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Valve clearance question

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wkilleffer

wkilleffer

Jedi Knight
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I tried to do a valve clearance adjustment last night, and ended up getting the clearance too loose. Barney Gaylord of mgaguru.com responded to my question on how to do it properly with an interesting, and potentially time-saving idea.

He said that the clearance can be adjusted according to the rule of nine as long as one of the valves in the equation is partially open. Then, to adjust the closed one, loosen the jamb nut, rotate the pushrod and tighten the adjusting screw until the pushrod won't turn anymore, then back the adjusting screw off a quarter turn. He said this gives a very near .015 clearance, then tighten the jamb nut.

His website sounds like this is a rough but serviceable method, but the email he sent was of the tone that this would work very well for an MGB engine.

Has anyone tried this for themselves, and would it work if the engine is still warm? Any advice would be appreciated.
Thank you,
 
Works great - only way to do it!
 
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Works great - only way to do it!

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I was hoping for such an endorsement. My car's still a bit warm, so I'm hoping that won't be too much of problem.

After this, maybe I can balance and adjust the carbs.
 
Sounds like the way to do it, fealer gages are for kids, hehe.
 
[ QUOTE ]
Sounds like the way to do it, fealer gages are for kids, hehe.

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I did it when the car was still slightly warm. It still clatters a bit, but not nearly so much as it did this morning. I'm hoping all is well.
 
When I use a feeler guage, I always get them too tight - & you want MG valves a little loose anyway.
 
Hard to hear the clatter from here, rev it up a bit.

It should clatter just a bit, is that with the cover on or off? Cover off should chatter some.
 
That's with the cover on. It's noticeable, but not deafening like earlier.
 
Sounds like you got it rev it again, ahhh, yep sounds good.
 
I take it that this is a better method than feeler gauges? I had a post in regards to adjust this valves & I don't remember this tip so I used the feeler gauge.
Are you only turning the push rod to determine when the adjusting screw is seated atop the push rod?
I take it that the 1/4 turn out is about .015"?
 
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I take it that this is a better method than feeler gauges? I had a post in regards to adjust this valves & I don't remember this tip so I used the feeler gauge.
Are you only turning the push rod to determine when the adjusting screw is seated atop the push rod?
I take it that the 1/4 turn out is about .015"?

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It's quicker than feeler gauges. Barney said that 1/4 turn was about .015.

I may have to do mine again, maybe even the "correct" way, as it sounds like one or two might be louder than the others. The noise didn't get much quieter once the engine was warmed up.
 
I don't like this whole "about" thing. A small amount of turning can through it off a thousandth or two. Why not check it with a feeler gauge? Also, it's difficult to tell when the valve is exactly at its widest point which could through it off another little bit. I can't see getting them all even this way and don't see any reason to not use a gauge when it's sitting five feet from my car.
 
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I don't like this whole "about" thing. A small amount of turning can through it off a thousandth or two. Why not check it with a feeler gauge? Also, it's difficult to tell when the valve is exactly at its widest point which could through it off another little bit. I can't see getting them all even this way and don't see any reason to not use a gauge when it's sitting five feet from my car.

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The funny thing is that in the email Barney Gaylord sent me on the subject, he showed the calculation on how to arrive at 1/4 turn back after the pushrod won't turn anymore. He said it's all about the thread pitch on a stock engine. He does it this way, and Tony said he's done it as well. But I think it's only good on a cold engine. His website says it's a good way to get home and fine-tune later. I'm going to use a feeler gauge to adjust the clearances according to the hot engine specs. Nothing wrong with using one, but some people, myself included at times, like to do things quick and simple with a minimum of tools. It works if you really know what you're doing most of the time.
 
I'm the culprit - & I don't use a timing light either. But I know I should use both feeler guages on valves and timing light when setting timing.

I just always tighten the valves down too tight when I use a guage...however, its not a bad idea to check with guage after everything is tightened.

...& a timing light is just too much of a hassle when I can hear if its right.
 
yeah... I found out the hard way, that if you set the valves too tight you'll burn out a catalytic converter faster than it takes for the engine to warm up completely.... /ubbthreads/images/graemlins/nonono.gif
 
The best time to check your work with a feeler gage is when the engine is running.
 
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....& a timing light is just too much of a hassle when I can hear if its right.

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This come with lots of experience which I hope to gain by learning from you guys. I "hear" that a lot with owners and their cars that you need to listen to every area of the car to determine what is right.
I can tell you with my personal truck (owned since new) that I can hear or feel when things ain't right. The GT on the other hand being close to 40 years old, I do not have the knowledge of what it may have sounded like new.
 
A good LBC engine/car sounds happy. No clue as to how to explain it, it just is.
 
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The best time to check your work with a feeler gage is when the engine is running.

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WHAT?!?!? Surely you jest!

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A good LBC engine/car sounds happy. No clue as to how to explain it, it just is.

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I couldn't agree more.
 
Rockers? What are rockers?

Real MGs don't have rockers, they have cam followers, don't they? /ubbthreads/images/graemlins/jester.gif

(Much harder to adjust, I grant you)

MGA_engine_compt.jpg
 
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