| Author | Message | ||
     Slaughter |
Since December is the ONLY month with no racing, it's Top End refresh time. Really pleased so far - 36 races, 3 track days and the motor was STILL running sweet. Took some random pics - by the way, the bores of both jugs really look clean!!!... will check run-out on bottom end but it really looks like I'm not going to have to split the cases (niiiiice):       | ||
| Slaughter |
Now it's on to Antelope Valley - working with Mitch on the top end, gotta look closely at the bores of the jugs before deciding whether to re-line them or not... some new rings at least - and then back together! First races in 4 weeks. | ||
| Reepicheep |
Sweet! How does that compare to the SV-650's? | ||
| Slaughter |
With the STOCK XB (but with chain drive) - the XB is WAY superior to the SV with just GSXR shock and cartridge emulators. When I upgraded the SV suspension to a GSXR front end (re-valved and re-sprung) and the Penske rear, the SV and XB were pretty equivalent. I never got into SV engine mods (except de-snorkelizing and re-jetting) Now that I wadded up the SV a few years ago, I'm JUST racing the XB and have punched the engine out to 1169cc (short stroke/big bore) and with cams, valves, massive re-mapping, the motor is 78ft-lb torque and 8,000 RPM redline. About 103 HP and handling is very well sorted. I used to go right from the SV to the XB in back to back races and it WAS a good transition since they were both setup pretty much the same - although the shift points were slightly different. The top-end rebuild on the XB is pretty stupidly simple compared to the SV however. | ||
| Buell2001b |
very cool pics, you make it look so simple nice post | ||
| Hutch |
Don't forget to look at the valve springs and make sure that the seat pressure is good. | ||
| Slaughter |
VERY good point on that Hutch. I'm debating on REDUCING the valve springs since they're SO FREAKING HEAVY that we're wonding IF we've overdone it on the 585 cams. The drag on the valve opening is HUGE... and I'm debating on "weaker" springs but since I'm spinning 8000 RPM, I dont want to risk floating. Just don't have enough experience to say just how little valve spring (seating pressure) is too little! | ||
| Hutch |
Slaughter if you want lower pressure springs you have to look at over all weight of push rods and keepers, retainers , valves,roller rockers. If your have light weight ti everthing you might be able to go down in seat pressure but like you said valve float can be a bad thing. | ||
| Slaughter |
Yeah... nothing lightweight. S&S Roller rockers aren't really any lighter than stock. The 585 cams really do call for a bit more spring than stock. I'll probably stick with the heavy springs. I'll have to see if I can lift a spec for the springs and measure the load. | ||
| Benm2 |
If I remember right Cycle Rama offers beehive springs. You can use them to reduce some weight at the valve. If you rob an armored truck, you could look at Jesel's setup. Their rockers & lifters are definitely lighter. Of course, "why" comes to mind... there are more radical cams that would probably get more straight-line performance than ti retainers would... | ||
| Slaughter |
The whole spring thing is academic at this point. The DUAL beehives are so heavy that they can't even be compressed with the standard valve spring compression clamps... it's not like I need MORE pressure against the valve seat. I don't have numbers but I'm NOT close to floating. Cam lobe wear is fine... probably get another year out of her before tearing the bottom end apart. | ||
| Benm2 |
Steve - just re-reading your post, you're saying the drag on the valve opening is high? Do you mean side force on the stem from the friction between the rocker tip and the valve? If that's so, then I'd go for roller rockers if you think its affecting valve guide life. | ||
| Slaughter |
I've been running roller rockers from day one. There's just an AMAZING amount of cam-based power loss - just turning the motor with the plugs out. Take the heads off and turn the motor with the pushrods gone and the difference is STARTLING! Heavy springs, more cams meant BIG spinning resistance. Still, there's NO significant wear anywhere so this is a "If it aint broke, don't fix it" decision. I'll stay with the springs I've got. | ||
| Benm2 |
And you call yourself an engineer... | ||
| Slaughter |
Good point, I guess I got carried away! | ||
| Alessio66xb12r |
nice pics +1 on s&s roller arms in my configuration stock cams and a little shim under stock new springs was more than enough for 7100 /7200 rpms on a big bore " long" . a found out how great stock cams were compared with other bikes with 610 , but maybe mine was just better tuned ...just an idea. anyway stock cams( time) on big bores give you a nice comp.ratio. bye Alessio thanks for your pics Steve | ||
| Xoptimizedrsx |
Look at tom wood woods cams and springs. they have all sorts of goodies you can drop in the heads. I use bee hives in mine from them. even guaranteed in race application to not fail. tomm woods cams and springs google them. made in the usa and he also makes a lot of springs used in Nascar. Cycle rama also has stuff for you on the heads. my 2 cents worth>. mike | ||
| Alessio66xb12r |
make you a present and buy a set of adjustable clamps for your front forks ... try to open one more deeg. | ||
| Buell101 |
Not sure if they make them for this monster but I've read about steering cups opening up the rake one deg for 1125r. It they exist I think it would be more wallet friendly, I know I'm looking for them.. Do a google search on "Buell 1125r steering cups" pull up the motorcycleusa site On the RMR part list Race Subframe (L1090.08AZ) $129.95 Race Battery Pan (Y1576.09AZ) $241.95 Race Exhaust (S2110A.08B2) $1,799.00 Steering Stop Limiter (J0001.08AZ) $16.95 Steering Cups (1-degree) $232.95 Vortex Clip Ons $140 | ||
| Fast1075 |
My take on the matter...the motor is a short stroke motor, capable of pretty healty RPM...so you need some pretty good springs...the actual seat pressure needed depends on the mass of the valvetrain components...at least the cams use roller lifters. Maybe talk to Pammy or Wes at Cycle Rama for specific recommendations...I'll bet that motor sounds sweet at around 8K... | ||
| Slaughter |
My problem is that I DO have strong, double-row conical (beehive) springs... my OTHER problem is that while I've set a "soft" rev limit at 8000 and a "hard" limit at 8200, I can't bring myself to operate at 7500-8000 except when starting or passing. I KNOW what the high revs do to the motor - and if I thrash the beast, I doubt that Sunny's gonna let me throw a couple $$ thousand at it in a few weeks to get it rebuilt for the next month's racing. An old fart who is "only" Club racing will have different priorities than a "real" racer. My primary racing strategy is to run ALL 44 races that I run in a year without incurring "unplanned" expenses. That means, keeping ALL my on-track decisions reasonable based on my MAIN focus - namely being able to race AGAIN. It served me well last season in finishing in top 10 in all 4 classes that I ran. Not impressive in the grand scheme of things - but it met MY goals for the season. I'm still investigating valve spring closing forces in order to get some more "cheap horsepower" - but since the top end I have has run 36 races and 4 track days without complaint, I'm content to stick with what I have for now. I just go back to the IMPRESSIVE amount of effort required to turn the motor over by hand just due to the resistance of lifting the valves... I have to do this hand-turning each time I'm adjusting the pushrods. I've got the jugs and new piston rings coming back from Revolution... and when I look back at how the motor has worked, a payment of less than $500 for ALL my engine wear-and-tear expenses for a 36 race season is just unbelievable. Yeah - I had an "operator error" when I had the countershaft bolt back out and bust the primary chain ... but that was due to my "staff" not installing the bolt properly in the first place. (That was LUCKY - throwning a primary chain can often end badly) |
