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newb doing a valve adjustment...

Old 04-17-2013, 03:19 PM
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Red face newb doing a valve adjustment...

Ok, this may be a stupid question, or I may have missed my answer when I was looking through the knowledge base threads.

If I'm shimming my valves (because I had the carbs off and did the APE CCT mod) and I want them to stay in spec longer which end of spec do I go too, bigger gap or smaller gap?

My left brain tells me I should make the gap the bigger end of spec cuz the valves stretch over time? Am I way off? Should I just make it dead on and check again in 20K?

Thanks guys! doing this myself is letting me avoid a 3 week wait at the shop.(and saving cash!)


PS: If you know any good ways for me to skip I-77 going from Rock Hill to south Charlotte PLEASE share..
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Old 04-17-2013, 03:30 PM
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Slightly bigger gap as you said (but dead on would be my personal preference). As the valves wear into the head/stretch, they close the gap between the cam buckets and the cams.

Keep it in spec and keep them consistent!
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Old 04-17-2013, 05:26 PM
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Thanks for the quick response!
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Old 05-28-2013, 05:34 PM
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Damn. I need to tackle this as well. I just got a quote for $600 to get it done by my mech. Fuuuuuuuuuuuuuuuuuuuuuuu......
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Old 05-28-2013, 06:21 PM
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You would want them loose as they will tighten up but it's not because they stretch. The seat and valve faces wear causing them to recess further into the head and thus making the lash smaller as they wear.
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Old 05-28-2013, 06:52 PM
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Originally Posted by GTS View Post
You would want them loose as they will tighten up but it's not because they stretch. The seat and valve faces wear causing them to recess further into the head and thus making the lash smaller as they wear.
Perfect response...

Thought for me loose means the loose end of the spec.... NO MORE than that.. And as you are limited to adjustments via available shim thickness.. you get as close as possible and live with it.
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Old 05-28-2013, 10:56 PM
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Are there any detectable signs of valves misalignment?
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Old 05-29-2013, 04:50 AM
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Originally Posted by Killemall View Post
Are there any detectable signs of valves misalignment?
"misalignment" Do you mean mis adjustment?
As a misaligned valve would be a bent one...and the signs of that are valves hitting piston.

If you meant misadjusted... like you made them too loose? Sure, loud clacking sounds.. Too tight poor running to no start.

If you did not mean mis adjusted, but just out of spec by wear from use...
Then as they get tighter from normal wear.. there is no performance difference until the running clearance is zero or less .. then you get runnability issues and eventually a no start.
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Old 05-29-2013, 08:42 AM
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Originally Posted by GTS View Post
You would want them loose as they will tighten up but it's not because they stretch. The seat and valve faces wear causing them to recess further into the head and thus making the lash smaller as they wear.
To be fair to both of you, I did say wear into the head (as well as stretch), so I wasn't completely wrong. Also, from what I've read, valves CAN stretch, it's just not often and adjusting valves to spec is to compensate for wear most of the time.

I also said keep it in spec after agreeing that loose is better than tight for prolonged wear
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Old 06-01-2013, 05:12 AM
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8541Hawk adjusts them to the loose side of spec which does 2 things. Motor will make more torque for harder 60-80 roll ons and you won't have to adjust them again for a longer period of time. I trust 8541Hawk's opinion like most others do, also.
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