I just noticed the same thing happening on mine sunday after sitting in traffic for about 25 minutes, but I just adjusted the valves less than 1500 miles ago. Also running 10w40, I have some 20w50 I'm gonna try next oil change. Hopefully that will help.

My take is that as it gets hotter the oil gets thinner and provides less protection.  I'm guessing that's why the valves are supposed to be adjusted when it's cold.

Hmmm, I did only use conventional.  I was worried that Synth would mess with the clutch and tranny (too slippery).

Would adjusting the valves help or are you implying that i'm running lean?  I have a 155 jet and no mods.  I find it hard to believe that too lean is my problem.

[The reason the valves get louder when hot is the head is aluminum and the valves are steel.  When I did a thermogrowth of the cam chain versus the cylinder the diference was ~.015".

So, the head being aluminum grows more the the valves.


Okay, I am trying to visualize the head, cam, rockers & valves. The cam sits in aluminum bearing surfaces cut ib the head. The rockers are mounted to,,, what? ( my minds eye goes blind right there) Then, the rockers slap down on the valve end when the cam lobe comes up & hits the rocker.

Now, aluminum expands more than steel, ( I happen to know that because you said so, else I would be guessing) Okay, Now, IF the part I cant visualize just happens to be on top of the hottest part of the engine, & I think it is, & IF that part gets taller, then it would increase the gap on each end of the rockers! Making it tick harder. Well,, since it does that about every time I ride, I guess if its hurting it, it will just have to die an early death, cuz I am not gonna stop riding when I hear that extra Tick, I will let you guys know if I lose an angine over it.

Ver, thanks man, those answers that include scientific fact really help me understand things,. Maybe I will & maybe I wont actually use what I learn, but that doesnt mean I dont appreciate the info,

Of course, If I have got this figured out wrong, I hope you can explain it so i can "get it", I may be a hundred miles off here.

Wow, with the ticking, timing chain tensioner, and oil leaks, I can't believe they are still using this engine!

it's certainly not the viscosity of the oil that's causing the noise.

We're using multi-grade oils in our bikes.  That means that the same oil will have different viscosity properties at different temperatures.  

In the case of the 10w40 that Suzuki calls for in the Savage/S-40:  At start up, the engine oil has a viscosity index of 10, meaning that it will flow very easily at temperatures above 32*.  At a around 212*, the base oil in the blend begins to thin out and loses it's lubricity.  Thats where the blended oil viscosity takes over.  At temps above 212*, the oil with a viscosity index of 40 is used to protect the moving parts and provide continued lubricity.   The 40w oil is good for temps approaching 400*.  Higher viscosity oils will protect to higher temps (such as in diesel engines where head temps can reach 600*)

Synthetic based oils can continue to provide lubricity at much higher temperatures than organic based oils.  But at normal operating temperatures, they provide little better protection than organic based oils.  

What makes the difference in the performance of the blended multi-grade oil is not only the quality of the base oil , but also the additive package of modifiers and detergents as well as the oil's ability to dissipate heat.

In a large displacement, single cylinder application such as the Savage/S-40, a synthetic base or synthetic blend oil will likely provide more upper cylinder protection and better cooling than conventional organic based oils.

My own experience with the different oils supports this opinion.  On my Savage, I do develop the valve tap after prolonged periods of idling (stuck in traffic).  But that noise diminishes when I get back up to speed and the passing air begins to cool the cylinder.    When using conventional oils, the valve tap happens sooner and seems louder than it does with the syntetic base oil that I selected.

On a related note, it is important to select motorcycle-formulated oils only and not use automotive formula oils.  Automotive oils have additional friction modifiers that can cause the wet-cluuch to slip, glaze and eventually fail.

Suzuki offers a synthetic blend as well as a full syntetic oil for it's air-cooled engines.  Mobil 1 also makes a very good full synthetic motorcycle formula oil as well.

Rotella-T's come up before as one recommended by many folks but there was also the discussion of it having been designed for diesel engines.  Something about it suspending a lot more soot that one designed for gasoline engines.  I don't know how bad this migh or might not be but I just seemed to remember it from one of the MANY preexisting oil topics on this site.