.
This thread is starting to turn into an oil related thread, which as I mentioned, I didn't want to do since that wasn't the original topic and I haven't seen the op ask about it but then I haven't read every one of the 2,678 posts either.
crazypj said:
I don't know if your being deliberately obtuse or just have no experience with the various Honda twins?
Yes I saw the Shawshank Redemption and no I am not "being deliberately obtuse" . . I am simply trying to understand what you really mean and also post what I personally know . . It is my experience that there are many people that know what they mean but are not able to articulate it in a clear concise manner where their comments will have no ambiguity and will be easily understood by most.
I definitely have experience with this system and actually had some of these exact models back in the day and also worked at Norm Reeves Honda from late 1974 to 1977 which I mentioned in a previous post, however, I have absolutely no doubt that your experience with this particular system is extensive and quite possibly far greater than mine, especially pertaining to failures that occur under sustained high rpm, however, one of my points is that unless controlled testing is done on many samples with varying setups starting with testing 10w-40 and 20w-50 using the EXACT same type of oil, it is simply impossible to say with any reasonable mount of certainty that using slightly thicker oil is the single cause of cam bearing failure at high speed . . I know this for a fact because I worked at a mfg that did testing.
DRAIN PLUG
crazypj said:
In my experience magnetic drain plug doesn't do much of anything in any of the Honda's with a centrifugal oil filter. It doesn't hurt anything to use one but it doesn't catch micro-particles from bearing or transmission wear..
imo, in this case, the amount of metal they catch is fairly irrelevant since catching any metal is better than catching none, and since they can't do any harm and only cost around $10.00, I see no reason not to . . Obviously if they cost a lot more, then the benefit for the amount spent is small, and at some price point , buying one won't make much sense.
EFFECTIVE COOLING AREA
crazypj said:
BTW, generally a good way to look at surface area and volume is look at little kit and an adult. Kids can stay cooler as they have less 'volume' to surface area compared to adults
Actually, average infants have nearly twice the blood volume that the average adult has, therefore, they actually have more blood volume per square inch of skin area than an adult has, therefore, as they grow, the percentage of blood volume a person has decreases until it stabilizes near adulthood.
OIL COOLERS
crazypj said:
Oil coolers, even factory fitted ones can bring their own problems, aftermarket, when not fitted correctly can cause major issues. (like waiting 4 hrs for track clean up after a Buell dumped it's oil tank contents when mounting bracket broke)
It's impractical to not use one simply due to fear of an oil line breaking or the cooler breaking . . By the same token, it is illogical to remove a factory oil cooler due to the same fear . . One might as well simply remove all the oil if they have these fears because its also possible that the drain plug could loosen causing all the oil to leak out on the track or elsewhere . . There is simply no protection against faulty parts or the incorrect installation of them.
It has been proven a zillion years ago that as long as oil coolers are installed properly with quality parts, they will rarely cause a problem . . This being said, it is best to have an oil temp gauge on any engine/vehicle that is not being operated as it was designed to be [such as the example I mentioned in my previous post] or on any that have have been modified . . Since this is the case, one could install the gauge and then see if their oil temp ever gets hot enough to warrant an oil cooler, thereby possibly avoiding an unnecessary risk by installing one when it is not needed . . The engine only needs to get a little too hot just once to cause damage.
TOP END OILING PROBLEMS
crazypj said:
IThe problem is just getting oil to the top end at high rpm. I have seized cam bearings on CB and CD175 motors ('sloper' motors) I've seen it literally hundreds of times on CB100/125/185 single cyl, CB175/CB200, CB250K/CB350K (and variants), CB250G5/CB360G5, (and variants) In every single case, sustained high rpm operation was the cause.
Ok, then, one of several different ways to cure that is an incredibly easy one which is to simply use a thinner, high quality oil, and I see in your previous post that you started using 10w-40 or something like that, but you did not specify what brand and type it is . . If the pressure relief valve still opens with the lighter oil, simply preload it with around a .040" washer then check your pressure gauge t determine how much that increased it. . This "should" still allow sufficient clearance for the spring to compress . . This will in turn increase the amount of pressure required to open the valve . . Increasing the pressure at which the valve opens on high perf automotive engines has been standard practice for eons and is still being done today as a very common practice.
An accepted rule of thumb for the "necessary" level of oil pressure on old school automotive engines is 10 psi per 1000 rpm . . Since most performance engines have a minimum of of around 30 psi at idle, the pressure increase is not in exact scale to the engine rpm, however, "close enough" has been proven to be "good enough" in this case.
A simple rule of fluid dynamics is that when pressure goes up, flow foes down . . This needs more explanation to be fully understood, but. in general, that's how it works . . One example is a typical oiling or hydraulic system . . If the system works properly, and then the size of the passage from the pump to the rest of the engine is reduced, the pressure will go up, however, the volume of oil exiting after the restriction less and the pressure will continue t go up ad the output volume will continue to become less with every decrease in the size of the passage until the passage is closed completely which would cause the pump to hydrolock which would cause the weakest link in the chain to break, which in the case of an automotive engine would be the oil pump drive shaft.
OIL COOLED PISTON DOMES
crazypj said:
The 'original' design with oil being pressure fed to underneath piston crown was used in pre WW II aircraft engines, only took about 40 yrs to appear on motorcycles.
That's possibly just because it wasn't necessary for the bikes being built at the time and not because the Motorcycle industry was unaware of it, and in fact, Kawasaki has an aviation and aerospace division and they actually built the ZEROS used in the war at the same plant I was at . . They also still had an original runway left over from the war that I did some testing on and the first Kawasaki motorcycle engines were designed by their aviation engine engineers.
OIL SYSTEM MODS
If you do two modifications at once, it can be nearly impossible to determine which mod had an affect, therefore, mods are typically tested one at a time . . If you modified the spring retainer plate AND went to a different viscosity and/or brand and/or type of oil at the same time, it is absolutely impossible to say with reasonable certainty which one o the mods cured the problem and in fact, it is possible that neither mod by itself cured the problem and I have seen occasions where this is the case.
It's also quite possible that the bearings could still fail if someone did the mod you did and used the same viscosity oil you did but used a different brand that had less ZDDP or used mineral oi where you may have used synthetic etc and had and still had a failure.
If we had had this exact same problem on a bike at Kawi, I couldn't possibly go to the chief engineer in Japan and tell him that modifying the spring retainer plate cured cam bearing seizure IF I switched to a different oil type at the same time because he would probably fire me.
I am not saying that your fix doesn't help, I am only saying that it needs to be tested the way I suggested to be definitive and thereby valid.
Enlarging the hole in that plate will have no affect if any single hole upstream that is before other galley branch off of it are smaller than it, than it is physically impossible for that mod to have any affect at all because they are the limiting factor just like a jet needle is in a caburetor . . The main jet cant flow any more than the area between the jet needle and needle jet will allow it to because it acts like a flow regulator.
OIL CAPACITY VS OIL TEMP VS OIL BREAK DOWN
crazypj said:
Increased oil capacity is generally a good thing as long as there is extra surface area to cool it, otherwise it just delays the inevitable oil overheating and breakdown,
This is not a concise explanation and can lead people whom read it to the wrong conclusion, and is one of the problems I mentioned before regarding peoples lack of understanding of thermal dynamics.
The continuing heating of the oil up to that of the engines running temp is only guaranteed if the container the oil is stored in prevents sufficient heat from dissipating . . In other words, if the storage container was insulated well enough, the oil in the container would definitely reach the same temp as the engine, but if it wasn't, then it is not a foregone conclusion due to other factors.
If you picture a 10 gallon oil pan being installed on a car and fill it will 10 gallons of oil, the oil will never reach the same temp as the oil in the engine, it's an impossibility that would defy the laws of physics . . This is because there is a threshold where the continual heating of the oil will be passed at which point cooling of the oil would begin . . This is due to a few reasons, and one of them would be the increased size of the pan which to some degree does act like a "radiator" but it is not a cooling device per se, if if it was, it would be made from aluminum and have additional cooling fins on it like the Shelby pan I posted a photo of.
The difficult thing is determining the exact amount of oil required for each particular engine to cause this to occur, but suffice it to say that more capacity for the oil AND water, is definitely better than less, and yes, there obviously is an amount that would be more than necessary.
OIL BREAK DOWN - For this particular scenario, no break down of the oil ever occurs in the oil pan unless someone lights the engine on fire, and for the most part, the base stock used in the oil doesn't exactly "break down" either per se . . What can occur is shear in non PAO and Ester based multi viscosity oils and the depletion of the additive package after the oil leaves the pan and goes thru the engine.
There are areas of an engine that can get hot enough to "cook" the oil, in which case, it basically evaporates, which one could refer to as breaking down I suppose because even if it simply "evaporates" from too much heat, it certainly is no longer doing its job, and the primary area this can occur is near the top of the piston followed by the sides of the piston . . "Boiling off" will never occur in a transmission pan either unless someone lights it on fire too.
There are multi viscosity oils that have a higher boiling point and are basically 99% shear free . . I mentioned these in a previous post and they are called Group IV oils which are PAO, mPAO [mPAO is Joe Gibbs oil only] with possibly some Ester, and ESTER [Mainly Red Line oil] based oils with possibly some PAO, however, none of these oils are 100% PAO or Ester etc because for the most part, the additives all oils use comes premixed with non synthetic oil and constitute an average of 15% of the bottles total volume.
AFFECTS OF OIL LEVEL/QUANTITY ON OIL TEMP
crazypj said:
Higher oil level in a stock engine will just cause oil to overheat much earlier
Higher oil levels in an engine never cause overheating in my experience or in the experience of literally thousands of other people so I would like to see a controlled test that determined this . . In a water cooled engine, the oil temp is basically controlled by the water temp because it has a radiator which can cool it, and unless the oil has a cooler or aluminum oil pan, it can not be cooled very much other than by the minor cooling effect the oil pan has on it by be being exposed to ambient air temps etc.
I have run additional oil in many engines and so have thousands of other people and there has never been a case where the additional oil caused an engine to overheat. . . The engine temp would have to get to a point where it would literally be unable to run for oil to "overheat".
Obviously, if someone has an engine that calls for 2 qts of oil like a motorcycle might and they fill it up to the top, it probably isn't a good thing but that's obviously an extreme example.
If you run your bike for a couple hours with the proper oil level, and it operates at a normal/acceptable temp, and you then add an additional 1/2 qt of oil and do the exact same ride under the exact same conditions and the engine melts, I will give you $1,000.00 to rebuild your engine.
Your references to overheating suggest to me that you have an issue with your bike that should be addressed.
HAPPY NEW YEAR IS NEXT
The title may be deceiving but its all engine. I don't think there is a better single read available on or off-line as it relates to these little Honda engine. http://www.dotheton.com/forum/index.php?topic=39814.0
