[Roadsters] Valve Adjustment hot or cold ?

[James Culp]

A little background...
The clearance values in the manual are based on OE equipment and design, the
associated coefficient of linear expansion of engine components and the valve
opening/closing duration.  You'll see in most engine applications the exhaust
valve clearance is greater because it usually gets hotter than the intake and
in turn grows in length more than the intake. Theoretically, if duration was
not being factored, the hot adjusted valve clearances would be the same for
both intake and exhaust.  When you replace OE components with newer or
different technologies the material is different and so is it's coefficient of
linear expansion.  No worries though since these different expansion
properties would be negligent unless you replacing a steel valve with one made
from vinyl siding.


Sent from VZ iPhone

On Jun 20, 2011, at 12:07 AM, "Gary and Cindy Ault" <aultgc at att.net> wrote:

> Bob,
>
> The specs below are from the Nissan factory manual, FWIW.
>
>   1600:  Intake      0.017"
>              Exhaust:   0.017"
>
>   2000:  Intake      0.008"
>              Exhaust:   0.012"
>
> Gary
>
> ----- Original Message ----- From: "robert k. smith"
<rksmith46 at hotmail.com>
> To: <pauljsouza at yahoo.com>; "roadster list"
<datsun-roadsters at autox.team.net>
> Sent: Sunday, June 19, 2011 4:21 PM
> Subject: Re: [Roadsters] Valve Adjustment hot or cold ?
>
>
>> hi paul, hot is the best, but you need to finish adj.  in 20-30 min. max.
>> the reason being, the clearance starts to change as the engine cools.
>> if you take too long, the last valves adj. will be looser.
>>
>> best of luck    bob smith, ohio
>>
>>  btw, cold engine(u-20) is .006 int.,.010 exh.,
>> and, i dont think that a reb. eng. has diff. valve settings, unless
>> the cam is after market, reground, and the manufacturer specifies
>> a diff. clearance.
>>
>>> Date: Sun, 19 Jun 2011 09:24:38 -0700
>>> From: pauljsouza at yahoo.com
>>> To: datsun-roadsters at autox.team.net
>>> Subject: [Roadsters] Valve Adjustment hot or cold ?
>>>
>>> Hi Everyone,
>>> How does everyone adjust their valves.  Hot or Cold ?
>>>
>>> What settings do you use?
>>>
>>> Cold engine: Intake 10 thousands and 12 thousands exhaust ?
>>>
>>> I am hearing never adjust cold.
>>> I am also hearing engines that are rebuilt have different settings.
>>>
>>> Please share what you do.
>>>
>>> Thanks,
>>> Paul
>>> 69 2000
>>> Vacaville, CA
>>> ________________________________________
>>>
>>> datsun-roadsters at autox.team.net
>>>
>>> Donate: http://www.team.net/donate.html
>>> Archive: http://www.team.net/archive
>>> Forums: http://www.team.net/forums
>>> Unsubscribe:
>>
http://autox.team.net/mailman/options/datsun-roadsters/rksmith46@hotmail.com
>> ________________________________________
>>
>> datsun-roadsters at autox.team.net
>>
>> Donate: http://www.team.net/donate.html
>> Archive: http://www.team.net/archive
>> Forums: http://www.team.net/forums
>> Unsubscribe:
http://autox.team.net/mailman/options/datsun-roadsters/aultgc@att.net
> ________________________________________
>
> datsun-roadsters at autox.team.net
>
> Donate: http://www.team.net/donate.html
> Archive: http://www.team.net/archive
> Forums: http://www.team.net/forums
> Unsubscribe:
http://autox.team.net/mailman/options/datsun-roadsters/james-culp@charter.net