Pushrods length


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By RayCarter18 - 11 Years Ago
I just went out and checked my pushrods and all were straight except one it is bent just a little is the an allowable amount I am guessing if it is bent a little it will bend under pressure. I have another pushrods but it is about 1/16 inch longer than the rest. Will that affect anything or will the rocker arms just adjust to take up the extra length ? Also when adjusting the cold valve lash what are the clearances and how do you know with all the rocker arms loosened up when the piston is at top dead center?
By NoShortcuts - 11 Years Ago
Ford used the solid steel 'knitting needles' for pushrods from '54 'til (?) 1960 (?).  Anyway, you didn't have to be pushing the engine to bend a pushrod.  Ford went to tubular pushrods because of it.  Consider replacing what you've got, Ray, IF they're the knitting needles...

From John Mummert's web site...  http://www.ford-y-block.com/valvetrain.htm         

PUSH RODS

PART # DIAMETER MATERIAL FOR HEADS Overall length
PR-1221 5/16" Steel 54-55 8.320
PR-1223 5/16" Steel 56-59 8.125
PR-1221 5/16" Steel 60-64 8.320
PR-1221 5/16" Steel Aluminum 8.320
PR-CUSTOM 5/16" Chrome moly   Specify
By NoShortcuts - 11 Years Ago
Ray,

IF you have the '54 through '59 length pushrods, I'll be glad to send you used original ones.

Use the Forum email or PM function to send me your address information.

Glad to help.  Smile
By RayCarter18 - 11 Years Ago
Mine is a 63 will the extra I have that is about 1/16 longer will that work? Also what about setting the valve lash what's the process?
By NoShortcuts - 11 Years Ago
It's interesting that the '60-'64 pushrods are the same length as the '54-'55 y-block pushrods per JMs chart.

I've got both lengths of the earlier style solid steel 'knitting needles', Ray, but none of the later tubular style to offer you.

I don't know about the appropriateness of using the longer length pushrod you've got as a substitute.  As you noted, there is the adjusting screw on the rockerarm to provide leeway for assembly variations, BUT.  The whole issue of rockerarm (valvetrain) geometry is what we're dancing with here.  I've always used 'what-you're-suppose-to-use' for the application and never gotten into the nitty-gritty of it as you do if you're building something that's going to be a serious performer and operate at raggedy-edge rpms.

Ted Eaton has an interesting article on this stuff on his web site.  See
http://www.eatonbalancing.com/blog/2007/12/10/rocker-arm-geometry/
and also his second article
http://www.eatonbalancing.com/blog/2007/12/10/altering-rocker-arm-ratio-by-varying-the-length-of-the-pushrods/

I've used the procedure found in old Ford shop manuals and the Motor's manuals I've got for initially adjusting y-block rockerarms prior to start-up .  Basically it has to do with properly positioning the crank damper so that you know certain cylinders are in the position so that both the intake and exhaust valves are closed.  There are multiple steps to the process that I haven't done enough times or recently enough to rattle off from memory.

I'll try to get this written-up for you tonight.  -Doing lunch at the moment.  Maybe someone else will be able to point you to this info. in the Forum archive.
By charliemccraney - 11 Years Ago
As long as the pushrod fits and allows for the clearance to be adjusted, there will be no real problem using it.

To adjust, I put the damper at tdc and start at either #1 or #6, whichever is on compression and follow the firing order from there.  To get started, You can probably tell which is at tdc on compression by looking at the height of the pushrods relative to the head.  The ones that are lowest should be the one you need to adjust.
By Ted - 11 Years Ago
RayCarter18 (8/19/2014)
....Also what about setting the valve lash, what's the process?

Here is the link to a past thread regarding some of the various valve adjustment procedures.

http://forums.y-blocksforever.com/FindPost8614.aspx