302 engine issues.
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Elder User
Joined: Jun 2015
Posts: 664
Likes: 2
From: York Pa.
You check the lash of each cylinder using the old procedure of turning the crank until the valves are closed. Then turn the bolts down until they take up all the gaps between the rockers, pushrods, and lifters. Then you should be able to turn the bolts about 3/4 turn to torque them down. That should push the rods about .030" into the lifter plungers. If the rods push in much more than that, you can install a shim under the pedestal. I did that recently with a newly rebuilt set of heads, and they've been running very quietly after warm up, with only a slight tick right after start up. Of course, mine are rollers, so they did not need that initial 2000 rpm for 20 minute break-in.
Hotshot
Joined: May 2003
Posts: 11,141
Likes: 25
From: south louisiana
It would help. I use a breaker bar and 15/16" socket on the crank when I do the valve lash on my 331. One quarter turn for each cylinder in the firing order. Start with #1 at TDC and one quarter turn for each till you get to #8
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Elder User
Joined: Jun 2015
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From: York Pa.
Moving at a snails pace, I have decided to remove all the rockers and examine them as well as the push rods before going through the torquing cycle. I found the #2 cylinder exhaust lash cap is wearing unevenly and the push rod rolls with a very slight wobble. So now I need to take the #2 exhaust pedestal rocker assembly with push rod to a shop that builds engines and ask their opinion on how to best handle this. I hope it's as simple as replacing worn parts. The #1 cylinder exhaust valve rocker was tapping and was the reason for opening up this whole can of worms.
Hotshot
Joined: May 2003
Posts: 11,141
Likes: 25
From: south louisiana
I would pull that lifter and see what's wrong there. Could be no oiling hole in the side. Someone in the FE big block section found a new roller lifter missing that feature.
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Elder User
Joined: Jun 2015
Posts: 664
Likes: 2
From: York Pa.
I've had the valve covers off this engine before and had a dry rocker but it was because of a blocked push rod. What ever is going on with this cylinder is something that began since the last time I had the valve covers off.
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Elder User
Joined: Jun 2015
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From: York Pa.
Okay so I got the valve lash set on all cylinders.
I have pedestal rockers and there is so much confusion as to how to torque down the rockers. My neighbor says to just tighten them down because they simply bottom out, many others seem to agree. I contacted the Ford racing tech line and the tech said to remove the rockers and watch as the push rods go up and down starting with cylinder one at TDC, when both push rods are all the way down put the rockers on and tighten the bolt by hand until all the lash (up and down play) is out between the rocker and push rod. Than torque both rockers down to 22 Ft. lbs.. He told me to just go from cylinder one to two to three etc.etc.etc.until done. All of the bolts torqued down between a 1/4 turn and just shy of one full rotation. I could shim various rockers to make them all closer to 1/4 turn, should I bother?
I have pedestal rockers and there is so much confusion as to how to torque down the rockers. My neighbor says to just tighten them down because they simply bottom out, many others seem to agree. I contacted the Ford racing tech line and the tech said to remove the rockers and watch as the push rods go up and down starting with cylinder one at TDC, when both push rods are all the way down put the rockers on and tighten the bolt by hand until all the lash (up and down play) is out between the rocker and push rod. Than torque both rockers down to 22 Ft. lbs.. He told me to just go from cylinder one to two to three etc.etc.etc.until done. All of the bolts torqued down between a 1/4 turn and just shy of one full rotation. I could shim various rockers to make them all closer to 1/4 turn, should I bother?
Hotshot
Joined: May 2003
Posts: 11,141
Likes: 25
From: south louisiana
Okay so I got the valve lash set on all cylinders. I have pedestal rockers and there is so much confusion as to how to torque down the rockers. My neighbor says to just tighten them down because they simply bottom out, many others seem to agree. I contacted the Ford racing tech line and the tech said to remove the rockers and watch as the push rods go up and down starting with cylinder one, when both push rods are all the way down put the rockers on and tighten the bolt by hand until all the lash (up and down play) is out between the rocker and push rod. Than torque both rockers down to 22 Ft. lbs.. He told me to just go from cylinder one to two to three etc.etc.etc.until done. All of the bolts torqued down between a 1/4 turn and just shy of one full rotation. I could shim various rockers to make them all closer to 1/4 turn, should I bother?
I have pedestal rockers and there is so much confusion as to how to torque down the rockers. My neighbor says to just tighten them down because they simply bottom out, many others seem to agree. I contacted the Ford racing tech line and the tech said to remove the rockers and watch as the push rods go up and down starting with cylinder one, when both push rods are all the way down put the rockers on and tighten the bolt by hand until all the lash (up and down play) is out between the rocker and push rod. Than torque both rockers down to 22 Ft. lbs.. He told me to just go from cylinder one to two to three etc.etc.etc.until done. All of the bolts torqued down between a 1/4 turn and just shy of one full rotation. I could shim various rockers to make them all closer to 1/4 turn, should I bother?FTE Stories
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Thread Starter
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Elder User
Joined: Jun 2015
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From: York Pa.
Question, I'm still working through trying to understand this whole adjusting valve lash on pedestal rockers. I was told to adjust them on TDC compression stroke and be sure not to adjust them on the over-lap stroke( I assume that's 180 degrees wrong). With the rockers removed from cylinder one I measured both intake and exhaust push rods at the completely closed position on both TDC and on over lap(180 degrees from TDC) and they both measured within 2/32 inch from TDC to overlap. I don't understand why that matters?
Lead Driver
Joined: Sep 2003
Posts: 7,016
Likes: 208
From: SoCal
The most important thing about adjusting rocker preload is to make sure that the valve is closed when you do it. Otherwise, it doesn't matter what part of the cycle the piston is at. It's just convenient to get both valves of a cylinder closed so you can adjust them both at the same time. There's nothing that says you have to do that; you can adjust just the one closed valve on a cylinder, regardless of how the other valve is at the moment.
Lead Driver
Joined: Sep 2003
Posts: 7,016
Likes: 208
From: SoCal
You want to set the lifter preload to about 0.03". That is, once you've torqued the rocker bolt to spec, the pushrod should have pushed into the lifter plunger about 0.03". If it's more, you can reduce it by installing a shim under the pedestal. If it's less, you will need to order longer pushrods.
If the preload is to much, valve may not fully close when it should, so the cylinder can not build as much pressure as it normally should. Worse, if the valves don't close completely, their faces may be burned.
If the preload is too little, or if you find clearance between the parts, you need to order longer pushrods. In this case, you might want to get a pushrod length checker to find the exact length you need.
Neither situation should be run at all regardless of their effects on HP.
If the preload is to much, valve may not fully close when it should, so the cylinder can not build as much pressure as it normally should. Worse, if the valves don't close completely, their faces may be burned.
If the preload is too little, or if you find clearance between the parts, you need to order longer pushrods. In this case, you might want to get a pushrod length checker to find the exact length you need.
Neither situation should be run at all regardless of their effects on HP.
Thread Starter
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Elder User
Joined: Jun 2015
Posts: 664
Likes: 2
From: York Pa.
You want to set the lifter preload to about 0.03". That is, once you've torqued the rocker bolt to spec, the pushrod should have pushed into the lifter plunger about 0.03". If it's more, you can reduce it by installing a shim under the pedestal. If it's less, you will need to order longer pushrods.
If the preload is to much, valve may not fully close when it should, so the cylinder can not build as much pressure as it normally should. Worse, if the valves don't close completely, their faces may be burned.
If the preload is too little, or if you find clearance between the parts, you need to order longer pushrods. In this case, you might want to get a pushrod length checker to find the exact length you need.
Neither situation should be run at all regardless of their effects on HP.
If the preload is to much, valve may not fully close when it should, so the cylinder can not build as much pressure as it normally should. Worse, if the valves don't close completely, their faces may be burned.
If the preload is too little, or if you find clearance between the parts, you need to order longer pushrods. In this case, you might want to get a pushrod length checker to find the exact length you need.
Neither situation should be run at all regardless of their effects on HP.
Lead Driver
Joined: Sep 2003
Posts: 7,016
Likes: 208
From: SoCal
I don't know about that 1/3 rotation, or where that trick comes from. I take measurements using a dial gauge on the pushrod oil hole of the rocker arm from the point where clearance is taken up to the point where I achieve 22 lb-ft of torque on the bolt. If it's more than .03", I add shims until it gets there. I never counted how many turns of the bolt it took to get from no-clearance to 22 lb-ft torque. But that would be a dead-reckoning method that would only work if all the components were exactly the same. The fact that we have to use shims sometimes tells us that there are enough variations that need to be compensated for.
Thread Starter
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Elder User
Joined: Jun 2015
Posts: 664
Likes: 2
From: York Pa.
I don't know about that 1/3 rotation, or where that trick comes from. I take measurements using a dial gauge on the pushrod oil hole of the rocker arm from the point where clearance is taken up to the point where I achieve 22 lb-ft of torque on the bolt. If it's more than .03", I add shims until it gets there. I never counted how many turns of the bolt it took to get from no-clearance to 22 lb-ft torque. But that would be a dead-reckoning method that would only work if all the components were exactly the same. The fact that we have to use shims sometimes tells us that there are enough variations that need to be compensated for.
