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Message started by adberns on 07/12/11 at 08:06:13

Title: Valve Adjustment Survey: Loose or Tight?
Post by adberns on 07/12/11 at 08:06:13

Alright, searched the forum and found a decent number of people that go both ways on valve adjustments - some prefer to do 0.003", some go loose at 0.005", and some in the middle at 0.004". Planning on doing a valve adjustment this weekend, and thought I'd found out everyone's opinion:

1) What do you adjust your valves to (both intake and exhaust)?

2) From your experience, have you noticed your valves getting tighter or looser over time (I know they aren't shim adjusted, but some people have said they still get tighter, so just checking).

Title: Re: Valve Adjustment Survey: Loose or Tight?
Post by drums1 on 07/12/11 at 08:46:48

Maybe they meant they get tighter as the motor warms up. But then they loosen back up when it cools. I can't imagine how they would get tighter over time. Metal on metal, even with oil, is gonna wear parts. Thus, they would become looser over time. That's why you would need to adjust them. Personally, when I have done it, I set mine right where it says. .004

Title: Re: Valve Adjustment Survey: Loose or Tight?
Post by adberns on 07/12/11 at 09:05:14

Depends on what's wearing. If the valve is wearing down the valve seat on the head, the valves will actually get tighter. If the valve stem itself is wearing, then they will get looser, yes. I have seen both stories about what the Savage does.

Title: Re: Valve Adjustment Survey: Loose or Tight?
Post by Bubba on 07/12/11 at 09:11:00

I adjusted mine about a month ago. .003 is where I set them. I'm a little concerned they may be too tight since I don't hear the familiar tick, tick I'm used to. I'd hate to burn them up so I may go back and try for .004 but then again, I'm lazy too... ::)

Title: Re: Valve Adjustment Survey: Loose or Tight?
Post by verslagen1 on 07/12/11 at 09:19:14

Look at it from a different point of view. Experienced and hve a fine touch set it to ,003 newbs set it to .005

Title: Re: Valve Adjustment Survey: Loose or Tight?
Post by justin_o_guy2 on 07/12/11 at 09:29:25

The pointy tip on the adjuster isnt real hard,, & on a new engine, will pound down a bit,loosening the valves up,. eventually work hardening,7 needing adjusted less often, Theyre not gonna tighten up. Just not gonna happen, unless an adjustment changes,, & if that happens, it should loosen, not tighten. I no longer have to adjust valves every 5,000 miles,, cuz they dont open up as easily, since the parts have formed themselves & hardened from all the banging, Set them close & listen to them, then pay attention to the sound,, when it gets noisy, go in & play with it.

IDK if after head work & valve adjustment things may settle & change the valves making them tighter,, I just cant think that clearly right now.

Title: Re: Valve Adjustment Survey: Loose or Tight?
Post by Oldfeller on 07/12/11 at 09:32:02

Note in a post any advanced techniques that you use and why you do it

Title: Re: Valve Adjustment Survey: Loose or Tight?
Post by Oldfeller on 07/12/11 at 09:38:40

Wickers see wear on tappet follower pads and on the face of the adjustment screws themselves, so we tend to adjust tighter to get the adjustment to last longer between adjustments.

Once you get over 10,000 miles, your valve tulips have seated themselves in the head seat pretty much and you aren't going to see a lot of "tighten" as the wear on tappet followers to cams and the wear of the tip of the valve stem to the screw head is going to be greater than the wear of the valve down into the seat.

Title: Re: Valve Adjustment Survey: Loose or Tight?
Post by Digger on 08/13/11 at 20:16:28

According to my archives (my bike is in my signature):

5600 miles, all clearances measured 0.005", no adjustments done.

10,100 miles, all clearances measured 0.008", all four lashes changed to 0.003".

I did a check at 600 miles but did not record those results.

So, on my bike, at least, the valve clearances appear to open up over the miles.

FWIW, I'll be checking the valve clearances again sometime after I get to 14,100 miles (the bike currently has 11,900 miles on it).

Title: Re: Valve Adjustment Survey: Loose or Tight?
Post by Gyrobob on 08/15/11 at 06:20:59

As mentioned by the Savage-knowledgeable folks above, there are a few things going on that change clearances as the miles roll by. For example the valve seat and valve face erode a little; decreasing the clearance as the valve moves closer to the adjuster. Simultaneously, the valve stem and the adjuster rub against each other and wear a little, hopefully canceling out the valve seat/face wear.

The engineers at Suzuki put a LOT of effort into metallurgy, geometry, etc., to balance out that wear.

It is safer to go a bit loose to make sure the valves are seating all the way. Tick tick tick. Some folks say, "a ticky valve is a happy valve."

The primary danger from too little clearance is burned valves from the valve not being able to fully seat.

I am fairly new to the LS650, but with most motors, the clearance decreases as the motor warms up. This is from the valves lengthening from thermal expansion. Being exposed to combustion heat, they get pretty stinkin' hot. This is why we set clearances in the first place,... to make sure the valves don't lengthen so much that all the clearance goes away, thereby burning a valve in short order if the valve isn't allowed to seat all the way.

One other interesting effect: Looser clearances fatten and lower the torque curve, because the valve timing is changed. (more torque at lower rpm) The valve overlap is lessened, the valve duration is lessened, and the valve lift is very slightly lessened. This effect is not huge, but it is a factor race tuners keep in mind.