"I cannot think of any reason for this to happen except for piston to valve contact or sticking valves"

Wow, color me impressed. I pulled the heads, both exhaust valves associated with the ejected lifters were stuck.

Would the short push rods cause this? something still isn't adding up.

 

On second thought maybe it does. All the unexhausted partially burned gas and oil from the out of whack timing seems to have left a pretty sticky residue. I imagine if it started to make a valve stick it would quickly become exponential because you have no compression and poor detonation

 

Interesting! I'm assuming you pulled the keepers and valve spring off to confirm this. The only way I can see them sticking is if the valve guides were too tight from the machine shop. However I can see it's possible the push rod some how put a side load on the valves when they came out bending the valve? It doesn't take much of a bend to stick them for sure. Either way those heads are in for a trip to the machine shop.

 

Just a quick note for you guys.
Really impressed with how you guys are working together.
Great diagnosing and great willingness to take on the job and get it done.

 

Thanks, but I had to get the job done, co425 deserves the credit. After I was a **** head, I never expected him to be the one to see me through to the end. Sincere thanks.

Yes, heads are stripped down and are in the parts washer. I'll tell you one thing, if I do another engine I'm getting a different valve spring compressor. Using this one from harbor freight without a c-clamp is like playing with a jack in the box that can break your fingers.

I really think it was just gunk. Maybe pre-lube flarn from the cam, coupled with all the zinc additive and rotten timing makes for a nasty cocktail?

I don't know. Nothing is bent and I see no abnormal wear. After scrubbing the crud off it slides in the guide just fine. I'm inclined to build it back up and run it.

Getting from the uh-oh moment to here wasn't all that bad. Not saying I want to do it again, but I think there are too many variables given how much was done wrong to start with. I'm inclined to try and eliminate some by running it. Well, I hope to eliminate all of them by running it Truthfully, I'm out of time and money. I won't do anything foolish if it isn't running right. If it starts to take a dump on me, I'll borrow a rig so I can go back to work and get back to it in a month.

 

You are welcome.

Hey, that's cool if it's just gunked up. Sticking because of a bend V.S. just being sluggish to slide is two different things. If you are sliding them with finger pressure then you should be fine. If they were bent you'd feel a bind in them. If you have a straight edge you can see with out a doubt that they are not bent. Making an un needed trip to the machine shop costs too much damn money.

Get those new push rods, and take care of the lifter issue. Put her back together and make some fire.

 

I had to take a day off to save my relationship, but I am back at it now.

Sadly, I am back at it only to find I am not out of the woods yet.

I was just finishing and getting ready to fire her up when I thought "oh, while I can still see the springs and rocker arms I might as well set her TDC". Well, I cranked that sucker round and round with my finger over the spark plug hole and got nothing. I knew my pistons and cylinders were fine because I just inspected them top and bottom when I had the heads off. Rotated the crank and everything looked beautiful.

All I could think was the longer push rods were keeping the valves from closing. So I set it to tdc (by timing marks and watching the valve springs), removed the #1 rocker arms, backed the crank off 1/4 turn, put my finger over the hole, advanced it back to TDC and it blew my finger off the hole.

So, now what? The machine shop ordered the cam and the springs were a strong recommendation from comp cams to go with the cam. Is it possible that they made the same mistake I did? Just used 1976 f-150 with a 460 as their criteria and got a cam/springs that are designed for approximately 3/16 shorter push rods? I will call them and see if they have any memory of such. Probably call comp cams too and see what they have to say.

Damn this is disappointing. Last question, has anyone ever had a situation where the springs were a little too tight on a cold rebuild, but firing her up and doing the break in loosened them up a bit? Where they would then close properly?

 

one other note, when I ran this before, the same springs were on and I was able to set the timing by finger test. So I know the longer push rods are the culprit.

Also, I did the same test on cylinder 2 with the same results.

Lastly, the machine shop originally said the mild cam/spring setup would be fine to break in without removing the inner spring. I have since read that most remove this inners no matter what. But that ship has sailed

 

Well, I wonder how many times I will learn this particular lesson before I'm done: Know what you have!!!!

Not sure what it means yet, but I'm sure it matters. Somewhat major changes were made to the 460 heads in 1972. My block is a 71, just found out my heads are 73. Going to have to dig around and find out what that means for push rod length. My guess is I'm going to end up somewhere in the middle.

Anyone ever run into this?

 

I'm wondering how much they decked the head, and block. Your machine shop should be able to tell you the proper length based on your parts and how much they removed.

 

I talked to the machine shop today and they weren't much help. To be honest, though I think they did fine work, the shop seemed a little informal. Like they might not keep the best records, and it's been 2 months so memory might be fading. In fairness, it was even difficult for me to connect the dots well enough to explain how I ended up concluding push rods were a big part of the problem. It may have been mostly the oil pump after all. Either way, the 1971 block does call for the longer push rods. The issue gets more cloudy though, as the 73-85 years have 7 different call outs for push rod lengths.

When I took the rocker arms off I payed close attention to the valve stems. If they moved 1/16th of an inch I'd be shocked. The mechanical geometry at play when joining a 1973 head to a 1971 block is completely out of my depth. However, since the first length of 8.550 inches was short, and the second 8.6475 was long, i ordered the 8.616 variety. Fingers crossed it works and I am running tomorrow.

On an embarrassing side note, I'd like to post a public service message: If you are short on time and money, don't ever decide to re-use a head gasket. Even if it ran for only 20 minutes, you are very careful removing it, you clean the surfaces with solvent, and recoat all surfaces with gasket seal/adhesive; it may very well leak. This was my post christmas tree night realization. Not just one leak but two. Not under the pressure of heat and steam, just gravity. I just got done tearing it down and thoroughly scraping/cleaning all sides of the heads for new head/exhaust/intake gasket re-installment tomorrow. On the bright side, I am getting pretty good at taking her apart and putting her back together. I might even be able to do the turn around in 3 hours at this point! Off to bed. Hopefully good news tomorrow.

 

you need to buy a pushrod length checker from summit.

It will tell you how long your pushrods need to be.

This cannot be guessed at, but must be measured.

you should shoot for 0.030" lifter preload.

borrow a dial indicator or buy one...even a cheap one is better than none and will be "good enough" for this exercise.

Since you reused your head gaskets, did you also reuse the lifters?

If so, don't.

 

10/4 on the dial indicator and pre-load. Thanks for the information.

I'm not sure why the lifters must not be re-used. Other than the two valves that stuck (replaced), none show any ill effects. They were new when I put them in. I pumped each one up with oil before installing them the first time and tested their resistance, and did the same after removing them. They appear to be exactly the same. I know this is far from scientific, must be some measurable way to test them?

I know I don't want to install any part that is damaged or operating sub-par, but the bleeding has to stop. You can see the lifters give a little when installing the rocker arms and the old vs. new look identical. If I get a dial indicator and the old vs new both compress about .03 under the same spring load, shouldn't I feel ok using them? Am I missing something? I'm happy to heed your warning if you would please explain a little more.

 

Based on the pictures of your damaged lifters, I would run new ones for those two.

in my opinion the risk isn't worth the reward....

I personally am not convinced that your issues are gone - don't see how the valves are stuck closed from gunk on a fresh head.

I hear you on the bleeding has to stop.

I always justified it to myself that I was learning and I have never went to a free school - have you?

 

That is really funny you should mention that. I was talking to a neighbor who said, "well, you probably aren't going to do something like this again soon, huh?". I replied with: "Hell yes I am! With what I payed for this education, I'm going to do one ASAP!" In reality probably not, but I have learned more about engines in the last 10 days than I had the 37 years of my life. I can see the bright side, it's just getting a bit more dim!

I have already replaced the 2. The rest seem fine. I'll do some research on bench testing them, but I am inclined to run them.

I agree that something is still not adding up. But I have been over nearly every component of the engine so far. I haven't taken the water pump/timing cover off, but TDC by the timing mark is right on TDC both using finger test and watching the piston with the heads off. I'm guessing a jumped tooth would result in a pretty significant shift in timing (on the order of 10-15 degrees)?

Need to confirm the push rod length, but i am out of guesses after that. Time to start her up again and see what she tells me.

Quick question: is there a torque value out there for the approximate force required when turning the oil pump manually? It pumped just fine but when the system became full it got harder, nothing extreme but did seem like maybe it was having to work too hard. Also there was a bit of a pulsation you could feel through the ratchet. Probably all normal, but it would be nice to know a torque value for it to put my mind at ease.