Push Rod damage
Thread Starter
Racer
Joined: Nov 2020
Posts: 265
Likes: 76
Going back to post 4 photo, unless you cleaned those heads with a shop towel, they are way too dry for my liking. Should be some puddles here & there.
My money is lack of lube top side as the culprit.
When you prime it later with the tool and a HD drill, that will tell you what's going on upstairs. You can jog the IGN key every so often to get all 16 lifters oil fill hole lined up with the oil galley in the block. That will build up some pressure up through the pushrod, hopefully. Don't expect a gusher come out of the pushrod, but there should be a dribble at all 16 rockers eventually. Also, slotted rocker ***** do seem to keep the rocker arm well lubed as opposed to std.
I think this is just a case of a rocker running dry, got really hot until the metal stud fatigued and failed. And if that is the case, the lifters did not supply oil for some reason.
My money is lack of lube top side as the culprit.
When you prime it later with the tool and a HD drill, that will tell you what's going on upstairs. You can jog the IGN key every so often to get all 16 lifters oil fill hole lined up with the oil galley in the block. That will build up some pressure up through the pushrod, hopefully. Don't expect a gusher come out of the pushrod, but there should be a dribble at all 16 rockers eventually. Also, slotted rocker ***** do seem to keep the rocker arm well lubed as opposed to std.
I think this is just a case of a rocker running dry, got really hot until the metal stud fatigued and failed. And if that is the case, the lifters did not supply oil for some reason.
Melting Slicks
Joined: Jun 2014
Posts: 2,236
Likes: 498
From: NJ
Didn't read all the posts but lifter side of pushrods look better than rocker side. which would indicate lifter side was getting some lubrication but still not enough. rocker side looks very dry even the head itself looks dry. So why no upper oiling? Were the lifters completely bottomed out?
Thread Starter
Racer
Joined: Nov 2020
Posts: 265
Likes: 76
Didn't read all the posts but lifter side of pushrods look better than rocker side. which would indicate lifter side was getting some lubrication but still not enough. rocker side looks very dry even the head itself looks dry. So why no upper oiling? Were the lifters completely bottomed out?
Thread Starter
Racer
Joined: Nov 2020
Posts: 265
Likes: 76
I have a question that I hope someone can answer. Can I use self aligning rockers with guide plates and hardened push rods? If not am I better off with guide plates and non-self aligning rockers or no guide plates and self aligning rockers?
Thanks
Thanks
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
One or the other. Not both.
Self align are for those that prefer not to use guide plates. You are better off with the plates.
You also need to address the stud hole threads. Maybe clean them out with a thread chaser. Then use a thread sealant on the rocker studs because they are exposed in the Intake runners.
When you install your guide plates, just snug them down for now. Install two pushrods & rockers, then check the alignment of the rod in the slot. The plates can be moved up / down & sideways.
When both Exh & Int rods are aligned perfect, remove rockers and torque the studs to specs. Move to the next cyl repeat.
Self align are for those that prefer not to use guide plates. You are better off with the plates.
You also need to address the stud hole threads. Maybe clean them out with a thread chaser. Then use a thread sealant on the rocker studs because they are exposed in the Intake runners.
When you install your guide plates, just snug them down for now. Install two pushrods & rockers, then check the alignment of the rod in the slot. The plates can be moved up / down & sideways.
When both Exh & Int rods are aligned perfect, remove rockers and torque the studs to specs. Move to the next cyl repeat.
Last edited by HeadsU.P.; Mar 8, 2023 at 08:16 PM.
Thread Starter
Racer
Joined: Nov 2020
Posts: 265
Likes: 76
One or the other. Not both.
Self align are for those that prefer not to use guide plates. You are better off with the plates.
You also need to address the stud hole threads. Maybe clean them out with a thread chaser. Then use a thread sealant on the rocker studs because they are exposed in the Intake runners.
Self align are for those that prefer not to use guide plates. You are better off with the plates.
You also need to address the stud hole threads. Maybe clean them out with a thread chaser. Then use a thread sealant on the rocker studs because they are exposed in the Intake runners.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
I just did a set last week on a 383 and it took about an hour of straight time....I use a brass rod and a small drift to do this...
Self aligning rockers are bolt on and go.....
They work because they made their debut on the infamous LT4 Vette engine.....good for what you can throw at them....the LT4 rockers were a full anodized roller from the factory.
Using both is redundant but would not harm anything as long as one is not binding the other.
Jebby
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
With the 1.6 rockers, its critical to check bottom of valve spring retainer to top of valve guide for a minimum clearance. I don't remember your cam lift but if those two parts crash, it could get really ugly.
Off hand, don't remember that minimum gap. Someone will chime in. Use a feeler gauge when valve is fully open.
Bottom of retainer > top of valve guide.
Off hand, don't remember that minimum gap. Someone will chime in. Use a feeler gauge when valve is fully open.
Bottom of retainer > top of valve guide.
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Thread Starter
Racer
Joined: Nov 2020
Posts: 265
Likes: 76
I believe the plates are more stable but here's the rub....some aftermarket heads have a shift in the intake rocker to provide pushrod clearance as the port gets larger.....the self aligning rocker is a easier bet on this....if not...you sometimes need a split guide plate to shift the intake rocker over and these can sometimes be tricky to setup....at the engine shop years ago, we would set them up, number them and weld them in that position....
I just did a set last week on a 383 and it took about an hour of straight time....I use a brass rod and a small drift to do this...
Self aligning rockers are bolt on and go.....
They work because they made their debut on the infamous LT4 Vette engine.....good for what you can throw at them....the LT4 rockers were a full anodized roller from the factory.
Using both is redundant but would not harm anything as long as one is not binding the other.
Jebby
I just did a set last week on a 383 and it took about an hour of straight time....I use a brass rod and a small drift to do this...
Self aligning rockers are bolt on and go.....
They work because they made their debut on the infamous LT4 Vette engine.....good for what you can throw at them....the LT4 rockers were a full anodized roller from the factory.
Using both is redundant but would not harm anything as long as one is not binding the other.
Jebby
Thread Starter
Racer
Joined: Nov 2020
Posts: 265
Likes: 76
With the 1.6 rockers, its critical to check bottom of valve spring retainer to top of valve guide for a minimum clearance. I don't remember your cam lift but if those two parts crash, it could get really ugly.
Off hand, don't remember that minimum gap. Someone will chime in. Use a feeler gauge when valve is fully open.
Bottom of retainer > top of valve guide.
Off hand, don't remember that minimum gap. Someone will chime in. Use a feeler gauge when valve is fully open.
Bottom of retainer > top of valve guide.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Thanks Jebby. I'm concerned that my previous Rod issue may have been worsened by bad rocker lash setup and that would be deadly with self aligning rockers so I'm not sure which way I will go. Can you recommend what you think would be the best procedure to set 0 lash and how much turn you use after zero lash?
Jebby
Thread Starter
Racer
Joined: Nov 2020
Posts: 265
Likes: 76
With each cylinder at TDC….spin the loose poly loc nut with your fingers to verify it is free….tighten with thumb and forefinger until you JUST feel the lash taken up and starting to plunge the lifter….you will feel the slight resistance as this happens- THIS IS ZERO LASH….from there, one half turn…
Jebby
Jebby
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Jebby
Thread Starter
Racer
Joined: Nov 2020
Posts: 265
Likes: 76
Hello All
I got the rockers and rods installed today. I set the lash pre-load at 1/2 turn and the car started right up running very smooth. I ran it set the timing and took off valve covers to confirm that they have plenty of oil. The car is running great under regular throttle but when I hit the throttle it doesn't have any power and has a backfire. I changed the oil pump to a high volume pump since I was concerned about oiling issues and my oil pressure is now 60-65lbs on cold idle versus 40lbs previously. When the car is warm and rev's up the oil pressure is up around 65-70lbs. Could the loss of power when I hit the throttle be related to a valve hanging open due to high pressure in the lifter not allowing it to properly close with that lash?
Tomorrow I plan to do a compression check as is and then again with the valves loosened to see if I get a difference in compression. Not sure what anyones thoughts or suggestions might be.
I really appreciate it!
I got the rockers and rods installed today. I set the lash pre-load at 1/2 turn and the car started right up running very smooth. I ran it set the timing and took off valve covers to confirm that they have plenty of oil. The car is running great under regular throttle but when I hit the throttle it doesn't have any power and has a backfire. I changed the oil pump to a high volume pump since I was concerned about oiling issues and my oil pressure is now 60-65lbs on cold idle versus 40lbs previously. When the car is warm and rev's up the oil pressure is up around 65-70lbs. Could the loss of power when I hit the throttle be related to a valve hanging open due to high pressure in the lifter not allowing it to properly close with that lash?
Tomorrow I plan to do a compression check as is and then again with the valves loosened to see if I get a difference in compression. Not sure what anyones thoughts or suggestions might be.
I really appreciate it!
Melting Slicks
Joined: Oct 2006
Posts: 2,417
Likes: 336
From: Texas
I had to reset my Howard’s hyd. lifters to 1/4 turn for the same reasons. After a valve seal change. Backfire and low power after warm up. I don’t know what lifters you have but mine had a short preload
Thread Starter
Racer
Joined: Nov 2020
Posts: 265
Likes: 76
Melting Slicks
Joined: Oct 2006
Posts: 2,417
Likes: 336
From: Texas
I rebuilt the engine in 2010 but didn’t remember how I set the initial lifter settings. But after seal repair and setting them as most do at 1/2 turn it ran terrible and I remembered and reset to 1/4.
been running fine since then 2021.
been running fine since then 2021.