Yes, on the nose of the cam there should be a stamping. Lifters did not cause the problem, but riding partially off the lobes may have scuffed their bottoms.

Yes, a 455 is mechanically the same in the valvetrain.

Still a good reference. Look at your top picture in the last set. There are marks where the lifter actually hit the unmachined surface of the cam. These parts, cam and lifters, are junk now.

Another clue.....

I went back and re-looked at the last 4 photos. It looks like in each photo, the most rearward lobe is the one that is showing the most discoloration.....and also the most out of alignment.

?????

David

Look at the 'witness marks'. I would check out the bores that the lifters slide in too. It looks like the lifters may be a little loose?

Jim,

I just went out an eye balled what you were talking about...it looks like that is from the factory to me. Unless the lifter base is completely gone, i dont see a way for that to happen.

But keep in mind, I am new to this engine and to Pontiacs, so I may be wrong!

Here is a pic of my '67 400, with its factory cam and lifters.

Note that the lifters are slightly off lobe center, which I believe helps keep them rotating...but at no point is the lobe not covered by lifter base. Contrast that to your rearmost cam lobe.

Yah. Those marks may be nothing..... You need to check that timing gear though.

Vikki, is it just me or do yours look a little out of alignment too?

Yes, they are slightly off center by design. But no portion of the lobe is left uncovered.

Jim and Vikki, Thank you BOTH for all the info you gave me. I'm going to see what a new cam, lifters & gear cost and tear the front of the engine off. I will post more info soon.

Thank you again!!!!!!!!!!!!

David

A good check would be front to back cam movement. It's supposed to be less than .008". That's not much.

And make sure the cam thrust plate is bolted to the front of the block once you get in there.

any photos of a cam thrust plate?

David

By the way, the rockers are Comp Cams, Magnum roller tip with a 1.5 stamped on them. I am assuming this means 1.5 ratio. I thought they were supposed to be 1.6 or 1.65, Maybe I am wrong, but what do ya'll think of this?

David

No pics, but once you have the water pump and timing cover off, and the timing chain and gears off, there should be a football shaped metal plate with a round hole that fits over the nose of the cam and bolts to the face of the block.

1.5 is stock rocker ratio. Only RA IV had 1.65 stock, and they weren't roller tip.

Interesting, the PO said this engine was built according to a Jim Butler article in HPP and had a cam that was similar to a ram air motor. I wonder if 1.65's would be any better or if I should just stick with what I have?

David

If you don't know exactly what is in the engine or how it was built, don't change things right off. And I've learned from experience that what a previous owner said was done is not often the case, whether by incorrect recollection or whether the shop did something other than what the PO thought was done.

The original RA IV cams did not have a lot of lift built into the lobes; 1.65:1 rockers added the remaining lift. That allowed for a quieter valvetrain and less radical lobe profiles.

Here is the progress so far, which is not much.....

Spun the engine with starter with no intake, valley pan, or valve covers or distributer......no noise

Took a dental mirror and stuck it in the dist hole to look at back lobe of cam to see if it may be hitting due to cam walk.....cant see any signs of that

Dropped cell phone into drain pan for antifreeze

Put the aforementioned cell phone in dryer with a load of clothes

This did not fix problem with cell phone

Luckily, I remembered to tell my buddy to watch out for gasoline spewing from fuel line, as he put out his cigarette, he said he would.

Then came the rain.

Problem will have to wait for a couple of days while we, and the weather regroup.

David

Sounds like a rough day!

Check inside your valve covers for signs of contact. Those rocker covers might be just tapping the roller tips.

Spin the distributor gear and listen for noises. If you hear a tapping sound (not the slight click of points), pull your distributor cap and look to see if it or the rotor have any damage to the contacts. While the distributor is out with the cap off, lift and press the rotor to check for endplay. Check for sideplay too.

To Update the situation, my buddy and I just found a bad lifter at the very FRONT passenger side of the motor. It seems the clip that holds it together had popped off and it was not working properly. The bad news is that the noise I was hearing seemed to come from the BACK of the engine on the passenger side. So now i figure that i will replace ALL the lifters with new ones. Are all lifters the same or do I need to know what the part number to the cam is in order to get the right lifters? In this process, I am going to check all the valve springs to make sure the inner spring is still intact. Is it possible that a front lifter could sound like it is coming from the rear?

Still a little confused,

David

Check for spring coil binding.
And how well the rkr arm pivots on the vlv stem.

So do ya'll think all lifters are created equal, or do I need to get the part number off the cam before replacing them all?

David

anybody?

Replace the cam and lifters after you check out all the cam bearings. Have the heads rebuilt right by someone who knows what they are doing. Short cuts seem to be plaguing you. No more short cuts....

Did you check the bolt on the front of the cam yet....