Lister Engine Forum

Lister Engines => Listeroid Engines => Topic started by: tyssniffen on October 19, 2019, 07:42:02 PM

Title: rocker spacing - distance from rocker to valve top
Post by: tyssniffen on October 19, 2019, 07:42:02 PM
I know there's specific numbers for the gap between the rocker arm and the valve top, and they're different for the inlet vs exhaust... but I can't  find those numbers anywhere. 

Can someone clue me in?
Title: Re: rocker spacing - distance from rocker to valve top
Post by: sirpedrosa on October 19, 2019, 08:05:53 PM
Hi tyssniffen

Yes I can! as long as you tell me what the brand and model of engine is.

Cheers
VP
Title: Re: rocker spacing - distance from rocker to valve top
Post by: tyssniffen on October 19, 2019, 08:09:32 PM
sorry, thought I had a signature on there.  a listeroid 6/1
Title: Re: rocker spacing - distance from rocker to valve top
Post by: tyssniffen on October 20, 2019, 05:48:25 PM

0.008 of an inch? I thought it was bigger than that. 
Title: Re: rocker spacing - distance from rocker to valve top
Post by: sirpedrosa on October 20, 2019, 11:34:09 PM
Hi tyssniffen

Take a look here: http://www.utterpower.com/lister_s.htm

Cheers
VP

Title: Re: rocker spacing - distance from rocker to valve top
Post by: listeroil on October 21, 2019, 12:22:02 PM
This is from a genuine 1971 Lister manual and shows

17 thou inlet and 32 thou exhaust for the 6/1 engine

8 thou inlet and 8 thou exhaust for the 8/1 engine

(http://listerengine.com/coppermine/albums/userpics/10039/normal_Valve_clearance.jpg)

Title: Re: rocker spacing - distance from rocker to valve top
Post by: mikenash on October 22, 2019, 06:10:53 AM
Hi there

Please see PDF attached which is a summary of some work by one of the "Masters" on here a while back

Briefly:  Valve clearances are about (a) operating clearance and (b) valve open-and-closing timing

(b) being the thing that matters as long as there's working clearance

So see PDF?  Try using the valve clearance adjustment to open the intake and close the exhaust at the degrees of rotation (timing) as per the PDF and never mind the actual clearance . . .

Others may wish to chime in?