Honda-SOHC

Other Stuff => Misc / Open => Topic started by: McCabe-Thiele (Ted) on December 17, 2021, 04:40:54 PM

Title: I'm loosing my numeracy mind on valve clearances!!
Post by: McCabe-Thiele (Ted) on December 17, 2021, 04:40:54 PM
Failing to Plan is Planning to Fail - so whislt I'm messing with my front wheel in the daytime - my mind started to wander into valve clearances come bedtime.

I've looked in the manual - it gives Inlet & Exhuast for a 400 engine as 0.05mm or 0.002 ". I haven't spotted the words Hot or Cold engine anywhere.

My feeler gauges - I have imperial & metric are probably 50 & 30 years old respectively - I can't read any numbers due to deterioration over the decades except on the never used thick ones - note to self buy replacements.

I thought okay I understand 0.002" it's two thousandths of an inch in words - I'm used to bigger gaps like 12 thousandths on a car. So 0.002" is the thickness of some medium grade paper.

Stupidly I then said to myself naaah it's got to be 20 thou surely - then I looked at the decimal and though no 20 thou is actualy 2 hundreths of an inch.

At 0.002" I'm amazed you can hear a tappet rattle at all - its close to naff all as gaps go.

Does this look suitable or will it be too wide ?

https://www.ebay.co.uk/itm/114686642402?hash=item1ab3db48e2:g:UH8AAOSwUylgKybE


 
Title: Re: I'm loosing my numeracy mind on valve clearances!!
Post by: smoothoperator on December 17, 2021, 05:17:56 PM
I'm pretty sure valve clearance applies to cold engine Ted. My old feeler gauges have fortunately kept their markings. I used the method of tightening the adjusters with the 3 thou gauge in, then when you remove the feeler gauge it is actually closest to 2 thou. I've done this on cars and bikes before and found that they tend to get too small a gap when tightened using the actual gap gauge, if this makes sense. Either way I wouldn't buy just a single gauge as you get a better measure of the gap by trying 1 thou up and 1 thou down to "feel" the gap. It does feel weird setting such a small gap.
Title: Re: I'm loosing my numeracy mind on valve clearances!!
Post by: Bryanj on December 17, 2021, 06:03:21 PM
The pitch of the thread on the adjuster is 1mm so 1 full turn is 40 thou 1/8 of a turn is 4 thou
Title: Re: I'm loosing my numeracy mind on valve clearances!!
Post by: Oddjob on December 17, 2021, 07:54:00 PM
To confirm Ted, it's 2 thou cold.
Title: Re: I'm loosing my numeracy mind on valve clearances!!
Post by: McCabe-Thiele (Ted) on December 17, 2021, 09:28:48 PM
Thanks for that Steve, Ken & Bryan.
Title: Re: I'm loosing my numeracy mind on valve clearances!!
Post by: royhall on December 18, 2021, 10:44:00 AM
Ted get yourself some 2 thou shim steel online. You can then cut and bend a piece to suit. Makes the job way easier and you get enough on the length to make about 6.
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