Date: Sun, 3 Aug 1997 23:16:40 -0700
From: Mike West <mwest@CDSNET.NET>
Subject: Re: HELP with valve geometry/lube!

>Hi all, I posted last night after a frustrating evening that started when I
>went to adjust the valves on my new engine (40hp, 83mm, single port). I can
see how the push rod oil lubes the rockers, but what abt the
>stem/guides?  I think Muir mentions assembling rocker mounting blocks with
>thte bevel out and the slot up...but my blocks have no bevel or slot!  Is
>this slot he speaks of relate dto lubrication of the valves?  Did someone
>put the wrong ones on my engine?  And what book/net resource has a good
>description of proper rocker geometry assembly?   Somebody, please HELP, I
>want to drive this for more than a few days without pulling the engine
>again!    TIA!  -Gerry


 Well,  . . . .   I have a couple posts on VTG and Rocker Arms up at

 http://www.armory.com/~y21cvb/west/darkness.html.

 David Raistrick has them on his web page.

 The rocker mouunting blocks do normally have 2 big chamfers on the
 top and bottom edges that face out. If yours don't, it's not a big  deal.
Also, said mounting blocks are split on the top side, exposing  the main
shaft that holds the rocker arms. The main shaft doesnt turn
 thru those bushings so the split can only be to get lurication to the
 ends of the rocker arm bushings.

 At best I wouldn't say it was all that necessary but I wasn't there
 when they decided to do it so  . . . . . who knows?

 From Muirs point of view, if you dont' have the bevels (chamfers)
 down on the head itself and the slots turned down relative to the
 engine you're in fat city.

 I don't have a head here in the house with me but I do have my   favorite
Rocker arms here. . . the hole in the mounting block is not
 evenly spaced from each end (symetrical) and the long side goes down.

 There is no lubrication for the valve stems/valve guides per se,
 just catch as catch can and there is even supposed to be a seal on
 the valve stem to keep oil out. Can't have oil  running down the stem
 into the combustion side.

 Bottom line: these rocker arms and guides are far from perfect in
functioning forever. Bentley recommends 25k miles as life of heads
 for that reason. Replace standard adjusters with "swivel foots" for
 max life of vave guides.
 The valves still need replacing and seats relapped at 25 k or so.

 west

Re: HELP with valve geometry/lube!