Anyone had a valve adjustmet before 30K
07-30-2003, 08:28 PM
#1
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Anyone had a valve adjustmet before 30K
I could swear my car needs one, but the dealer says ours engines don't need one till ATLEAST 30K...sounds like BS.
Input?
Input?
07-31-2003, 04:41 AM
#2
They need one when the adjustment is out of spec, regardless of mileage. If you will do a search you will probably find it done from new to 70K and everywhere in between. It has nothing to do with how many miles, they are either adjusted properly or not.
07-31-2003, 07:07 AM
#4
You really should consider adjusting the valves yourself if you want it done. The factory spec for valve clearances leaves plenty of room for a dealer to just "call it good". I've adjusted my valves 4 times in 28K miles (trying to find the perfect clearances), and I've noticed that very slight differences between them (all within spec) can cause a rough idle.
07-31-2003, 08:12 AM
#5
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I have done the valve adjustment about 3 times before 30k. It seems that each time I do it, the clearances need less and less tinkering. The first time they were adjusted, it seemed clearly evident to me they needed it what with differences between clearances, and some I think were out of spec. I think the last time I did it, individual variations were miniscule, but I wanted tighter clearances, so all the valves were adjusted.
As Gernby said, after breakin is a good time especially if there is some indication of rough idle. If smooth running, I might wait until after 1k or more.
As Gernby said, after breakin is a good time especially if there is some indication of rough idle. If smooth running, I might wait until after 1k or more.
07-31-2003, 09:46 AM
#6
Prolene, what clearances are you running? I have been making small reductions each time, and now I'm actually between .001" and .002" below minimum spec on both intake and exhaust. I went .001" below spec on the secondary valves, and .002" below spec on the primary valves to reduce the stagger that is designed into the cam lobes. I don't know if it is any better than just running minimum spec, but my last dyno pull was the best I've done yet. I was afraid that I would burn a valve or something, but I put several thousand miles on it and a couple hours of track time with no ill effects.
07-31-2003, 11:23 AM
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Gernby, I seem to recall it was .001" below spec on all valves. The S2000 seems to be strong, what with UL's dyno session, etc.
By primary and secondary, do you mean intake, exhaust?
By primary and secondary, do you mean intake, exhaust?
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07-31-2003, 12:03 PM
#9
For each cylinder there is 1 primary intake lobe, 1 secondary intake lobe, and a VTEC intake lobe each with their own profile. The primary and secondary look similar, but the secondary has about .01" more lift than the primary (I may have this backwards) to induce swirl. My theory is that the swirl was needed to improve low end torque, so I reduced the stagger by .001" by reducing the clearance on the primary valve by .001". I couldn't tell any difference, so I will probably just set them all the same next time.
A 'rough' idle is just as it sounds. When sitting at a stop light, the engine shakes the whole car. When I do a really good valve adjustment, you can't even tell the engine is running at a stop light.
A 'rough' idle is just as it sounds. When sitting at a stop light, the engine shakes the whole car. When I do a really good valve adjustment, you can't even tell the engine is running at a stop light.
