Why Is My Cam Wearing Into The Front Of My Block?

[turbodan1]

At startup oil pressure is great 80psi, the car would run for 15 to 20 min and then you could hear a knocking sound coming for inside of the motor..... it was an inconstant sound, and would come and go...but it would only do it after the car warmed up, and oil pressure drop down to 15psi to 20psi at hot idle.... the car has a PTE remote oiling system, and when you grab the oil lines with your hands you could fell the knock...and when it hit, it would hit hard..... dropped the pan, and saw alumanium shaving in the pan.... thought it was the oil pump.....pulled the front cover and saw the oil pump gears grinding into the cover....put a new FC on with a high voulme oil pump..... car did the same thing.... people told me it was in the bottom end...pulled the motor....and the bearings are perfect... the car had 11 miles on the motor, and problay 2 to 3 hours of idle timing...try to find the noise...my father had a feeling it could be the cam...so befor I pulled the cam out I removed the intake and moved the cam back an fourth with eye of sight...Im not a professional but it was moving at least 25 to 30 thousand from front to back.... when I pulled the cam out you could see where it was hitting the front of the block..... called the guy I bought the cam from and he said it was supposed to have 4 to 8 thousand clearance, and that I need to shim the cam button to make up for the clearance. I bought a new cam, it has a new front cover, new button, and a new cam sesor... going to shim it hope for the best.... SORRY THIS IS SO LONG BUT I REALLY WANT TO KNOW IF I PUT THIS MOTOR BACK TOGTHER IS IT GOING TO DO IT AGAIN????? AND IS THERE SOMETHING IM OVERLOOKING OR NOT DOING

ALL HELP IS GREATLY APPRRECIATED.....

 

[mybuick]

do you have a roller cam button. that would help alot.

 

[turbodan1]

ya its is a roller cam button....but theres no spring its uses shim instead of the spring..... complete roller setup 214/214....

 

[turbo2nr]

The instructions in my Comp Cam kit called for less movement. I believe around 4 thous. Just have to assemble and move cam carefully side-to-side with screwdriver and get an idea of how much to shim. Not very accurate, but it is hard to get a measurement with front cover in place. We need someone to make a two piece cover with an access hole for this.

 

[EightSecV6]

If it is a billet cam and you did not install a "thrust" system
(Torrington bearing style or Danny Bee bronze plate) it will wear the block out in short order. The billet cams are not designed to ride against the block, there is not enough surface on the flange to work properly.

 

[turbodan1]

Thank you to everyone how posted a reply on this topic... I dont beleve this is a billet cam, but I have heard of people putting bearings in between the block and the cam... but mostly on stage motor setup's...... But you think if I shim it to the correct thousand that it will not wearing into the front of the block anymore?????

 

[BobbyBuick]

Heavy duty oil pumps will drive the cam rearward.I always drill a 1/16 " hole into the oil galley behind cam.I know nothing about roller set ups but on flat tappets I know the cause and solution