61 mm cylinder block
- Thread starter Rolly
- Start date
X Project
Super Veteran
It's not hard acceleration that makes the H2O leak from the water jacket... It's more of using inferior head gasket provided that the top surface on the water jacket is even and has no holes or craters... Even if you place your engine on idle, H2O still leaks if you use crappy gasket especially if stud bolts are tightened unevenly... For steel bores, you have to be more concerned about cooling system such as the water jacket's depth and width... And of course the components used for the block itself... Also examine the surface of the block, need to make sure that it has a smooth and even surface...Rolly said:
low_budget
New Member
right sir X, that's the only reason why it leaks...
X Project
Super Veteran
You are right, the tightness of the stud bolts is not an assurance that leaks will be prevented, no one actually said that bro... But, it is very much necessary to have an equal tightness in each and every bolt... Good gasket, even block surface and equal and enough tightness on stud bolts will prevent leaks... In regard to your post "there's no sufficient material (in the cylinder wall) to hold the pressure", what exactly do you mean by this? Are you saying that there is no resolution to rectify this issue?Rolly said:Thank you for your feedbacks mga paps... but I've learned in other discussions that no amount of torque (on the cylinder bolts) would prevent leaks due to the thinness of the cylinder wall. there's no sufficient material (in the cylinder wall) to hold the pressure.
X Project
Super Veteran
Pressure will always find its' way out of the combustion chamber either the proper way or the wrong way... Pressure needs to go to the ex port, if you're experiencing H2O leakage, check the 3 necessary evils that makes it so, no more, no less...... Leaks on H2O pump, radiator etc is a different issue BTW... Please note that I have installed block kits ranging from 57mm up to 63.50mm with leakage issues resolved...
Rolly
Super Veteran
You are right, the tightness of the stud bolts is not an assurance that leaks will be prevented, no one actually said that bro... But, it is very much necessary to have an equal tightness in each and every bolt... Good gasket, even block surface and equal and enough tightness on stud bolts will prevent leaks... In regard to your post "there's no sufficient material (in the cylinder wall) to hold the pressure", what exactly do you mean by this? Are you saying that there is no resolution to rectify this issue?[/quote]
I agree with the things you have enumerated: proper tightening, good quality gasket and smooth and level block surface should prevent leakage. However, the area between the cyl head and cylinder is so small because of the very thin cylinder that remain after boring to 61 mm or larger.
This would not be the case if the manufacturers will make the cylinder thicker by adding more material outside the cylinder, but the coolant flow would also be affected because the volume of the water jacket will be lessened.
Rolly
Super Veteran
X Project said:
Very well then, I have been planning to upgrade my block to a 61 mm bore but due to some negative feedbacks I've read, I had second thoughts on the upgrade. My point of view was only purely theoretical since I haven't tried any of the bigbore upgrades.
Thank you for your feedback bro... I might proceed with the upgrade now. Did you change your camshaft when you installed big bore blocks? How about the carburetor? Can you give more feedback regarding your experience with these big bores? Thanks!
X Project
Super Veteran
Yes definitely, the wall will be thinnner but that shouldnt be an issue at all... I would like to take note that there is a very thin line between racing and engine's destruction... Even F1 tech, they tend to lean on optimum performance and sacrifice durability since they only need that for like 21K kms... Anyway, we're not pushing for that kind of extremity here are we? So the point is, yes there's not much risk in terms of boring up to 61mm like others say... Most of them might just have overheard that from someone who overheard that from someone as well without actually having to tried it for themselves...
X Project
Super Veteran
BTW, indeed DiAsil or stock is reliable but I never assume that they'll give you cease-free guarantee... That would be another cock and bull story here my friend... Ive seen countless stock and V Ixion blocks that ceased, and I think most of you here also did... Both DiAsil and Steel bore faced cease and overheating problems as well for long rides and races since hot weather and engine generated temp will definitely takes its' toll on the cyl bore one way or another... So the cooling system needs to be taken into deeper consideration... The water jacket should have a nice flow on it, for some, they do remove the thermostat and I have also done this to other bikes as well...