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RE: rocker shafts, and new vs old style rockers



> So what can be done about it?  (rocker shafts) Well of course the shaft
could be >replaced if  you can find one.  I'm not saying they aren't
available through current
> Navistar heavy or light truck dealers or maybe Light Line of LA... I
haven't
> checked.  Heck, NAPA may be able to order one for all I know.  

I checked into this recently.  NAPA said they didn't have rocker shafts
available.  Scout Pro did have the shafts and rockers available, but I
thought the price was ridicules.  (Something like $94 per shaft, and $15
per rocker, = $428 for a new valve train).  

>But as Digest member Rik said, if you have access to both styles of
rocker arm >assemblies (folded metal and boat), you can swap shafts
between the two types to >yield a wear free contact point for the old
rockers.  This is because the shafts
> (which are functionally identical) must be turned over when swapping
between
> the two style rocker arms.  The boat style rockers assemblies must have
the
> oil holes on the rocker shaft pointed down, and with the folded metal
it's
> just the opposite... pointed up.
>
> John L.

John, your timing on this post was perfect.   I'm using two sets of boat
style rocker assemblies to make one good set.  All four shafts had wear,
and I originally wanted to replace them (until I heard the price).  After
your post, I disassembled a set of old style rockers I had laying around,
and found no wear on the side of the shafts that the boat style rockers
will ride on.  It's like having two new shafts for free.  The lack of
wear on these shafts will also help take up some of the excessive play in
the valve train.

>>Do you know of any
>>advantages of new vs old style rockers?
>
>Not really.  The boat style seem to be less complicated and more sturdy
to
>me.... and less likely to clog.  The older folded metal style have oil
>channels pressed into them and conceivably they could clog up. 

I think I recall Bill Thebert saying he went to the boat style rockers
after breaking one or more of the "cups" that retain the push rod on the
old style rockers.  (Of course, most of us don't have 9.5 to 1
compression and use are Scouts for truck pulls).  Bill, was this correct?

I have both sets, and decided to use the boat style rockers for their
extra strength.  
Also, after disassembling both type of rocker assembles, I agree that the
older style would have a greater chance of clogging and creating
problems.  The older style assemblies didn't have the freedom of movement
as the boat style rockers.  It took more effort to move the rockers on
the shafts, which equals more friction, more wear, more chance of
breakage, and less power.  Of course, with normal use and good
maintenance, they'll probable last forever.  I just liked what I saw in
the boat style rockers after comparing the two types.

Take care, 

Mike Ryan
1977 Scout II, 304 (soon ported 345), automatic, Dana 300, 3.54 gears,
4" superlift springs, 1.25" body lift, 33 X 12.5 Swamper TSL Radials

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