| Author | Message | ||
     The4ork |
right now i have a mixture of a dyno jet kit for an tuber and a blast. i have a dyno jet immulsion tube and needle for an s1 dynojet brand, and bigger jets both main and slow. also have the dynojet spring, and drilled the vac port hole still using the stock setting for the mixture screw idles a tad high still getting 120miles before switching to reserve consistantly. stock exhaust with an extra hole drilled out the back (i like the look of the stock muffler, i just made it a tad louder) irridium race plug timing tweeked a tad still need to delete the emissions canister still need to do the cone-filter intake mod ____________________________________________ but here are my thoughts on how to get a few more HP... ive heard of people not running a base gasket or a thinner one (raises compression) and i know cometic makes thinner headgaskets for the bigger twins, which raises the compresion, and im not sure if the blast head gasket matches up to any other factory gasket, but cometic might carry a thinner blast gasket. i will find out about this. now we may be talking 1/4 point here, but thats still more power. of course this can be done really cheap. if i find a gasket and go this route, i plan on porting and polishing the head myself. just a light polish on intake/exhaust runners, and remove some aluminum around the valve guide and re-shape a bit. also the intake manifold is horribly port matched to the head on all 3 bikes ive seen so far. that obviously needs a remedy. but here is what id like to find out. are there any other HD motors that had the same bore as the blast? possibly with a higher compression?? (im thinking possibly out of a thunderstorm engine?) also, can we use a single cam out of a twin? is the blast cam more or less aggressive than say a D cam from an s1w or later tuber? or XB cam? im just thinking if there is a factory upgrade that would be easy to get our hands on similar to the XB head swap... | ||
| Ezblast |
You can go to about 510 max lift - after that replace seals, guides and get heavier springs capable of more lift. Rest sounds good. EZ | ||
| The4ork |
what about the cam? can we use another factory cam? XB/Thunderstorm? | ||
| Ezblast |
http://www.badweatherbikers.com/buell/messages/201 64/280643.html?1254343377 After the Pro-series/B-50 cams you would need better springs, seals and guides. Ever think of Ratio rockers? EZ | ||
| The4ork |
im not a big pushrod motor guy until i got into buells, i know SOHC/DOHC motors pretty well, so im not sure i know what a ratio rocker is? does it add in more duration and lift to a current cam? lol | ||
| The4ork |
im not sure why you posted that link? i saw something about a $75 cam but not much? | ||
| Gearheaderiko |
Correct, it just adds more lift. Ratio rockers may also need clearanced guides depending on what cam. You can find used XB cams (B70 equivalent) and Beehive valve springs have come way down in price (not to mention stock XB springs are cheap too). Pre-XB cams dont work and anything else but the XB head isnt worth the trouble. (some combinations can be better, but it'll be more expensive than finding an XB top end). Seriously, I've never had a problem finding used XB parts. There's probably a set of cams in the badweb classifieds right now. Used XB9 pistons and cylinders are probably there too. The XB front head is the most difficult to find, but I've never had that much trouble there either (they are also the same price new-or less- than a stage 3 Blast head). If you cant find it on e-bay, ask the guys selling Buell parts if they have stuff they want to list. There's one guy that probably has the parts, cheap, he just needs someone to identify them. New XB cylinder w/piston and rings is $220 from Buell (Harley). The XB top end is just the easier, cheaper and more fuel efficient way to go. Its all out there for sale, just watch what the prices are as some stuff is not a good deal. | ||
| Gearheaderiko |
PS: That link will lead you to others as there is a lot of info at the Thumper side on cams, etc. Also, make a plan. Its very easy to spend $2k on what could have cost you $1k. | ||
| The4ork |
you cant use xb9 cyl's and pistons with the stock blast head can you? i thought the combustion chambers were different... ? | ||
| Gearheaderiko |
Correct. You need the XB pistons with the XB head, but you can use any cylinder. XB cylinder has more fin area (just like an XB head), but you dont need it. | ||
| The4ork |
but a stock xb cam bolts right in? | ||
| Gearheaderiko |
Yes & No. Bolts right in with an XB head. Bolts in with a Blast head if you clearance (shorten) the valve guides.* Either installation requires a slight modification to the timing cup (rotor). The XB cams are also slightly 'smaller' but the hydraulic lifters take up the extra clearance. Screamin Eagle XL '04 cams bolt in without timing cup modification, but they are the same cams as the XB cams (only slightly bigger), so you'll still need extra valve clearance. * you'll also need better valve springs. If you use the stock valve springs you'll need to check coil bind on the springs (or find someone that knows if they will work) and it will also bring down your max rpm (or valve float rpm). The good news is that beehive valve springs have come down in price and are available from Revolution Performance for the Blast head. Hopefully I didnt confuse you with all that! | ||
| The4ork |
so what should be my next viable option? at this point id like to do a cam as i think it be the most noticeable. i dont think the xb head will do anything really, i upgraded my non-thunderstorm heads to stage3 nrhs XB heads on my s1 and it did pretty much nothing. so... im thinking both bikes need cams  | ||
| Gearheaderiko |
It will. I dont know about the twins, but on the Blast the XB head (w/piston) and cams is good for 7hp (results may vary). It should also get just as good mileage as a stocker and certainly better than if you used the Blast head. The XB head is also equivalent to a stage 2/3 Blast head including a 7500 rpm limit (using factory stock parts). *Jetting for the Blast head @ 10.5:1, 45/175 (or 180). *Jetting for the XB Head (w/cams) @10.5:1 45/150. The XB head has a much more efficient combustion chamber and you can do more with less $$ spent than a Blast head (using factory parts!). You'll also have a much easier time of finding used XB parts than Hi-po Blast parts. *Blast using B50's, XB using XB cams closely equivalent to B70s. I will be running the XB cams with the Blast head soon, but I dont expect it to increase HP to that of the XB set up. I'm not trying to talk you into the XB's, I'm just stating the facts. But if you want to run better cams than the B50's, you'll need some headwork on the Blast head. | ||
| Buellistic |
Here is a SECRET PART: 1.75 to 1 ROCKER ARMS with needle tips !!! | ||
| The4ork |
alright where can i get em :P | ||
| The4ork |
i just had an interesting thought... and im still new to pushrod motors so dont flame me... but if you go with a thinner headgasket, and a thinner base gasket it basically lowers the head closer to the cylnder when its at TDC = more compression ok so now that we have that out of the way doesnt it also make it so the pushrod is too long? i.e if you did that you would need adj pushrods correct? need as in manditory? and if you had adj pushrods, and you run a thinner gasket, and instead or running NO base gasket live ive heard, couldnt you just machine down the bottom of the cyl to have the same affect? and still be able to run a base gasket. | ||
| Buellistic |
You can get solid pushrods made to what ever length you want them ... "i" would never put those heavy adjustable push rods in my engine and make your valve train heavier than it already is !!! | ||
| Ezblast |
Concur with Buellistic on the adjustables - better to get them sized to need. I would get the B70 cam, very simular in profile to the SE 530 cam - which produces more torque and power than the more gently ramped SE 550. Then have the Blast head Stage 2'd and enjoy. EZ | ||
| Gearheaderiko |
Said the guys who DONT race!!!! LOL!!! When ya'll are building high horsepower one weekend only salt flat racers, then tell me about your 'solid' pushrods. Otherwise you can circle jerk all day long with your solid pushrods and 'superlight' valve trains. LOFL!!! ************************************************** ****** Yes, 'ork. You can do all those things. There are pro's and con's to all of them, just the choices you make. The stock hydraulic lifters take up a lot of slack, so you have room for a variance there and can usually keep the original pushrods (just keep them in the correct location). However, going to all that trouble and keeping the less efficient stock lifters is counterproductive. | ||
| Ezblast |
Well - its true - and unlike a race engine that will see the internals checked pretty regularly, a street bike needs that added longevity that sized pushrods provide. I well understand why you are pro adjustable pushrods, however, a street engine does have different priorities - and non-adjustable pushrods do better promote reliability. EZ | ||
| Gearheaderiko |
okie dokie. Whatever you want to believe.  | ||
| The4ork |
if you run a .010" thinner headgasket and you take .020" off the bottoms of the cyl's and keep the stock base gasket... couldnt i just send the push rods somewhere and have .030" taken off? | ||
| Gearheaderiko |
Stock lifters should take up that slack. | ||
| The4ork |
out of curiosity, is the rocker arm ratio different in the xb heads? | ||
| Gearheaderiko |
No. | ||
| Buellistic |
NO | ||
| Ezblast |
Cool - good to see everyone in agreement! Buellistic - is there anybody still making ratio rockers for the HD/Buell motors, or will they have to be custom made? EZ | ||
| Gearheaderiko |
They're generic parts that fit a multitude of Harleys (Big Twin and Sportster). Aftermarket rocker arms will be around for many years to come. | ||
| Buellistic |
Ezblast: Surely you remember CRANE CAMS in DAYTONA BEACH ??? The ROCKER ARMS PN 17360-83A F.IN./R.EX and PN 17375-83A F.EX./R.IN. are a retro fit from the BIG TWINS and "XB's"... CRANE PN 4-1015 OEM RATIO and 1.75 to 1 is PN 4-1020 | ||
| Ezblast |
Last I checked - Crane cams is shut down, & Zippers no longer makes them, neither does the other big names. Though there is a guy in upper NorCal who will make custom biilet for 750 a set. EZ | ||
| Ezblast |
LOL - when I lived in Fla I lived 2 blocks from Crane in Holly Hill. Toured the place several times - as a machinist I wanted to work there. EZ | ||
| Ezblast |
Woohoo! Crane Cams is back! EZ | ||
| Buellistic |
Eblast: Did a GOOGLE SEARCH: CRANE CAMS, INC 1640 Mason Ave. Daytona Beach, FLORIDA 32117 (866)388-5120 www.cranecams.com The way around that is just get a high lift cam as the price for the cams will be cheaper than the rocker arms ... "BUT", "i" still like 1.75 rocker arms as it is less labor intense to do rocker arms than cams ... (Message edited by buellistic on May 28, 2010) |
