1. Dismiss Notice
  2. Hey Facebook people... We've created a group for XS650.com members to connect. Check it out!
    Dismiss Notice

the xs1 valve springs, vs the xs650 valve springs cam specs also (maybe)

Discussion in 'The Garage' started by billy icon, Oct 12, 2019.

  1. billy icon

    billy icon test pilot,gunnie pig, and all around experiment

    hello, I am new to this site, altho I have built a few xs motors, mostly stock.. this build Im doing now has come to me via Europe, its gonna get wild here so be ready for the debating lol,

    its going to have a xs1 cyleder bored out to 80mm (750cc) the clynder came to me this way and it came with wiseco pistons and rings, yet sadly I gave those pistons to someone that needed them, so I will be reciving to new pistons this week (manufacturer unknow) I do have the xs1 head that was with this set up, but did not receive the rocker box so if you know xs1 the left exhaust vale cover has only 3 holes unlike all other xs 650 have 4 holes, soooo Im going to use a xs650 head that has been ported and polished... and its rocker box...I am also using a xs1 cam, I have removed the cam gear and replaced it with the xs650 (447) gear, I will degree it when the time comes.. and heres where the question I am asking the collective of all of you out there, like I said the cyl.. and head where sourced from the Europe and I belive it came from a side car race bike.. oh yeah the question here it is (the valve springs in the xs1 head are a thicker gauge than the xs650 447 head, does any one know if xs1 valve springs where more "agresive" so to speak?????

    again heres the parts, someone stop me if Im about to build a self destructing crotch bomb, we can get into the details of how Im going to tention the timing chain and what tentioners that im using, its weird but I believe its going to work,

    ok parts list is a
    xs650 447 bottom end in a 447 case, never opened before,low miles
    xs1 cylinder prepped for 80mm pistons
    ported and polised xs650 447 head, VALVE SPRINGS TO BE DETERINED by you and me.(spring measurments to come both coil dia. and free length)
    matching rocker box to above head
    xs1 camshaft with xs640 (447) cam gear
    xs 650 447 chain tentioner,and guides and with the photos to come this might make sence, I modified the bridge between the cylenders to except the 447 rear chain guide, My thought here was that the xs1 stuff wouldn't work with the diferent diameter of the cam drive sprockets (both top and bottom)

    And a bonus if some one has the specs, I would love to know what the "diference" between the xs1 cam and the xs650 (447) cam is, and the answer of "its bigger" is all I could find on the interwebs.. Ok the battery in my caliper is dead or I would have the measurements of the springs for comparison here and now, but that will be tomarrow when I update, my thought is since it was a race motor(and xs1 springs are not known to be bigger) then I have some aftermarket springs here (I doubt it) I think xs1 springs are different but I have no way to know that, but one of you does (I hope).. ok I don't think I forgot anything and I hope there is plenty of imfo here to start this roaring

    thank you all in advance
    gggGary and Jim like this.
  2. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Welcome to the forum, Billy icon.

    Sounds like you're pretty familiar with the early cylinders and camchain tensioner.
    Just to fill in any knowledge gaps, do a forum search on "tunnel bridge".

    Also, consider Jim's front guide mod.

    You'll want to eliminate the lower camchain guide block,

    Replacing it with the 447 rear tensioner, assuming that you've clearanced the bridge for it. As far as I know, you'll be the first to do this.

    I believe that the early 256 cam and the later 446 cam have the same lifts.
    XS1-XS2-TX650-CamSpecs.jpg XS650-CamSpecs02.jpg

    But, they have different timings.
    70-73-CamTiming.jpg 74-83-CamTiming.jpg

    Can't help you much with the valve springs, but here's the bulletin on the heavy duty valve springs.
    70-07-01_S237-01_HeavyDutyValveSprings.jpg 70-07-01_S237-02_HeavyDutyValveSprings.jpg

    And, be aware of the change to the valve stems and keepers.
    73-07-20_P386-01_ValveAndColletChanges.jpg 73-07-20_P386-02_ValveAndColletChanges.jpg
    Last edited: Oct 13, 2019
    XSLeo, Mailman and gggGary like this.
  3. billy icon

    billy icon test pilot,gunnie pig, and all around experiment

    thank you for that imfo "to many xs1s" and as for being the first to clearance the cly bridge and use a 447 adjuster , well Im a total test pilot since birth, lots of failures and lots of wonderful successes, that's the life of a test pilot I guess lol, I will document this build here for those interested in following along, but again to me it seams if you are using 447 gears that the alighnment of everything would require the 447 tentioning system.. but we will see.

    it seems the xs1 camshaft has more duration but similar lift,with the 447 cam having a touch more lift (256 cam 39.88) (447 cam 39.99) giving the 447 cam a greater lift of .11 , not a great diference in my book, and the exhaust lift is identical for the 256 and the 447at 40.03..... and the major diference is the cam timing being diferent,but also the duration, (side note I have a 447 running and riding and a 256 year of 69 (no starter 3000cc oil capacity) and I can tell the power diference in the cams from the diference in duration, it feels like the 256 has a great deal more tourque, especialy noticeable in top gear on the freeway.) ok where was I right the duration diference, is visable when looking at the two cams side by side, there is also a 00.10 larger base circle on the 256 cam, if any one has any imfo on how that might effect things let me know.. oh but again duration lol...ok ok let me put these specs here in a list so people don't have to look from one photo to another and well it just seems easier to get it when its all in front of you (and me ) at once...

    256 cam intake opens at 47' and closes at 67' open for 294'
    447 cam intake opens at 36' and closes at 68' open for 284' 256 cam opens 9' earlier and open for 10'more
    256 cam exhaust opens at 60' and closes at 41' open for 281'
    447 cam exhaust opens at 68' and closes at 36' open for 284' 256 cam opens 8' later and open for 3' less

    if I understand camshaft technology , I belive this is whats called lobe separation. and as for the earlier opening of the intake valve on the 256 cam the only reference I have to understand the effect of this is my own experience with the ford 460 in my truck, in 1972 ford retarded the cam timing in the 460 to meet new emission standards and that was the only change they made, they retarded the cam timing 8' and lost something like 18 hp and 20ft of torque.. so what guys like me do is buy an adjustable cam gear for our post 72 460 engines and put the timing back to the pre 72 cam timing specs( side not the retarded timing also made the intake temps skyrocket on the 460) … also when engines are built for tow trucks they put the timing back (forward) to the pre 72 and then add another 5' for a total of 13 degrees advance on the cam for more torque and better low end power, soooooo lol in conclusion (my opinion) It seems to me that not only doe the 256 cam have the earlier opening intake cam timing to create better off idle torque, but that its also open for 10 degrees longer providing better cyl volumetric efficiency (cylinder filling) as for the lobe seperation let me see if I can compute that ...Nope i tried any one else wanna give it a shot, I have some knowlege but that one escapes me right now , oh another side note I read something online about a guy building a " performance xs650 build with 447 parts and he was advancing the cam timing(interesting) he didnt state how much thou...

    if you made it this far thru my ranting insanity about camshafts then the last question is has enyone seen or tried these valve adhuster screws , it seems there is an abundance of imfo on the "elephant" swivel 8mm Porsche adjusters but I havents seen anyone try these and for 19 bucks why the heck not just to see, maybe theres not room for them but this test pilot will let you know :) did I link it right?? and I hope more people will chime in here besides to "many xs1s" , I know there are people here with knowledge of camshaft dynamics , look close at these adjuster they have a flat spot on the ball , not just a round head, and well what do you guys think????

    after much reading about how the bugpak and other vw swivel adjusters are just low quality I went on a search for the real Porsche ones part #901 105 370 02 made by MAHLE, a well know quality supplier and manufacturer , problem is they range from 35 dollars up... but after an hour of searching we can now get them for 19 dollars here
    hope you guys don't buy them all before I get some lol
    Last edited: Oct 18, 2019
    gggGary likes this.
  4. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Ranting insanity? Well, that's how we learn.

    To get cam lifts, subtract base circles from lobe heights.

    Honda did a similar cam profile change between the CB350 and CL350, the CB for high-rpm HP, the CL for mid-torque. The exhaust geometries are also different, to match their cams.

    I've suspected a similar tactic in the 256 to 447 models, but found little in documentation.

    My '90 F-350 has the EFI 7.5L 460. Interesting about the cam timing history. Old truck, I'm sure it's running retarded.

    Lots of "elephants foot" info in here, just search on that term.

    I'm running the Kedo flat ball adjusters.

    Post #31.
    grizld1 and gggGary like this.
  5. billy icon

    billy icon test pilot,gunnie pig, and all around experiment

    yes indeed "to many xs1s" your ford truck does have the retarded c am timing, and I forgot to mention alkong with the massive hp and tourqe losses from the retarded cam timing ford also caused a loss in MPG like 2 to 4 miles per gallon, and in almost any engine past 72 you can buy an adjustable timing gaer and put it back to the 72 cam timming, and obtain the 18hp and 20ft tourque and best of all get the 2 to 4 mpg back, .. if you interested in doing it to your truck search "strait up 460 cam timing" I can probably shoot you some links if your interested. the funny thing is, I keep all my DEQ slips and it had a cleaner exhaust after I put the timing back to the 72 specs, but that all for ford 460s here on xs650 com lol, I would be very interested in getting those valve adjusters you have, I personally belive a high quality part with properly machined and polished parts is where the gains are to be had, I know from vw stuff I have worked with in the past that the quality has gone to crap, it used to be that companys like SCAT and others mad extreamly high quality parts for racing aplications but in the past decade it seems like mass production and profits have taken over the vw world, that's why I was going to go with the actuall MAHLE Porsche elefants foot, but I belive the ones you have are even better and a reduction in mass.. if you can point me in the direction of a set of thouse I would appreciate it
    TwoManyXS1Bs likes this.
  6. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    I got mine from an eBay vendor. After the buzz about an adjuster failure on the XT500 forum, they pulled the product. I think I saw them still available on the Kedo website.

    gggGary likes this.
  7. billy icon

    billy icon test pilot,gunnie pig, and all around experiment

    thanks to many, so even with all the failures on the xt500s ….do you still feel they work good for you ,on xs650 motors, , I am building a slightly modified or "performance" and I do plan on pushing it hard, It seems to me the only way the ball can fall out is if the valves get way out of adjustment, what do you think?
  8. JAX71224

    JAX71224 jax71224

    Don't think any have fallen out but maybe seized in the socket it sits in.......and that is just a GUESS ! I have a set of them in my newly-done head but it's not on the engine yet. I think they are great stuff and not gonna worry......
  9. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Well, let's take a crack at summarizing valve adjusters.

    The original stock adjusters have a long successful history in the racing circles. Due to their slight offset to the valve stem, you'll get the designed valve rotation. Over the long haul, high mileage daily riders show adjuster and valve stem tip battering.

    Member Aldo5468 advocates using Virago adjusters, P/N 4X7-12159-00-00, used on large Viragos and V Stars from 1981 through 2014. Newer materials, slightly shorter and lighter.

    Elephants foot adjusters have been used here for quite a while. Various offerings. A bit larger and heavier than OEM adjusters. Their swivel feet have crimp retention to the ball end. Installation requires grinding clearance modifications to the rocker arms.

    The MikesXS elephants foot adjusters are retained by plastic, and have a dismal history.
    The Empi adjusters have a long successful history, but have reduced thread engagement.
    The CB adjusters have been used, full thread engagement, but are brittle.
    Porche & Mahle adjusters are high quality, expensive, also reduced thread engagement.

    I only know of 1 failure with the Kedo flat ball adjusters, on an XT500. It appears that the failure was from side loads, ball into socket, probably at 9,000 rpm, and the socket walls expanded. I believe that the XT500 rockers rotate more than the XS650's minuscule +/- 6° rotation, so the side loading is less on our bikes.

    The flat ball has no retention, it just fits into the adjuster's socket. Installation is easy, just swap out adjusters.

    I've had the Kedo adjusters in my XS1B for 2 years now. It's only been up to 7,000 rpms a few times. Quieter than the OEM adjusters, but that is probably due to my oversized oil pump, getting more oil upstairs. I'm running them at 0.003" and 0.006"...
    Last edited: Oct 22, 2019
    Paul Sutton, gggGary and GLJ like this.
  10. billy icon

    billy icon test pilot,gunnie pig, and all around experiment

    ok guys I started this thread when I joined the site , and I have felt like I left it undone,
    so origanaly I was trying to figure out if xs1 valve springs where diferent that xs650 256 vs 447..
    so I finally got a bettery for my dial calipers (with no dial lol)
    when I first wrote this thread I said I had an xs1 head with valve springs that looked like they had thicker springs, now I have 3 heads,
    1 xs1 256
    1 xs2 256
    and one im not sure but its old, and definatly 256
    they all have springs that measure 4.50mm
    and I have 6 sets of xs650 springs 447
    and they all measure 4.15
    another thing I knoeticed is that the xs1 springs are not progressive wound,
    here is a photo of a 447 xs650 spring I don't have a photo of the xs1 spring, but you can belive me there 4.50 ..now I also know a little about springs and you can have one spring thicker with with less spring weight due to the way they make them and how they heat and cool down the spring steel, so I guees these measurement don't tell us anything, tell me what yall think IMG_0481.JPG
    gggGary likes this.
  11. JAX71224

    JAX71224 jax71224

    I bought Kibblewhite springs to use with a Shell Thuett replica cam from Hoos Racing for my 706cc engine. Still to be assembled . Head is ready but cylinder bore on hold due to health problems with machinist friend with boring equipment..........
  12. billy icon

    billy icon test pilot,gunnie pig, and all around experiment

    jax71224 can you measure the thickness of your springs , just out of sheer curiosity, I wonder how thick the spring is?? also does Kibble white give you and installed height to achive??
    also did you buy the complete set with the lower rings and the aluminum top rings ? I knoticed they sell just the springs for 63 dollars but the entire set up is 200,

    and again for every one following this thread Im an overly curious guy and love measuring tools, so Im going to either make or buy a spring preshure tool, I know they list "installed height for the factory springs, and I don't know if the kibble whites give a different meashurment, but in my experience that's just to get you close, and there is an :installed spring preshure to be achived, and yes these aren't rockets going to the moon, but this is where I find the fun in building engines, is in the details.. so when I start myh engine build thread be ready for meashurement upon meashurement lol
  13. arcticXS

    arcticXS XS650 Junkie

    Twomany, what are your thoughts about Kedo adjusters with a Shell camshaft? (My cam is a rephased one from Mr Riggs)
    gggGary and TwoManyXS1Bs like this.
  14. billy icon

    billy icon test pilot,gunnie pig, and all around experiment

    there must be a tool like this for our aplications, If it ends up being rediculas expencive, I may purchase it and then "LOAN" it out to other members here, by shipping it to them when they need to use it,
  15. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    The greatest loads on the adjuster and valve stem tips (at hi rpms) are near the beginning of valve lift, and near the end of valve closing. Due to the long rocker arms, the adjuster angles are a rather small and symetrical +/- 6° relative to the valve stem, max loads occurring at about 5°. The side loads on the Kedo adjusters should be low, as compared to the 500cc singles they were used on. Also, I recall that the Shell grind didn't make a lot of extra lift, keeping those angles low...
    gggGary and billy icon like this.
  16. Jack

    Jack XS650 Junkie Top Contributor

    With KW springs you must use the bottom springs cups due to spring design,the guy selling the 63.00 springs should know this or stop selling them. Spring height with KW is set up like stock.
    gggGary likes this.

Share This Page