2QUIK6

Which cam retainer bolts should be used with the LT4 Extreme Duty timing set, the rounded torx head stockers or did some different ones come with the set?
The stockers are hitting the back side of the cam sprocket when installed at the req torque.

If the stockers are used, should I grind off a tiny bit of the head as they are barely making contact after engine gets to op temp??

Javier97Z28

Something is *definitely* wrong if the cam sprocket is rubbing the cam retainer bolts. Which could explain your issue with the back of the cam sprocket rubbing the cam retainer plate. The bolts and plate seem to be sticking too far out on the block?

The stock torx retainer bolts are the correct ones to use. I used them with my LT4 ED and my double roller.

seawolf06

Yeah, the stock definitely shouldn't be rubbing. I don't think it matters which way it's on either. Sure you have the right cam and it's all the way in?

Projectz28

No way those bolts should be hitting the gear. If they are you have something else wrong. That bevel on the cam is not right either. It looks like the cam was hitting to make marks like that.

Again you need to check your camshaft endplay! Go out and buy a magnetic base dial indicator and check it.

2QUIK6

It will be Thanksgiving before I can measure the end play, my brother is a machinists and has the measuring micrometer.
Placing the retainer bolts on their head inside the sprocket and using a small straight edge shows that the heads is the exact height as the depth of the grove in the back of the sprocket, so any expansion will cause them to contact each other.
From the shinny marks on the back of the sprocket, it does not appear that this gear made the marks on the retainer, it must have been the stocker and I don't have the original stocker gear to know for sure.
I think the bevel is ok, there's nothing there that could have cut that bevel as its all flat surfaces and the marks on it are not consistant with a rotating motion.
Here's a pic on shoebox's site of a Comp cam and it has the exact bevel on the leading edge.
http://shbox.com/ci/ci289.jpg
It looks just like a center section journal on my stocker to aid in installing the cam thru the bearings instead of having a sharp edge like on this pic of the stocker

Projectz28

now that its out it doesnt look like its out of place. Looks ok to me now. Just check that endplay and see what ya got.

2QUIK6

That's actually a picture of the stock cam just showing that it has the same bevel on the journals with the same markings, but the stocker does not have that bevel on the front journal since its not passed thru a bearing, not sure why Comp Cams puts the bevel on the leading front journal too as shown in that Shoebox cam dowl comparison pic I posted up earlier.

2QUIK6

Here's better pic of the cam nose and the bevel is more clear here, I'm just about 100% sure it was made this way...this is the cam in the motor currently, not an example just to clarify.
The surface of the cam is flush with the block decking, so with the retainer on, the cam will not come forward any further, measuring the nose then protruding out past that is less than the retainer thickness plus the recessed depth in the back of the sprocket...so that should tell them there should be no rubbing if the cam did not walk back any from its current position while running...the differences in the length/depth as very small, less than 1/64 of an inch...I'll get a more scientific reading when my brother comes by with the tools for it. Many thanks for your help with this!!
Still not sure why the cam retainer bolt contacts the back of the sprocket...maybe just luck of the draw since a small percentage of folks have siad there's makes noise...maybe the tolerances of the ED gear are too tight and as it expands it begin to rub, maybe they should have made it 1/128" thinner there because the retainer bolt head is as tall as the recess is deep that it fits in.

2QUIK6

Ok, checked the end play today when by brother came over.
With the cam retainer bolts as is, it was 0.002 but the head is hitting the backside of the sprocket.
There' is nothing that would change this, its simply that the recess in the sprocket is either not deep enough for the stock torx bolt head to clear, or the bolt head is higher than usual for some unknown reason...no matter how its setup, when you push on the front of the sprocket to make the sprocket back contact the retainer, the bolts hit first...there is nothing in the cam or otherwise that would change this.
So I ground down a slight bit of the head, now using the grease film test shows the sprocket back is contacting the retainer plate instead of the bolt head when pressed upon..which is what should happen when pressure is put on the front of the cam sprocket.
Don't know why the tolerence is so tight, but may explain alot of the grinding noises from the front with ED LT4 sets that some folks have had for sometime with no ill effects....
And now I have 0.005 end play which is within the .004-.012 spec..