Valve gap help

[piper]

I feel like a dummy

 

 

 

Can some one help me I am having a hard time trying to work out what shims do I buy to give me the clearance of (I want to keep them on the tite side) to save the valvs I have cam were

 

Inlet .11 to.15 Exhorts .16 to .2

 

Gap ..... 0.08.. ... 0.09..... 0.19....... 0.18

Shims....2.278... 2.282.... 2.275 .....2.278

 

Thanks

Edited June 7, 2009 by piper
fix numbers

[Squeeze]

............Gap ..... 0.08.. ... 0.09..... 0.19....... 0.18

..........Shims....278... ....282........275 .......278

....new Shim... 270.... 275 ......OK.......OK

 

Calculatting is easy. You have a Gap 0.08 and a 278 Shim, the Goal is 0.15 Gap, Difference between 0.15 and 0.08 is -0.07. So, you subtract 0.07 from 278 which is in at the Moment and come to 271, there's no 271 Shim, so you choose 270. It's better to keep the Valves on the loose Side. The Clearance will get tighter on it's own.

[piper]

Thanks Squeeze

[RandyR]

............Gap ..... 0.08.. ... 0.09..... 0.19....... 0.18

..........Shims....278... ....282........275 .......278

....new Shim... 270.... 275 ......OK.......OK

 

Calculatting is easy. You have a Gap 0.08 and a 278 Shim, the Goal is 0.15 Gap, Difference between 0.15 and 0.08 is -0.07. So, you subtract 0.07 from 278 which is in at the Moment and come to 271, there's no 271 Shim, so you choose 270. It's better to keep the Valves on the loose Side. The Clearance will get tighter on it's own.

 

Why do the clearances get tighter please? One would think that as parts wear, they would get looser.

 

thanks in advance

[Rottdoglover]

Why do the clearances get tighter please? One would think that as parts wear, they would get looser.

 

thanks in advance

Heat will expand metal thus reducing clearance. Also valves will wear down the face and seat area allowing the valve stem to move closer to the tappet. This also reduces clearance. Hope this helps explain why clearances DECREASE with wear.