Let me just mark this post of yours and see what the mods have to say regarding your posts about this thread.

And about your "non-belief", I see you haven't spent more than a month or two on this forum. I suggest you to go around the forum for some more time before you start questioning reputations of senior members here. But yes, one thing you say is definitely commendable, "it looks unused". That's my point, that's why I keep saying this 165cc bore seems better made.

I would like the moderators to pitch in here, Your post is totally misleading fellow XBHPians with some math and metallurgy jargons. Those lines on the block show there is no proper coating on the sleeve (like ceramic) or the block was not built based on a rigid die-casting process like the DiAsil TM.

And you claim the below,

I will have your post reported to Moderators marking misleading info and you comment on Yamaha's block.

So you are saying Dyno is not trust worthy and feel is all that matters ?? Dude... if you are really a automobile guy.. no one will expect you to give such a comment. forget the cheap races that happen in India. even internationally.. company's use Dyno to test engines and power output. Have you gone to race track ?? you will find lot of race engineers and ask them about cam timing and ignition timing and you will see the look on their face. even Honda CBR racing its the same. guys from Japan comes in to set the engine timing. are you aware of that ?? and the basic race class for r15 and TVS is full of local mechanics and all they know is bigger carburator compression ratio and exhaust. some do cam as well. but do they know race timing ?? how to get RPM and power out of the engine ?? you will see most of them revving the engine to 5 or 6k rpm to modify timing without even using a dyno.. and you will see them fail. some times in motogp you will see satellite team beating a works bike.. it doest mean that the bike is better or the team has better engineer. its basically the rider who had that extra bit in him. because works bike makes 5 to 10 bhp more than satellite bikes.


are you a mechanical engineer too ? or automobile engineer or mechanic ?? what calculation ?? i dont see any calculation other than few comments on what you feel.

I never said no body runs but if you run high compression your piston and con road should be able to take the extra pressure or else you will end up braking your engine like many did.


yes any one who looks at that picture will know that. but the picture you posted saying 10000km is not a bore that has done 10000km and it still has Honing marks deep.. r you saying the metal has not worn even a little ?? even the hardest materiel will not be like that after 800km and if it is like that then it means the rings are not sitting properly and will have old leak. so there is no logic not sense in that. sorry man i will not bite that...


I completely agree with what you say.. and that's not a 10000km run bore..
1 out of 100 bores working good for some people is pure luck..



as i mentioned it was just a joke and was pointing out that i was not sarcastic in my earlier posts..... i think you did not understand what i meant..

Guys!!! Why do I feel like the Joker is sitting somewhere saying 'Here we go again'

Sridhar; that was not very polite or nice... you can't call people 'side kicks'... its uncalled for... some people are staunch supporters and some are skeptics... but calling people names... not done boss...

Also your comment; 'if someone wants to learn something and do it by experience, we dont call them professional..': So by your definition Erv Kanemoto is not professional and nor is a race engineer... he is a simple mechanic... So the Gates, Ellisons, Jobs of this world are not professionals and technocrats???

Dude, if you don't know something, just ask and we'll point you in the right direction. But don't just assume everything we say is baseless. Here's some reading material for you about honing:

"When a cylinder is new or overhauled the surface of it's walls are honed with abrasive stones to produce a rough surface that will help wear the piston rings in."
"Every renowned piston ring manufacturer states all cylinder bores must be honed correctly when fitting new rings. This applies to every type of engine. Piston ring manufacturers know more about this than someone who has simply fitted a few sets of rings in the past. "

-Source: Motorbike Cylinder Bore Work


"together with a correctly angled cross-hatching, piston rings can now be expected to bed-in in a matter of minutes. When you consider the amount of effort that goes into the design and manufacture of the piston and rings, surely only the most carefully prepared bore surface will suffice?"


Source: Cylinder Bore Honing RET-Monitor

honing is done in every rebore and its known.. the point is the picture you posted is not a 10000km done bore but you are saying it is. because after 10000km you will not see honing mark.. that is all i say... because honing mark will go away one the rings sits well on the bore.

That is what i was saying if you still have honing mark after 10000km the seating is not correct and no way that can happen.


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Ok i think we should stop here.. this is going no place... this thread will get locked if it goes this way...

if you cant answer then leave it... i dont want an answer after all this...

please leave this topic and move on...

Thanks everyone.

I said dyno is just "half" the story, never said it's "not a part of the story".


Look up the link I posted as "Hint" over there. You'll find the discussion that me and HarishK had sometime back with all the calculations you need.

I've always talked only about my engine, and the 165cc bore. I myself have witnessed seized 165cc blocks, but not due to "con rod failure". It was due to lubrication issues.





Nobody needs you to bite everything that's here man. I put the information I had, and it's for the public. Well, the xBhp members from Hyd who were with me when my bike's bore was opened 3 days back very well know what the facts are

But just to let you know, one sign for rings not sealing properly is "Blow By". Just try and see if you can spot any blow by in my bore. I never said the metal didn't wear off either, I just said it's substantially lesser. I have my experiences, don't mind it if you don't find them believable There're several others on this forum who find my experiences helpful, just don't mislead the rest.


Again, look above

Buddy, I aint a Joel supporter, neither am i taking sides with anyone, but this post does make a lot of sense.
just for the sake of knowledge, i would like to have the answer to this.
because now i understand why my friend said that increasing the bore on a stock head will increase compression. i hought that this was because a new bore has lesser percent leakage but now i understand why...

@someone who posted a pic of the honned bore...
buddy, can you explain how a smooth bore is determinal to engine performance? with all due respects, as far as my engineering knowledge and automotive assly testing experience says that most of the blocks are rejected after machining process if they have the deep visible spiral marks as visible in your picture.
also, since you have put this up, i will open up the engine on my bike to check if what you claim is right...
this is supported by the fact that rough surfaces assist in surface scoring (the main reason for compression leaks). so how can a HONNED bore so rough be considered good?

I do hope to get my doubts cleared. And i am not sarcastic here

Dude, why don't you just read the material I linked to? Why post without even reading it?

Here:

"Our goal when seating the rings on new steel cylinders is to flatten out these peaks to give more surface area to support the rings, while leaving the bottom of the groove intact to hold enough oil to keep the surface of the cylinder wet with oil."

Source again: Motorbike Cylinder Bore Work

The Mods REALLY need to pitch in here now!

Enthusiasm is always encouraged as long as you're willing to learn!

Well, just look up the links I posted above, it has answers to all the questions you asked.

Honing-marks are different from "spiral marks".
Spiral marks could be due to incorrect finishing of the bore. As in, if you know how boring and milling machines work, you might be knowing how they could leave rough surfaces(traces of cutting and milling). These aren't the rough surfaces we intend to have during assembly. These are rejected.

The bore is then smoothened, and only then do we hone them to achieve this pattern http://www.ret-monitor.com/articles/...-sleeves-4.jpg


"When a cylinder is new or overhauled the surface of it's walls are honed with abrasive stones to produce a rough surface that will help wear the piston rings in. This roughing up of the surface is known as "cross-hatching". A cylinder wall that has been properly "cross hatched" has a series of minute peaks and valleys cut into its surface. The face or portion of the piston ring that interfaces with the cross hatched cylinder wall is tapered to allow only a small portion of the ring to contact the honed cylinder wall. When the engine is operated, the tapered portion of the face of the piston ring rubs against the coarse surface of the cylinder wall causing wear on both objects. "

More info here: Motorbike Cylinder Bore Work

This is what I got about Honing from WIKI

Note: I am absolutely a non techie person. I am hungry for knowledge.

Dude i don have to read it because we have been doing re boring for past 11 years.. from the first Hero Honda sleek engine i re bored, but mind you.. i re bored does not mean i personally did. the lathe guy did and he did honing which lasted almost 2000 km and in best case it will last 4000km if it is really deep and engine will be rough

But you are saying 10000km which is not possible. because if there are 2 contact surfaces, if one is not wearing then the other is... so your rings would have got toasted.. anyways... please leave this here..

Did i do a mistake of asking question ??

I am new here but not to this world buddy.. now what if i prove that i am chef race engineer for official repsol Honda team ?? will you support me ??

and i dont know why some people are taking it as if i have something against Joel.. i have nothing against him and i dont care who Joel is.. coz i dont know him.. all i did is ask few questions but now its been dragged to very bad state...

Joel is no body to me.. and i dont care what he does. if he or someone can answer my questions then i am happy..

and you are saying accept the fact. yes if it is a fact i will accept but someone tells a story and says that's true story will not make it true story.

Again i am repeating that i have no hate nor love towards Joel because i dont even know who he is till i entered xbhp.

If some one says asking question is wrong then something is fishy..

Anyways... if a question is asked.. i would expect answers not questions again asking why i asked question..

I think yes, because, even after so much of discussion, things got carried away so much that, the basic point of the 165cc cylinder remains a myth!!!
Each time I go through these posts, I get different perspective that I've listed below...

1. The standard R15's 150cc cylinder is rebored here
2. The standard R15's 150cc cylinder is rebored here according to certain specification
3. The standard R15's 150cc cylinder according to certain specification is constructed abroad & imported here
4. A 165cc cylinder suitable for R15 that is already available in the market abroad & is imported here

This is only for cylinder, pistons...whew!!! I don't want to draw a permutation!!!

No one wants to address the basics but get into personal fight; it has become a multi directional fight now.

Would someone be able to clarify (or kind enough to add few more) the above points pls?

Where s the Like Button when you need one??!! But seriously Sridhar, just watch the tone... Irrespective of the nature of questions, just try not to aggravate people man. Helps keep the discussion on track..

What is the moral of the story? Joel Honed the block for you? or you honed it yourself? or its Pre-Honed from the manufacturer and the hone lines are visible after usage? You make me laugh honestly.

If you say yes to any of these then it clearly shows that you are arguing just for the sake of it. Can you disclose the brand of your block?


Its one of the cheap blocks that you can get for 55USD and what do you expect in it? a Ceramic/Teflon coating? Its a poor sleeve which is subject to wear n tear under normal usage. Which the stock DiAsil block withstands for many years.

You have mentioned articles about Honing, did you check why honing is done and at what point? Not sure why still moderators are not in action on these crap sold on XBHP.

Let me be straight, I do not need any gyan about your 165CC block, coz I know the manufacturer myself and I give a damn about it.

All I want from you is to, NOT TO COMMENT ANY CRAP ON YAMAHA OEM BORE. Its way much refined and advanced than your 165CC. Lets end this in peace.