| Author | Message | ||
     Mpg |
1st time posting. I've put about 1,500 miles on my 06 Blast since buying it. I like the way it handles but want more power. My previous bike was a Honda VF500. It was much faster. The Blast has developed a very bad oil leak from the head/pushrod sleeve. Pictures of leak attached. Since I have to remove the head I want to add power while I'm in there. I plan to port and polish the stock head. I plan on putting in beehive springs as well. My question is: Can I use a b 50s cam with 1.75 rockers? A new ignition for a higher redline will done down the road. Does the oil pump drive gear need replaced in the 06 models? Thanx for any help!!! | ||
| Gearheaderiko |
I dont have the numbers with me, but its very doubtful with stock guides. However its not hard to modify the stock guides or you can replace them with better guides that will allow the extra clearance (but you'll need probably need to recut the valve seats if you change the guides). If its just a question clearance notwithstanding, B50s with 'ratio rockers' (1.75's) should be a nice set up for a wide powerband, low end torque and high rpm flow. In theory it should produce a nice wide powerband, but not the peak HP you'd get from B70s or XB cams. I dont think the 06 has the upgraded 'race' bronze oil pump drive gear, though I believe they upgraded the XBs. Sorry, I dont have those numbers with me either  My opinion: The B50's dont hit peak until 6500-6800 rpm which is at the stock redline and beyond. So if you dont raise the redline, B50's are definitely the way to go, but you still lose a little at the top end. But adding an extra 500-1000rpms will make it whole different motorcycle!!! Far, far away, having a white Christmas this year! | ||
| Gearheaderiko |
From the Buell website: High Performance Oil Pump Drive Gear 26391-06 $49.25 High Performance Oil Pump Drive Gear Developed from the Buell® racing program, this gear provides additional longevity. Fits '95-later Buell® tube frame, '00-later Blast®, and '03-'05 XB models. Stock on '06-'07 XB models. That indicates to me, without looking at the parts book, that you dont have the 'good' OPDgear in your Blast. Though there doesnt seem to be anywhere as near the OPD gear failures as with the 2000-2001 year Blasts, indicating that the gear was improved.(EZ-?) | ||
| Gearheaderiko |
PS Welcome to Badweb! | ||
| Gearheaderiko |
The "Dark side" would not let me forget to mention that if you have to take the cylinder off, why not replace the piston with a little something better. Say 10.5:1 ?! | ||
| Ezblast |
The only internal improvements made to the Blast motor has been bearings, oh Sidth Lord! - lol - I concur! And Welcome! EZ | ||
| Mpg |
I'm considering a big bore if I decide to keep the Blast long term, don't want to buy two pistons. Since have to get new gaskets, I plan on using the thinner base and head gaskets to bump the comp. Do the valve guides need to be done by a machine shop to a certain size? Is there a do it yourself way? Thanx for the quick responses. Gonna crack it open after New Years. Merry X-mas everyone. | ||
| Gearheaderiko |
You can modify the valve guides yourself with a good drill bit. Just drill(cut) it down to the designed size for clearance. You will need to 'polish' the cut end with a dremel (or other suitable device) or you risk scoring the valve stem leading the possible early failure of the valve and/or seal. You can buy an actual cutter that will do a better job, but hard to come by. You'll need a valve spring compressor of course and a way to measure clearance (vernier caliper works well). Not hard to do, but prior headwork experience helps or patience and reading. A 515 big bore kit isnt really that much bigger than stock (not enough to justify it to me) and DONT buy a 515 kit that uses CP pistons. CP oversize (.015", .030") pistons are fine, but the 515 (.063") kits have had numerous failures (which may due to overmachining of the valve pockets). But the higher compression of aftermarket pistons adds a punch and better burning over stock pistons. a note: converting to a stock XB head and piston will do more for your bike than most Blast stock head modifications. It will also allow the ready installation of XB grind cams (comparable to B70's). And get better mpg! | ||
| Mpg |
The valve guides sound easy enough. http://www.richardnallinmotorsports.com/products/r ollerRockers.html has 1.67 rockers. I wonder if they will fit with out the guide modification. If I get a big bore it would be the 600. I know it is involved, that is why I'm not attempting it now. Can you really feel the high compression piston? If so I'll do it. I'm OK with the B 50 vs the B 70. The Blast needs the low end power. I have read mixed things about the XB head. Is it really worth it? I'll still have to get new cams and springs anyways. Plus no choice but to buy a piston. (Message edited by mpg on December 22, 2010) | ||
| Gearheaderiko |
Sorry, but I dont have the specs with me but..... I'm 95% sure that the B50 cams put the stock valve guides at minimum clearance. 'Ratio' rockers w/B50's would exceed that. The only single performance mod that you really feel (imho) is an exhaust. The rest are just steps to better performance(or need other mods to work). You might feel them, but even a 10% increase in power at the rear wheel is 2.7hp. Hardly neck snapping. I've never read anything bad about the XB heads. A stock XB head with stock springs and valves will rev to 7500rpm and can run B70 comparable cams. Its also engineered to last and the valves and springs are ridiculously cheap. So good that some performance shops are selling them as a stage 2 set up. The parts again are off the shelf stock. No looking for hard to find parts if you break it and no high pressure springs beating up your valvetrain. Bolt on a stock XB top end (head,piston and cams) and its good for 7hp and still gets good mpg (60+). 7hp on a stock head will drop your mpg down to *40 My opinion is, if you have a choice, its hardly worth it to use the Blast head when a superior 'stock' head is available. *Extensive tuning can really improve mpg and performance. Average Joe tuning will get the average results I posted (and thats what most of us will do anyway). | ||
| Gearheaderiko |
PS Low end torque is great for twins, but rev a Blast out to 7000rpm+, thats fun and addictive! I've never seen much point to build a stump puller out of a Blast. You'll just beat up the bottom end, which is a lot more work and money to repair. But thats just me. | ||
| Mpg |
I read somewhere on this forum that the stock blast head has better flow then the xb head, plus it would save me some cash. However after reading lots of posts to the contrary I've decided to get an xb head. I can't seem to find one on ebay, anyone got a line on an xb head? | ||
| Ezblast |
In stock config. using the same size valves the Blast head flows better, per the Hoban Brothers who checked it for a dirt-tracker, however, the XB can take larger valves in stock config. and so in the end can flow more with less work. However, Brian N. did tell me that a Blast head can be reconfigured to take larger valves, and flow equally as well as the XB, but it is an large extra charge to do so, making the price point of the XB head a better deal, though slight mods, or different front mounting bracket would be required. EZ (Message edited by ezblast on January 13, 2011) | ||
| Ezblast |
Actually the stock push rods could be used up to .550 lift point, and are only marginally different in size from the XB, with the 1.67ratio, no mods should be necessary. EZ | ||
| Mpg |
The XB springs should be able to handle the b50 and rocker, right? Now I need to find a used XB head. | ||
| Ezblast |
yes - that total set up would work - good hunting! EZ | ||
| Mpg |
Thanx man. | ||
| Jsracer |
>> In stock config. using the same size valves the Blast head flows better, per the Hoban Brothers who checked it for a dirt-tracker You must have misunderstood. Setting up an XB head and a Blast head to have the same size valves would be major work to at least one of the two heads, so it's not going to be "stock config" anymore. The XB port is light years better than the Blast port. It's not even close. There are huge improvements to the floor, to the short side, and to the roof area through the bowl. They also have much larger seats and better blending and a whole lot better chamber. Sure if you do enough work to a Blast port you can make it as good or better. That's true of anything. But in stock form the XB head is much much better in every respect. | ||
| Ezblast |
No, what I mean is, that to a certain point a Blast and XB can carry the same size valves, then the XB stock configuration can take larger sizes, while the Blast can't. You have to re-configure the combustion chamber to fit in even larger valves, therefore not in a stock configuration. | ||
| Ezblast |
A lot of Blast racers used the XB head for the larger valves and combustion chamber, however, there where "stock" classes - where only stock sized valves could be used, and the Blast head has been used (the XB chamber the wrong size for the smaller valves) - several of the older 500cc classes had that as a rule, though I think that has been lifted in today's classes, could be wrong. Of course the XB head is a better head, made for performance, It just doesn't fit for every application - Stock Blast drag racing like Pruett used to do, used the stock head,for the valve size range. The thing is folks forget that you are referring to a certain set of circumstances only - EZ | ||
| Gearheaderiko |
Pinwall cycles frequently sells Buell parts on e-bay. Did you do a search of the classifieds on Badweb? I havent had a problem finding used XB top end parts. You just cant need the parts, tomorrow. Keep watching. Also 2004 XL1200 should be the same head (not 883 heads). Just look at the combustion chamber. That will tell you if they are 'XB' heads. In case any of the above confused you: get an XB head! | ||
| Gearheaderiko |
See this pic for the difference in heads: http://www.badweatherbikers.com/buell/messages/201 64/288003.jpg | ||
| Ezblast |
Porn! | ||
| Ezblast |
lol | ||
| Gearheaderiko |
LOL! | ||
| Crackhead |
in the pic, left : is the XB / post 2004? 1200 XL head. the Right: is the Blast head | ||
| Jsracer |
>> No, what I mean is, that to a certain point a Blast and XB can carry the same size valves, I'm sorry that's absolutely not true without doing major work. I think you understand that you can't take a Blast's valve sizes up without changing seats and remachining to match, which is major work. So the only other way to get an XB head and a Blast head to "carry the same size valves" would be to put Blast sized valves into an XB head. Well, that's even more work, because not only would you have to change seats, but while the seats are out you'd have to weld up the seat pockets and into the bowl to get everything small enough to handle the small seats. So this notion that there's a common valve size that can be put into both a Blast head and an XB head without major work is false. If a person is limited by the rules to stock valve sizes maybe you'd want to use a Blast head. But the XB head is far better in every respect including flow. To get a Blast head up to the level of even a stock XB head is major, major work. Even taking the valve sizes up to the XB sizes wouldn't get you there. | ||
| Mpg |
I clicked the link and did not find the kind of head you would expect to see on a porn site, very disappointing LMAO Is the 1200xl identical? Same valves, springs, rockers... | ||
| Jsracer |
Mpg the hierarchy of factory heads is like this: 88-03 XL1200 heads are the worst 96-03 Lightning heads were the first factory performance head. They have a smaller chamber than the 88-03 XL1200 heads but are otherwise the same. This is what comes on a Blast. 98-02 Thunderstorm heads were the next factory performance head. They got much bigger valves and better ports. The chamber is similar to the Lightning head but a little bigger to unshroud the valves for better flow. 03-up XB heads were the next factory performance head. They got an improved chamber and better ports than the Thunderstorms. Same valve sizes as Thunderstorms but 7mm stems and beehive valve springs. 04-up XL1200 heads are the same as XB heads except for the finish. Yes same valves and springs. Rockers are the same on all the bikes. | ||
| Jsracer |
>> DONT buy a 515 kit that uses CP pistons. CP oversize (.015", .030") pistons are fine, but the 515 (.063") kits have had numerous failures (which may due to overmachining of the valve pockets). There's an old saying in racing: "Pistons don't die, they're murdered". Breaking a piston at the valve pocket is almost always caused by detonation. A stock Blast is very forgiving because it's compression ratio is so low. You can run it lean (and the factory does to get a big mpg number) or run a lot of timing and get away with it. When you bump it up to 10.5:1 the tune becomes a whole lot more critical. If the timing is too advanced or the jetting is lean you're much more likely to break a piston at 10.5:1 than at 9.2:1. How many people who had these failures had properly dyno tuned their bikes? Blaming the piston is almost always missing the root cause of the problem. It's just the messenger. |
