Monday, January 9, 2012

New Pushrods & Setting Lifter Preload

I plan on taking some time each night this week to work on the Mustang.  The goal is to have all the small things done by the end of the week so I can try to start the car on Saturday.  I'll then have Sunday to fix any issues or get the car inspected.

My Comp Cams Magnum pushrods (#7634) arrived in the mail today.  Pushrods are not normally something to get excited about but these seem very well constructed.  They are a one piece,  5/16" .080" wall, chromemoly pushrod which works with the guide plates installed in my Edlebrock E-street (#5025) heads.  I rolled them all on a flat counter to make sure they were straight, looked through the oiling hole of them all to make sure there was no blockage, and then cleaned them all with the Crown mineral spirits.  Suprisingly, a large amount of dirt and oil came off these new parts.


I removed the intake I temporarily installed to install the lifters, pushrods, and rockers.  The lifters have set in a bowl of 5w30 Pennzoil for six days straight.  I took them out of the bowl and set them in the lifter valley of the motor with the cam surface facing up.  This allowed the oil to run off the surface which touches the cam so I could put on some of the Comp Cams Break-In Lube (#103). 


Once the lube was on all the lifters, I dropped them into the proper locations.  I then filled the top cup of the lifter where the pushrod sits with more of the lube.  Finally, I dropped a pushrod into each of the guide plate locations and slid them down to contact the lifter. 

I watched a few videos and read a few different ways to set the lifter preload.  The instructions varied on the amount of preload needed.  However, the instructions with my lifters stated you need a fulll turn of preload.  The process of setting rocker clearance or preload on lifters seemed so complicated until I started.  It then seemed quite simple as long as you understand the cam events.

I worked through the cylinders in order starting with the first.  I'd rotate the engine and watch the exhaust pushrod rise.  This indicated the piston was coming up in the bore on the exhaust stroke.  I'd then see the intake push rod move up and once the pushrod dropped back to the closed position, I gave the crank another 120 degree turn.  This placed the lifters for that cylinder on the base circle of the cam. 

The video I watched last suggested you loosen the guide plate at this point and turn the rocker studs until they are snug on the plate.  You then move the pushrods back and forth in the openings to ensure the guideplate was centered.  You then torque the guideplates back down to 50 ft/lbs.  The process did not seem like it did much to the alignment of the guideplates.  However, I was glad I did it as several of the studs did not seem very tight. 

I then cleaned each of the roller rockers (Comp Cams High Energy 1.6 ratio) with the Crown mineral spirits, put the Comp Cams lube on the pushrod cup and roller tip, and placed them on the rocker stud.  I tightened the polylock nut until it was no longer possible to move the pushrod up and down.  At first you can see and hear the pushrod moving.  At the end, I looked to see if moving it caused the rocker to move at all.  Once I could not move the rocker with the pushrod, I was ready to start setting the preload.

Before setting the preload, I would check the lifter and make sure the plunger in the middle was still at the top.  I would then turn the polylock one turn with a 5/8" wrench.  I then tightened the set screw with a 3/8" allen wrench.  I started with just a normal allen wrench but eventually move to one installed in a socket wrench.  This gave me the ability to torque the allen head set screw the best.

When I was done, I tried to tighten the poly lock more on each rocker.  This should not be possible if the set screw is torqued properly (no special setting just as tight as you can get it).  I was able to turn the polylock on the #1 cylinder so I redid those. ( I actually then checked them all two days later to make sure they did not loosen for any reason and they did not).


The job was finished up at near 10 o'clock at night.  I took my time and tried to do it as perfectly as possible.  If you are not paying attention, you can forget to torque a rocker stud so I checked all of those again.  You can also forget to turn the trunion the correct way beofre installing the polylock so I checked that as well.  Once I was sure everything was properly installed, I covered the lifter valley with plastic and called it a night. 

Those reading along as I throw all these new parts at my motor likely think I have more money available than I really do.  Turth is, I have a hard time doing things half way.  I don't have much money and have just really overextended myself with this motor build.  I had not even intended on rebuilding it when I pulled it out.  You just nickle and dime your way until you are damn near broke on these cars. 

As I worked on the engine tonight, it seemed somewhat unreal.  I've watched them build motors with these same parts on TV but never thought I'd really be able to pull the trigger and do it myself.  Now that I am, it really does not seem real yet.  I don't know that it will until I turn the key and start it up.

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