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Author Topic: Are valves like tires?  (Read 1076 times)

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Offline Tugboat

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Are valves like tires?
« on: August 14, 2012, 08:00:07 PM »
If you have to replace one, should you replace the opposite one too?
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If it's worth doing, it's worth doing twice.

Offline Doctor_D

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Re: Are valves like tires?
« Reply #1 on: August 14, 2012, 08:08:12 PM »
No, they're not balanced in that way.  Very small amounts of material are removed or worn-off in maintenance or wear.

But Kibblewhite valves are nicer than stock, good-modern valve-work is an improvement over stock, and you've done almost all the work necessary to do the job -- so why not do it while you're in there?
« Last Edit: August 15, 2012, 09:53:20 AM by Doctor_D »
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Offline shinyribs

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Re: Are valves like tires?
« Reply #2 on: August 14, 2012, 09:51:10 PM »
Do you mean engine valves or tire valves? If you mounting new tires i'd definitely replace the valves. I could be completely confused though...again...
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Offline Tugboat

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Re: Are valves like tires?
« Reply #3 on: August 15, 2012, 08:45:05 AM »
Engine valves, sorry.. just wondering if you should replace them in pairs.
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Offline MCRider

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Re: Are valves like tires?
« Reply #4 on: August 15, 2012, 08:50:15 AM »
Quote from: Tugboat on August 15, 2012, 08:45:05 AM
Engine valves, sorry.. just wondering if you should replace them in pairs.
First, I see no need to replace tires in pairs. Never have.  Usually get 2 - 3 rears to a front.

As to valves, you mean the Ex/IN pair? per cylinder?

Again, no reason to replace as a pair as long as its the match to its kin. (Although that's probably not a big deal either) Like an OEM Intake valve should be replaced with an OEM intake valve to match the others. Leave the Ex alone and either or.
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Offline lucky

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Re: Are valves like tires?
« Reply #5 on: August 15, 2012, 10:52:00 AM »
Quote from: Tugboat on August 14, 2012, 08:00:07 PM
If you have to replace one, should you replace the opposite one too?

If one valve is bad you may have to replace all of them depending on the milage and condition of the valves and guides.
And they are sort of like tires because they all start out life together in your engine.
You would not benefit by having one set of new valves in one cylinder and the other three cylinders all have 30,000 miles on them.

But the amount of wear on the valve and the condition of the valve guides is also a determining factor.

If I had the engine that far apart I would put in new guides and all new valves.

IF the engine only has 10,000 miles on it and one cylinder had been running lean and destroyed a exhaust valve, then I would just replace those two valves.

Consider all of the factors. Make sure to measure valve wobble in the guide with the valve springs removed.


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