really need a Ghia or maybe a 914 now. | ||
| Vagelis46 |
There is nothing wrong with air cooled XB engines....You have not tried a right hand side air scoop, have you ?? This will make a "little" wonder, regarding operating temperatures of the XB engine. Since installed, the fan never operated on the open road, no matter how hard I ride and with a 12:1 compression ratio. It makes a huge difference, try one. I kind of agree with you that the XB is not a perfect race (or even track) bike. Too much torque and not enough power to fight the IL600s.......but it is possibly the best street bike out there, up to 200km/h is as fast as anything, and it just corners better than anything, although I have not properly tried a 1125R..... I love Buell ! H-D is STUPID ! | ||
| Slaughter |
In actual RACING, you're among "your own kind" - middleweight twins (SV650, 650 Ninja and 748/749 Ducks) It's only track days or street racing where you're out of your league. | ||
| Firebolteric_ma |
Haha... Same bike, almost the same story. I only got one track day out of it, but used N2O to help it along the rest of the way... Get a bike that can stay together if your doing track days... As for the bike....part the bike out and buy another one for the street and be done with it. Cost is to much to rebuild unless it's something you want to do just "Because". | ||
| Prowler |
I'm figuring around 160-175HP from the 2184cc V-dub motor with a counterweighted stroker crank, Engle cam w/straight cut gears, CDI ignition, Porsche cooling fan assembly, big valve heads, large pistons, 9.5 to 1, etc. These motors are really very similar to the Sportster engine design other than cylinder orientation. Horsepower comes the same way, cams, ports, valves, compression ratio, RPMs, carbs and internal parts weight reduction. EFI is available, but there's nothing better than a crude set of downdraft carbs for simplicity. Also, carbs ran about $700 where as a good EFI system is about $1200. I've been itching to try a downdraft 45mm Dellorto on a Buell XB motor, but will have to wait until I suffer an EFI failure and electrical parts aren't available anymore. I think it'd work great, and look cool, too, not to mention eliminate most of the wiring and little black boxes on the bike..... | ||
| Greg_e |
Look at Megasquirt, shouldn't run you $700 for a simple system with only two injectors, VW even made some of the manifolds for the 76 and later machines that you could modify. That and weld on injector seats and fuel rail stuff is not that expensive anymore. Grab a throttle body from a GM car that has similar horsepower and start making manifolds. I really want to convert my 9R to a Microsquirt EFI system, I have some of the pieces that I need already to be modified. May happen sometime soon. | ||
| Vagelis46 |
I would prefer to convert my girlfriend to Megasquirt-er instead...  | ||
| Jstfkndi |
Hahahahahaha  !! |
