Slick 60's

I have a 66 F100 with a 77 300 six, and one or more lifters is making a lot of noise. Is there any valve adjustment? If I have to replace the lifters, must pushrods and/or cam be replaced, also?

All suggestions appreciated.

(Long way) Mark harmonic balancer at 0, 120 and 240 degrees beginning with the timing mark.
Remove plugs. Find TDC on the power stroke # 1 cylinder.
Collapse lifters. Adjust to .125 clearance. Turn engine 120 degrees and do the next cylinder in the firing order.
Continue through all 6 cylinders. Turn engine over with starter (coil wire removed) to pump up lifters.
If you still have rattling or missing then you may have bad lifter. Use vacuum gauge to confirm all valves are closing properly.

(Short way) With engine running loosen each valve til it rattles. Tighten while counting turns til it misses.
Back off half way. This will put you in the middle of the lifters range of motion.

Valves are better off a little lose than to tight. Valves too tight equal burned valves.

Valve tick went to more of a clack, so finally removed the valve cover to have a look and hopefully adjust the valves. The problem was that #1 cylinder had a bent pushrod. Here's how the situation looked:

Rocker at one extreme


Rocker at other extreme


Rocker bottom


Valve stem and retainer


Naturally, the pushrod must be replaced and, with the wear, the rocker arm.

First question: Could a bad lifter be the cause of the bent push rod, and do I need to check there, too?

Second question: Can I just replace the necessary parts, or must I replace all lifters, rockers, etc.? I'd rather not replace all, for now anyway, as I haven't yet decided how much I want to spend on this truck. Got some major rust problems.

Third question: Can I skate by on the valve and retainer for now?

Incidentally, I made a couple of 150 mile plus trips recently in this truck, and I got 19+ mpg the first time and 18+ the second. I was very pleased with that.

1) Could be at least a contributing factor.
2) Refer to #1; I would not hesitate to just do the one valve set. Lifters are fairly cheap and easy to access on the 300. I would change rocker arm, push rod and lifter. If you are really ambitious, you could inspect the other rockers and push rods. Clean the push rods and roll them on a pane of glass to check trueness.
3) Other than honing any sharp edges off the mating surface of the valve stem, I would not go thru the procedure of pulling the valve prior to running it with the new operating parts.

Paul

If your replacing a push rod, lifter and possibly a rocker, why not replace all of the rockers with chevy rockers. They're only about $15 at a parts store, and will give you a bit more lift. The rockers are for a chevy 250. You can find lots of information on it at the fordsix.com site.

Jerry D

Jerry D wrote:If your replacing a push rod, lifter and possibly a rocker, why not replace all of the rockers with chevy rockers. They're only about $15 at a parts store, and will give you a bit more lift. The rockers are for a chevy 250. You can find lots of information on it at the fordsix.com site.

Jerry D

Thanks for the suggestion. A couple of questions: $15 for one or for a set? Seems cheap for a set. Also, I read somewhere that, in the stock configuration, the 300 is a "non-interference" engine. If that is true, then would the slightly higher lift change that?

Thanks again.

Toyz wrote:1) Could be at least a contributing factor.
2) Refer to #1; I would not hesitate to just do the one valve set. Lifters are fairly cheap and easy to access on the 300. I would change rocker arm, push rod and lifter. If you are really ambitious, you could inspect the other rockers and push rods. Clean the push rods and roll them on a pane of glass to check trueness.
3) Other than honing any sharp edges off the mating surface of the valve stem, I would not go thru the procedure of pulling the valve prior to running it with the new operating parts.

Paul

Sounds like good advice. Thanks for the reply.

Also, something I had not noticed before: In the picture of the valve stem and retainer, if you look at the stud, you can see a groove where the rocker was wobbling back and forth. there is another on the opposite side. I thought I was in pretty good shape until I saw that. I would be grateful for suggestions on this, as well.

I would check the cam lobe fro this valve. The only time I aver bent a push rod it was because that lobe was worn down. Not wishing bad things for you, but I would at least check it.

Obviously, there is some risk in the possibility of the rocker stud failing. As you stated, it IS a non-interference design. Personally, unless I had other reasons to pull the head, I would probably try it with the new components, ignoring the damaged stud.
Mellvis's statement warrants investigation; it's pretty easy to check lobe lift; in fact, if severely worn, it will be obvious without precision measurement.
Paul

Two things:

1. I'm thinking I need to replace this stud. I'm afraid it will cause the rocker to bind and bend another pushrod. From what I read elsewhere, they are pretty easy to get out, but what about putting in a replacement? How hard would that be? This stud is not loose, so I would think that oversize is not necessary.

2. Once I get it all back together, I would like to do the adjustment with the engine running as described earlier, as I understand that, but how to I know how far to screw the retainer nuts on to start with - before I start the engine?

Okay, finally got it running and the valved adjusted. The engine is now spooky quiet. Sounds and runs good. I now think, though, that I have a throwout bearing problem that I couldn't hear before. I will later post the procedure that we used, but for now I have another issue - low oil pressure.

The truck always used to have relatively high pressure, but now it is around thirty running at speed and goes to zero at idle. Could this be in any way related to what we did?