In yet ANOTHER South Florida S2000 owners group tech day (a clearing lights session was held on Saturday and today we completed five valve adjustment sessions), I will post the results of the valve adjustments before/after. The weather was gorgeous and
CoralDoc (Josh) was generous enough to lend us his expertise and two car garage and
all of us who attended cannot thank him enough for what essentially became an all-day (and into the night) affair.

As for the results, it certainly speaks well for Honda quality that despite the various
mileage and years of the vehicles, all were within spec but in the end, all the owners
decided to adjust the valves towards the aggressive side of the spec range, well within
tolerances.

Here's the results in a nutshell. All valves on the intake side were spec'd to .008 and .010 on the exhaust side.

BEFORE ADJUSTMENT results below:

Russ, 2002, 22K,
1. Intake .011 .011
Exhaust: .012 .013
2. Intake .011 .011
Exhaust .013 .012
3. Intake .011 .011
Exhaust .012 .012
4 Intake .010 .011
Exhaust .013 .012

S2KSuzuka, 2002, 13K
1. Intake .011 .011
Exhaust .011 .012
2. Intake .010 .011
Exhaust .012 .014
3. Intake .011 .011
Exhaust .012 .013
4. Intake .010 .011
Exhaust .012 .013

BigPurp, 2000, 55K
1. Intake .011 .012
Exhaust .012 .013
2. Intake .011 .011
Exhaust .011 .012
3. Intake .011 .011
Exhaust .010 .011
4. Intake .010 .009
Exhaust .011 .012

JeffBrig, 2002, 9600 miles
1. Intake .010 .010
Exhaust .012 .013
2. Intake .010 .011
Exhaust .012 .012
3. Intake .011 .012
Exhaust .011 .012
4. Intake .011 .011
Exhaust .011 .012

Keith, 2001, 26K
1. Intake .010 .010
Exhaust .012 .013
2. Intake .010 .011
Exhaust .011 .012
3. Intake .010 .010
Exhaust .012 .012
4. Intake .010 .010
Exhaust .011 .012

Speaking only for my car, it definitely felt smoother throughout the rev range
on the 1-hour drive home. Placebo? Hard to say because I really didn't know what to expect from the adjustment...certainly not horsepower but the car seemed to idle more smoothly and accelerate from say, 60-85 (5th gear) a bit more smoother than before so who knows? Hard to quantify things with the butt suffice to say it was
well worth the effort and a big hat's off to the gang who showed up and especially to Josh, again.
Tight group down here. It seems there is something going on at somebody's home every other week. Hang in there northerners....I was once (for three decades) an annual cabin fever non-S2000 driver but after Vermont's 8-month winter last year, I'd had enough.
80-degrees tomorrow!


On another note, while we were waiting for the gang to show up, Josh weighed my tire/wheel combo and his. Mine was 32-lbs front, 29-lbs rear. The stock front tire/wheel weighed 42-lbs, I assume the rear would be heavier by 3-lbs at least. The scale was accurate, FWIW. For some reason, as Josh explained, the LSD of the S2000 creates more wear on the passenger rear tire than the driver's side and this was plainly obvious (might be the main reason I was only coming in at 29-lbs for the tire AND the wheel). That right rear tire would kick a Lincoln penny's ass. I couldn't believe the difference in wear from the right to the left rear. Strange. Anyone want to chime in on that....I guess it's normal but have no idea how the LSD would cause
the wear pattern to be so aggressive on the right rear.

 

Congrats on your meet, sounds like you guys had a lot of fun and probably learned a bit about our motors. As far as your tire wear question the right rear tire is your primary drive wheel, if you did not have an LSD (open differential) it would be the only tire to spin if you dropped the clutch. This is where the "limited" part comes into play in your Limited Slip differential. The LSD will do it's best to keep both tires spinning equally in a straight line but it still allows them to spin at different speeds while cornering (tires following a different radius). That little bit of allowance also carries over to your straight line acceleration and thats what causes the passenger tire to wear quicker. You could have your spider gears inside the pumpkin locked which would make it a closed differential this would guarantee both wheels would be spinning at the same speed (common for drag cars) but try making some tight manuevers in the grocery store parking lot and you will know that this is not the way to go for a road car. However your wear patterns could also be thrown off if you make your righthand turns more aggressive than lefthand turns or vice versa. Or it could just be you make more of one than the other.

 

Russ,

For reference, could you possibly post the specs. in which the valves should be for optimal operation?

 

I wish I could find someone in California to do my valves. They're getting really loud and I don't trust Honda.

 

send Speeeding a PM if you're in the SF Bay Area. he had a mechanic he really trusts install is Toda cams and do the necessary valve adjustments. he seemed very happy with the quality of the guy's work when he told me about it 6 months ago.

of course, quality work does come at a price.

 

I will say the car seemsto feel a little smoother, and is be running great. However, I'm not sure that i can feel a real difference or that it's just the placebo effect. I do feel better knowing that my car is absolutley within the tight end of the factory spec's and that everything is now consistant. It's also great to know that next time around I can do this myself

Josh thanks again for the tutoring, and the hospitality.


Mitch

 

I enjoyed everyone's company and was happy to host the event. It was interesting to see the range of valve clearances present in the various cars.

Valve clearance specified by Honda are 0.008-0.010" for the intake valves and 0.010-0.012" for the exhaust valves. A consistent pattern was that every car had clearances set near the upper end of this range, or slightly over. We chose to stay within spec, but at the lower end of that range. Honda has a 105k mile recommended service interval for valve clearance checking, and I suspect that the larger clearances measured in these cars are designed to accommodate that long interval. With more frequent adjustment, I am comfortable running tighter tolerances.

"Optimal Operation" could have several meanings; do you want maximum power, or longer service intervals. The theory is that tighter valve clearances allow for greater valve lift and duration, resulting in slight power improvement. However, if valves get too tight, they do not cool as efficiently and that could lead to valve train problems. I'm speculating, but it may lead to increased likelihood to float the valve - anyone with knowledge able to comment?

Photos to follow ...

 

The Group


The Parts


The Valves - With novice valve adjuster Jeff hard at work.

 

Always good to add a new talent to my repertoire. A big thanks to Josh for hosting and sharing his experience. I adjusted my own car and bigpurp's (shown in the pic above), and had never done a valve adjustment previously. It's somewhat tedious when you take the time to do it right (what isn't), but it's not a difficult task.

On the drive home, I thought the car was running quite a bit smoother, and idle is VERY quiet. I also felt like the car was more eager on the non-VTEC cam lobes (like Russ mentioned above). Since temps had dropped 25 degrees since noon, I figured the weather probably had more to do with it. But on the way to work this morning, temps were already back in the 70s and I got the same impression.

Most of my valves adjusted down .002 or .003", which would give more lift and increased airflow. Wouldn't it make sense that any improvement would be more apparent on the non-vtec cams, since the adjustment is larger relative to the lift height?

Another observation...... My car has long had a tendency to make a slight fluttering sound between 3-4k rpms. It's only noticeable in low gears (less wind noise), driving with the top down, with a building or hedge on the passenger side to reflect the sound back at the car. I didn't hear that sound on the way to work today where I normally hear it. This isn't conclusive - I still need to drive the car more - but it would be interesting, since I never thought it sounded like valve chatter.

Thanks again to Josh, and it was great meeting everyone!

 

Big thx to all the guys yesterday, especially Josh for allowing us to work pretty much all day on his driveway. I learned A LOT about this engine. And the car does seem to run smoother, but until I get some more time in 'er, I'll chalk it up to the placebo effect.