john73bb

My cam has been walking and bumping on the front of the timing chain cover. I pulled the sprocket, and found these two threaded holes with nothing in them. Is there supposed to be a plate here to hold the cam in place?
This picture is of the front of the block, that is the end of the camshaft.



[Modified by john73bb, 7:16 PM 1/23/2002]

PatsLs1vette

IF YOUR USING A ROLLER CAM THERE IS A PLATE THAT BOLTS TO THE BLOCK.

john73bb

So, if I am not using a roller cam, should I not use one, or can I go ahead and put one in with my standard hydraulic lifter cam?

Any idea why the thing is walking so much that it bumps the front cover? Is my chain too loose?

clem zahrobsky

a taper ground on the lobe of a flat tappet cam uses the lifters to push the cam to the rear of the block. just install a cam thrust bearing available from any speed shop that fits into the hole in the center of the cam gear.

norvalwilhelm

Like Clem said the flat tappet cams have a tapper ground into them that forces the cam back. I think you would need a special cam with a grove in it to fit a plate on the block. The trust buttons are for roller cams. Maybe your cover is bent back and needs replaceing. With a flat tappet cam no plate and no button required.

john73bb

My timing chain cover is not bent, but I did find out that I need to replace it (I found a nice chrome one . . . :yesnod: ). If the cam is tapered, then the only thing that would cause it to move forward would be a bad lobe, right? :( Or perhaps a bad lifter :( :( . I guess I better pull the intake manifold this evening and take a look :cry .
Thanks for the help.
I'm on the comp cams web site now, :) :) :) The silver lining :yesnod:

Alwyn678

Watch out for a chrome timing chain cover...They are NOTORIOUS for leaking..I would use aluminum instead...I lived and learned

john73bb

Hmmmm,

I'll look it over very carefully before installing. It is quite heavy (unlike some of the cheap ones I have seen) so I am hoping it will be straight.

john's '81 mouse

Get the AC Delco Chrome timing cover manufactured by Chevrolet, around $18, if memory serves me correctly, and you should have no problems. Note for the $18, you get a cover, and installed AC Delco crankshaft seal, dont' remember if it comes with a gasket. You might want to install new timing cover bolts as well, and I suggest ARP bolts if you can get them.

If your camshaft is walking out toward the front, believe it's time for a new camshaft and lifter set, as problem will be with the camshaft lobes, not the lifters.

john73bb

HMM, That is kind of what I am thinking. I better pull the intake manifold and make sure.

Comp Cams suggested a 224-230 cam (similar to XE268) with a 114 degree angle (can't remember which angle). Maybe I'll get it and give it a try. Dekstop Dyno says it should give me similar performance to my old crower baha cam, with a little less low end torque but a bit more mid range. Hate to lose the low end, but more torque midrange won't hurt.