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This is the spring at maximum lift at .525" with 7.18" stock pushrods. The valve seals are completely unscathed with a clearance of .050" between it and the retainer at max lift. This was covered in posts #3 and #19.
I thought the same thing too. The bent rods actually happened with the stock self aligning 1.5 rockers. I bought the 1.6 self aligning Comps because I thought that the small slots of the factory. The marks you see on the stud are from when the rods bent and the rockers laid over and rubbed the studs.
rockers were causing the bind. However, I did the same thing with the 1.6s. Here is a pic of the Comp rockers at valve seated and max lift.
This is the spring at maximum lift at .525" with 7.18" stock pushrods. The valve seals are completely unscathed with a clearance of .050" between it and the retainer at max lift. This was covered in posts #3 and #19.
Do that with out the spring installed and without the valve seal. Those heads are not made to run that cam in stock form.
Another thing to consider was valve lash too tight.
The only thing for sure is it was valve train interference so SOMETHING is binding.
I would pull a spring and measure the actual valve guide to retainer clearance at full lift.
How would I do this? Wouldn't the valve seals be smashed if the retainers were making contact? Im not trying to be lazy, Im just very limited on tools and time.
I did a little experiment today. I took some spare stock pushrods and installed them on the number one cylinder. one of the lifters was primed (very stiff) and the other one was bleed down (squishy feel). I adjusted them to zero lash without the 1/2 turn. I ran the starter for a bit and the stiff lifter bent that pushrod. The bleed down lifter did not, but I noticed that the pushrod was down deep in the lifter at max lift. With the heads, pistons, valves and seals in perfect condition and the pushrods not making contact with anything in the head, it seems like a valve adjustment / rod length issue. I am out of ideas.
How would I do this? Wouldn't the valve seals be smashed if the retainers were making contact? Im not trying to be lazy, Im just very limited on tools and time.
I hear ya. The seals would be hammered but then again, it never actually ran right? Maybe not enough to trash the seal.
I would remove one valve spring (only check one cylinder) and run it manually through a cycle slowly by hand so you can watch it. Hold the valve up if you do not have a checking spring. You DO have a bind in there SOMEWHERE. Just gotta find it. As the engine turns over manually, you will feel the bind.
Last edited by stingr69; Jun 24, 2018 at 12:14 PM.
I hear ya. The seals would be hammered but then again, it never actually ran right? Maybe not enough to trash the seal.
I would remove one valve spring (only check one cylinder) and run it manually through a cycle slowly by hand so you can watch it. Hold the valve up if you do not have a checking spring. You DO have a bind in there SOMEWHERE. Just gotta find it. As the engine turns over manually, you will feel the bind.
The engine ran for about a minute total up to 2000 rpm. How would the rocker adjustment hold (lash) if im holding the retainer up with my hand?
The engine ran for about a minute total up to 2000 rpm. How would the rocker adjustment hold (lash) if im holding the retainer up with my hand?
Try to zero lash the rocker without a spring and it will not compress the lifter when you rotate the crank manually. Go through a cycle and see where the bind is. If the retainer is closing in on the top of the seal, you will see it. Checking spring would help.
Try to zero lash the rocker without a spring and it will not compress the lifter when you rotate the crank manually. Go through a cycle and see where the bind is. If the retainer is closing in on the top of the seal, you will see it. Checking spring would help.
At max .525 lift. there is .11 distance between the retainer and the seal.
If there is no bind between the retainer and guide/seal yet you still bent a pushrod with just cranking the starter, my money is on piston to valve clearance (or lack thereof). What am I missing?
I think it's time to go real slow. You've done a great job of eliminating things...so time to turn engine by hand and watch things closely. Something is going solid..we know that. As mentioned..maybe inner spring? Did you take any real closeup pics of pistons and valves?
Get some light springs to hold valves up on one cylinder. Hardware stores have them. Turn it by hand and when you're about 20* from TDC...push down on rocker until valve hits piston. Turn motor 5* by hand and keep doing it until 20* after TDC to verify PV clearance. Or put some clay on the piston and snug it back together with no head gasket to see what you can measure on one cylinder.
JIM
Last edited by 427Hotrod; Jun 24, 2018 at 03:36 PM.
I take it these are brand new roller lifters, correct? Was it ever verified that the lifters are truly returning back down fully into their bores? Or are they jammed and staying off of the cam lobe slightly?
I still vote for piston to valve contact even though marks were never left on the slugs for some reason. I find it hard to believe that any valvestem / valveguide / valvespring binding was not observed during the time the valvelash was set. However, the lifters could have went wonky when the engine built up oil pressure during start-up. (owner said it ran a minute or less)
I would tag where every lifters present position is now, pull them and soak them overnite in oil before your next valvelash setting session. And verify the lifters are doing what they are intended to do.
And I would put those self aligning rockers on eBay and purchase the other style along with new guide plates to get those rocker studs up where they belong. Especially after you drilled out the pushrod holes in the head.
Last edited by HeadsU.P.; Jun 24, 2018 at 04:03 PM.
After seeing the massive amount of pushrod recession in the lifter at max lift, I decided to focus on the inner spring. I noticed some contact marks on the I.D. I then removed the inner spring and installed it using hose clamps to replicate the outer spring on the top and bottom. From the pics, you can see some serious coil bind. I think we may have found the culprit.
