Noisy valves a problem?

[Tinster]

Maybe a really stupid question; maybe not.
I have never heard a real TR6 engine operating; only my own.

My cylinder pressure is 155 psi across the board
My manifold intake vacuum is 19psi and very constant.
All vacuum gauge tests indicate a healthy engine.
My timing is now at 12* advance, valves .010, plugs .025
New rocker shaft and refurbished rocker assembly.
Carbs tuned and balanced. Warm idle 800 to 900 rpm .

It has been suggested my engine top end is very loud
and I might have a problem. Does this engine sound "wrong"?
If so, what might be the cause? I have been driving this car
a whole bunch of miles and don't want to blow up the engine.

Thanks,

dale(tinster)

 

[KVH]

From what you describe, I'd suspect you actually might not have set the valves to .010. I thought I "set" mine correctly, then came across an article at Macysgarage.com better describing how to be sure the valves were "just" opening or "just" closing, which is the required test. Mine are much better now.

I really never quite understood the Rule of 9 and all that, but proper adjustment has to do with when the intake valve just starts to close (you adjust the exhaust), or when the exhaust valve just starts to open (you adjust the intake), etc. Eyeballing total up or down didn't work. For me.

Maybe see if you can call up that article. Other than a worn rocker or tappet shaft, I'm not sure what else the problem might be.

 

[Brosky]

Dale,

It's really kind of hard to tell, but to me, they do sound a bit loose, or if you will, loud. I really wouldn't want to go entirely my my ears from a recording heard on my monitor speakers though.

If someone you trust, who is knowledgeable brought this noise to your attention, then it's worth looking into. By that, look at the other article and mybe tighten them up a thou or two.

 

[TR6oldtimer]

Dale, the problem is the chrome valve cover. Send it to me and I will give you my painted one and all will be well.

Seriously, it sounds to me like you have maybe a couple valves that appear to be set at a wider gap then the others. They become clearly heard at the lower rpm. If you have check the gaps cold and cannot find the culprits, I would check them hot, not for the specified gap, but for the difference in gap between each intake, and the same check for exhaust, that is the high and the low. Hopefully you will be able to find the noisy one.

 

[DougF]

Keep in mind too that these engines, when set up perfectly are louder than most engines people are used to hearing.

 

[sail]

Maybe you just need to install a custom auto sound alternative and crank it.

 

[martx-5]

...

I really never quite understood the Rule of 9 and all that, but proper adjustment has to do with when the intake valve just starts to close (you adjust the exhaust), or when the exhaust valve just starts to open (you adjust the intake), etc. Eyeballing total up or down didn't work. For me.

Maybe see if you can call up that article. Other than a worn rocker or tappet shaft, I'm not sure what else the problem might be.

Here's the article from Macy's Gararge. It shows how to do it on the four cylinder cars, where you use the "rule of 9". On six cylinder TR engines, you have to use the <span style="font-weight: bold">"rule of 13".</span> It's the same procedure, just four more valves to adjust.

 

[Tinster]

KVH- I did use Macy's alternate method of adjusting
the intake and exhaust valves of one cylinder and then
moving onto the next cylinder until all 6 were completed.

I'll check rocker gaps again. But what makes the actual
noise?

thanks as always. Car getting better and better with
each tweak now.

dale(tinster)

 

[TR3driver]

Dale, the noise is a series of 'clicks', caused as the valve lash for each valve is taken up when the valve opens. Solid lifter engines (like the TR6) always make some noise, because they have to always have some lash. Most modern engines (and most American engines for the past 60 years) use hydraulic lifters that automatically adjust the lash to zero (hence no valve noise). Without the automatic adjustment, some lash is needed because the lash will change somewhat as the various components get hot. If the lash ever goes negative, that valve won't close fully and various kinds of mayhem ensue (including backfiring and burned valves).

It's a bit hard for me to judge from your recording, but it seems reasonably close to normal, for a cold engine under the hood. And certainly too loud (indicating the lash is a bit too much) is much better than too soft (indicating not enough lash).

Honestly, if it were my car, I'd leave well enough alone. Do check the valve lash occasionally (I like to make it part of my annual tune-up) and of course inspect for loose nuts, etc. whenever the rocker cover is off but otherwise, just drive it!

 

[Tinster]

Thanks Randall!

I'll take a piece of hose and "listen" to determine if
maybe one or two valves are louder than the others.
I'm confortable doing valve adjusts now, so it's no big
deal. My valve cover gasket is sealed to cover but sits
in a bed of grease on the head. NO oil leaks. Easy to remove
and replace.

One of my pals is going to do a video of a TR6 engine running
and send it to me for comparison.

Thanks everyone for your input.
The car is running very well.

dale)tinster)

 

[bgbassplyr]

Honestly, if it were my car, I'd leave well enough alone. Do check the valve lash occasionally (I like to make it part of my annual tune-up) and of course inspect for loose nuts, etc. whenever the rocker cover is off but otherwise, just drive it!

You could also install a sound proofing pad to the underside of the hood to help lower the decibles.

 

[TRDejaVu]

Dale, as Randall says, better for them to be slightly loose and a bit noisy than too tight.

 

[SkinnedKnuckles]

About 20 years ago I went to a local shop in Delaware on a Saturday to get a part for my then new TR6. The shop wasn't open, but the mechanic was there catching up and let me in. He had the part I needed, and then proceeded to tell me a bunch about tuning up a TR6. One tid-bit was that a stock engine valve train should sound like a sewing machine, otherwise there will be valve float at high rpm. So the 0.01" rocker gap was not enough in his opinion.

Ever consider an external oil line to the top?

 

[Brosky]

Brent,

IMHO an external oil line will not help that problem. To me it sounds like one or two slightly loose valves, not all of them. Dale has good oil flow up there now and all new parts, so it's not a lack of lubrication.

 

[KVH]

Dale, I just listened to your engine using your link. That sure sounds like loose tappet clearance to me. All disclaimers aside, unless you've got something more serious like a bad chain tensioner or worn timing chain, or something flopping around near your fan belt, or maybe a bad gear in the distributor, all of which seems beyond the realm of first possibilties, I'd pop that valve cover and re-adjust.

Back to that Macy's article, I just want to explain something. The reason you have to understand "just starting" to open or close is that you have to pull the engine crank around another (I'm only estimating) 1/4 to 1/2 turn to get to the "just" point. That's what I meant when I said "eyeballing" full up or down won't do the trick. That's not the proper point. There is an art to it. Or, there isn't.

Finally, the gauge will be snug at .010. I usually use the .010 gauge and make sure that .011 won't fit as well (a form of neurosis I can't beat).

By the way, did you note that Moss now sells both of those front end tools you were looking for last year?

Good luck

 

[14dna]

Dale;

I have a real good trick for adjusting valves om one rotation of the engine. It was shown to me by the F1 Honda guys at Montreal back in the '80S.
E-mail me if you want it.

Dave

 

[Don Elliott]

Dale - Many have suggested that you check the valve gaps, but no-one has mentioned that the rocker arms (where they tap onto the top end of the valve stem) can become worn. If you remove the rocker arm - all in one piece - and turn it over, you can see the bottom sides of the "curved end" on the rockers. If you see a rectangular wear pattern and a "step" where the rocker arm taps down on the top end of the valve stem, this could be your problem. Let's say that you have worn a stepped flat which is 0.010" deep onto that curved surface. Then when you use your 0.010" feeler gauge to check the gap, the feeler gauge is measuring from the flat top end of the valve stem to the original curve. Now you slide out the feeler gauge and the true gap is 0.020" up to the top of the flat spot stepped wear on the rocker arm which is no longer curved.

I have taken my hand grinder on three occasions during the last 52 years (182,000 miles) to re-establish the original round curve. I did this with the rocker arm assembly on my workbench. After re-grinding a similar curve, reinstalling the rocker arm and re-setting the gaps, I could notice a quieter engine in my 1958 TR3A.

 

[Andrew Mace]

Dale - Many have suggested that you check the valve gaps, but no-one has mentioned that the rocker arms (where they tap onto the top end of the valve stem) can become worn....

Dale did mention a "refurbished rocker assembly"; hopefully that has not worn out in such a short period of time. Dale, I concur with others that one or more clearances are just a bit too large...that's all!

 

[Tinster]

Don- Here are two photos that show the the spots where the rocker arms
push against the valves.

They are very uniform all 12. A small rectangle with a slight radius
at the 4 corners. Do these look OK, or could they be the culprit?
In any event- I'll pull the valve cover and listen for a noisy arm or two.

Thanks,
Dale(tinster)