RockSolidEngines billet head.

[gothicguy64]

opps my bad

 

[bigdan]

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

 

[speedracer831]

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.

 

[speedracer831]

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! DD

 

[Skyliner70cc]

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

 

[EnFlaMEd]

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.

 

[jlebh1]

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.

 

[KeepOnKeepnOn]

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.

 

[Fabian]

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.

Fabian

 

[DIYMark]

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.