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Valve adjustment intervals?

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nevets

nevets

Jedi Knight
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How often is it necessary to adjust the valves? Given how little these cars are driven, once set correctly, do the valves really need to be adjusted with every tune-up? Assuming the adjustment screw lock nuts are tight, shouldn’t adjustment only be required to account for wear?

The 2nd part of the question...except by checking with a thickness gauge, is there an indication that the valves do need to be adjusted?
 
+ 1 no need to adjust when there is no wear
I use to listen for a ticking sound that indicates wear

Hans
 
Nevets,

I ageee with the wear scenario...I think the book says every 6 months or 6K miles whichever is sooner to check and adjust as required.
That being said, I have adjusted mine 3 times in 10 years of ownership with about 2500 miles between checking them. They were all about right on each time I checked them. I have had no problems with my engine that was rebuilt in 1996 by the prior owner.

Others can chime in but with the way we drive these cars(most of us)I think it would be tough to comply by the letter of the law!

Cheers,
 
When they get a little noisy
 
I pretty much agree with the above, but I just want to relay my experience with a current high performance engine that requires periodic valve adjustment.

The 2000 - 2008 BMW S-54 3.2 Litre I-6 with continously variable intake/exhaust cam timing, 4 valves/cylinder, 11.5:1 compression ratio and 6) individual 50mm throttle bodies requires a valve check/adjustment at approximately 20 - 30k miles (service interval is computed by fuel consumption). I find MORE engines where the clearance has lessened than grown, as you would see from component wear. The only explanation that I can come up with, is that sustained high RPM is causing the valve stems to stretch.

Remember, loose valves won't cost you money, but tight ones will! The ONLY time an exhaust valve gets any cooling, it when its touching the seat, disipating heat to the cylinder head. The tighter the clearance, the less time it touches the seat. Intake valves get a cool blast of air/fuel every time it opens, so much less of a concern.

Behold a glorious engine...

The engine in my gray car:

01tck_003.jpg


Adjusting valves on a customer's car:

IMG_0006.jpg
 
I just adjusted my valves to .015" cold and I still have a ticking sound, is it somewhat "normal"? Other than a slight ticking the motor runs great and I have no idea how many miles since it was rebuilt.
My initial measurements were:
1 .011"
2 .010"
3 .013"
4 .012"
5 .011"
6 .010"
7 .011"
8 .011"
9 .013"
10 .010"
11 .013"
12 .010"
 
With all due respect I believe some of the posts are treating the valve train in a cavalier fashion and going here may give some food for thought: https://www.enginelabs.com/engine-t...ech-lash-is-much-more-than-just-a-little-gap/

On race cars with pushrod engines I generally do the valves prior to each event. On the Healey I probably run them twice a year. My time costs me nothing, something that cannot be said for parts.
 
Say Randy, wouldn't valve seat wear also cause the valve adjustment clearance to get smaller. I knew of a fellow with an MG that was trying to get home (over 1000 miles away) to replace his cylinder head. He had such bad valve seat recession that he stopped along the way, took his rocker shaft off, and filed the tops of his valve stems to get enough clearance to keep the engine from running poorly. When he first took the valve cover off he had near no clearance on many of his valves. Gave each valve a little bit of a hand fileing to just get perceptible clearance, put everything back together and drove the rest of the way home.
 
I agree with the Michael 50%. When I was a racer I adjusted the valves every event. On the other hand on my solid lifter Corvette the valves get adjusted every 12 or 15 thousand miles (and they are never off by more than a mil or two) !
 
CessnaTPA said:
I just adjusted my valves to .015" cold and I still have a ticking sound, is it somewhat "normal"? Other than a slight ticking the motor runs great and I have no idea how many miles since it was rebuilt.
"
Click to expand...

I rebuilt my engine in 2013 and set the tappets to 15 thou cold - my engine ticked too and still does. I have a racer brown cam in mine and somewhere down the line either no. 1 or no. 12 lobe ( I should have made a note) got mashed and was built up and reground, this could be the cause of my trouble. Other than that the engine runs real smooth and I have just put over 700 miles on it a week and a half ago driving from Portsmouth to mid Wales and back without a hitch.

:cheers:

Bob
 
I doubt that its possible to file valve stems to get clearance .....any way ignoring that do them once a year irrespective of mileage. Its essentially free insurance. Beware a silent valve train...
alve train
 
haasad, you shouldn't doubt fact. If you file anything you will get clearance.
 
Should have been clearer, I agree removing metal from the stem of a valve would increase clearance however I'm skeptical that the process of hand filing would be successfully due to the relative hardness of the valve stem and a normal hand file.
Is that better put.:encouragement:
 
Haasad, I am sorry that I was not quite clear enough also. The individual used a 12v powered dremel tool of sort which he carrys in his tool kit. I saw a picture of him doing it and then later their was a picture of the valve seats after the head was removed at the end of the trip. The seats were visibly mashed into the head.
 
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