Seems to me like 18ft-lbs is the correct spec.

 

basic first thing is that when a shim is put under the pedistal rocker... THIS LOOSENS THE PUSHROD EVEN MORE.... so, if it spins now with no shim..adding a shim will make it even looser...!!!!

pushrod "spin" is actually not the correct mannor...

what you need to notice is the amount of lifter depression or preload....

 

what you need to notice is the amount of lifter depression or preload....

Are you suggesting to break out a dial indicator and measure lifter preload as you tighten the rocker down? Never considered doing that, but my car only has to take me to and from work. I trust my senses to tell me when I've reached the zero lash.

 

I know shims will loosen the pushrod i'm not stupid lol. The reason I was asking about the shims is because when my rockers are torqued down to 15 ft lbs with valves closed I can't get the pushrods to budge trying to spin with my fingers they're tight. I am junking the proforms that came on my engine for a set of crane 1.6's that come with shims unlike the proform junk. So I will just read the instructions when I get them. I was under the impression that with properly adjusted rockers you should be able to spin the pushrods with a good amount of drag on them, I realize you wouldn't want them to be really loose in there.

 

you TOTALLY MISS THE POINT...!!!!

the pushrod has to be checked for proper length FIRST,...
... and then,
you have to put it in and make certain that when YOU START to tighten down the bolt that the PLUNGER only depresses .030"... the plunger is relaxed and "up" when there is no pushrod load on it.


...and naturally, the cam lobes have to BOTH be on the base circle.

when people describe that the pushrod "does not spin" ...the issue could be that the plunger is allready bottomed out... or that there is oil in the lifter keeping the plunger from depressing at all or any amount.

your pushrods could be allready , ALLREADY TOO LONG to begin with....!!!!

 

Actually I got your point, shims will only make the pushrod looser. I do realize it's important to have the correct length pushrod to begin with. In my situation I bought my engine as a long block and assuming the correct length pushrods were used I was thinking about shimming to get the correct adjustment. I am going to be starting over fresh with new rocker arms so I will need to figure out the pushrod length afterall. Not looking forward to this because I don't want to take my lower intake off again!

 

buy a pair of adjustable pushrods and remove the lifters and make a pair of them into solid with washers inside.

there are many posts that detail the procedure...

 

Yeah I know, I really don't want to take my intake off and drain coolant into my fresh 7 quarts of royal purple! I wish I could put this off for a couple thousand miles lol. With my current setup heads rocker arms and everything the pushrods are the same length as a stock replacement I got from the parts store. I'm wondering if these stock length pushrods will work with a new set of crane rockers. These will be a different brand but will be the same 1.6 ratio 5/16" pedestal mounts as the current proforms. I want to do it right but need to get this car driveable asap beings it is my only mode of transportation at the moment.

 

Spinning the pushrod has nothing to do with anything - unless one just likes spinning pushrods....

Preload can be measured with a dial indicator -- but the reason the proper pedestal (and that's the proper spelling of that word) installation procedure involves counting the number of turns of the bolt until the proper torque is reached (between 1/4 and 1 turn) is because that translates based on the thread pitch of the pedestal bolt to the proper amount of lifter preload.

It's easy -- there is only adjustability via shim to account for pushrods that are too long. If they're too short, you have to buy new pushrods. Put the lifter on the base circle of the cam for the rocker you're installing. Tighten the rocker bolt with one hand while rocking the rocker with the other. Stop tightening when you've just barely gotten to the point that the rocker won't rock because there's no gap on either side -- you've reached 'zero lash'. At that point put your torque wrench on the bolt and tighten to 18-20 ft-lbs. while simultaneously counting the number of turns of the bolt it takes to reach that torque -- again, START YOUR TORQUING/COUNTING AT ZERO LASH. If it reaches the specified torque within 1/4 to 1 turn, you're done, and pre-load is in a reasonable range. If it takes more than 1 full turn to reach the torque, then your pushrod is too long and you can shim the rocker up -- each .030" shim reduces the number of turns by about 1/4. So, if it took you 1 1/2 turns, you're likely gonna need at least .060" worth of shim to get the rocker high enough to work with that pushrod. If it takes less than 1/4 turn, or you can't reach zero lash at all, then your pushrods are too short and the only solution is buying longer pushrods.

All this procedure does is assure you have the correct pushrod length to be able to set lifter pre-load appropriately. It has absolutely nothing to do with establishing optimum valvetrain geometry.

If you want to do that, go to www.mid-lift.com and study up. With pedestal or stud mount rockers, if the contact tip isn't pretty close to being centered over the valve stem tip -- there's not a lot you can do short of repositioning the holes in the head where the studs/bolts screw in. As for achieving maxium lift at the valve relative to the what the cam's trying to achieve -- you have to play with the height of the rocker and the way it arcs through contact with the valve. Most pedestal set ups will have to have the rocker arm raised up quite a bit to achieve optimum. You can play with this simply by putting your dial indicator over the valve stem end of the rocker, installing an adjustable pushrod, and playing with shims under the rocker arm. Simply adjust the height until you're achieving the maximum peak lift at the valve that you can. You might have to raise the pedestal at tenth or two to achieve optimum lift at the valve - that will require custom shims to go UNDER the rocker channel, as well as custom length pushrods.

For what this guy wants to accomplish -- just follow the installation procedure above. And please, everyone, forget everything you ever heard about twisting pushrods. It has nothing to do with anything.

 

actually mikey,


.....I think that the spin the pushrod thing is from when we used to use solid flat lifter s and cams....
and it still is one of the mannors that some use to check preliminary adjustments..

but for a hydraulic lifter of any type,...it does not work...unless the operator has years of experience and can feel what is actually happening.

 

I don't think I have a problem telling when I've tightened the pedestal to zero lash by spinning my pushrod. All I'm feeling for is the slightest change in drag. I'll try the mic next time, but only on one set per side.

 

I know Kato - I'm not talking about adjustable flat tappets -- I'm talking about THIS engine.

 

the reason that i brought this up was because someone now is telling some to use the process on a hydraulic lifter....

 

I know - you're right....

 

Butt shark. ;-) Why aren't you correcting his grammar and spelling too? (Michael, if you can't see the humor in that <-, then I apologize in advance)

I've removed all the offending tech. But I swear, if you can't tell when you've reached zero lash while feeling the pushrod on a pedestal mount rocker, you have no business removing the valve covers in the first place.

 

It's all funny noslo - especially the part about not removing the valve covers in the first place....

Oh - and in England it's 'apologise'.....

 

Oh - and in England it's 'apologise'.....

Doh!