RockSolidEngines billet head.

Discussion in 'Performance Mods' started by EnFlaMEd, Sep 1, 2009.

  1. EnFlaMEd

    EnFlaMEd Member

    Hey people. I just received the new head for my bike today. Its a performance billet head manufactured by

    I thought I would create this thread just to let people know how I go with the installation and what difference it makes. Here are a couple of pics I took after opening the package today. Hopefully by this time tomorrow I will have some results.


    The head is going on my Skyhawk GT5 "80cc"/66cc

  2. fetor56

    fetor56 Guest

    Looks impressive,hope it fits all means let us know what u think.
  3. gothicguy64

    gothicguy64 Member

    i like you have a rocksolid motor
    its only the hp1 50cc but the head , clutch cover an arm an inlet all billet parts ohh its running a poo poo long street exhaust ..
    with orig rocksolid exhaust it goes 64kmh
    with poo poo its only 55kmh
  4. EnFlaMEd

    EnFlaMEd Member

    Wow that sounds nice. My engine is actually just a skyhawk gt5. The only other mods I have are a SBP expansion pipe and a boost bottle. With the SBP shift kit I can currently get around 55kmh top speed. It will be interesting to see what difference this head makes with an unported engine. If I had known about rocksolids engines before I ordered mine I definately would have bought from them. Not that Ive had any bad experiences with mine I just would have liked the ported package.
  5. EnFlaMEd

    EnFlaMEd Member

    Well, using the supplied gasket and nuts I fitted the new head in about 5 minutes. I turned the engine over a few times and then pulled the plug to check for fouling. Unfortunately the plug tang had made slight contact with the piston and had bent toward the electrode leaving a miniscule gap but not enough to be safe or provide spark. On Tony from rocksolids advice I shaved the electrode, sidecut the tang and re gapped. I re checked for fouling and no problems.

    The first thing I noticed on starting the engine was that it was much harder to pedal start due to the increased compression but when she fired up I nearly popped a mono. The engine sounds much smoother and runs nicer. Its almost like these engines where designed to run at a higher compression. I havent had a chance to take the bike for a decent ride due to the weather but a quick run up the road and back and I have noticed a definate gain in performance. The engine is significantly stronger and I am now able to climb hills in higher gear. The bike accelarates quicker, pulls easier from everywhere in the rpm range and holds higher speeds easier. I can pretty much make it the entire way up my driveway now without pedalling. My driveway is very steep and some cars stuggle to make it up. I'll get some more footage when the weather permits but for now you can compare the engine note with how it used to be and how it is now. So far I am impressed.



  6. fetor56

    fetor56 Guest

    If u get in the experimental mood remove the washer from an old plug(or fab one) & add it to an unshaved plug....see how that clears.

    BTW...your bike sounds deeper,less 2-stroke.
  7. EnFlaMEd

    EnFlaMEd Member

    I might give that a shot fetor56. I did try to get a shim for the plug but I could only find them in packets to do an entire v8 and at $48 I couldn't really justify the expense :p Might try a few other stores when I get the chance but its hard with no transport other than my bike and the way the weather is at the moment.
  8. gothicguy64

    gothicguy64 Member

    have you tried a old plug from the garage for a washer ...
    if all else fails the cj8 from supercheep works an is 4 bux
    ohhh i have the chainless rocksolid with the worked 50cc an billet head ,cover an inlet
    all rocksolid ....
    only pipe is mbb imports the long street poo poo but lost 10kmh top speed an gained my hearin..yipee
    next is a 36 tooth rear sprocket
    bike done 1500 km
    an i just broke my accel on handle ..bloody cheep plastic
    to fix a whole 10 bux from ezicycles in artamon
  9. EnFlaMEd

    EnFlaMEd Member

    That sounds like a sweet ride dude. Their chainless system is awesome. How do you find it? If it were possible I would love a chainless version of their chopper and some way to still have a shift kit :D
    I got my engine through MBB and have done a touch over 600kms on it. I havent broken anything yet except an engine mount but shes all good now.
    I'll keep the washer and different plug ideas in mind. At the moment my modified plug seems to do the trick and supposedly side cut plugs give more power. If it flogs out really quick though Ill have to try something else out.
  10. gothicguy64

    gothicguy64 Member

    bike is brillant .only no chainless for a 24inch wh Picture 15.jpg eel only for the 26...
  11. gothicguy64

    gothicguy64 Member

    opps my bad
  12. bigdan

    bigdan Member

    That head looks real nice but for $95 AUD, that's pretty expensive. Even after conversion that's still aprox. $82 USD. Also, has any one compared the volume of this combustion chamber vs the slant head combustion chamber? I like the fact that it's domed which should provide better combustion/efficiency
  13. speedracer831

    speedracer831 Member

    well i just recieved an email from rocksolid, the head jacks up the compression ratio to 16:1!!! stock, these engines are 6.5:1. that compression increase would more than double the engine's horsepower output- if done correctly. the carb would need to be readjusted, much higher octane fuel would need to be run (100 octane and up, an less and it will be constantly knocking)... double the horsepower for more expensive fuel and an $82 head seems completely reasonable, and a great modification at that! i doubt its 16:1 though, ill see if i can find out more. oh, and it also has a better combustion chamber for a smoother and stronger running engine.
  14. speedracer831

    speedracer831 Member

    just got another email from tony at rocksolid. apparently its fine to run on 98 octane racing fuel, its gets no predetonation whatsoever with that octane.. ON MY CHRISTMAS LIST!!! this has got to be one of the coolest motorized bike products out there, aside from the shift kit. cant wait till december! :DDD
  15. Skyliner70cc

    Skyliner70cc Active Member

    No need for special expensive fuel. E85 has 100-105 octane ratio and using larger jetting should take care of the mixture change too.
  16. EnFlaMEd

    EnFlaMEd Member

    Pitty they canned it here in South Australia. A lot of import car enthusiasts around here are spewing because they spent thousands on upgrading fuel systems and remapping computers to take advantage of e85 only for it to get canned.
  17. jlebh1

    jlebh1 Member

    WOW ive got one of those heads I new it would up the compression but 16:1!!! wow ive been using old petrol I drained out of a car at work that had about 10 litres of diesel in it and a bit of diff oil, lol. I might try some premium fuel see how it goes, all ive got on mine is the head SBP expansion chamber and .76mm jet and I got just over 60kmph and unbelievable torque for a HT engine with a 44 tooth sprocket.
  18. To go from 6.5:1 to 16:1 the volume of the new head would have to be cut down to less than half of the stock head volume... and that is assuming the piston strokes all the way to the end of the cylinder.
  19. Fabian

    Fabian Well-Known Member

    Is it just me, but i don't see a squish band on the Rock Solid Engines cylinder head.

    Tony did mention that he spent a full year, developing and refining the combustion chamber shape for optimal performance.

    Maybe it's just the camera angle, but the head doesn't look like it's got a squish band, having said that, the combustion chamber almost looks like it has a slight toroidal shape to it - very nice design if it has that feature.

    Last edited: Nov 7, 2009
  20. DIYMark

    DIYMark Member

    The head does have a squish band and it does increase the CR to 16:1 BUT this is the swept volume he used not that actual sealed volume used in the calculation. So rather the CR is more like 9.5:1 which is a tad high for a 2 stroke hence using 98 Octane fuel is needed.

    Further more, to get any benefit of it you will need to set your squish clearance to 0.5-0.7mm - other wise all you gained for your 100 odd dollar investment is a nice looking head.