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Changing Intake ports to a D shape for better flow.

Discussion in 'The Garage' started by Jack, Sep 13, 2019.

  1. arcticXS

    arcticXS XS650 Guru Top Contributor

    But look at the bends in the head pipes. Pretty much identical to the stock pipes. Which no other aftermarket pipes are, definitely not my 1 1/2" pipes from Heiden/MikesXs. If I knew all the issues from the get go, I'd happily paid $1000 for that stainless setup.
     
  2. spungle

    spungle XS650 Enthusiast

    Yes holy crap, but I've paid only 300€ , was a very good deal lucky for me. This mufflers are handcrafted German made, so the quality is very very good, not compare able with the Asien made:poo:.

    The best is, i can open the engine side covers and remove the rear axle without demount the exhaust. With the other after market system I have to do so...
     
    Last edited: Apr 15, 2020
    arcticXS likes this.
  3. spungle

    spungle XS650 Enthusiast

    Thanks for that hint, did you have a recommendation?
     
  4. arcticXS

    arcticXS XS650 Guru Top Contributor

    Made in (West) Germany may well be the most recognized sign of quality :)
    Krupp Stahl, Mauser rifles, BMW cars and motorcycles, MTU ship engines, Zeiss optics, and so it goes on and on. Just properly made stuff.
     
  5. Jack

    Jack XS650 Junkie Top Contributor

  6. spungle

    spungle XS650 Enthusiast

    Last two days small test drives. 3 times the Simmerrings rubber seals from points advance are popped out, oil every where:confused: To much pressure inside the engine. My investigations lead me to the engine breather. Bingo, the original rubber of the breather reduction has swollen. From outside this piece looks alright. But no air gone through it. :cool: I throw it away and swapped on a tiny reedvalve from an car...

    Now sky is the limit. I accidentally throw it in the five gear to 7200 RPM with no power los. My personal limit was 6500...:eek: But I must mention that i have a one teeth smaller rear sprocket. Till this head 130km/h was the limit for the engine, above no power. Now only my personal red rpm scale is the limit. There is no loss in power still over red. Also I must mention that the head adapted spigot manifolds are to long, so today I ride with the original one's. If I have finished adapting the spigots there will be more power. :lmao: I like it very much:love: This engine rocks the limit:whistle: Thanks jack! Thanks folks!
     
    Last edited: Apr 17, 2020
    TwoManyXS1Bs, beano, Mailman and 4 others like this.
  7. spungle

    spungle XS650 Enthusiast

    Last edited: Apr 17, 2020
    Hudriwudri, beano, Mailman and 2 others like this.
  8. Jack

    Jack XS650 Junkie Top Contributor

    You need to be careful when swapping the manifolds or you'll pull the epoxy off the floor no matter what type anchoring is being used but yes you'll see more power with D manifolds and pull alot harder. Glad you're enjoying the performance:cheers:
     
  9. gggGary

    gggGary I'm listening, change my mind XS650.com Supporter Top Contributor

    Nice oil stain on your jeans. :lmao:
    Wow! I want a set of ports like this!
     
    spungle and Mailman like this.
  10. ReycleBill

    ReycleBill Part Time Tyrannicide XS650.com Supporter

    What sprockets are you running?
     
    gggGary likes this.
  11. Jack

    Jack XS650 Junkie Top Contributor

    Now that I know what two short turn radius profiles flow best, there's honestly just a hair more power in those intakes ports.
    I can remember one member who long ago told me there was nothing to be gained by restructuring the intake ports based on his
    theoretical paper pushing BS and this was a guy with a flow bench who didn't quite understand what I was trying to accomplish
    outside the box of porting the XS. Another member tried his best to steal or obtain this porting idea from behind my back because of the
    intake flow curve that I posted, so he could make a fast buck and another member suggested I could be working
    backwards cuz my data wasn't based off dyno testing and that I was flow bench racing,well this flow bench racing payed off
    in a positive way thanks to Chris. If Chris would gear it to pull around 8ooo and let those long rods do their job, he'd see
    more performance output from that engine but he's satisfied and that's what madders.
     
  12. spungle

    spungle XS650 Enthusiast

    this afternoon i will count the teeth for you, but in my memorys i have changed from a 33 to 32 sprocket :umm:
     
  13. spungle

    spungle XS650 Enthusiast

    The 6500 is my limit for the first miles. Witch limit with the welded crank and my engine combination are safe to drive, so that the engine is not over stressed? 8500 9000. I don't want to race this thing like hell, but if i must pass some cars or a harley then i will give all:devilish:.

    When I have saved enough money and tuned the carbs to best i can then i will dyno test it. But the project was so expensive that it may take some time. I have a neughbour with an mostly stock XS, witch he is overhouling. He don't have much time, but someday this summer I will testdrive against the stock. A friend of me is boulding a XS 650 bobber with 750ccm kit. Will hopefully finished the next 2 till 3 months. Then we will compare. Sadly i don't know other XS driver around here to compete with... So we have to be patient:cheers:
     
    TwoManyXS1Bs, Jim, Tiesco and 2 others like this.
  14. spungle

    spungle XS650 Enthusiast

    And i will change the rear sprocket in the near future to the stock one, i now have enough drehmoment:cool:
     
    arcticXS and Jim like this.
  15. arcticXS

    arcticXS XS650 Guru Top Contributor

    Jack,
    Any reason to not use weld instead of epoxy? Tight access, warping, tricky alloy to weld? Or something entirely different?
     
  16. ReycleBill

    ReycleBill Part Time Tyrannicide XS650.com Supporter

    Locally I am the only person I know that owns an XS650. I know there are others here in North Carolina but other than Hugh of Hugh's Hand Built I don't know them and Hugh is 3 hours away.
     
    gggGary likes this.
  17. Jack

    Jack XS650 Junkie Top Contributor

    Poor quality aluminum with burn throughs at the short turn, tight quarters not allowing a good tip angle. But most important
    is the workability of the epoxy over aluminum when re profiling the short turn. When porting the intakes to bias the flow in the lower lift ranges
    like for the Shell #1 you don't want a laid back radius and corrections are made easier working with epoxy. If anchorage preparations are top
    quality and no flow resistance at the spigot near floor edge, no lifting of the epoxy will occur.
     
    Jim likes this.
  18. spungle

    spungle XS650 Enthusiast

    I have fabricated some spigot Übergänge. So today I've driven the first time with full throttle in high rpm's. What I can tell is this thing goes like hell. Even with the small xs perfomance airpods from 7000 to 8000 rpm it pulls like a frightened train;) really it's crazy. My arms getting longer and longer. Above 8000 the power goes out. Could be the airfilters and carb adjustment, or it is what is it. But that what it is, is very good. I will further investigate the influence of carbs and airfilters. Must earn some money to do so...
     
  19. ReycleBill

    ReycleBill Part Time Tyrannicide XS650.com Supporter

    Yep, sucks don't it. Just when things start to go right the money pot runs dry.
     
  20. Jack

    Jack XS650 Junkie Top Contributor

    Unless you retard the shell#1 timing,your at the pull limit of 8000-8200, starts dropping off at 8000. I would focus on jetting, play with gapping plugs wider till misfires or till power drops off, then maybe the filters but from your feed back,the filters might be sufficient. Thanks for taking a chance and believing in what I've been preaching all these years about the D-port smaller port volumes and using cut down virago valves to enhance the XS heads performance. If you ever feel like unleashing more power out of the head,step up to the Megacycle cam 250-00, just make sure to check valve retainer to guide tip clearance.

    I'll be working on my head this coming winter,starting to collect things now.
    Be safe Chris and Thanks again!:thumbsup:
     
    Last edited: Apr 23, 2020
  21. spungle

    spungle XS650 Enthusiast

    I count 17/ 34 teeth... Stock euro is 17/33
    What's US stock?
     
    Last edited: Apr 24, 2020

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