TwoJugs
Excess XS
Anbody using beehive valve springs on their motor?
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There's a guy on E-bay selling them with retainers. The stock cams or any of the modified cams don't really call for such a spring. A R&D double spring is more than adequate plus the inner spring acts as a back-up in case the outer spring breaks.
hoffman900
XS650 Addict
If any of the springs break, your valve spring rate is going to go down so much that odds are you're going to float the valve and the valve is going to hit the piston anyway.
If I was looking to take the XS to the next level, I'd go with the beehive set-up. Overall, it's lighter set-up and you don't need as much seat pressure. Less seat pressure = less wear and tear and less friction.
TwoJugs
Excess XS
I have R&D springs now. They are not giving me enough room. They advertise use for up to .460 lift. The cam I am using in this build has almost .510 lift at the retainer. I see Kibblewhite advertises they go .510. Also Webb cams have some listed that will work well over .500 lift. Just looking to see what beehives are being used and if they will give me the right specs to try in my build.
hoffman900
XS650 Addict
Web is probably selling KB valve springs. Web just does cams, but both them and Megacycle will either sell KB or R/D valve springs as a kit or possibly rebrand them.
Call Chris Schumann (he sells the beehives on ebay). http://www.schumannmotorworks.com/
No point in beating around the bush on the internet when you can go right to the source.
I've ordered retainers and valve stem seals from him and he was good to deal with. That said, it looks like you can only order this as a kit: http://www.ebay.com/itm/23086615536...ries&cmd=ViewItem&hash=item35c0b1f766&vxp=mtr
Probably has to do with the retainer design and the valve stem length.
IMO beehives are the way to go if they will fit. Motorcycles don't have heavy enough valves to make double valve springs worthwhile. You still see them on V8 applications with over 500lbs of open pressure. Per a conversation I had with an engineer at KB, these Yamaha kits were designed a long time ago.
I'll stick to the standard dual set-up knowing the inner spring will suffice in limping home safely. You have no back-up with a single set up and I have seen bee-hives break,of course that's with very aggressive cam profiles that an average rider or a XS race will ever see but in any case they DO BREAK. To the original poster if you needing more spring height shave the spring pad some or change the spring retainer and stay away from KB springs ,they're not robust as R&D .
TwoJugs
Excess XS
My primary concern is finding a setup that will work with my .510 lift cam (Shell #3 402). I have R&Ds but they are rated for .460 lift. I have unkown sets that might be KBs? Taller unloaded but allow for more compression before binding. I am trying to borrow a spring tester to spec them and see if they might work out. I am also working on the retainer to guide clearances. The titanium retainers have larger keepers that reduce your clearances. The pistons are ready to go to the shop and get some fly cutting done to remove the yamaha logo stamped in them while claying the tops checking for clearance. There was none!
This is going in my dragbike and might only see a track once or twice a year. I inherited lots of parts when the previous owner passed away a while back. No info at all so this has become an educating mystery hunt of info. I don't have much of a budget here. The stuff on ebay looks sweet but out of my range. I am trying to get this together for a few runs in memorial to the passed owner. His widow keeps in touch with my projects and enjoys what I am doing. It is lots of fun for me too. Been away from this for 30 years and it makes me think again. I know tech has come a long way but I want to use what I have and save a few dollars even if I leave something on the table at the track.
This is going in my dragbike and might only see a track once or twice a year. I inherited lots of parts when the previous owner passed away a while back. No info at all so this has become an educating mystery hunt of info. I don't have much of a budget here. The stuff on ebay looks sweet but out of my range. I am trying to get this together for a few runs in memorial to the passed owner. His widow keeps in touch with my projects and enjoys what I am doing. It is lots of fun for me too. Been away from this for 30 years and it makes me think again. I know tech has come a long way but I want to use what I have and save a few dollars even if I leave something on the table at the track.
hoffman900
XS650 Addict
What you need to do is talk to the engineers at R/D. Tell them what you want to do, where you need the springs at, etc.
Also don't be afraid to go outside the motorcycle guys if you're looking to do further development. PAC makes springs for some many application. Call up their tech line with measurements in hand (inner and outer diameter, spring height, what kind of spring rates you want, etc.). I highly suspect the springs in the Schumann kit are sourced from PAC ( http://www.racingsprings.com/ )
Schumann also makes chromoly retainers. They're slightly heavier than titanium (still lighter than stock), but they will not gall like the titanium will and they're thinner than both the titanium and aluminum. I'm using them in a different application.
Also don't be afraid to go outside the motorcycle guys if you're looking to do further development. PAC makes springs for some many application. Call up their tech line with measurements in hand (inner and outer diameter, spring height, what kind of spring rates you want, etc.). I highly suspect the springs in the Schumann kit are sourced from PAC ( http://www.racingsprings.com/ )
Schumann also makes chromoly retainers. They're slightly heavier than titanium (still lighter than stock), but they will not gall like the titanium will and they're thinner than both the titanium and aluminum. I'm using them in a different application.
TwoJugs
Excess XS
One of the issues I am hving with the titaniums is they have a ridge on the top that is much higher then everywhere else. The rockers hit on that ridge as you tighten down the rocker cover until a certain point where the rocker contacts the valve tip finally. It does put a dent, wear on the titanium retainer doing this, even removes some metal. The stocks are flat across, not a problem there. I see Comp Cams has a good page showing dimensions and specs on the springs they stock. Yes automotive aps but if the dimmension fit and the spring rates are simliar they should work. Pricing is good too.
hoffman900
XS650 Addict
IMO, any metal removed from the titanium in that manner is no good and is a failure point.
The chromoly ones are essentially flat:
And yep. Springs are springs. If the dimensions and rates are where you need them, then you'll be fine. There are different tiers of springs and spring manufacturers, but you don't have to worry about it at this level.
mrriggs
XS650 Junkie
These are the springs I plan to use in my next engine.
http://www.summitracing.com/parts/cca-26123-1/overview/
Steel Retainers
http://www.summitracing.com/parts/cca-799-1/overview/
Ti Retainers
http://www.summitracing.com/parts/cca-798-1/overview/
The Ti retainers aren't any lighter than the steel ones so it's probably not worth the added cost. A set of four beehive springs with steel retainers is only $80.
However, these are made for 7mm valve stems and probably won't work with 8mm valves. The added cost of 7mm guides and valves make it a spendy proposition if you can't make them yourself.
http://www.summitracing.com/parts/cca-26123-1/overview/
Steel Retainers
http://www.summitracing.com/parts/cca-799-1/overview/
Ti Retainers
http://www.summitracing.com/parts/cca-798-1/overview/
The Ti retainers aren't any lighter than the steel ones so it's probably not worth the added cost. A set of four beehive springs with steel retainers is only $80.
However, these are made for 7mm valve stems and probably won't work with 8mm valves. The added cost of 7mm guides and valves make it a spendy proposition if you can't make them yourself.
Contact Gary at hossracing.com,he races the XS. Is there any particular reason why you have to run such a big cam? After around .440 the intake ports begin to fall on their face with no real gains to be had above that lift unless you completely alter the port and valves.
There are cheap automotive springs that'll work within your bugget, you'll have to search knowing your required spring height along retainer clearance. You can easily take down the stock spring shims(.030 off I believe) for added SH.
For the retainer to guide clearance,remove the guide and reduce the thickness of the step for the inner spring from the bottom, you only need enough to prevent guide from falling through the port
There are cheap automotive springs that'll work within your bugget, you'll have to search knowing your required spring height along retainer clearance. You can easily take down the stock spring shims(.030 off I believe) for added SH.
For the retainer to guide clearance,remove the guide and reduce the thickness of the step for the inner spring from the bottom, you only need enough to prevent guide from falling through the port
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TwoJugs
Excess XS
The reason I am trying this set up is because I have it. I have a few motors laying around too and they are heading in different directions in the near future. I plan on using this a the drag strip only. As long as it stays together and I can do some tuning on it then all is good.
hoffman900
XS650 Addict
Jack,
Who said lifting where the stops gaining is a bad thing? A very noted and top cam designer said it's not a bad thing to do as long as the head does not go turbulent.
Who said lifting where the stops gaining is a bad thing? A very noted and top cam designer said it's not a bad thing to do as long as the head does not go turbulent.
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TwoJugs
Excess XS
I would go that route but as you said, the costs to go to 7mm is not in my plans. I am looking into APE and Comp Cams to see if they have something that will fit my needs.
