383 cam button?

[Ray70Chrg]

Just installed new cam, lunati 703,( degreed ) lifters and eventually new springs. Getting ready to button it up for cam break-in. When I pulled this apart there was no cam button and I had run this car for about 800 miles with no problems. I have read in several threads about how guys have welded metal onto the chain cover to reinforce the cover so that cam button can push out against the cover. What am I missing here ?. The chain cover from this car is original and has no evidence that anything rubbed against it. Any info would be appreciated.

 

[33 IMP]

Unless that is a roller cam, you don't need a cam button on the nose. A flat tappet cam, hyd or solid, has a taper ground onto the lobes, and a radius on the face of the lifter. The idea is for the lifters to continuously rotate for wear reasons, but it also imparts thrust to the cam, backwards into the engine. This thrust is stopped by the timing chain gear.
With a roller, the taper can't be put on the lobes, and the cam might float forward and back, if not limited in some fashion, most often a button for a retro fit, or a flange for a factory roller motor.

 

[zyzzyx]

Also, If you look at the direction of rotation of the camshaft while running, You'll notice that the
45 degree bevel gear that drives the distributor and the oil pump keeps the cam pinned against the
thrust face. The only instance that anyone would need a cam button on a 440 is if the engine had
a dry sump oil system and a crank triggered ignition and no intermediate shaft. I'd really like someone
to explain where this cam button idea came from??? Chebby guys maybe???

 

[RemCharger]

Roller cams need them .

 

[zyzzyx]

So, If I put a Rolller in my 440, it's going to float foward and back and either shear the teeth off of the
intermediate shaft or change the indexing on the distributor timing? Think about it. . . .
Can't happen!

 

[zyzzyx]

If the 440 engine turns clock-wise looking at the front of the engine,

and the intermediate shaft is driving the oil pump and distributor, so it's trying to stop turning, The cam is always
thrusting against the block. Always.

 

[PRHeads]

Ugh.