some basic parameters:
stock:
IN duration - 225 deg
OUT duration - 275 deg
IN-OUT overlap - 30 deg

my design
IN duration - 245 deg
OUT duration - 275 deg
IN-OUT overlap - 50 deg
increase IN lift by 1mm, increase OUT lift by 0.5mm

It will sacrifice torque below 3000rpm (which we seldom use for do full acceleration). Torque from 3000rpm - 5000rpm should be similar to stock, but 5000rpm and above will increase.

I would say, from mid range to high end, the engine response and power will be much better, while maintaining the mid-low rpm torque.

[/quote]

Wow, looks like the next thing to do is vtec for LC. Serious.

Questions:
1. By increasing valve lift by 1mm, did you have to machine the block too?
2. IN duration is increased before TDC or after BDC? Based on the overlap calculation, my guess is you increased it before TDC. This would impact torque performance because more waste gas is being recycled.
3. Any plan to modify OUT duration? This would be similar to powervalve in providing higher RPM and hence a 2nd powerband.

What's the topspeed now?

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Added on June 2, 2009, 11:45 amAnyone thought of changing to stainless steel allen-key bolts? imo philips screw is not as nice leh.

This post has been edited by alexei: Jun 2 2009, 11:45 AM

Looks like Charge done a lot of homework on this. Kudos to you.
Even more impressive is he took it to machining the parts.
This is not the usual 'Enjin empat lejang' class...

Anyone does this kind of work in Penang?

Charge,
What steel you use to mill the cam? Or BeeHock provides that?
This is where I'll have to stop asking technical questions, and find out more about calculating compression ratio, ignition timing etc after all the mods you have done.

What is the idling RPM? My guess is slightly higher than stock?

Buy Anchor spray semi-transparent type?

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Added on June 4, 2009, 9:20 pmLower liner? Which part of the block is that?

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Added on June 4, 2009, 9:25 pmNot riding LC yet... still a 2-stroker.
So, you using a programmable CDI, or just adjust the crank?

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Added on June 4, 2009, 9:31 pmChain tensioner... I think we know the purpose, but not the benefit.
I can only imagine off road bikes need it because of the rear swing arm travel too much.
I think for me, its to spend money scratch my swing arm only...

This post has been edited by alexei: Jun 4 2009, 09:31 PM

I've seen red and clear tranparent before... black not sure.

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Added on June 5, 2009, 12:27 amthere are two different parts, the inner sleeve which looks protruding out, and the outer block, where coolant circulate inside.
Avoid modding the sleeve. It matches the piston length, conrod and crankshaft to make sure the piston stress is applied evenly at every stroke.

I am not sure how the top part looks like - where it connects to the engine head. If it doens't have any interaction with the coolant flow, maybe its a better place to skim.

This post has been edited by alexei: Jun 5 2009, 12:27 AM

Agree with charge. skim the part towards the top contacting the head.
the point of skimming block is to increase compression ratio. Make your own calculation to increase by say 0.5.

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Added on June 10, 2009, 11:51 pmGoogle it lah...

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Added on June 10, 2009, 11:58 pmCheck the thickness of std gasket vs racing. My guess is racing gasket thinner.
If shave block, need to either deepen piston valve pocket.
Note: Deepen the valve seat on the head will not help.

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Added on June 11, 2009, 12:08 amWell, there's always one bike that can smoke the rest. there's R1, then there's Haya, then there's B2K...
Belang should be very similar to FXR150 - if not mistaken, the same engine from a sports bike to a kapcai frame to appeal to the urban riders.

How can a 140kmh Belang goreng an LC? Should be on-par, right? Or do you mean pickup time lost?

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Added on June 11, 2009, 12:10 amWanna meet up? When you'll be in Penang? Maybe you'll outrun me, and motivate me to mod my RGV... hehe. I'm still pretty old school.

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Added on June 11, 2009, 12:11 amCan I bring my RGV or TZM to the discussion? haha...

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Added on June 11, 2009, 12:26 amAbout helmets: I have one carbon fibre full face. Collecting dust waiting for the day for my big bike to come. Daily use Index.

About fuel economy: Last time TZM millenium 10liter for 300-350km. Now using TZM '94 only 220-250km - Need full service.
RGV: 3liter for 120km.

This post has been edited by alexei: Jun 11 2009, 12:26 AM

32mm. Not sure TM or VM, its round slide, not flat slide.
I think it's a custom model, with a Yamaha 4HF part number.

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Added on June 12, 2009, 8:36 pmOk, I don't mean to offend anyone by outrunning LC-ian here, just making friends.
For the record, my bikes all stock, no mod. I appreciate and satisfied with the original performance.

Belang... someday i smoke them for you guys la, ha?!

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Added on June 12, 2009, 8:46 pmI think it's 32mm, as measured on mine.
It's the inner diameter of the smaller out port.

Haha, I no sir, just son of a motorsmith.
Do you need to deepen the valve clearance on the piston? Just make sure the valve's won't hit on the piston after the 0.5mm shave...
Did you mean deepen the valve pocket on the engine head? You would need a stiffer valve spring to handle that extra travel.
As for the compression, like Charge said, as long as no knocking would be fine. It's not easy to detect knocking as far as I know, so need luck here.
Additional 1mm? what's the diameter of the valve tapet head?

Ok, would love to meet Sang Belang on the road. Just to say hi...

This post has been edited by alexei: Jun 12 2009, 08:46 PM

Then we'll do 0-100 on the safe side, ok?
Find someday we convoy, then we do top speed? Mine is only 140... drag for a minute it'll touch 150. Not sure meter accurate or not.

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Added on June 12, 2009, 8:53 pmMay I ask, feel free to answer, why u guys don't choose a 2-stroke bike?

This post has been edited by alexei: Jun 12 2009, 08:53 PM

My bad, it's 30mm.

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Added on June 12, 2009, 8:59 pmEh? Wait a minute.. the measurement is taken from the inner diameter of the venturi or airway, right?
Measure the LC standard carb and see?

This post has been edited by alexei: Jun 12 2009, 08:59 PM

I'm holding a TZM carb and a ruler...

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Added on June 12, 2009, 9:02 pm Oh, you mean the valve clearance on the piston surface ha? You'll lose a bit of compression, but still gain more compression overall after the shaving.

This post has been edited by alexei: Jun 12 2009, 09:02 PM

Normal daily ride like how? 2-5km to go college/work? In this case, engine barely warm up to maximum protection... I would suggest a 20W-50.

If you ride >5km, engine consider properly warmed up then can go with recommended stock, which one is that?
I would go for the 15W-50... 10W40 is the thinnest there, for race days.

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Added on June 13, 2009, 12:37 amAiya, you modify like that of course la poket kering... what's the major problem after those mods?
Your LC now also you wanna mod block and head, same la bro. Good luck yo.

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Added on June 13, 2009, 12:38 am30mm at the venturi or the slide area. That's the diameter of the airflow cross-section.

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Added on June 13, 2009, 12:41 amconvoy need to make ground rules, that is the cruising speed at ~110-120.

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Added on June 13, 2009, 12:43 amHow far are you guys willing to travel?
I've done PG-S'pore once. PG-Seremban twice. PG-KL couple times... etc etc...

This post has been edited by alexei: Jun 13 2009, 12:43 AM

Firing timing should be different at each rpm range.
Advancing or aggressive timing means it fires much earlier... more power but engine not so smooth.
Retarding or less aggressive gives a smoother ride less performance.

The degree in timing terms, is the angle at which the timing sensor pick up the timing marker, usually on something attached to the crankshaft... either the magneto, or for cars, the flywheel. The earlier it picks up, the earlier you 'trick' the CDI to firing the plug, and vice versa.

IMHO, 4 degree is a lot to play with. My guess, 0 degree would be the std setting.

Tuning:
At low RPM, if you bring timing forward, the idling RPM will drop and you can feel the firing less 'explosive'. Bring timing backwards, the engine starts to have knocking sound, and then at some point it will die...
At high RPM, try this, switch one notch to the negative side, do you feel difference? Then another notch...

Warning - making over-aggressive timing will cause engine damage. One explanation is the expansion stroke will work against the rotation of the engine, but your transmission and the movement of the vehicle will force the rotation to continue. This opposing force will damage the engine. This is similar to engine knocking (Happens when fuel too lean, or over-compression).

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Added on June 14, 2009, 12:54 amMy bike just did 150km using 3.6liter fuel...

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Added on June 14, 2009, 12:57 amI like a normal pick up of a race bike, something like 0-60 in 5 seconds.

I prefer a higher cruising speed than good topspeed... which is the speed before you hear the engine stressing. I cruise at 90 on my RGV, and 120 on my TZM...

Topspeed RGV 140, TZM 180 (very small rear sprocket, 44 vs 49).

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Added on June 14, 2009, 12:57 amWhat is TT?
What is TT?
What is TT?

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Added on June 14, 2009, 12:59 amSaranjeevi,
What's your experience with RGV? Boleh lawan ah?
I haven't test ride with a 125Z before...

This post has been edited by alexei: Jun 14 2009, 12:59 AM

You mean RGV cannot lawan 125Z or rxz?
The CDI, for long distance, I suggest use standard... Smoother engine and riding more comfortable bah.
If you want pickup, then increase timing by a notch or two.

I can't think of a reason to retard the timing.

Ok, thanks.

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Added on June 14, 2009, 5:28 pmgood to know. at least i won't play play 125Z now.
CDI should be optimized for the riding style, cam setting, fuel type etc. Customizeable gives more headache, esp for itchy hands like us. haha.
Imagine this, if one rider full throttle every time the light turns green, vs another that control throttle carefully, they would want a different CDI... an aggressive vs laid back.

If you want, if you reallyx2 want, find a timing strobe light, and measure the firing angle like a workshop mechanic. Who knows, the adjustable knob may turn out to be a fluke (Time to ask for a refund).

This post has been edited by alexei: Jun 14 2009, 05:28 PM

Ok, then 90km then?
I was referring to the highways la, of course. Doing that speed in city among cars is rempit already.
Well, the safest speed is to follow the herd, any slower or faster is endangering other road users... Even bulls know this.

Did you also notice an RGV up down left right Penang also? Haha, do you have that GIVI box with you when you did that trip?

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Added on June 15, 2009, 11:24 pmI don't like ppl with no road ethics or courtesy. Overtake ppl close close, or brrrrng loud loud passing by ppl. Really wanna 'gan' those ppl sometimes.
I highlight or double-honk from afar if I need to overtake, what do you guys think?

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Added on June 15, 2009, 11:25 pmCharge, what tyre and size do you use?

This post has been edited by alexei: Jun 15 2009, 11:25 PM

How about Tyre? Brakes? Suspension?
I use TT9, Bridgestone. Options open to IRC and Michelin. Won't do cheap tyres.
Brakes use Ferodo or original parts. Other brands I not familiar.
Suspension YSS or KYB. Other brands I not familiar. Of course we're not talking Ohlins or the likes.

1) Normal sports jacket. Dry Rider 2-piece rain coat with 1.5 inch reflective stripes.
2) Bare finger leather gloves with palm padding (RM9.90 pasar malam, but it's leather...)
3) Nike backpack
4) Helmets:
- Index (RM45 bought since Uni, used daily)
- JAX Fibreglass (RM100 just bought, to replace Index) Anyone know where to get tinted or Iridium visor? Please help me to ask in shops, can? I belanja TT even if you in Seremban...
- Michel full face with smoke visor. Anyone know if this is a good helmet or a cheapo one? Less used as its uncomfortable.
- HJC Carbon Fiber (New, waiting for right opportunity to use)
5) Long distance I'd wear my DM leather boots or other sports shoes I have.

Plan to get:
- Protective vest with spinal guard.
- Leather jacket to be used and seasoned.

Recommendations: In order of preference for long distance preparation:
- Good helmet that fits and ventilates well.
- Protective jacket or vests (Or at least a riding jacket). Must have good ventilation.
- Rain jacket with a lot of reflectives and ventilation. I noticed Givi offer riding jackets with silver reflective lines... this is barely visible from a far.
- Gloves with knuckle guard and good ventilation.

Paiseh, I no pro lah...

For the powerband, you must be referring to the exhaust valve control mechanism. Wikipedia has more information on the names every maker use, example Yamaha YPVS, Kawasaki KIPS, Honda RC Valve, Suzuki AVACS etc...

2-stroke engines that doesn't have such mechanism does not have the additional powerband (RG*, TXR Gamma, Panther, 125Z etc).

Per my understanding, this mechanism controls the exhaust valve opening. In brief, at certain higher the RPM, it 'opens' to allow earlier exhaust stroke. This causes a major change in the 'acoustics' of the 2-stroke engine and allows the RPM of the engine continue to rise creating a secondary powerband.
To replicate this effect, a race tuned 2-stroke engine will have an earlier exhaust porting to extend powerband to higher RPM. By doing so, performance at lowend sucks...

This is just a part of 2-stroke engine design. Exhaust design is another story. In brief, 2-stroke exhaust system is an expansion chamber that is 'supposed' to resonate at every RPM to increase the back-pressure which in turn, increase the compression ratio of the engine. Notice all 2-stroke exhaust cannot end with a huge tail pipe, else its a design failure.

Now, a bit on 4-stroke... 4-stroke exhausts generally sticks to a no-backpressure design, ie the bigger and straighter the better... and the compression ratio is modulated by cam timings. However, there may be literature that suggests benefits from back-pressure, similar to the effect of the 2-stroke design, that would benefit engine performance - which maybe why for cars, 4-2-1 exhaust manifold is for stock cars and 4-1 is for race tunes.

This is why Charge's LC has higher idle RPM than normal.

I hope can understand la... any clarification please ask lah... I don't mind explain.

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Added on June 16, 2009, 12:47 amI didn't go to Farlim tho.
Duro racing good? Would you recommend to us? What's your rim size? Mine is 1.25 front, 1.4 rear... Cannot go more than 80 front, 90 rear.

This post has been edited by alexei: Jun 16 2009, 12:47 AM

so, we have a mix of students and working adults here?

Haha... sounds more like capalang brand to me... Thanks buddy.

Scout? BB? PBSM? Or geng?
Bringing your bike along not?

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Added on June 18, 2009, 10:15 pmHaha. Agree... everyone here idea dry is it? Dunno what else to do with LC modding already?
Btw, since Are_Keem going camping, thought I mention that just came back from Mount Kinabalu last week.
Good weather, fun climb...

Tomorrow TT at McD greenlane is it?

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Added on June 18, 2009, 10:16 pmWhat is the format? I've not done sticker design before... Use photoshop, or MSPaint will do?

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Added on June 18, 2009, 10:17 pmHow was it 'nearly' stolen? They broke your ignition?

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Added on June 18, 2009, 10:18 pmBtw, Yashiro, can share your KIPS racing mods?

This post has been edited by alexei: Jun 18 2009, 10:18 PM