Hey guys, im currently becoming a diesel technition and were learning how to rebuild engines. My dad's 4.9L has over 270,000 miles and needs rebuild. I took it all down and measured everything, the only thing it needed was new rod bearings, new ring gear on the fly wheel and new gaskets while i was at it. I got everything put back together, and painted the block ford blue. Just got the head on and was wondering how to adjust the valves. My chilton manual only says tighten until snug? I know i have to adjust each cylinder to TDC on the firing order, but how tight? so the rocker doesnt move? so the push rod spins alittle or not at all? Thanks for your help!
I think that the rocker pivot just comes to a shoulder on the stud and the nut may have a torque spec,but I think they may have changed pivot types,I'm not sure,I know they did on the SBV8's.So the year may help.I have never had to adjust valves on any of my Fords,8's or 6's,that's the nice thing about hydraulic lifters,they will adjust themselves to the fixed position of the rockers.They bleed down when the engine isn't running and pump up to zero lash when it's started up.I just looked it up in my Haynes '80-'96 manual and it says 18-23 ft lbs.That should do it.
Thanks, we figured it out. Im pretty sure ours are solid lifters, it is a 95. We couldn't find a torque spec. We went through every cylinder when it was on TDC and tightened it up until the rod could barely move, but could still move.
The only way it would have solid lifters,is if you replaced them,stock lifters are hydraulic.You better keep a close eye on them if you didn't torque them,or they will loosen up,then eventually a pushrod may dance out,or other BAD things.
R u sure? im pretty certain these were solid because they didn't give at all. O and i didn't mean adjusting the valves i meant setting the valves, my bad lol.
I am certain,unless someone put solids in,and I don't know why anyone would.They feel solid because they are hydraulically locked,it takes quite a while for them to bleed down.If you can push one down quick enough to even see movement,it's bad .Believe me,you need to torque the rocker nuts,if you don't,they can back off and cause you a lot of grief.I'm surprised someone else on here hasn't jumped all over this.If you don't believe me,then at least call your local Ford garage or mechanic and ask them.The spec in my Haynes manual calls for 18-23 ft lbs.
If your valve timing is correct,and it is unless your timing gears went south,you can draw the rocker nuts down with out turning the engine,as the piston is in the proper position to receive the opening valve,then,when it tightens up,torque it to spec.Hydraulic lifters were a fantastic advancement over the solid lifters,they had some problems with them in their infant years,and when the hi-pos came out in the early '60s a lot of engines used solids,but what a pain adjusting your valves every weekend.Then they came out with racing anti-pump up hydraulics and everybody lived happily ever after.Many hi-po engines were blown over miss adjusted valves or broken adjusters,usually beating the valve top off and you know where the valve went.I lost a '66 GTO 389 w/tri-power over a rocker pivot ball failure,when I pulled the heads,Iwas looking at 4 empty crank journals,busted block and it looked like someone took a machine gun to the cylinders,crank,widage tray and oil pan.I found that valve head and kept it many years,just as a reminder to never get sloppy.Never under estimate any aspect of your valve gear.There,that's the whole story.Torquing those nuts is as important as torquing your rod nuts,you can have the same results.
I am finishing up a rebuild in my 77 300 I6, the shop manual said to tighten them until the push rod no longer turned freely, then turn the nut one more full turn. Now this is with the cylinder at TDC. A friend told me afterwards they always turn 1/4, to 3/4 of a turn. He said the motor usually ran better, and was not as tight. I am leaving mine as the shop manual instructed me.
Before I got the shop manual, every person I ask gave me a different way of doing it.
PS: I don't know if this methood will work for different years or not.
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Harold
Molly Hatchet: No Guts, No Glory
^yep that's what we did on our 305 at school, tighten till rods dont move then 3/4 turn. I wasn't sure if ford called for this so i didn't tighten it 3/4 turn. Looks like im gonna do that today.
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