[KD5ITM]

Iv got just under 1000 miles on my GT.  Iv noticed over the last few rides that im hearing a bit more valve lash coming from the upper end of the motor.   I looked in the service book for the valve tolerances but didn't see a section on valve adjustments.  Does anyone know what the valves should be adjusted to?

[Farmer_John]

The engine uses hydraulic lifters...

Here's some bad quality screen shots from the manual I bought. You should too. Then you could reference and learn.

[KD5ITM]

I have the service training manual and was told by Nfield Gear that that was the manual.

[Farmer_John]

It is, for the bits particular to the GT.  But what good is a manual without engine stuff?

You need the regular UCE manual for that.

But, did that answer your question?

[KD5ITM]

I didn't know the GT had hydraulic lifters.  I figured the bike being what it is would have solid lifters  which would explain some of the engine clatter .

[ace.cafe]

The UCE engines have hydraulic lifters.

However, it is possible that the pushrods may not have sufficient preload into the lifters, which can cause clatter when the engine expands after it warms up.
I am not saying that this IS what causing it on your engine, just that it COULD be happening if there was a tolerance issue with the parts in the factory build.

Another possibility is that perhaps the lifters are not getting fully pumped up at idle, if you are hearing the noise primarily at idle or very low rpm.

Be aware that others have heard this ticking noise, and AFAIK, none of them have actually deduced the cause. At least not that they have reported finding any cause on the UCE forum with their C5/B5/G5 bikes. So, they just chalk it up to the way things are, and move on. I am not aware of any catastrophe occurring because of it.

[Farmer_John]

"Loud valves save lives"

[KD5ITM]

Ill try to take a video of it with something that will save it as a file that will actually load on here unlike the mystery file my phone saves it as.

[ace.cafe]

Ill try to take a video of it with something that will save it as a file that will actually load on here unlike the mystery file my phone saves it as.

Sometimes you can load your file into a hosting site such as Photobucket, and then you can post it as a link here.

It's an interesting issue. Nobody so far has found any actual mechanical basis for the issue, but I don't think that there has been any deep detailed investigations by the users. My guesses in my other post above might yield an answer if investigations are done after full warm-up, which may only occur when the engine is at full expansion. The pushrods are steel, and don't expand as much as the alloy barrel and head castings do. If the pushrods are a little too short to provide much depth of preload into the lifters, and since there is no adjustment screws available to set lifter preload, then when the engine expands from heat, the preload into the lifter goes away, and can even end up with some lash clatter that would only show up when hot. The lifter plunger is held in by a circlip, and can only come up to a certain height, and then stops at the circlip. Once it is pumped up to the top at the circlip, it then is like a solid lifter without any hydraulic take-up mechanism if lash grows any further than that.

[KD5ITM]

I've noticed the noise the past couple of rides when pulling into the garage after a long ride. What my concern is, the noise that nobody can figure out, may not have any effect short term but 20000 miles down the road what's the effect going to be if any. I understand that an air-cooled engine is built a little loser  so it can adjust for the higher temperatures at  full operation  and interns is going to be a little bit more noisy .  I'm just not sure what noise is a good noise and what noise is of concern .  I don't have much experience  around air cooled engines. I took a video. I just need to upload it

[mevocgt]

Here's a silly question, do you notice the sound outside of the garage?  I ask this, because it could just be a frequency being absorbed, making the engine sound off.  I use to have this problem with a 750 Vtwin when I road next to a flat 6 motor.  Just a thought....

[Ice]

 Lacking the sound and vibration dampening of a water jacket, air cooled motors do transmit more sound.

[KD5ITM]

And just to be clear, depending on the make and model of engine you're working on you can adjust some hydraulic lifters. I have a 1970 302 sitting on an engine stand that came out of a boss Mustang that has hydraulic lifters and you can adjust them one turn from 0 lash. In high rpm applications I prefer adjustable hydraulic lifters so you can adjust it so your valves won't float on you at high RPMs. So yes, you can adjust some hydraulic lifters.

[KD5ITM]

And yes, I noticed the sound outside of the garage. The other night I did the screwdriver to the ear checked and it seems to be coming from the upper end of the motor. My computer is on the fritz so as soon as I get it back from getting looked at I will post the video. I definitely want to see if anybody recognizes what the sound is and if its normal operation or something to be concerned about.

[ace.cafe]

And just to be clear, depending on the make and model of engine you're working on you can adjust some hydraulic lifters. I have a 1970 302 sitting on an engine stand that came out of a boss Mustang that has hydraulic lifters and you can adjust them one turn from 0 lash. In high rpm applications I prefer adjustable hydraulic lifters so you can adjust it so your valves won't float on you at high RPMs. So yes, you can adjust some hydraulic lifters.

Yes,  some engines have adjustable rockers so that the preload in the lifters can be adjusted.  As you pointed out, American cars often have them.  My Ace Billet GT head has them too.
However, the stock UCE/GT does not. The stock UCE/GT has non-adjustable rockers, and the preload is set at the factory by installing non-adjustable pushrods of standard lengths.  If there was any variation in the height of the barrel/head/rocker above the lifters, the pushrods 'could possibly ' be a little too short  for the application,   and it 'could' create a condition of too little preload,  which 'could' cause valve clatter on a hot expanded engine.

Now, I am NOT saying that this is definitely the case in these situations.  I am only saying that this 'could possibly' be the cause, and it might not be a bad idea to check it out if you hear valve clatter when hot.