i had a buddy of mine help me do this today on my 2000 ITR with 30k miles on it. It had never been done. Most of them were too tight robbing me of compression he said? Anyway he taught me how to do it sorta.

Mike

 

compression

 

I guess the theory is that is the valve is too tight, it might not let it close all the way and allow blow-by?

 

don't start me lying. I am not a motorhead. anyone know what can happen with having the valves too tight?

mike

 

I was wondering: Did it get tighter after 30K miles? By itself? I thought the gap can only get bigger due to wear, stress etc....

 

My valves were with-in spec. or a little loose. If it was tight (allowing blow-by/loss of compression) someone must have been in there before.... no?

Will

 

Talkie said it (valve adj.) was never done before with his ITR....

 

I would hope that the factory did not adjust the valve incorrectly...

fyi... my "loose" valves were exhaust ones on the middle 2 cylinders.

Will

 

Hmmmmmm... How many miles/km was on it at that time?

 

~21,750 miles
~35,000 km's

Will

 

That's what I was told by a Acura.

 

After 32k miles, my valves still on the looser end of the spectrum. A valve that is too tight will lower compression. When adjusting valves though, it is better to adjust them closer to the tight limit, this will alow the valve to stay open longer. With a loosely adjusted valve, the cam lobe must "take up the lash' before the valve actually will begin to open. The only downside of adjusting the valves tight is you will need to stay on top of valve adjustments and do them more frequently. This is , at least, what they told us a t Honda's training schools.

 

I don't understand this. I thought it will take longer before the cams will be too loose then.

 

ALL of my valves were loose at 15,500 every single one

 

EuroITR1869

The valves will tighten. This happens to engines that are constantly run at high rpms. The valve seats, which are made of stellite and pressed into the cylinder head will seat deeper into the cylinder head.

 

Which spec's were they adjusted to/from?

too tight?
...used the wrong "feeler" ....

 

Too tight meaning minimum spec. If I remember right .006" intake and .007" exhaust. .005" intake and .006" will get you in trouble.

 

Don't know about Hondas but it is well known that BMW 6 cylinders will tighten up over time.

 

we used the feeler gauges according to the manual under the hood. i think intake was 19 and exhaust was 17? Might be the other way around. those are correct #'s, right?

mike

 

I think that's why he said they were tight.
Did the "valves" make more noise after the adjustment?
Were they noisy before?

I don't remember the specs off hand (because I don't do it myself), but as I recall, the guy above had it right (see below).

 

yeah the vavles will get lower into the seats over time with wear and tear so the clearances do get tighter, so yes you do need to check them more often if set on the tight side of the spec.

 

You are supposed to do a valve adjustment every 15,000 mi. The fact that we all run our cars harder than almost everyone else..plus we have a motor that is more finely tuned (meaning that it is more likely to fall out of proper adjustment) means that it should be done at least that often to maintain its directed factory spec.

 

we did the specs whatever is listed under the hood. valve lash. isn't that the same thing?

Mike

 

Contrary to what was said here, it is better to set the valves on the looser side than tight. too tight can lead to burn't valves by them not closing all the way... not good. adjust to within specs, but if you have to make a choice, stay on the looser side(larger number) of the recommended specs.

as JSIR said, valves can tighen up by the valve smashing the valve seat area, allowing the valve stem to rise higher. sport bikes, with their high rpm redlines (15k), are notorious for this.

check your valves and do it often, especially with a high reving engine like the R has. every 15k miles is about right.

 

Let's try it this way.

There is a spec on valve lash.

If it is set to the maximum or larger, the motor wil be noisy (tappy) and the valves will stay seated for a longer period of time. This effectively lowers the duration that the valves will be open reducing the time period that gas and air will flow into the cylinder and the time period for exhaust gas to flow out.

If the valves are set tighter, the opposite occurs. The valves are open longer allowing more gas and air to flow in and more exhaust gas to flow out.

Looking at the carbon build-up that I have seen in exhaust ports, I don't think that the valves will be 'burnt' by the results of the longer duration/less seat time. This was one of the long term discussions on the Endyn website and everyone who tried it had positive results.

This would be a good 'dyno test' especially if done in stages with adjustable cam gears to control the overlap period.

John